WO2013015442A1

WO2013015442A1 - Pathogen-resistant plant body, fruit and leaf stem and induction method thereof, and plant cultivation system

Info

Publication number: WO2013015442A1
Application number: PCT/JP2012/069289
Authority: WO
Inventors: 伊藤　真一; 康臣荊木; 和正吉村
Original assignee: 国立大学法人山口大学; 地方独立行政法人山口県産業技術センター
Priority date: 2011-07-28
Filing date: 2012-07-30
Publication date: 2013-01-31
Also published as: JPWO2013015442A1; JP6097977B2

Abstract

[Problem] To provide a pathogen-resistant plant body that is disease resistant, even with little to no use of chemical agents, without the risk of detrimentally affecting the growth, morphogenesis, or photosynthetic activity thereof, in an environment where natural infection of phytopathogenic bacteria can occur. [Solution] A pathogen-resistant plant body (1) induced by being irradiated with violet light, the leaves of the plant body are irradiated with violet light (11) having a peak wavelength in the range of 390-420nm, and said pathogen-resistant plant body is characterized in that: more genes associated with a pathogen-protective response are expressed in comparison to a plant body of the same species not subjected to the violet light irradiation; and the genes associated with a pathogen-protective response are genes associated with pathways of salicylic acid synthesis or gene groups induced by salicylic acid.

Description

Pathogen-resistant plant, its fruit, its leaf stem, its induction method and plant cultivation system

[Technical Field] The present invention relates to a pathogen-resistant plant whose pathogen resistance is enhanced by irradiating purple light, its fruit and its leaf stem, a method for inducing such a pathogen-resistant plant, and a plant cultivation system.

Generally, when crops (including flower buds) are produced, there is a problem that if a plant body is ill, growth failure or death occurs, resulting in a significant decrease in productivity or a defective product. For this reason, in order to control diseases caused by plant pathogens, chemicals (agricultural chemicals) are constantly sprayed.
However, residual agricultural chemicals in crops are concerned about undesirable effects on the human body, and establishment of a technique capable of controlling diseases that occur in crops without using chemicals has been desired.
In recent years, it has been reported that irradiating plants with light in a specific wavelength range increases the pathogenic resistance of plants, and it is possible to control plant pathogens safely without using pesticides. The possibility of being able to be found is being discovered.
The following are known as prior art documents related to the present invention.

Patent Document 1 discloses an invention relating to a plant disease control illumination device including a light source that emits light including ultraviolet rays under the name “plant disease control illumination device”.
The plant disease controlling lighting device disclosed in Patent Document 1 includes a light source 2 that emits light including ultraviolet rays when described using the reference numerals described in the document as they are. The plant P can be irradiated by superimposing UV-B having a wavelength component of 280 to 340 nm and UV-C having a wavelength component of approximately 255 nm or less of the wavelength components of approximately 100 to 280 nm cut off. Is.
According to the invention disclosed in Patent Document 1 as described above, by irradiating a plant with UV-C and UV-B, diseases such as gray mold disease, powdery mildew, downy mildew, anthracnose etc. It is possible to reliably suppress spore formation and hyphal growth of the filamentous fungi, and to reliably induce plant disease resistance.

Patent Document 2 discloses an invention relating to a control method for protecting a plant from a disease by increasing disease resistance and a device and a system using the method, under the name “disease control method and disease control device”. ing.
The method for controlling plant diseases disclosed in Patent Document 2 will be described using the reference numerals described in the document as they are, and a light emitting diode D1-Dn that emits green light and a drive for lighting the light emitting diode D1-Dn. And a control device 2 for controlling the circuit 1. The drive circuit 1 is controlled by the control device 2 to emit green light from the light-emitting diodes D1-Dn to irradiate the plant. It is characterized by increasing resistance.
According to the invention disclosed in Patent Document 2 as described above, the amount of agricultural chemicals used can be drastically reduced because the plant is irradiated with light to increase the disease resistance of the plant. Environmental pollution can be prevented without adversely affecting the human body.

Non-Patent Document 1 is a paper titled “Suppression by Red Light Irradiation of Corynespora Leaf Spot of Cucumber Caused by Corynespora cassiiicola”. By cultivating cucumbers by irradiating red light in a greenhouse, the occurrence of lesions on leaves It has also been reported that the transmission of disease can be suitably prevented.

Non-Patent Document 2 is a tile paper titled “Disease resistance and control effect of scab of sunflower by ultraviolet light (UV-B) irradiation in eggplant”, 5 after irradiation with UV-B (wavelength 290-320 nm) in eggplant leaves. From the 7th day onward, it has been reported that the activity of resistance-related enzymes increases, disease resistance is induced, and pathogen invasion is blocked. Further, Non-patent Document 2 recognizes that there is a report in other non-patent documents that a pathogenic resistance gene is not expressed by irradiation with UV-A (wavelength 400-315 nm).

JP 2009-22175 A International Publication No. 2007/105599

According to the technical contents disclosed in Patent Document 1 and Non-Patent Document 2 described above, pathogenic resistance (disease resistance) of a plant can be induced by irradiating the plant with light in a specific wavelength region. However, when light in a specific wavelength region is particularly ultraviolet (ultraviolet), there is a possibility that it may have an unfavorable effect on workers, and it is actually difficult to introduce it to the site. There was a problem.
In general, "ultraviolet light" is a general term for radiation in which the wavelength of a monochromatic light component is shorter than the wavelength of visible light and is longer than approximately 1 nm (exhibited by JIS Z 8120 optical terminology), and of these, those having a wavelength of 200-380 nm Is called "Near UV". In addition, from the viewpoint of the influence on human health and the environment, the “near ultraviolet rays” may be divided into UVA (wavelength 315 to 400 nm), UVB (wavelength 280 to 315 nm), and UVC (wavelength less than 280 nm). In general, the shorter the wavelength of “ultraviolet rays”, the greater the adverse effect on the human body. In the claims and the specification of the present application, apart from the general definition of “ultraviolet rays” as described above, a light beam having a peak at a wavelength of 390 to 420 nm irradiated for imparting pathogenic resistance to a plant body. Is referred to as “purple light” and “ultraviolet rays” that are considered to be harmful or harmful to the human body are referred to as radiation having a wavelength of 1 to 390 nm.
In addition, it is conceivable to irradiate light of a specific wavelength region at night when a person does not work, but if light is continuously irradiated to the plant body, it will cause stress on the plant body, resulting in inhibition of photosynthesis. There is a possibility that the growth of the plant body may be adversely affected, and introduction into the field was not realistic.

According to the invention disclosed in Patent Document 2, although it is considered that the disease resistance of a plant can be induced by irradiating the plant with green light to suppress the occurrence of the plant disease, the green light itself Has no bacteriostatic / bactericidal action, and thus the ability of phytopathogenic fungi to cause disease in plants could not be stagnated or reduced by irradiation with green light.
For this reason, if the ability of plant pathogens to cause disease in the plant body has overcome the disease resistance of the plant body, it is not possible to cope with the disease only by irradiating with green light. In particular, there was a problem of having to rely on drugs.
Therefore, the effect obtained by irradiating with green light was limited.

According to the report disclosed in Non-Patent Document 1, although there is a possibility that the occurrence and propagation of plant diseases can be suppressed by irradiation with red light, in particular, red light and blue light are healthy growth in the form of plants. (For example, plant cultivation and growth sensing using RGB three-color high-intensity LEDs, Kenji Okamoto et al., Applied Physics, Vol. 68, No. 12, p156-160) (1999) etc.). Therefore, when a plant is irradiated with red light for the purpose of inducing pathogenic resistance, it can be expected to have a disease-suppressing effect by inducing pathogenic resistance, but as a side effect, it is not preferable for morphogenesis during plant growth. There is a risk of impact, and it cannot be said that the technique is necessarily highly reliable in the field of crop cultivation.

The present invention has been made in response to such conventional circumstances, and its purpose is that there is no possibility of adversely affecting the growth and morphogenesis of the plant body, or the photosynthetic action, and natural infection of phytopathogenic bacteria may occur. It is an object of the present invention to provide a pathogen-resistant plant that is unlikely to cause disease even when no drug is used or the amount of the drug is reduced in the environment.
Moreover, it is providing the fruit or leaf stem as a harvested thing which has no residual agricultural chemicals or few residual agricultural chemicals.
Furthermore, it is providing the method of inducing | guiding | deriving pathogenic resistance plants as mentioned above.
And it is to provide a plant cultivation system that can grow while making it difficult to cause diseases caused by phytopathogenic bacteria while inducing pathogenic resistance of the plant, and does not adversely affect the human body of the worker. is there.

In order to achieve the above object, the pathogen-resistant plant according to the first aspect of the present invention is a pathogen induced by violet light irradiation treatment for irradiating leaves with purple light having a peak between wavelengths of 390-420 nm. It is a resistant plant, and the pathogen defense response-related gene is expressed more than the same type of plant that is not treated with purple light. The pathogen defense response-related gene is induced by a salicylic acid synthesis pathway-related gene or salicylic acid. It is characterized by being a gene group.
In addition, the pathogen-resistant plant that is the invention described in claim 2 is the pathogen-resistant plant according to claim 1, wherein the genes that are induced by salicylic acid are genes that induce acidic PR proteins. It is characterized by this.
In the first and second aspects of the invention described above, the violet light having a peak between wavelengths 390-420 nm irradiated in the violet light irradiation treatment works directly on the plant pathogens adhering to the plant body, and is static. Has the effect of sterilizing bacteria.
In addition, since this purple light is difficult for plants to use for photosynthesis, single irradiation with purple light is stressful for plants, but there is a risk of adversely affecting the morphology and growth process of plants. It has a very low property. Further, this purple light has a very low possibility of adversely affecting the human body.
Further, in the plant body, the violet light irradiation treatment is performed, so that the pathogen defense response-related gene is expressed more than the same type of plant body that has not been subjected to the violet light irradiation treatment, more specifically, the salicylic acid synthesis pathway. A related gene or a gene group induced by salicylic acid is expressed. More specifically, a gene related to a salicylic acid synthesis pathway or a gene group that induces an acidic PR protein is expressed, and resistance to phytopathogenic fungi is expressed in plants. It has the effect of being elevated throughout the body.
Therefore, according to the pathogen-resistant plant according to claim 1, while the pathogen resistance of the plant is enhanced by the purple light irradiation treatment, it adheres to or infects the plant and causes a disease to the plant. Since it acts directly on the phytopathogenic fungi to be bacteriostatic and sterilized, the risk of causing diseases in the plant body is greatly reduced when these actions occur simultaneously.

The fruit according to the invention described in claim 3 is harvested from the pathogen-resistant plant according to claim 1 or claim 2.
The leaf stem which is the invention according to claim 4 is harvested from the pathogen-resistant plant according to claim 1 or claim 2.
The invention described in claim 3 or claim 4 is a fruit or leaf stem harvested from the pathogen-resistant plant according to claim 1 or claim 2, and the action thereof is claimed in claim 1 or claim. It is the same as the pathogen-resistant plant described in 2.

The method for inducing a pathogen-resistant plant according to claim 5 irradiates at least 10% of the total leaf area of the plant with violet light having a peak between wavelengths 390-420 nm. A violet light irradiation process is performed.
The invention of the above configuration is obtained by capturing the invention according to

claims

1 and 2 as a method invention, and the action of purple light and purple light irradiation treatment in the invention according to claim 5 is This is the same as the effect of the purple light and purple light irradiation treatment in the described invention.
Moreover, the stress to the plant body by purple light irradiation is reduced by making purple light irradiation intermittent in purple light irradiation processing.

The invention according to claim 6 is a method for inducing a pathogen-resistant plant according to claim 5, which is related to a salicylic acid synthesis pathway, which is a gene related to a pathogen defense response in a plant by performing purple light irradiation treatment. It is characterized by expressing a gene or a gene group induced by salicylic acid.
The invention having the above-described configuration is obtained by capturing the inventions according to

claims

1 and 2 as the invention of the method, and clarifies the purpose of performing the violet light irradiation treatment. Therefore, the operation of the invention described in claim 6 is the same as that of the invention described in claim 5.

The pathogen-resistant plant that is the invention according to claim 7 is characterized by being induced by the method according to claim 5 or claim 6.
The action of the pathogen-resistant plant having the above structure is the same as the action of the pathogen-resistant plant according to

claims

1 and 2.

The plant cultivation system according to claim 8 is a plant growth space capable of directly or indirectly irradiating a plant leaf with outdoor natural light or artificially adjusted natural light. A medium or culture solution that contains roots and supplies nutrients and water necessary for the growth of the plant and a peak at a wavelength of 390-420 nm in a region of at least 10% of the total leaf area of the plant It has a violet light source that irradiates violet light intermittently, and a control unit that controls turning on and off of the violet light source.
In the invention of the above configuration, the plant growth space has an effect of supplying outdoor natural light necessary for photosynthesis or artificially adjusted natural light to the leaves of the plant. In addition, the medium or the culture solution has the effect of containing the roots of the plant body and supplying nutrients and water necessary for the growth of the plant body. Further, the violet light source has an effect of intermittently irradiating purple light having a peak between wavelengths 390 to 420 nm to a region of at least 10% of the entire leaf area of the object. In addition, the control unit has an action of controlling turning on and off of the violet light source.
Further, in the invention according to claim 8 as described above, in the plant body irradiated with purple light intermittently, the pathogen defense response-related gene is expressed more specifically than the same kind of plant body not irradiated with purple light, and more specifically, Specifically, a salicylic acid synthesis pathway-related gene or a gene group induced by salicylic acid is expressed, and more specifically, a salicylic acid synthesis pathway-related gene or a gene group that induces acidic PR protein is expressed, Resistance to plant pathogens is increased throughout the body of the plant.
On the other hand, the purple light directly acts on phytopathogenic bacteria attached to or infecting the plant body, and has an effect of bacteriostatically / sterilizing the phytopathogenic bacteria. In addition, since purple light is light that is difficult for plants to use for photosynthesis, it causes stress for plants, but has a very low risk of adversely affecting morphogenesis and growth of plants.
Furthermore, it has the effect | action of reducing the stress which a plant body receives and suppressing photosynthesis being inhibited by irradiating a plant body with purple light intermittently.
According to such invention of Claim 8, while increasing the pathogenicity resistance of a plant body, on the other hand, the plant pathogenic microbe which adheres or infects a plant body and is going to cause a disease to a plant body is obtained. It has the effect of bacteriostatically and sterilizing, and the simultaneous action of these has the effect of growing the plant healthy while greatly reducing the risk of causing disease in the plant.
Furthermore, since violet light is extremely unlikely to adversely affect the human body, the use of a violet light source has the effect of providing a safe working environment for the worker.

The plant cultivation system which is the invention according to claim 9 is the plant cultivation system according to claim 8, wherein the violet light source can be changed in its mounting position or the number of mounting, or the mounting position and mounting. Both of the numbers can be changed.
The invention according to the ninth aspect has the same action as the invention according to the eighth aspect. In addition, in the invention described in claim 9, the position and size of the leaf can be changed with the growth of the plant body by changing the mounting position or the number of the violet light source, or by changing both of them. Even when the light intensity changes, it has an effect of reliably irradiating the target leaf with purple light.
In addition, by making it possible to change the attachment position or the number of attachments of the violet light source, or to change both of them, a place where a disease is particularly likely to occur in the plant (for example, a lower leaf) or a disease has occurred. It has the effect of enabling the irradiation of violet light to the point.
And in the case of the former especially, it has the effect | action which prevents that a disease produces on a plant body using the bacteriostatic and bactericidal action of purple light. Moreover, in the latter case, it has the effect | action which suppresses that a lesion part expands and is transmitted in the plant body which disease produced using the bacteriostatic and bactericidal action of purple light.

According to the invention described in

claims

1 and 2 of the present invention, by performing purple light irradiation treatment on the plant body, without causing an unfavorable influence on the growth and morphogenesis of the plant body, or the photosynthetic action, The pathogenic resistance of plants can be increased. Thereby, it can make it hard to produce a disease in a plant body.
On the other hand, since the phytopathogenic bacteria that adhere to or infect the plant body are bacteriostatically and sterilized by the purple light irradiated to the plant body during the purple light irradiation treatment, it is also difficult to cause diseases to the plant body from this point can do.
That is, the purple light irradiation treatment not only makes the plant body less susceptible to disease, but also reduces or reduces the force of plant pathogens attached to or infected with the plant body to cause disease.
As a result, when a single type of the pathogen-resistant plant according to

claims

1 and 2 is planted at a high density in a field or house, the risk of causing a disease in the pathogen-resistant plant can be reduced. it can.
Therefore, according to the pathogen-resistant plant according to

claims

1 and 2, it is possible to reduce the amount of a drug used for suppressing the occurrence of disease during cultivation, and thus a highly safe plant is provided. can do.

The fruits and leaf stems according to

claims

3 and 4 are all harvested from the pathogen-resistant plant according to claim 1 or claim 2, and the invention according to claim 1 or claim 2 Has the same effect.
Moreover, according to the fruit and leaf stem of

Claims

3 and 4, it is possible to efficiently produce and provide foods and raw materials for processing that have no residual chemicals or little residual agricultural chemicals.

The invention described in

claims

5 and 6 is obtained by capturing the invention described in

claims

1 and 2 as a method invention, and the plant obtained by the method for inducing a pathogen-resistant plant described in

claims

5 and 6 is The pathogenic resistance plant according to

claims

5 and 6 has the same effect as that of the pathogenic resistance plant according to

claims

1 and 2. The same.
According to the method for inducing a pathogen-resistant plant according to

claims

5 and 6, a gene related to a salicylic acid synthesis pathway or a gene induced by salicylic acid, which is a gene related to a pathogen defense response in a plant by irradiation with purple light. As the group is expressed, it not only works well to improve the pathogenic resistance of plants, but also the purple light itself has bacteriostatic and bactericidal action, so crops while reducing the amount of drugs used in fields and houses Can be cultivated.
As a result, it is possible to provide safe foods and raw materials for processing with little residual agricultural chemicals.

The invention described in claim 7 is a pathogen-resistant plant obtained by the method described in

claims

5 and 6, and the pathogen-resistant plant is the pathogen-resistant plant described in

claims

1 and 2. The same.
Therefore, the effect of the invention described in claim 7 is the same as the effect of the invention described in

claims

1 and 2.

According to the eighth aspect of the present invention, pathogenicity resistance can be enhanced in the whole body of the plant body by irradiating the plant body with violet light, so that it is possible to suppress the occurrence of disease caused by the plant pathogen. In addition, since the plant pathogenic bacteria can be bacteriostatically and sterilized at the site that is directly irradiated with purple light, it is efficient to irradiate purple light on the site that is likely to cause disease in the plant body (for example, lower leaves). The occurrence of disease can be suppressed.
Therefore, according to the plant cultivation system according to claim 8, the plant body can be made less susceptible to illness by irradiating with purple light, and the plant pathogen can be bacteriostatically / sterilized. It is possible to reduce the amount of chemicals used for disease control during cultivation.
As a result, it is possible to produce and provide crops with little residual agricultural chemicals and raw materials for processing.

The invention according to the ninth aspect has the same effect as the invention according to the eighth aspect.
In addition, in the invention according to claim 9, since the attachment position or the number of attachments of the violet light source can be changed, or both of them can be changed, the size and position of the leaves have changed with the growth of the plant body. Even in such a case, a necessary number of violet light sources can be installed at necessary positions.
In addition, in the unlikely event that a disease occurs in a plant, a purple light source is newly added or a purple light source that irradiates a site where no disease has occurred is used to irradiate the site where the disease has occurred Therefore, purple light can be irradiated to the site where the disease has occurred.
As a result, phytopathogenic bacteria at the site where the disease has occurred can be bacteriostatically sterilized, so that the spread of the disease and the spread of the infection can be effectively prevented.
In addition, since the leaves can be preserved by irradiating the leaves where the disease has occurred with purple light, the damage to the plants when the disease occurs can be minimized.
In addition, even when a disease occurs in a plant body, the possibility that it can be dealt with by irradiating purple light without using a drug increases. Cultivation of plant bodies can be continued while reducing the amount used, and it becomes easy to produce foods with little residual agricultural chemicals and raw materials for processing even after diseases occur in the plant bodies.
That is, a safe harvest with little residual agricultural chemicals can be obtained from a plant body in which a disease has occurred.

(A)-(c) is a conceptual diagram showing a mechanism for inducing a pathogen-resistant plant according to Example 1 of the present invention. (A)-(c) is a conceptual diagram showing the progression of disease when no treatment for inducing pathogenic resistance is performed on the plant body P. FIG. (A)-(c) is a conceptual diagram which shows the mechanism by which the pathogenic resistance of the plant body P is induced when irradiated with green light. (A)-(c) is a conceptual diagram of a plant cultivation system according to Example 2 of the present invention. (A)-(c) is a conceptual diagram showing a plant cultivation system according to a modification of Example 2 of the present invention. It is a graph which shows the change of the colony diameter accompanying a time-dependent change at the time of irradiating each wavelength light, making a photon flux density constant (95 micromolm- ² s- ¹ constant). It is a table | surface which shows the ratio (recovery rate) of the number of the recovered colonies (colony which did not kill | disinfect a microbe) with respect to the total number of colonies after irradiating purple light (wavelength of 405 nm) for a predetermined time. B.cinerea spores images of spore when irradiated with light of each wavelength (405 nm, 415 nm, 450 nm, irradiance 60 Wm ^-2 ) for 72 hours, and after irradiating each wavelength light for 72 hours It is the figure which contrasted and showed the image which shows the mode of the spore at the time of culturing for 24 hours in the dark. Changes in the germination rate of spores of B. cinerea spores when irradiated with light of each wavelength (405 nm, 415 nm, 450 nm, irradiance 60 Wm ^-2 ), and the spores of the spores after 72 hours in the dark It is a graph which shows a time-dependent change of a germination rate. It is the figure which contrasted and showed the image of the mycelia front-end | tip part of the phytopathogenic fungi cultured in the darkness, and the image of the mycelial-tip part of the phytopathogenic fungi cultured while irradiating purple light with a wavelength of 405 nm. An image showing the appearance of spores (B. cinerea) cultured while irradiating purple light of wavelength 405 nm for 24, 72 and 168 hours, respectively, and an image showing the appearance of spores cultured in the dark for 24, 72 and 168 hours It is the image which contrasts and shows. It is a graph which shows the expression change of the division control gene in B.cinerea irradiated with 405 nm purple light. (A) is an image showing the appearance of the tomatoes irradiated with 405 nm wavelength violet light, and (b) is an image showing the appearance of the tomatoes in the control section. Moreover, (c) is an enlarged image showing a state of bacterial (gray mold) staining when tomato leaf tissue is stained with lactphenol cotton blue when irradiated with purple light having a wavelength of 405 nm, and (d) is a control. It is an enlarged image which shows the mode of a microbe (gray mold fungus) dyeing | staining at the time of dyeing the leaf tissue of a tomato of a ward with lactophenol cotton blue. It is an image which shows the cut leaf paper disk inoculation test result using the tomato leaf irradiated with wavelength 405nm purple light, and the tomato leaf of a control group. It is a top view which shows arrangement | positioning of the test material in the greenhouse in Experiment 1. FIG. It is a top view which shows arrangement | positioning of the test material in the greenhouse in Experiment 2. FIG. It is a top view which shows arrangement | positioning of the test material in a greenhouse in Experiment 3 (12 / 7-1 / 16). It is a top view which shows arrangement | positioning of the test material in a greenhouse in Experiment 3 (1/17 or later). It is the graph which compared the time-dependent change of the plant height in the population which irradiated purple light with a wavelength of 405 nm in Experiment 2, and the population for control. It is a graph which shows the time-dependent change of the number of compound leaves in the population irradiated with purple light of wavelength 405nm in Experiment 2, and the control population. It is a graph which shows the time-dependent change of the SPAD value in the population which irradiated purple light of wavelength 405nm in Experiment 2, and the population for control. It is a graph which shows a time-dependent change of the disease index based on the number of diseased leaves in Experiment 1 (summer autumn cultivation). It is a graph which shows a time-dependent change of the number of diseased leaves based on the number of diseased leaves in Experiment 1 (summer autumn cultivation). It is a graph at the time of calculating the time change of the disease index in Experiment 2 (summer autumn cultivation) in the whole individual. It is a graph at the time of calculating the time-dependent change of the disease index in Experiment 2 (summer autumn cultivation) with the compound leaf of the irradiated leaf position. It is a graph which shows the change of the disease incidence index in Experiment 3 (winter spring cultivation). It is a graph which shows the change of the number of diseased leaves in Experiment 3 (winter spring cultivation). It is the graph which compared the expression level of the pathogen defense response related gene in the control group at the time of using tomato as a test material, and a 405 nm purple light irradiation group. It is the graph which compared the expression level of the pathogen defense response related gene in the control group at the time of using tomato as a test material, and a 405 nm purple light irradiation group. It is the graph which compared the expression level of the pathogen defense response related gene in the control group at the time of using tomato as a test material, and a 405 nm purple light irradiation group. It is the graph which compared the expression level of the pathogen defense response related gene in the control group at the time of using Arabidopsis thaliana as a test material, and a 405 nm purple light irradiation group. 10 is a graph showing wavelength characteristics of light sources AC used in Test 11. FIG. It is a graph which shows the relationship between PPFD and (DELTA) F / Fm 'when light intensity is gradually raised with respect to the same leaf. It is a graph which shows the relationship between PPFD and (DELTA) F / Fm 'when light intensity is gradually raised with respect to the same leaf. When the mold of A. nig is cultivated in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), and light at 640 nm It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength and white light, respectively. When gray mold fungus (B. cin) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), and 640 nm It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength and white light, respectively. When anthracnose fungus (C. glo) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), and 640 nm It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength and white light, respectively. When the rice blast fungus (F. pro) is cultured in the dark, it has light with a peak wavelength at 375 nm, light with a peak wavelength at 405 nm, light with a peak wavelength at 470 nm (purple light), and peak at 640 nm. It is an image which shows the reproduction state after 144 hours at the time of culture | cultivation, irradiating each with the light which has a wavelength, and white light. When cultivating another blast fungus (F. pro) in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), 640 nm It is an image which shows the breeding state after 144 hours at the time of culture | cultivating, irradiating light which has a peak wavelength, and white light, respectively. Is a case where another blast fungus (F. pro) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively. When cultivating another blast fungus (F.ver) in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), 640 nm It is an image which shows the breeding state after 144 hours at the time of culture | cultivating, irradiating light which has a peak wavelength, and white light, respectively. When cultivating another blast fungus (M.gri) in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), 640 nm It is an image which shows the breeding state after 144 hours at the time of culture | cultivating, irradiating light which has a peak wavelength, and white light, respectively. When black rot fungus (S. cep) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively. After inoculating gray mold fungi on the test plants that had been pre-irradiated with purple light or white light at a wavelength of 405 nm, after the inoculation with gray mold fungus, there were two groups: It is an image which shows the mode of the plant body after 3 days in each. After inoculating the gray bean of the test plant that had been pre-irradiated with purple light or white light with a wavelength of 405 nm, after the inoculation with the gray mold fungus, there were two groups: It is an image which shows the mode of the plant body after 3 days in each. After inoculating the gray mold of the test plant that had been pre-irradiated with purple light or white light with a wavelength of 405 nm, after the inoculation with the gray mold fungus, the group that was continuously irradiated with purple light or white light with a wavelength of 405 nm It is a graph which shows the result of having measured the diameter of the diseased part of the plant body after 3 days in each. After inoculating the gray bean of the test plant that had been pre-irradiated with purple light or white light with a wavelength of 405 nm, after the inoculation with the gray mold fungus, there were two groups: It is a graph which shows the result of having measured the diameter of the diseased part of the plant body after 3 days in each. It is a graph which shows transition of the disease index of the case where the purple light of 405 nm is irradiated to Murasaki which is a test plant, and when not irradiated.

Example 1 will be described in detail with respect to the pathogen-resistant plant according to the embodiment of the present invention, the fruit thereof, the leaf stem thereof, and the method for inducing the pathogen-resistant plant, and the plant cultivation system will be described in detail with reference to Example 2. To do.

The pathogen-resistant plant according to Example 1 of the present invention, its fruit, its leaf stem and its induction method will be described in detail in comparison with the prior art.
First, a pathogen-resistant plant according to Example 1 and a method for inducing it will be described with reference to FIG.
1 (a) to 1 (c) are conceptual diagrams showing a mechanism for inducing a pathogen-resistant plant according to Example 1 of the present invention.
In order to obtain the pathogen-resistant plant 1 according to Example 1, first, as shown in FIG. 1 (a), for example, a violet light source 3 or the like is used on the leaf 2 of the plant P, and the wavelength 390- A violet light irradiation process of irradiating purple light 11 having a peak between 420 nm may be performed.
In this case, in the plant body P, the pathogen defense response-related gene is expressed and the pathogen resistance is increased in the whole body of the plant body P as compared with the same plant body P that is not subjected to the purple light irradiation treatment as described above. It becomes the pathogen-resistant plant body 1.
In addition, the pathogen defense response related gene expressed in the plant body P by the purple light irradiation treatment is specifically a salicylic acid synthesis pathway related gene or a gene group induced by salicylic acid, and more specifically, It is a gene group that induces salicylic acid synthesis pathway-related genes or acidic PR proteins.

And according to the pathogenicity-resistant plant body 1 which concerns on Example 1, since pathogenicity resistance is raised in the whole body of the plant body P, generation | occurrence | production of the disease by the plant pathogenic microbe 4 in the plant body P can be decreased.
In this case, the phytopathogenic fungus 4 is more cultivated when the plant P (pathogen-resistant plant 1) subjected to the purple light irradiation treatment is cultivated than when the plant P not subjected to the purple light irradiation treatment is cultivated. Since the amount of a drug (agricultural chemical) used for controlling disease caused by the above can be reduced, or it can be made pesticide-free, it is possible to provide a plant P that is highly safe for the human body.
In addition, when the plant body P itself is edible, or when fruits and leaves and stems harvested from the plant body P are edible, it is possible to provide safe foods with little or no residual pesticides. it can.

As described above, it has been known that the pathogenicity resistance of the plant body P can be enhanced by irradiating the plant body P with light having a peak in a specific wavelength region (see Patent Document 1 described above). 2 and non-patent documents 1 and 2).
However, when the light irradiated to the plant body P is ultraviolet light (ultraviolet light), there is a possibility that it may adversely affect the human body, and it is desirable to irradiate in places where people constantly enter and exit, such as in farms and houses. It was not a practical technology.
On the other hand, in the case of the technique of irradiating the plant body P with red light, the red light is usually indispensable for the photosynthesis of the plant body P, although there is little possibility that the red light has an unfavorable effect on the human body. In addition, it has been reported that it is particularly relevant to normal morphogenesis and growth of the plant body P, and it cannot be said that it is a highly reliable technique when cultivating commercial crops.
On the other hand, in the case of the technique of irradiating the plant body P with green light, unlike the case of irradiating red light, the green light is usually light that is not used for photosynthesis in the plant body P, and Since there is little risk of adverse effects, it is considered that such a problem as in the case of using ultraviolet light (ultraviolet light) or red light does not occur.
However, since green light has no bacteriostatic / bactericidal action against the phytopathogenic fungus 4, the ability of the phytopathogenic fungus 4 to cause disease to the plant P has overcome the pathogenic resistance of the plant P. In that case, it was no longer possible to deal with it only by irradiating green light, and eventually it was necessary to rely on drugs to control the disease.

The inventors have obtained the knowledge that purple light 11 having a peak between wavelengths 390-420 nm has bacteriostatic / bactericidal action against pathogenic bacteria that adversely affect the human body. Thinking that bacteriostasis and sterilization could not be performed, first, the phytopathogenic fungus 4 was directly irradiated with purple light 11. As a result, it was found that the purple light 11 has a bacteriostatic / bactericidal action against the phytopathogenic fungus 4.
And as a next step, the inventors irradiate the plant body P with the purple light 11 on the assumption that the generation of the disease caused by the plant pathogen 4 can be suppressed by irradiating the purple light instead of using the drug. The inventors have found that irradiation with purple light 11 increases the pathogenic resistance of the plant body P and can suppress the occurrence of disease.

Therefore, in the pathogen-resistant plant 1 according to Example 1, as a first effect, as shown in FIG. 1B, at least a part of the plant has a purple light having a peak between wavelengths 390-420 nm. By irradiating 11, the pathogenic resistance can be enhanced in the whole body of the plant body P, and thus the plant body P after being irradiated with the purple light 11 can be made difficult to get sick. In FIGS. 1B and 1C, the fact that the whole plant P is hatched indicates that the pathogenic resistance of the plant P is induced. The same applies to other embodiments.
Furthermore, in the pathogen-resistant plant 1 according to Example 1, the second effect is that the plant P has a purple color, particularly at a site directly irradiated with purple light 11 having a peak between wavelengths 390-420 nm. Since the bacteriostatic and bactericidal action of the phytopathogenic fungi 4 by the light 11 is exerted, the ability of the phytopathogenic fungi 4 attached or infected to the plant P before irradiating the purple light 11 to cause the disease to the disease Can be stagnated or reduced.
More specifically, as shown in FIG. 1 (a), even if the phytopathogenic fungus 4 is already infected or attached to the leaves of the plant body P, for example, before the purple light 11 is irradiated, the purple light By performing the irradiation treatment, as shown in FIG. 1 (b), the phytopathogenic fungi 4 are bacteriostatically sterilized by the violet light 11 at the site irradiated directly with the violet light 11, and the phytopathogenic fungi 4 are transferred to the plant body P. Since the force to cause the disease is stagnated or weakened, the occurrence of the disease in the leaves 2 of the plant body P can be suppressed or prevented as shown in FIG.
That is, in the case of the pathogen-resistant plant 1 according to Example 1, not only the pathogenic resistance of the plant P is increased, but also by stagnating and reducing the ability of the phytopathogenic fungus 4 to cause disease. It is possible to suppress the occurrence of disease in the plant body P.
Of the above two effects, the latter effect is due to the use of purple light 11 having a peak between wavelengths 390-420 nm in the pathogen-resistant plant 1 according to Example 1. This is a unique effect of the invention.

About the original effect of this invention, the case where no process which raises pathogenic resistance is performed, and the case where pathogenic resistance is improved by irradiating green light will be described in more detail.
Generally, the plant body P also has resistance induced by direct damage caused by the phytopathogenic fungi 4 or the like, but in the present specification, it is induced by direct damage by the phytopathogenic fungi 4 or the like. The pathogenic resistance is distinguished from the pathogenic resistance induced by irradiating light having a specific wavelength region, and the former resistance is ignored.

First, the progression of the disease in the case where no treatment for increasing pathogenic resistance is performed on the plant body P will be described with reference to FIG.
FIGS. 2A to 2C are conceptual diagrams showing the progression of disease when no treatment for inducing pathogenic resistance is performed on the plant body P. FIG. In addition, the same code | symbol is attached | subjected about the part same as what was described in FIG. 1, and the description about the structure is abbreviate | omitted.
As shown in FIG. 2 (a), if the plant P, for example, leaves 2 are attached or infected with the phytopathogenic fungi 4 are left as they are, the phytopathogenic fungi 4 are attached or removed as shown in FIG. 2 (a). A large number of lesions 5 appear on the infected leaves 2 to cause a disease, and further, the infection of the phytopathogenic fungi 4 spreads to the surrounding leaves 2 and other plant bodies P (not shown). If the state is left as it is, the leaves 2 in which a large number of lesions 5 have appeared become dead leaves 7, and the infection of the phytopathogenic fungi 4 has further expanded while a large number of the lesions 5 have occurred in the other leaves 2 thereon. In the worst case, the plant body P will die.

Next, the case of irradiating green light as disclosed in the above Patent Document 1 will be described in detail with reference to FIG.
FIGS. 3A to 3C are conceptual diagrams showing a mechanism by which pathogenic resistance of the plant body P is induced when irradiated with green light. In addition, the same code | symbol is attached | subjected about the same part as what was described in FIG. 1 or FIG. 2, and the description about the structure is abbreviate | omitted.
As shown in FIG. 3A, for example, when green light 12 is irradiated to a plant body P in which a phytopathogenic fungus 4 is attached or infected to a leaf 2 using, for example, a green light source 6, irradiation with green light 12 is performed. While the pathogen resistance is enhanced in the whole body of the plant body P, the green light 12 has a bacteriostatic / bactericidal action like the purple light 11 used in inducing the pathogen-resistant plant body 1 according to Example 1. Since it does not have, the force which the plant pathogenic microbe 4 tries to cause a disease to the plant body P is maintained as it is.
In this case, even if the resistance of the plant body P is increased, if the plant pathogenic fungus 4 has a sufficient force to cause disease to the plant body P, FIG. As shown in FIG. 5, the lesion 5 is generated on the leaf 2 of the plant body P, or the spread of infection to other leaves 2 occurs.

On the other hand, in the pathogen-resistant plant 1 according to Example 1, as shown in FIG. 1, the bacteriostatic / sterilization of the phytopathogenic fungus 4 is performed in the plant P directly irradiated with the purple light 11. Since the action is exerted, the force of the phytopathogenic fungus 4 to cause the plant body P to be ill is stagnant or weakened.
Therefore, in the pathogen-resistant plant 1 according to Example 1, the possibility that the phytopathogenic fungus 4 still has sufficient power to cause disease on the plant P after the irradiation with the purple light 11 is greatly increased. To be low.
Therefore, in the case of the pathogen-resistant plant 1 according to Example 1 of the present invention, the occurrence and progression of the disease caused by the phytopathogenic fungus 4 can be further slowed compared to the case where the green light 12 is irradiated. .

For this reason, when the pathogen-resistant plant body 1 according to Example 1 is a seedling of the plant body P cultivated in a field or a house, the whole body of the plant body P is subjected to violet light irradiation treatment. In addition, it is possible to efficiently suppress the occurrence of disease when seedlings are transplanted into a field or a house. This method is particularly effective when the target irradiated with the violet light 11 is relatively small.
Alternatively, in a specific plant P, for example, when it is clear that a disease caused by the phytopathogenic fungus 4 is likely to occur in a specific part (for example, a lower leaf), the disease is caused when the purple light irradiation treatment is performed. The generation of diseases caused by the phytopathogenic fungi 4 can be efficiently suppressed by selecting a specific part that is likely to occur and irradiating the purple light 11 with priority. This method is particularly effective when the target irradiated with the violet light 11 is large.
In this example, the purple light irradiation site is a leaf, but if it is a plant chlorophyll-containing site (for example, a stem or a petiole), a pathogen defense response-related gene is expressed by purple light irradiation. There is a possibility that it can be made. On the other hand, when the plant body is efficiently irradiated with purple light and the bacteriostatic / bactericidal action of the plant pathogen is expected by the purple light, it is preferable that the irradiation site of the purple light is on the leaf of the plant body.

Moreover, the process for inducing the pathogenic resistant plant 1 according to Example 1 as described above is the method for inducing the pathogenic resistant plant according to Example 1.
More specifically, in the method for inducing a pathogen-resistant plant according to Example 1, purple light 11 having a peak between wavelengths 390-420 nm is applied to a region of at least 10% of the total leaf area of plant P. The violet light irradiation treatment is performed intermittently.
According to the pathogen-resistant plant body induction method according to Example 1, the pathogen-resistant plant body 1 according to Example 1 as described above can be induced.
As a result, when the plant body P which is the pathogen-resistant plant body 1 is cultivated and supplied to the market for ornamental use in the field or house, etc., or when the pathogen-resistant plant body 1 is edible, In the case where a harvested product such as a fruit or a leaf stem is obtained from the sexual plant 1 and used as an edible or processing material, it is possible to provide a product with little residual agricultural chemical.
Moreover, since the induction | guidance | derivation method of the pathogen-resistant plant which concerns on Example 1 can be easily integrated in the process for producing the seedlings etc. which are cultivated conventionally in a field, a house, etc., it is more in the field | area regarding agriculture or facilities gardening. Practical disease control technology can be provided.

Further, a purple light having a peak between wavelengths 390-420 nm used in the pathogen-resistant plant body 1 according to Example 1 and the pathogen-resistant plant body induction method for inducing the pathogen-resistant plant body 1 No. 11 has a very low possibility of adversely affecting the human body, so even if the purple light source 3 is installed in a place where a person works such as in a farm or house, the worker can safely work in the farm or house. be able to.
Further, the purple light 11 having a peak between wavelengths 390-420 nm is a light that has the potential to reduce the photosynthetic quantum yield of the plant body. Any continuous irradiation of the purple light 11 on the body P may cause stress to the plant body P and inhibit photosynthesis.
More specifically, if the plant body P is continuously irradiated with the purple light 11 for a long time, it may negatively affect the photosynthesis of the plant body P (decrease in the quantum yield), and the purple light 11 is intermittently irradiated. It is considered that the negative influence on the photosynthesis can be alleviated by alternately performing the time zone in which the purple light 11 is irradiated and the time zone in which the purple light 11 is not irradiated. In the present invention, it is considered that disease (pathogenicity) resistance is induced by applying a certain amount of light stress to the plant body P (irradiation with purple light 11). Therefore, when the stress on the plant body P is too large (when the purple light 11 is continuously irradiated for a long time), the negative effect on the plant body P becomes significant, and conversely, the stress on the plant body P is insufficient. (When the irradiation time of the purple light 11 on the plant body P is short), there is a possibility that disease (pathogen) resistance is not sufficiently induced in the plant body P.
For this reason, when performing purple light irradiation processing with respect to the plant body P, the purple light 11 is irradiated to the plant body P superimposed on natural light or artificially adjusted natural light, or the purple light 11 is intermittently irradiated. It is desirable to irradiate purple light 11 intermittently. More preferably, it is desirable to irradiate the plant body P with the purple light 11 in addition to the light necessary for photosynthesis, and at that time, the purple light 11 is intermittently irradiated. In the present specification, switching between irradiation and non-irradiation of the purple light 11 in units of seconds, minutes, or hours is referred to as intermittent irradiation or intermittent irradiation.
Moreover, if it is the plant body P which is easy to receive the stress by the purple light 11, even if the purple light 11 irradiated to the plant body P is pulsed light, disease (pathogenic) resistance may be induced.

As described above, when emphasizing the bacteriostatic and bactericidal action on the plant body P, it is desirable to irradiate the entire plant body P with the purple light 11 to reduce the stress on the plant body P and improve the pathogenic resistance. In the case where importance is attached, a sufficient effect can be expected only by irradiating the purple light 11 to a region of 10-30% of the total leaf area of the plant body P.
When the plant P to be irradiated is large and it is difficult to irradiate the violet light 11 as a whole, or when it is difficult to introduce the large violet light source 3 from the viewpoint of cost effectiveness. The pathogenic resistance of the plant body P can be increased by simply irradiating the purple light 11 to a region of at least 10% of the total leaf area of the plant body P. In this case, the disease caused by the phytopathogenic fungus 4 is particularly likely to occur. By irradiating the lower leaves (several leaves arranged on the root side of the plant body P) with the purple light 11, the occurrence of the disease in the plant body P is caused. Can be efficiently suppressed.

A plant cultivation system according to Example 2 of the present invention will be described in detail with reference to FIGS. 4 and 5.
FIGS. 4A to 4C are conceptual diagrams of the plant cultivation system according to Example 2 of the present invention. The same parts as those described in FIGS. 1 to 3 are denoted by the same reference numerals, and description of the configuration is omitted.
As shown in FIG. 4 (a), the plant cultivation system 10A according to the second embodiment can directly or indirectly irradiate the leaves 2 of the plant body with outdoor natural light or artificially adjusted natural light. One or a plurality of plant bodies P are arranged in the plant growth space 8 and contains the roots of the plant bodies P, and includes a medium 9 for supplying nutrients and water necessary for the growth of the plant bodies P. At least part of the leaves of the plant body P, more specifically, at least 10% of the total leaf area of the plant body P is intermittently irradiated with purple light 11 having a peak between wavelengths 390-420 nm. A purple light source 3 is provided, and the purple light source 3 is controlled to be turned on and off by a control unit (not shown).
In the plant cultivation system 10A according to Example 2 as described above, by providing the plant growth space 8, natural light (visible light) L necessary for plant growth is provided in the space where the plant P is arranged. Can be supplied. The natural light L may be outdoor natural light or a combination of a plurality of colors of light (a plurality of types of light having different wavelengths) having the same effect as the artificially adjusted natural light L.
Moreover, by providing the culture medium 9, while accommodating the root of the plant body P, the nutrient and water required for the growth of the plant body P can be supplied. Furthermore, by providing the purple light source 3 and a control unit (not shown), the leaves of the plant body P can be intermittently irradiated with the purple light 11 having a peak between wavelengths 390-420 nm. In addition, when the plant body P is a thing which can be hydroponically cultivated, it can replace with the culture medium 9 and can also use a culture solution.

And according to the plant cultivation system 10A which concerns on Example 2 as mentioned above, since artificial light which has an effect | action equivalent to natural light L or the natural light L can be supplied in the plant growth space 8, the plant body P Can be grown normally.
Furthermore, in the plant cultivation system 10A according to Example 2, in addition to the natural light L or the artificial light having an action equivalent to the natural light L, the purple light 11 is superimposed on the leaves 2 of the plant P by the purple light source 3. Can be irradiated. In this case, since the plant body P cultivated in the plant body cultivation system 10A according to Example 2 becomes the pathogen-resistant plant body 1 described in the previous Example 1, it is preferable that the disease caused by the phytopathogenic fungi 4 occurs. Can be suppressed.
In addition, in the plant cultivation system 10A according to the second embodiment, the bacteriostatic / bactericidal action of the phytopathogenic fungi 4 as described in the first embodiment is performed at the portion of the plant P that is directly irradiated with the purple light 11. Therefore, as shown in FIGS. 4B and 4C, it is possible to prevent or delay the occurrence of a disease such as the appearance of a lesion 5 at a site directly irradiated with the violet light 11.
That is, according to the plant cultivation system 10A according to the second embodiment, the plant P becomes the pathogen-resistant plant 1 so that it is less likely to become ill, and the aggressiveness of the phytopathogenic fungus 4 against the plant P is also improved. Therefore, even if the plant pathogen 4 adheres to or infects the plant body P, it becomes easy to maintain a state in which no visible disease is caused.
That is, it is possible to prevent or greatly delay the occurrence of disease in the plant body P.

Therefore, according to the plant cultivation system 10A according to Example 2, seedlings and plant bodies P (seedlings and plant bodies P that are considered to have been naturally infected by the phytopathogenic fungi 4) are cultivated by conventional methods. Thus, it is possible to cultivate while suppressing the occurrence of diseases caused by the plant pathogenic bacteria 4 by inducing the pathogenic plant 1. In this case, since the usage-amount of the chemical | drug | medicine at the time of cultivating plant body P (pathogenic resistance plant body 1) can be reduced significantly, plant body P with few residual agricultural chemicals and high safety | security can be provided. .
In addition, leaf stems and fruits harvested from the plant body P cultivated in the plant body cultivation system 10A according to Example 2 can also be made highly safe with little residual agricultural chemicals.

In addition, in the plant cultivation system 10A according to the second embodiment, when a site (for example, a lower leaf) that is particularly likely to cause a disease is known for a specific plant P, the site is selected and purple light 11 is selected. Can be efficiently suppressed. In addition, even if a lesion that is a disease appears in the part irradiated with the purple light 11, the bacteriostatic / bactericidal action is exhibited by the purple light 11, so that the progression of the disease is greatly delayed or stagnant. It is possible to prevent the plant pathogen 4 from infecting other parts of the plant body P (pathogen-resistant plant body 1) and other adjacent plant bodies P. Can be suppressed.
Further, in order to efficiently induce the plant body P to the pathogen-resistant plant body 1 in the plant body cultivation system 10A according to Example 2, the intensity of the purple light 11 when the plant body P is irradiated with the purple light 11 It is desirable to make the intensity higher than the intensity of the purple light 11 included in the natural light L or the artificially adjusted natural light L.
In the case of the outdoors, the light intensity of the purple light 11 in the natural light L during the day is particularly stronger than that in the morning and evening, so more specifically in the morning and evening hours, for example, from 7 am to 10 am The purple light 11 that is stronger than the purple light 11 contained in the natural light L is emitted by superimposing the purple light 11 on the natural light L in the morning until 3:00 pm to 6:00 pm The plant body P can be irradiated.
Further, it is preferable to irradiate the purple light 11 with the natural light L only during the morning and evening hours because the purple light 11 is intermittently irradiated.
In the case where a sufficient effect of improving pathogenicity resistance is exhibited only by irradiating the purple light 11 only in one of the morning and evening time zones, it is not always necessary to irradiate the purple light 11 in the morning and evening.
Alternatively, the disease (pathogenicity) resistance of the plant body P can be suitably achieved by repeating irradiation and non-irradiation of the purple light 11 every hour with respect to the leaves of the plant body P in a time zone where there is sunlight. Can be increased.

Here, a plant cultivation system according to a modification of the second embodiment of the present invention will be described with reference to FIG.
The plant cultivation system according to the modified example of Example 2 has the same configuration as the plant cultivation system 10A shown in FIG. 4, and in particular, the attachment position or the number of attachments of the purple light source 3 can be changed, or Both are configured to be changeable.
FIGS. 5A to 5C are conceptual diagrams showing a plant cultivation system according to a modification of the second embodiment of the present invention. The same parts as those described in FIGS. 1 to 4 are denoted by the same reference numerals, and description of the configuration is omitted.
For example, as shown in FIG. 5 (a), when the purple light source 3 is arranged at the same position as in FIG. 4 (b) and the plant P is cultivated while being irradiated with the purple light 11 In addition, the attachment or infection of the phytopathogenic fungus 4 has occurred on the leaves 2 that have not been irradiated with the purple light 11, and later, as shown in FIG. 5 (b), the lesions on the leaves 2 that have not been irradiated with the purple light 11. When 5 occurs, according to the plant cultivation system 10B according to the modified example of Example 2, the violet light source 3 irradiating the violet light 11 to the leaves 2 where the lesion 5 has not occurred is removed. The violet light 11 can be irradiated to the leaf 2 where the lesion 5 has occurred. Or the purple light 11 can be irradiated to the leaf 2 in which the lesion 5 was produced by newly adding the purple light source 3.

In this case, due to the bacteriostatic / bactericidal action of the purple light 11 emitted from the purple light source 3, as shown in FIG. 5 (c), the progression of the disease in the leaf 2 where the lesion 5 appears is delayed, Can be stopped. That is, in the plant cultivation system 10B according to the modified example of Example 2, since the purple light 11 can be used as having an action equivalent to a drug such as a bactericidal agent, a disease has occurred in the plant P. In some cases, there is a possibility that the progression and spread of the disease can be suppressed without using a drug.
Therefore, even when a disease occurs in the plant body P, there is an extremely high possibility that a safe fruit, leaf stem, or the like can be harvested from the plant body P without any residual agricultural chemical or with little residual agricultural chemical.
Therefore, according to the plant cultivation system 10B according to the modification of the second embodiment, even when a disease occurs in the plant P, there is a high possibility that a decrease in productivity can be prevented without using a drug. As a result, it is possible to minimize a decrease in the safety of fruits or leaf stems harvested from the plant P in which the disease has occurred as a food.

Usually, when a disease occurs in the plant body P, the site where the disease has occurred (mainly leaves) is removed to prevent the spread of the disease, or the spread of the plant pathogen 4 and the disease by spraying a chemical However, in the former case, it is not desirable to remove the leaves that are responsible for the growth of the crop, because it may lead to a reduction in the quality and size of the crop. On the other hand, in the latter case, although the possibility of preserving the leaves responsible for the hypertrophic growth of the crop increases, there is a problem that the safety of the crop decreases due to the residual agricultural chemicals.
On the other hand, according to the plant cultivation system 10B according to the modification of Example 2, the ability of the phytopathogenic fungus 4 to harm the plant P only by irradiating the purple light 11 without using a drug is stagnated or reduced. Therefore, even when a disease occurs, the possibility of preserving the leaves responsible for the hypertrophic growth of the harvest increases. In addition, the risk of the drug remaining in the harvest can be reduced.
Therefore, when the plant cultivation system 10B according to the modified example of the second embodiment is employed, even when a disease occurs in the field or the house, the quality of the harvest can be minimized.
Therefore, when cultivating a crop in a field or house, a more practical technique can be provided for reducing the amount of medicine used.

Hereinafter, Tests 1 to 13 performed for the purpose of verifying the operation and effect of the present invention and the results thereof will be described.
First, the verification results of the bacteriostatic / bactericidal action against purple light phytopathogenic bacteria having a peak between wavelengths 390-420 nm used in the present invention will be described.
[1] Bacteriostatic / bactericidal action of phytopathogenic bacteria by purple light irradiation For the purpose of confirming bacteriostatic / bactericidal action of phytopathogenic bacteria by purple light, Test 1 as shown below was performed.
(1-i) Test method The bacterial flora of tomato gray mold B. cinerea on the surface medium is scraped with a platinum loop and placed on an SNA plate medium (the composition is shown in Table 1 below), at 25 ° C in the dark. For 4-5 days. Thereafter, the outer periphery of the bacterial colony was extracted together with the medium with a cork borer having an inner diameter of 4 mm, and the bacterial cell plug was placed in the center of a new SNA plate medium and used as a bacterial cell plate for the irradiation test.

Put SNA plate medium cell plate in artificial meteor equipped with LED light source, and culture at 25 ° C while irradiating 405nm, 415nm, 450nm and white light with constant irradiance 60Wm- ² , growth rate every 24 hours Was observed. Moreover, what was cultured in the dark was used as control. After irradiation, the bacterial cell plate was transferred to 25 ° C. in the dark and cultured, and growth was observed.

(1-ii) Test Results FIG. 6 is a graph showing changes in colony diameter with time when irradiated with light of each wavelength with a constant photon flux density (95 μmolm ⁻² s ⁻¹ constant).
As shown in FIG. 6, when light of each wavelength was irradiated with the photon flux density constant (95 μmolm ⁻² s ⁻¹ constant), the most remarkable growth suppression was observed in the 375 nm light irradiation section with high energy as expected. However (data not shown), when the irradiance is constant (60 Wm ^-2 ), the most remarkable growth inhibition is observed in the 405 nm purple light irradiation area, and the longer the wavelength of the irradiation light, the more bacteriostatic and bactericidal action is. A tendency to decrease was observed.
FIG. 7 is a table showing the ratio (recovery rate) of the recovered colonies (the number of colonies in which the bacteria were not killed) to the total number of colonies after irradiation with violet light (wavelength 405 nm) for a predetermined time.
As shown in FIG. 7, when violet light with a wavelength of 405 nm was irradiated, the death of all colonies was confirmed after 144 hours of irradiation.

From the above test 1, it was confirmed that purple light having a peak in the wavelength range of 390 to 420 nm has a bacteriostatic / bactericidal action.
In the present invention, the bacteriostatic / bactericidal action does not mean a state in which all phytopathogenic bacteria irradiated with purple light are bacteriostatic or sterilized, but one of the phytopathogenic bacteria irradiated with purple light. As part of the plant becomes inactive and another part is killed, and these phenomena occur at the same time, the growth ability of the whole phytopathogenic fungi irradiated with purple light is stagnant, decreasing, or dead Is meant to be.

[2] Spore germination inhibitory effect of phytopathogenic fungi by purple light irradiation Test 2 as shown below was performed for the purpose of confirming the spore germination inhibitory effect of phytopathogenic fungi by purple light.
(2-i) Test method Tomato gray mold B. cinerea spores irradiated with light of each wavelength (405 nm, 415 nm, 450 nm, irradiance of 60 Wm ^-2 ) and in the dark, spores The germination situation of was observed.
In addition, in order to confirm the spore life after irradiation with each wavelength light (405 nm, 415 nm, 450 nm), each wavelength light was irradiated for 24, 48, 72, and 96 hours, respectively, and then the medium was moved in the dark. Furthermore, after culturing for 24 hours, spores were observed again.

(2-ii) Test results FIG. 8 is an image showing the state of spores when B.cinerea spores are irradiated with light of each wavelength (405 nm, 415 nm, 450 nm, irradiance 60 Wm ⁻² ) for 72 hours. FIG. 5 is a diagram showing contrasted images showing the state of spores when irradiated with light of each wavelength for 72 hours and then cultured in the dark for 24 hours. In addition, the image of what was cultured for the same time in the dark as a comparison object was shown in the lowermost stage.
FIG. 9 shows the time-dependent change in the germination rate of B. cinerea spores when irradiated with light of each wavelength (405 nm, 415 nm, 450 nm, irradiance of 60 Wm ⁻² ), and the spore was placed in the dark for 72 hours. It is a graph which shows the time-dependent change of the germination rate of a thing. FIG. 9 also shows the germination rate of spores after irradiating each wavelength of light for 72 hours and then culturing in the dark for 24 hours.
When B.cinerea spores were irradiated with light of each wavelength (irradiance 60 Wm ⁻² ), a particularly high suppression effect of spore germination was observed in the 405 nm purple light irradiation section (see FIG. 8). In order to confirm the viability of the spore (proliferative ability), after irradiating 405 nm purple light, moving the medium under dark and observing spores cultured for another 24 hours, when 405 nm purple light was irradiated for 72 hours, No germination was seen after moving to darkness (see FIG. 9).
From these results, it was found that violet light irradiation not only suppresses germination but also sterilizes B. cinerea spores.
8 and 9, the violet light used in the present invention is less effective in spore germination and sterilization as the wavelength of irradiation light is shorter (closer to the lower limit of wavelength of 390 nm). It is considered high.
In addition, regarding the upper limit of the wavelength of purple light used in the present invention, there was no significant difference between the germination rate of spores when irradiated with purple light having a wavelength of 450 nm and the germination rate of spores in the dark. It is estimated that the upper limit of the emission wavelength at which spore germination suppression and bactericidal effects of phytopathogenic bacteria can be expected is between 415 nm and 450 nm.

According to the above-mentioned

tests

1 and 2, it was confirmed that purple light having a peak in the wavelength range of 390 to 420 nm has a bacteriostatic / bactericidal action against phytopathogenic fungi. In addition, since the bacteriostatic and bactericidal action against phytopathogenic fungi when irradiated with violet light with a wavelength of 405 nm was particularly high, in other tests shown below, purple light with a wavelength of 405 nm was used as an example of violet light according to the present invention. It was used.
Note that the violet light (purple light with a wavelength of 405 nm, violet light with a wavelength of 405 nm, and violet light with a wavelength of 405 nm) used in Tests 1 to 13 shown in this specification is light having a peak wavelength at a wavelength of 405 nm. The same standard was used. Further, a graph showing the wavelength characteristics of the violet light (wavelength 405 nm violet light, wavelength 405 nm violet light, 405 nm violet light) light source used in Tests 1 to 13 is shown in FIG.
As shown in FIG. 32 (a), the violet light used in Tests 1 to 13 is not a single wavelength light, but has a particularly high emission within a wavelength range of 390 to 420 nm while having a peak at a wavelength of 405 nm. It is. Therefore, if the radiation has a peak wavelength within the wavelength range of 390-420 nm, the bacteriostatic / bactericidal effect of the phytopathogenic fungi 4 and the pathogenic defense response in the plant P are advantageous effects described in the present specification. It is highly possible that the effect of improving the resistance to pathogen (disease) due to the expression of the related gene is exhibited at the same time.

For the purpose of confirming bacteriostatic and bactericidal action against seven typical plant pathogens, Test 3 as shown below was conducted.
(3-i) Test method Seven species of plant pathogenic fungi preserved at Yamaguchi University as test bacteria, Aspergillus niger (black mold fungus), Botrytis cinerea (grey mold fungus), Colletotrichum gloeosporioides (anthrax fungus) Fusarium proliferatum, Fusarium verticillioides, Magnaporthe grisea (blast fungus), and Sclerotium cepivorum (black rot sclerotia) (9 strains in total) were used. Each fungus on the slant medium was scraped with a platinum loop and cultured on a potato dextrose agar (PDA) plate medium for 3 days. Thereafter, the cells were extracted together with the medium with a cork borer having a diameter of 5 mm, the cell plug was placed in the center of a new PDA plate medium, and this was used as a cell plate for the irradiation test.
Using the small artificial meteor equipped with the LED light source, 375 nm (spectral integration value: 10.9 Wm ^-2 ), 405 nm (spectral integration value: 64.7 Wm ^-2 ), 470 nm ( spectral integration value: 89.0Wm ^-2), 640nm (spectral integration value: single wavelength light 67.9Wm ^-2), and white light (spectral integration value: 22.7Wm ^-2) at 25 ° C. while applying a 144 Incubate for hours. Thereafter, all the bacterial cell plates were cultured at 25 ° C. in the dark, and the morphology, color, and growth rate were observed every 24 hours for 144 hours.

(3-ii) Test results FIG. 35 shows a case in which a black mold (A. nig) was cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, peak wavelength at 470 nm. It is an image showing the breeding state after 144 hours in the case of culturing while irradiating with light (purple light), light having a peak wavelength at 640 nm, and white light.
FIG. 36 shows a case where gray mold fungus (B. cin) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light). FIG. 6 is an image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 37 shows the case where anthracnose fungus (C. glo) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light). FIG. 6 is an image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 38 shows a case where a blast fungus (F. pro) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light), It is an image which shows the reproduction state after 144 hours at the time of culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 39 shows a case where another blast fungus (F. pro) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light) ), An image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 40 shows a case where another blast fungus (F. pro) was cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light). ), An image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 41 shows a case where another blast fungus (F.ver) was cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light) ), An image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 42 shows a case where another blast fungus (M.gri) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple light) ), An image showing a breeding state after 144 hours when culturing while irradiating light having a peak wavelength at 640 nm and white light, respectively.
FIG. 43 shows a case where black rot sclerotia (S. cep) is cultured in the dark, light having a peak wavelength at 375 nm, light having a peak wavelength at 405 nm, light having a peak wavelength at 470 nm (purple color) Light), a light having a peak wavelength at 640 nm, and an image showing a breeding state after 144 hours when cultivated while being irradiated with white light.
As shown in FIGS. 35-43, purple light (light having a peak wavelength at 405 nm) strongly inhibited the growth of all the strains tested. Therefore, it was confirmed by the test 3 that violet light irradiation has bacteriostatic and bactericidal effects on all plant pathogenic bacteria.
Moreover, when the light (blue light) which has a peak wavelength at 470 nm was irradiated, the remarkable growth inhibitory effect of the phytopathogenic fungus was not recognized. Therefore, it is presumed that the possibility of exerting the growth inhibitory effect of phytopathogenic fungi is very low when irradiated with green light having a longer wavelength than that.
Further, even when light having a peak wavelength at 640 nm (red light) was irradiated, no significant phytopathogenic growth inhibitory effect was observed.

[3] Morphological change of phytopathogenic fungus by irradiation with purple light The morphological change of phytopathogenic fungus by irradiation of purple light was examined in detail by Test 4 as shown below.
(4-i) Test Method The morphology of the mycelium of a phytopathogenic fungus (B. cinerea) irradiated with purple light having a wavelength of 405 nm was observed in detail (see FIG. 10 below). In addition, the appearance of spores when irradiated with violet light having a wavelength of 405 nm for 24, 72, and 168 hours was also observed (see FIG. 11 below).

(4-ii) Test results FIG. 10 shows a comparison between an image of the mycelial tip of a phytopathogenic fungus cultured in the dark and an image of the mycelial tip of the phytopathogenic fungus cultured while irradiating purple light with a wavelength of 405 nm. It is a figure.
As shown in FIG. 10, abnormal enlargement was observed at the tip of the mycelium on the outer edge of the fungal colony after irradiation with 405 nm purple light (irradiance 60 Wm ⁻² ) for 24 hours.
FIG. 11 shows an image showing the state of spores (B. cinerea) cultured while irradiating purple light with a wavelength of 405 nm for 24, 72, and 168 hours, respectively, and the appearance of spores cultured for 24, 72, and 168 hours in the dark. It is an image shown in contrast with the shown image.
As shown in FIG. 11, 405 nm purple light (irradiance 60 Wm ⁻² ) was observed after irradiating each spore (24, 72, 168 hours) on B.cinerea spores on SNA plate medium (see Table 1 above). A similar enlargement of the spores was observed with the lapse of irradiation time.
Therefore, when the phytopathogenic fungus is irradiated with purple light, it is presumed that the morphological change of the phytopathogenic fungus is promoted, and the normal growth of the phytopathogenic fungus is hindered by this change and the bacteriostatic / bactericidal action is exhibited.
Therefore, it was shown that the purple light used in the present invention acts directly on phytopathogenic bacteria to cause morphological changes.

[4] Changes in expression of genes related to bacteriostatic bacteriostatic fungi The following tests for the purpose of clarifying the causes of hypertrophy of mycelial tips or spores in phytopathogenic fungi (B. cinerea) irradiated with purple light 5 was done.
In the phytopathogenic fungi irradiated with purple light, the hyphae tip or the part in which the spores are enlarged is likely to be abnormal in cell division control, and this was verified.
(5-i) Test method Real-time RT-PCR analysis was performed on B. cinerea irradiated with 405 nm purple light (irradiance 60 Wm ^-2 ).

(5-ii) Test Results FIG. 12 is a graph showing changes in the expression of mitotic control genes in B. cinerea irradiated with purple light having a wavelength of 405 nm.
As shown in FIG. 12, in B.cinerea irradiated with 405 nm purple light (see legends in FIG. 12, 1h, 3h, and 6h), while the expression of the cdc20 gene that promotes chromosome segregation decreases, The expression of cdc48 gene that promotes cell repair was increased.
From these results, it was suggested that violet light irradiation at a wavelength of 405 nm caused inhibition of chromosome segregation and cell repair in B. cinerea, resulting in a bacteriostatic state.

Therefore, from the results of Tests 1 to 5, the purple light having a peak in the wavelength range of 390 to 420 nm used in the present invention acts directly on the phytopathogenic fungus and exhibits bacteriostatic / bactericidal action. confirmed.

Next, the verification result regarding the disease generation | occurrence | production suppression effect at the time of irradiating a plant body with purple light is demonstrated.
[5] Plant plant disease-inhibiting effect by purple light irradiation The plant disease occurrence suppressing effect by irradiating purple light having a wavelength of 405 nm, which was found to have a particularly high bacteriostatic and bactericidal effect in Tests 1 to 5 above. For the purpose of verification, tests 6, 7, 12, and 13 as shown below were performed. Here, the test method and the results will be described in the order of

tests

6, 12, 7, and 13.
(6-i) Test method Tomato (variety: microtom) seeds were sown on artificial soil (vermiculite: perlite = 1: 1), and 25 ° C, light / dark period (16h / 8h) in an artificial meteorograph. , PPFD was grown under conditions of about 100 μmol ⁻¹ m ⁻² s ⁻¹ . The tomato in the fifth leaf stage is transferred into a desiccator equipped with an LED light source installed in an artificial meteorograph, temperature 25 ° C, humidity 50%, PPFD 100 µmol ^-1 m ^-2 s ^-1 , light period / dark period (12h / 12h) It was grown under conditions for 3 days. Thereafter, purple light and white light (each 60 Wm ⁻² ) having a wavelength of 405 nm were irradiated for 7 days under the conditions of irradiation / non-irradiation (15 min / 45 min) in accordance with the start of the light period (12 h) (total 12 cycles / day). The control group was irradiated only with white light. Tomato treated with tomato gray mold fungus spore suspension (2 × 10 ⁷ cells / ml) suspended in potato dextrose medium at 1/2 concentration was spray-inoculated (2.5 ml / individual) on the tomatoes after irradiation treatment, the same as before the inoculation Grows under conditions. In order to microscopically observe the growth of tomato gray mold, lactophenolcotone blue staining was performed.
Alternatively, inoculation test using excised leaves (paper disc inoculation test) Tomato leaves are cut out and placed on a moist filter paper in a petri dish, and gray mold fungus spore solution (1 × 10 ⁷ cells / ml) in the center of the leaves ) Was placed, and violet light and white light (each 60 Wm ^-2 ) were irradiated for 7 days under the conditions of irradiation / non-irradiation (15 min / 45 min) according to the start of the light period (12 h) (total 12 Cycle / day). The control group was irradiated only with white light. Thereafter, the symptom was observed by culturing under white light for 2 days without violet light irradiation.

(6-ii) Test Results FIG. 13A is an image showing the appearance of the tomato when irradiated with 405 nm wavelength violet light, and FIG. 13B is an image showing the appearance of the tomato in the control section. . Moreover, (c) is an enlarged image showing a state of bacterial (gray mold) staining when tomato leaf tissue is stained with lactphenol cotton blue when irradiated with purple light having a wavelength of 405 nm, and (d) is a control. It is an enlarged image which shows the mode of a microbe (gray mold fungus) dyeing | staining at the time of dyeing the leaf tissue of a tomato of a ward with lactophenol cotton blue.
As is clear from FIG. 13, in the control group, the symptom of gray mold disease (water-immersed lesion) appears on the entire leaf (see FIG. 13B), and the mycelium of the gray mold fungus is present in the leaf tissue. Was proliferating (see FIG. 13 (d)). On the other hand, only a small brown spot was produced in the 405 nm purple light irradiation section (see FIG. 13A). Furthermore, when the leaves of the wavelength 405 nm purple light irradiation section were expanded, the spores of gray mold disease were not clumped as they adhered to the leaf surface (see FIG. 13 (c)). These small spots were probably caused by the tomato resistance response (hypersensitive reaction).
FIG. 14 is an image showing the results of an incision leaf paper disc inoculation test using tomato leaves irradiated with 405 nm wavelength purple light and tomato leaves in the control group. Note that the cut leaves accommodated in the upper two petri dishes in the image in FIG. 14 are irradiated with only white light, and the cut leaves accommodated in the lower two petri dishes are irradiated with 405 nm purple light and white light. It is a thing.
Although it is difficult to see FIG. 14 in a monochrome image, the cut leaves contained in the upper two petri dishes are faded to yellow-green when viewed in color, and a brown water-immersive disease around the portion where the paper disk is placed While the spots were formed, the cut leaves in the two petri dishes in the lower stage were bright green as a whole, and no signs of lesions were found around the paper disk, and the appearance was sound.
Therefore, as is apparent from the image shown in FIG. 14, also in the excised leaf paper disk inoculation test, the gray mold disease inhibitory effect was observed in the 405 nm purple light irradiation section.

Next, the test method and the result of Test 12 will be described in detail.
(12-i) Test method Lactaceae medicinal plant Mebouki (scientific name: Ocimum basilicum, English name: basil) and leguminous vegetable kidney bean (scientific name: Phaseolus vulgaris, English name: kidney bean) Was transferred to a desiccator equipped with an LED light source installed on a plant growth shelf in an air-conditioned laboratory. Temperature 25 ° C, humidity 50%, PPFD 100 µmol ^-1 m ^-2 s ^-1 , light period / dark period ( 16h / 8h) under the conditions for 3 days. Thereafter, purple light or white light (each 50 Wm ⁻² ) having a wavelength of 405 nm was irradiated (pre-irradiation) for 7 days under the conditions of irradiation / non-irradiation (15 min / 45 min) in accordance with the start of the light period (16 h) (16 cycles / day). Plant leaves after the pre-irradiation treatment were inoculated with 5 μl of a spore solution (2 × 10 ⁶ cells / ml) of a gray mold fungus (Botrytis cinerea) suspended in a potato dextrose medium at a concentration of 1/2. After inoculation with bacteria, the effect was compared by dividing into a group where purple light was not irradiated (only pre-irradiation) and a group where irradiation was continued (pre-irradiation + post-irradiation). The disease symptoms were observed 3 days after the inoculation, and the lesion diameter was measured.

(12-ii) Test results FIG. 44 shows that after inoculating the gray mold of the test plant that had been pre-irradiated with purple light or white light with a wavelength of 405 nm, followed by irradiation with purple light or white light with a wavelength of 405 nm. It is an image which shows the mode of the plant body after 3 days in each of the section which did and did not irradiate.
FIG. 45 shows a case in which the kidney bean of the test plant that had been pre-irradiated with purple light or white light having a wavelength of 405 nm was inoculated with gray mold and then irradiated with purple light or white light having a wavelength of 405 nm. It is an image which shows the mode of the plant body after 3 days in each of the ta ward.
In addition, in FIG.44,45, the image of the plant body of the non-inoculation area which has not inoculated the gray mold fungus as a comparison object was also shown collectively.
In addition, FIG. 46 shows a group in which purple fungi or white light having a wavelength of 405 nm was continuously inoculated after the inoculation of gray mold fungi on the test plants that had been pre-irradiated with purple light or white light having a wavelength of 405 nm. It is a graph which shows the result of having measured the diameter of the diseased part of the plant body three days after in each of the ward which did not do.
Furthermore, FIG. 47 shows a group of kidney beans of a test plant that had been pre-irradiated with purple light or white light having a wavelength of 405 nm, inoculated with gray mold fungus, and subsequently irradiated with purple light or white light having a wavelength of 405 nm. It is a graph which shows the result of having measured the diameter of the diseased part of the plant body three days after in each of the ward which did not do.
46 and 47, “405 nm” in the legend of each graph indicates a case where purple light having a wavelength of 405 nm is irradiated, and “white” indicates a case where white light is irradiated.
In the image shown in FIG. 44, it is difficult to determine the position of the diseased part, but the diseased part of the leaves of the test plant was only exposed to purple light or white light with a wavelength of 405 nm. It spread to 1/3 of the area. In addition, the group in which the white light was pre-irradiated had a larger spread of the disease than the group in which the purple light having a wavelength of 405 nm was pre-irradiated.
Furthermore, in the group that was pre-irradiated and post-irradiated with violet light or white light having a wavelength of 405 nm, the spread of the lesion was smaller than the group that was just pre-irradiated, and in the group that was pre-irradiated and post-irradiated with purple light having a wavelength of 405 nm, The size of the lesion was about ¼ compared to the group irradiated with white light before and after irradiation. Such a result is clear also from the graph shown in FIG.
In the image shown in FIG. 45, it is difficult to determine the position of the diseased part, but in the group of the kidney bean of the test plant that was only pre-irradiated with 405 nm purple light or white light, the diseased part was about 1 / 3 area.
In addition, in the section pre-irradiated and post-irradiated with violet light or white light having a wavelength of 405 nm, the spread of the lesion is smaller than the section just pre-irradiated with each light, and pre-irradiated with purple light with a wavelength of 405 nm. In the group irradiated with post-irradiation, the size of the lesion was about 1/5 compared with the group irradiated with white light before and after irradiation. Such a result is clear also from the graph shown in FIG.
Therefore, as described above, in both the Japanese boxfish and the kidney bean, in the section where the purple light having a wavelength of 405 nm was pre-irradiated and post-irradiated (pre-irradiation + post-irradiation), the lesions did not expand after inoculating the pathogen with the plant body. From this, it was confirmed that it has a remarkable disease suppression effect.
As is clear from the graph of FIG. 46, the Mebouki of the test plant exhibited a significant disease suppression effect only by performing pre-irradiation with purple light having a wavelength of 405 nm.

Subsequently, the test method and the result of Test 7 will be described in detail.
(7-i) Test apparatus First, a violet light source (hereinafter referred to as a 405 nm LED auxiliary light apparatus) used in this test will be described.
The 405 nm LED light supplement device used in this test has a conical unit (φ25 mm × H30 mm, hereinafter referred to as LED unit) in which 9 or 12 LED lamps are arranged on the line. The one having a wavelength peak of 405 nm (45 °: SL405AAUE, 15 °: SL405ADUE, Sun Opto) was used. Moreover, in this 405 nm LED light supplement device, the sealing of the LED unit part (light emitting part) and the power source part was strengthened to improve the waterproofness. Furthermore, the LED unit can be attached and detached so that it can irradiate the optimal location of the tomato community, and the length between the LED units can be freely adjusted by making the cord between the LED units detachable. It was configured as follows. And, by reducing the weight of the LED unit and making the size of the mounting clip variable, the LED unit can be directly attached to the stem and branch of the tomato. Of purple light.

(7-ii) Test Method Next, the test method of this test will be described in detail.
Tomatoes (solanum lycopersicum, varieties: Momotaro and Reika) are used as test plants, and cultivation is carried out in the greenhouse (North-South Building) inside the Yamaguchi University Faculty of Agriculture. This was done twice in summer autumn and winter spring in order to prevent anyone other than those who have a confidential duty from entering the greenhouse. For summer / autumn cultivation, 36 individuals (Reika: 18 individuals, Momotaro: 18 individuals) were cultivated, sowing was performed on May 24, 2010, and fixed planting was performed on July 21, 2010. In winter spring cultivation, 48 individuals (Reika: 24 individuals, Momotaro: 24 individuals) were cultivated, sowing was conducted on September 24, 2010, and fixed planting was conducted on November 19, 2010. Seeds were sown directly on rock wool cubes, and planting was done by placing rock wool cubes on rock wool slag. Irrigation is performed at regular intervals, and fertilizer is 60g / day / all in Otsuka No. 1 (Otsuka Chemical, Otsuka House No. 1) and 40g / Otsuka No. 2 (Otsuka Chemical, Otsuka House No. 2) in summer and autumn cultivation. Day / all individuals, fed, only 15-30g / day / all individuals of Otsuka No. 1 were given during winter spring cultivation. A ventilation fan was set to operate when the temperature in the house reached 30 ° C or higher, and ventilation was performed. In winter and spring cultivation, when the temperature in the house is 10 ° C. or lower, heating by a boiler is set to operate. The temperature and humidity, PPFD, and UV intensity in the house during the irradiation period are measured with temperature / humidity sensors (CHINO, MR6661), PPFD sensors (Apogee, QSO-S), and UV sensors (Apogee, SE-UVS)), respectively. Measured and recorded.

(7-iii) Irradiation method Next, the irradiation conditions of this test will be described in detail.
In a greenhouse under natural light, irradiation experiments were performed three times on tomato communities using a 405 nm LED light supplement device. The irradiation period (The period of irradiation), the number of individuals in the irradiation group (Number of Plants irradiated), the number of individuals in the control group (Number of control plants), and the irradiation time (Time of 405 nm LED irradiation) are shown in Table 2 below. The arrangement of irradiated individuals in Experiment 1-3 is shown in FIGS.
FIG. 15 is a plan view showing the arrangement of the test materials in the greenhouse in Experiment 1. FIG. FIG. 16 is a plan view showing the arrangement of the test materials in the greenhouse in Experiment 2. FIG. FIG. 17 is a plan view showing the arrangement of the test materials in the greenhouse in Experiment 3 (12 / 7-1 / 16). FIG. 18 is a plan view showing the arrangement of the test materials in the greenhouse in Experiment 3 (1/17 and later). 15 to 18, squares represent irradiated individuals, white circles represent target individuals, and black circles represent individuals omitted from each measurement.

Irradiation of purple light by a 405 nm LED supplementary device was performed from three directions, ie, diagonally upward (Downward), group dropping part (Upward), and side surfaces of a tomato individual. Irradiation from diagonally above is done by attaching an LED unit (light emitting part) to the column suspended from the upper part between the tomato cultivation baskets, and irradiation from the lower part passes the horizontal column in the tomato community, or attaches the LED unit to it, The LED unit was directly attached to the tomato stem. In addition, irradiation from the side was performed by placing a lighting tripod (Velbon, LS-1) attached with an LED unit on the side of the tomato individual. In each irradiation method, the LED unit was installed such that the intensity of irradiation was about 30 Wm ^{−2 at the} leaf closest to the LED unit. Table 3-8 shows the irradiation position of each irradiated individual and the number of LED units used in Experiment 1-3. Under the current irradiation conditions, the power consumption per LED unit is about 0.7 W, and when 12 LED units are installed in one tomato individual, the power consumption per individual tomato is about 8-9 W Met.

(7-iv) Disease evaluation method The disease evaluation method in this study will be described.
(A) Identification of disease This time, the disease that naturally occurred without spraying pesticide in the house was Pseudocercospora fuligena as a result of analyzing conidia.
(B) Evaluation of disease The degree of disease was evaluated by the disease index based on the number of diseased leaves against naturally occurring fungi. The disease evaluation was carried out by visually determining the diseased leaf index, assuming that the number of diseased leaves was 0% = 0, 50% or less = 1,> 50% = 2 with respect to the total number of leaves of each compound leaf. The diseased leaf index in each compound leaf was averaged for each individual and used as the disease index based on the number of diseased leaves of the individual. In Experiment 2, the measurement was started in a state where all the diseased leaves that had appeared before the start of irradiation were cut off, and the leaves were cut off when three lesions were confirmed per leaf.

(7-v) Disease Evaluation Method The growth evaluation method in this test will be described.
In order to examine the effect of 405 nm purple light irradiation on tomato growth, plant height, the number of compound leaves, and the amount of chlorophyll (SPAD value) were measured at intervals of 5-7 days. The plant height was measured by measuring the length of the tomato root along the tomato stem by attaching a tako thread with a clip at the tip to an attracting string at the height of the top of the tomato individual. For SPAD values, a SPAD meter (KONIKA MINOLTA, SPAD-502) was used, and the second leaf from the top of the second inflorescence from the top of the tomato and the second leaf from the tip of the third leaf down to a total of 10 times each. The average value of 10 times was used as the SPAD value of the individual.

(7-vi) Test results First, the effect on the growth of a plant by irradiating purple light with a wavelength of 405 nm will be described.
In any of Experiments 1-3, no influence on growth was observed due to irradiation with violet light having a wavelength of 405 nm. As an example, changes over time in plant height, the number of compound leaves, and SPAD in Experiment 2 are shown in FIGS.
FIG. 19 is a graph comparing the changes in plant height over time in a population irradiated with purple light having a wavelength of 405 nm in Experiment 2 and a control population. FIG. 20 is a graph showing changes over time in the number of compound leaves in a group irradiated with purple light having a wavelength of 405 nm in Experiment 2 and a control group. FIG. 21 is a graph showing temporal changes in SPAD values in a group irradiated with purple light having a wavelength of 405 nm in Experiment 2 and a control group. In addition, Bar (error bar | burr) in each graph shown by FIG. 19 thru | or FIG. 21 represents a standard error, As a result of t-testing at the significance level of 5% regarding the average value of the test section on each measurement day, a significant difference is shown. In some cases, it was decided to put an asterisk (*), but no significant difference was observed between the individual irradiated with purple light with a wavelength of 405 nm and the control individual in any of plant height, number of compound leaves, and SPAD.

Next, the evaluation results based on the disease index will be described.
FIG. 22 is a graph showing the change over time in the disease index based on the number of diseased leaves in Experiment 1 (Summer Autumn cultivation). FIG. 23 is a graph showing changes over time in the number of diseased leaves based on the number of diseased leaves in Experiment 1 (cultivated in summer and autumn). In addition, bar (error bar) in the graphs shown in FIGS. 22 and 23 described above represents standard error, and as a result of performing t-test at a significance level of 5% on each measurement day, there was a significant difference in the test interval. Is marked with an asterisk (*).
As shown in FIG. 22, in Experiment 1, as a result of the average irradiation period, about 10.8% of the disease suppression effect was observed for both varieties, and there was also a significant difference between 8 / 27-9 / 2. It was. Although no particular data is shown here, no varietal difference in the disease control effect (sample seedlings: Reika, Momotaro) was not observed.
In addition, as shown in FIG. 23, an average of about 20% of disease control effect was observed even in the number of diseased compound leaves (index 2), and it became clear that the occurrence of subtilis disease was suppressed by 405 nm purple light irradiation. . Furthermore, even when lesions occurred on one leaf, a tendency for the lesions to hardly spread to other leaves in the compound leaf was observed.

FIG. 24 is a graph in the case where the temporal change of the disease index in Experiment 2 (Summer Autumn cultivation) is calculated for the whole individual, and FIG. 25 is a graph of the leaf position irradiated with the temporal change in the Disease Index in Experiment 2 (Summer autumn cultivation) It is a graph at the time of calculating with a compound leaf. Note that bar (error bar) in the graphs shown in FIGS. 24 and 25 described above represents standard error, and as a result of performing t-test at a significance level of 5% on each measurement day, there was a significant difference in the test interval. Is marked with an asterisk (*).
As shown in FIG. 24, in Experiment 2, although no significant difference was observed, the disease index of the 405 nm LED group was lower than that of the control group throughout the irradiation period, and an average suppression effect of 12.3% was recognized. In addition, the period until the disease spreads to more than half of the leaves in the compound leaves was 9 days longer in the 405 nm LED group than in the control group (10/7 in the control group, 10/16 in the irradiated group). Furthermore, as shown in FIG. 25, when comparing the leaf position (27th to 33rd compound leaves) irradiated with 405 nm violet light, although no difference was observed at first, the LED unit was detected on 10/20. Immediately after adding, an average of 25% suppression effect was observed.
More specifically, in the state immediately before the addition of the LED unit, the number of compound leaves irradiated with 405 nm purple light by the LED unit is 3-4 (the number of LED units: 8) with respect to the number of 37 leaves. The ratio of 405 nm purple light irradiated compound leaves in the compound leaves was 10% or less. After the LED unit is added, the number of compound leaves is 37 to 44 (depending on the growth after the LED unit is added), and the number of compound leaves irradiated with 405 nm purple light by the LED unit is 6 to 8 (number of LED units: 17- 18), and the proportion of 405 nm purple light-irradiated compound leaves in all compound leaves was 10% or more.
Accordingly, it is considered desirable to irradiate at least 10% of the total leaf area with violet light in order to suitably exert the disease occurrence suppressing effect by violet light irradiation.

FIG. 26 is a graph showing a change in disease index in Experiment 3 (winter spring cultivation), and FIG. 27 is a graph showing a change in the number of diseased leaves in experiment 3 (winter spring cultivation). In addition, bar (error bar) in the graphs shown in FIGS. 26 and 27 described above represents standard error, and as a result of performing t-test at a significance level of 5% on each measurement day, there was a significant difference in the test interval. Is marked with an asterisk (*).
As shown in FIG. 26, in Experiment 3, an average suppression effect of 10.8% was observed throughout the irradiation period for the overall disease index. Further, as shown in FIG. 27, the number of disease index 2 was significantly different from about 1/20 as a whole, and the disease was suppressed to about 1/4 at maximum.

Subsequently, the test method and the result of Test 13 will be described in detail.
(13-i) Test material and test method Murasaki (Lithospermum erythrorhiozon), a medicinal plant belonging to the family Lamiaceae, was used as a test plant, and the test cultivation was performed in a plastic house in Yamaguchi Prefecture. In addition, using the same 405 nm LED light supplement device as used in Test 7 above, use 1 unit when the plant is small, and 2 units after it grows, and irradiate for 3.5 hours in the morning and evening. (Total 7 hours) Or, irradiation was performed every hour for a total of 7 hours. The degree of disease that occurred naturally without spraying the pesticide was compared with the group that did not perform 405 nm LED supplementary light (control group). As for the degree of disease, the disease evaluation criteria (onset index) in each individual is 1: gill, browning and mold formation are seen in the flowers, 2: gag, browning is seen not only in the flowers but also in the leaves (1 , 2), 3: Brown, not only flowers, but also leaves are seen (several, local), 4: browning is seen throughout the plant body, it is dead, Judgment was made visually.
In addition, the test in the greenhouse was performed so that the inside was not visible from the outside, and no one other than the related person having confidentiality obligations could enter the greenhouse.

(13-ii) Test Results FIG. 48 is a graph showing the transition of the disease index when the murasaki as a test plant is irradiated with 405 nm purple light and when it is not irradiated. Note that in the legend in FIG. 48, “LED” indicates a 405 nm LED supplementary light area, and “Control” indicates a control area.
Although not particularly shown in FIG. 48, from the beginning of July 2011 (50-60 days after the start of irradiation), symptoms of gray mold disease began to be observed in both the 405 nm LED supplementary zone and the control zone. Furthermore, in the period from August 12, the same year (90 days after the start of irradiation) to September 1, the same year (110 days after the start of irradiation) shown in FIG. 48, the degree of disease is suppressed in the 405 nm LED supplementary zone. It was.
As of August 12 of the same year, the disease suppression rate of the 405 nm LED supplementary light zone compared to the control zone calculated by the following formula 1 was 24%, and the disease suppression rate as of September 1 of the same year was 13%. It was.
Therefore, it was confirmed by this test 13 that irradiation with violet light having a wavelength of 405 nm has a significant disease-suppressing effect on plants of the family Lamiaceae.

Here, a summary of the results of

tests

6, 7, 12, and 13 will be described.
From the results of Test 6 above, it was confirmed that the occurrence of diseases caused by phytopathogenic bacteria can be suitably suppressed by irradiating the leaves of the plant with purple light.
In addition, from the results of Test 7, it is possible to suppress the occurrence of disease by irradiating purple light when cultivating the plant, and when the plant is irradiated with purple light after the occurrence of the disease, It was confirmed that it can be suppressed. Furthermore, from the result of the test 7, it was also confirmed that intermittent irradiation of purple light on the plant does not affect the growth of the plant.
Although detailed test results and the like are not shown here, the inventors have shown that purple light irradiation has a suppressive effect on diseases caused by powdery mildew fungi, which is a pathogen defense response-related gene. It was confirmed by expression (test material: tomato).
More specifically, the inventors investigated the expression of pathogen defense response-related genes in tomatoes inoculated with powdery mildew on 405 nm purple light pre-irradiated leaves. In tomatoes that had been pre-irradiated with 405 nm purple light, a tendency to reduce the number of powdery mildew spots was observed. In particular, the number of lesions decreased in leaves pre-irradiated with 405 nm purple light. Moreover, the natural infection to the powdery mildew non-inoculated tomato irradiated with 405 nm purple light was remarkably suppressed as compared to the natural infection to the powdery non-inoculated tomato without 405 nm purple light. Furthermore, using these tomato leaves, the expression level of pathogen defense response-related genes was quantified based on the presence or absence of 405 nm purple light irradiation and powdery mildew inoculation. As a result, PR1a1, phospholipase D, PR1a1, acidic chitinase, acidic The gene expression of glucanase, PAL2, PAL4, ICS (isochorismate synthase), and omega 3FAD (omega-3 fatty acid desaturase) was increased more than 5 times.
Therefore, the purple light irradiation to the plant body has a disease-suppressing effect on both the plant pathogen causing the disease to the living cells of the plant body and the plant pathogen causing the disease to the dead cells of the plant body. It has been confirmed that it works.
In other words, purple light irradiation to plants is not only against diseases caused by biotrophic pathogens (such as powdery mildew and downy mildew), but also due to diseases caused by dead-nutrient pathogenic bacteria (such as gray mold and anthracnose). However, there is a very high possibility that there is a suppression effect.

Furthermore, when the results of

tests

6, 7, 12, and 13 are summarized, irradiation with violet light having a wavelength of 405 nm has a disease-suppressing effect on solanaceous plants, perilla plants, legumes, and purple plants. It was confirmed that it was demonstrated. Moreover, when the result of the test 9 shown in detail below is also combined, it is thought that the disease suppression effect is exhibited also to the cruciferous plant in addition to the said plant.
Therefore, from these test results, it was suggested that the disease suppression effect by irradiation with violet light having a wavelength of 405 nm is exhibited in many plant species regardless of the family of plants.
Further, for example, edibles of rose family plants (for example, strawberries), cucurbitaceae plants (for example, melons), primaceae plants (for example, cyclamen etc.) that are not handled in the tests described in the present specification. The same effect can be expected for various plants cultivated for ornamental purposes.
In addition, as a plant which can expect the disease generation | occurrence | production suppression effect by irradiation of wavelength 405nm purple light, the following are mentioned, for example.
Eggplant family: eggplant, tomato, pepper, capsicum, potato, tobacco, petunia, hyos, hashiridokoro, mandrake, etc.
Labiatae: perilla, basil, mint, rosemary, sage, marjoram, oregano, thyme, lemon balm.
Legumes: soybeans, peas, licorice, kawara tsumei, shrimp, habusaw, tagayasan, nambansaikachi, ogi, etc.
Murasaki Family: Murasaki, Forget-me-not, Heliotrope, Comfrey, etc.
Brassicaceae: Komatsuna, Mizuna, Wasabi, Watercress, Chingensai, Broccoli, Power reflower, Cabbage, Chinese cabbage, Kale, Mustard, Brassica, Maca, etc.

Subsequently, the verification result of the gene expressed in the plant body when the plant body is irradiated with purple light will be described.
In general, defense response-related genes are a general term for a group of genes that play an essential role in the "response mechanism that recognizes and eliminates attacks by external enemies (pathogens and pests)" in plants. , Receptors that recognize the attack of external enemies (pathogens, pests) (for example, CERK1 protein that acts as an immune receptor for rice), factors that act in pathways (signal transduction pathways) that convey pathogen recognition (cell kinases, C kinase), enzymes (phenylalanine ammonia lyase and chalcone synthase) that work in a low molecular defense substance synthesis pathway represented by phytoalexin, and genes encoding PR proteins are known.
And in the pathogenic resistance plant body in this invention, it was confirmed that the resistance with respect to a phytopathogenic fungus is improved by performing purple light irradiation treatment.
In this regard, the inventors recognized the attack of the pathogen in the plant body by irradiating the pathogen-resistant plant body in the present invention with purple light having a peak between wavelengths of 390-420 nm. It was clarified that “pathogenic defense response-related genes”, which are genes that have an essential role in the response mechanism to be eliminated, are expressed.
Moreover, it was confirmed that the “pathogenic defense response-related genes” expressed in the pathogen-resistant plant according to the present invention is a salicylic acid synthesis pathway-related gene or a gene group induced by salicylic acid. Furthermore, it was also clarified that the “gene group induced by salicylic acid” expressed in the pathogen-resistant plant in the present invention is more specifically “gene group inducing acidic PR protein”.
The verification results regarding these points will be described in detail below.

[6] Genes expressed in plants by purple light irradiation treatment For the purpose of investigating the expression of pathogen defense response related genes when purple light irradiation treatment is performed on a tomato, a solanaceous plant, as shown below Test 8 was conducted.
(8-i) Test method Seeds of tomato (variety: microtom) seeded on artificial soil (vermiculite: perlite = 1: 1), and 25 ° C, light period / dark period (16h / 8h) in an artificial meteorograph , PPFD was grown under conditions of about 100 μmol ⁻¹ m ⁻² s ⁻¹ . The tomato in the fifth leaf stage is moved into a desiccator equipped with an LED light source installed in an artificial meteorograph. The temperature is 25 ° C, the humidity is 50%, PPFD is 100μmol ^-1 m ^-2 s ^-1 12h) It was grown for several days under conditions. Then, 405 nm purple light and white light (each 60 Wm ⁻² ) were irradiated under the conditions of irradiation / non-irradiation (15 min / 45 min) in accordance with the start of the light period (12 h) (total 12 cycles / day). The control group was irradiated only with white light. After 1 day and 3 days, fully expanded upper leaves were collected as samples, frozen using liquid nitrogen, and stored at -80 ° C. Cryopreserved leaves were ground in a mortar cooled with liquid nitrogen, 1 ml Sepazole (Nacalai Tesque) was added and ground further. After transferring the grinding liquid to a 1.5 ml tube, 200 μl of chloroform was added and mixed by inversion. After leaving still at room temperature for 3 minutes, it centrifuged at 12,000 xg for 10 minutes. Of the phenol phase and the aqueous phase, 500 μl of the aqueous phase was transferred to another 1.5 ml tube, and an equal amount of isopropanol was added to the aqueous phase and mixed. After standing at room temperature for 10 minutes and centrifuging at 12,000 × g for 10 minutes, the supernatant was removed. After adding 1 ml of 80% ethanol to the pellet and stirring, it was centrifuged at 12,000 × g for 5 minutes. After removing the supernatant and air-drying the pellet for 30 minutes, 50 μl of RNase free water was added. Using a ReverTra Ace (registered trademark) qPCR RT Kit (Toyobo), single-stranded cDNA was synthesized in a reaction solution having the composition shown in Table 9 below.

The above solution was incubated at 37 ° C. for 15 minutes and then incubated at 98 ° C. for 5 minutes. The reaction solution was stored at −20 ° C.
Real-time PCR was performed using THUNDERBIRD (registered trademark) SYBR (registered trademark) qPCR Mix (Toyobo) using the synthesized cDNA as a template. The primer sequences used are as shown in Table 10 and Table 11 below.

(8-ii) Test Results FIGS. 28 to 30 are graphs comparing the expression levels of pathogen defense response-related genes in the control group and the 405 nm purple light irradiation group when tomato is used as the test material. In FIG. 28 to FIG. 30, the Ctrl section is the control (one irradiated with only white light), the processing section 1 is the one treated with 405 nm purple light for one day, and the processing section 2 is the 405 nm purple color. Each of them means that processed for 3 days.
As shown in FIG. 28 to FIG. 30, in the 405 nm purple light irradiation region, ERF5 (ethylene responsive element binding factor 5) (see FIG. 28), PR1a1, PR-1a (P4), acidic chitinase, acidic glucanase, basic The expression of each gene of chitinase, basic glucanase (see FIG. 29), and PAL4 (phenylalanine ammonia lyase 4) (see FIG. 30) was increased by 5 times or more compared to the white light irradiation section.
Therefore, by performing purple light irradiation treatment, a salicylic acid synthesis pathway-related gene (see FIG. 30) and a defense response-related gene induced by salicylic acid (see FIGS. 28 and 29) in the solanaceous tomato Was confirmed to be expressed.

Test 9 as shown below was conducted for the purpose of examining the expression of pathogen defense response-related genes when Arabidopsis, a cruciferous plant, was treated with purple light.
(9-i) Test method Seeds of Brassicaceae Arabidopsis (Ecotype: Colombia) seeded on artificial soil (vermiculite: perlite = 1: 1), 25 ° C, light / dark period (16h) in an artificial meteorograph / 8h) and grown under conditions of PPFD of about 100 μmol ⁻¹ m ⁻² s ⁻¹ . Move the Arabidopsis thaliana in the 5-leaf stage into a desiccator equipped with an LED light source installed in an artificial meteorograph, air temperature 25 ° C., humidity 50%, PPFD 100 μmol ⁻¹ m ⁻² s ⁻¹ , light / dark period (12h / 12h) It was grown for several days under conditions. Thereafter, 405 nm purple light and white light (each 50 Wm ⁻² ) were irradiated for 9 days under the condition of irradiation / non-irradiation (15 min / 45 min) in accordance with the start of the light period (12 h) (total 12 cycles / day). Thereafter, the leaves were collected as samples, frozen using liquid nitrogen, and stored at −80 ° C. Thereafter, extraction of total RNA was performed in the same manner as in Test 8 above, and real-time PCR was performed. Table 12 shows the primers used for real-time PCR.

(9-ii) Test Results FIG. 31 is a graph comparing the expression levels of pathogen defense response-related genes in the control group and the 405 nm purple light irradiation group when using Arabidopsis as a test material. In the graph shown in FIG. 31, “white” means data in the control section where only white light was irradiated, and “405 nm” means data in the 405 nm purple light irradiation section.
As shown in FIG. 31, in Arabidopsis thaliana, expression of genes (PR1, PR2, PR4, PRB1) indicating that systemic induction resistance was generated was confirmed in Arabidopsis thaliana irradiated with 405 nm purple light. This result shows that 405 nm purple light irradiation induces the resistance of the plant body even in cruciferous plants.
That is, it was confirmed that a defense response-related gene induced by salicylic acid is expressed in Arabidopsis thaliana irradiated with 405 nm purple light.

According to the

tests

8 and 9, it was confirmed that a pathogen defense response-related gene was expressed by irradiating purple light in both a solanaceous plant and a cruciferous plant. Therefore, it was confirmed that the phenomenon that a pathogen defense response-related gene is expressed by irradiating purple light is not a characteristic phenomenon in plants belonging to a specific family.
In general, the pathogen defense response-related genes are not unique genes that only plants belonging to a specific family have, but are genes that plants have universally. It is considered that there is a very high possibility that a pathogen defense response-related gene can be expressed by irradiating purple light in the plant body to which it belongs.

Furthermore, the test 10 as shown below was performed in order to confirm that the gene group involved in the establishment of the whole body acquired resistance was expressed by irradiating the plant body with purple light.
(10-i) Test method Tomato (variety: Momotaro) was sown on 6 × 6 cm rock wool and grown in a glass greenhouse to the 8th leaf stage of the main leaf. Using a cylinder made of aluminum (diameter 1.9 cm), a tomato leaf disc was produced by cutting out the leaf vein (main vein portion) of the fully developed leaf. This leaf disk was floated on a 1 mg /

ml

3,3′-diaminobenzidine (DAB) (pH 4) solution and allowed to stand for 3 hours. Thereafter, the leaf disk was floated on deionized water and placed in a desiccator equipped with an LED light source (405 nm purple light and white light) (each 60 Wm ⁻² ), and each was irradiated for 1 hour. After the irradiation treatment, the leaf disk was placed in hot ethanol (70 ° C.) and decolored for 30 minutes, and this was used as an observation sample. The observation sample was photographed using an optical microscope digital camera (Olympus, DP25) attached to the optical microscope (Olympus, BHS-323N).

(10-ii) Test result When the 405 nm purple light was irradiated to the tomato leaf that had absorbed the H ₂ O ₂ detection reagent (DAB), browning of the leaf tissue was observed. On the other hand, no browning was observed in the white light irradiation zone and the non-irradiation zone.
From this result, it was clarified that H ₂ O _2, which is a starting material for whole body acquired resistance (systemic induction resistance), was produced in tomato leaves irradiated with 405 nm purple light.

The verification result about the influence which irradiation of purple light other than the above has on the gene expression of a plant body is demonstrated.
In general, there are two types of systemic acquired resistance acquired in plants: salicylic acid-induced resistance and jasmonic acid-induced resistance, and these are known to be antagonistic to each other. ing.
In a test using tomato as a test material (data not shown), an enzyme involved in resistance induced by jasmonic acid (eg, lipoxygenase A) is reduced in plants irradiated with purple light. Or it stopped expressing. In addition, gene expression of MYB transcription factor and NADPH oxidase was greatly reduced.
Therefore, from these facts, it can be said that the resistance induced in the plant irradiated with purple light is not the resistance induced by jasmonic acid but the resistance induced by salicylic acid.

[7] Influence of purple light on plant photosynthesis In the above [1] to [6], pathogenicity and bactericidal effect on purple light phytopathogenic fungi, and pathogenicity in the plant by purple light irradiation to the plant. Although the verification results have been described for the improvement effect of resistance and the expression of the pathogen defense response-related gene when the plant body is irradiated with purple light, the pathogen-resistant plant body of the present invention is a disease control means during crop cultivation. In order to utilize it as one of the above, it is necessary to know the influence on the plant body when violet light is irradiated, more specifically, the influence of the purple light on the photosynthesis of the plant body.
Here, Test 11 which is a verification result of the effect of purple light on the photosynthesis of a plant body and the result will be described. Here, as an example of purple light, purple light having a wavelength of 405 nm in which a particularly high bacteriostatic and bactericidal action was observed in the previous test 1 was used.

In Test 11, in order to investigate how much 405 nm violet light can be used for photosynthesis, PSII real quantum yield ΔF / Fm ′ upon single irradiation with 405 nm violet light was investigated by chlorophyll fluorescence measurement.
In Test 11, the effects of single irradiation of 405 nm purple light on the PSII actual quantum yield and maximum quantum yield, the effects of far-red light addition irradiation, and the effects of intermittent irradiation were investigated using tomato as a model plant. And the possibility of the irradiation method which suppresses stress (it does not have a bad influence on a photosynthetic system) was investigated toward the realization of disease control by 405 nm purple light irradiation. Here, single irradiation means irradiating light of only 405 nm LED.

(11-i) Material and method (1) Experiment 1
The material was sown on rock wool on September 28, 2010, transferred to the room about 30-50 days after germination, and grown on a stainless steel plant cultivation shelf with five white fluorescent lamps attached in parallel. Four tomatoes (Solanum lycopersicum L. 'Momotaro') 33 days and 36 days after sowing were used. The plant height at the time of measurement was 17.5 cm to 20.5 cm, the number of compound leaves was 5, and the SPAD value was 35.9 to 39.7. The SPAD value is measured using a chlorophyll meter (MINOLTA, SPAD-502), and the chlorophyll fluorescence measurement leaves are measured three times and averaged. The PPFD on the cultivation shelf was about 200 μmolm ⁻² s ⁻¹ on the upper leaf surface, and was set to 12 hours light period and 12 hours dark period. The room temperature and humidity are controlled by air conditioner, and the tomato grows under the conditions of light season temperature 21.0 ° C, humidity 30.0%, dark season temperature 19.0 ° C and humidity 30.3%. Went. While growing on the cultivation shelf, water is irrigated to the bottom with tap water almost every day, and fertilizer is diluted with a liquid fertilizer (Hyponex Japan, Hyponex 6-10-5) diluted about 500 times per week instead of tap water. Gave to.
(2) Experiment 2
Six tomatoes (Momotaro) 48 days after sowing that were sown on rock wool on November 22, 2010 and grown on a stainless steel plant cultivation shelf after germination were used. The plant height at the time of measurement was 17.5 cm-20.0 cm, the number of compound leaves was 7-8, and the SPAD value was 30.5-43.0.

(11-ii) Irradiation method and chlorophyll fluorescence measurement (1) Experiment 1
As the light source, a light source A: 405 nm LED (Sun Opto, SL405AAUE) and a light source B: halogen lamp (HOYA-SCHOTT, JCR15V150WM) were used. Chlorophyll fluorescence is measured using a portable chlorophyll fluorescence measurement device (Walz, MINI-PAM, hereinafter referred to as MINI-PAM), with the measurement leaf sandwiched between leaf clip holders (Walz, Leaf Clip Folder) attached to the measurement fiber. Measurement was performed for each light source. First, the measurement leaf was covered with aluminum foil and darkened for 30 minutes. Thereafter, the light intensity of each light source was increased stepwise at intervals of 5 minutes or 15 minutes, and ΔF / Fm ′ was measured each time. The light intensity at the time of measuring chlorophyll fluorescence was measured using a micro photon sensor of a leaf clip holder. As the measurement leaf, the second leaf from the tip of the second compound leaf was selected.
(2) Experiment 2
As the light source, light source A: 405 nm LED, light source B: halogen lamp, light source C: white fluorescent lamp (TOSHIBA, FL20SSEDC / 18LL) was used. 6 tomato seedlings for measurement were transferred to a dark room and darkened for 30 minutes, and then 2 individuals were irradiated with their respective light sources (light sources AC). After 30 minutes of irradiation, ΔF / Fm ′ was determined for each individual. Fully expanded leaves were measured on 8-9 sheets. At that time, the first compound leaf and the apex compound leaf were excluded from the measurement target. The light intensity was measured using a micro photon sensor with a leaf clip holder. The average temperature at the time of measurement was 21.3 ° C., and the average humidity was 30.3%. The wavelength characteristics of each light source (light sources AC) used in Test 11 are shown in FIG.
32A is a graph showing the wavelength characteristics of the light source A, FIG. 32B is a graph showing the wavelength characteristics of the light source B, and FIG. 32C is a graph showing the wavelength characteristics of the light source C.
Note that the wavelength characteristics of the violet light source used in the other tests 1 to 10 shown in this specification are the same as the wavelength characteristics of the light source A shown in FIG.

(11-iii) Test result 1) Experiment 1
FIG. 33 is a graph showing the relationship between PPFD and ΔF / Fm ′ when the light intensity is gradually increased for the same leaf. Here, PPFD is a value based on the LI-COR photon sensor (LI-190).
As shown in FIG. 33, ΔF / Fm ′ decreases in all test sections as the light intensity increases, and when the light intensity is low (about 50 μmolm ⁻² s ⁻¹ ), the difference in ΔF / Fm ′ is different for each test section. When the light intensity is high (about 200 μmolm ⁻² s ⁻¹ ), a difference is observed in the test interval, and ΔF / Fm ′ of the leaves irradiated with 405 nm LED at 15-minute intervals is the lowest. It was. Table 13 shows regression line equations (intercepts unified to 0.8) of the relationship between PPFD and ΔF / Fm ′.
The absolute value of the slope of the regression line was larger for the 405 nm LED light than for the halogen lamp light, and the slope of irradiation for 405 nm LED for 15 minutes was -0.0001, which was the largest absolute value. In other words, when compared with the same PPFD, a single irradiation with 405 nm purple light shows a decrease in ΔF / Fm ′ compared with a single irradiation with halogen lamp light, and the difference increases as the light intensity increases. It was shown that.

2) Experiment 2
FIG. 34 is a graph showing the relationship between PPFD and ΔF / Fm ′ when the light intensity is gradually increased for the same leaf. Table 14 below shows the regression line formula (intercept unified to 0.76) for the relationship between PPFD and ΔF / Fm ′.
As shown in FIG. 34, when the light from each light source was irradiated at about 150 μmolm ⁻² s ⁻¹ , ΔF / Fm ′ under 405 nm purple light decreased by 15% from the halogen lamp and decreased by 13% from the white fluorescent lamp. . With the same PPFD, 405 nm violet light irradiation had lower ΔF / Fm ′ than halogen lamps and white fluorescent lamps, and the higher the PPFD, the greater the difference with other light sources. In other words, even in the leaves of various leaf positions fully developed by tomato seedlings, the quantum yield may be reduced when 405 nm purple light is irradiated as compared with white light of a halongen lamp or a fluorescent lamp. Indicated.

From the above, when a single 405 nm purple light is irradiated, the actual quantum yield of PSI is lower than that of halogen lamp light or white fluorescent lamp light. Of the photons absorbed by PSII, photons that cannot be used for photosynthesis electron transfer It was suggested that the percentage of increase.

In addition, the inventors have examined PSII quantum yield Fv / Fm and oxidative stress index in order to investigate whether the decrease in PSII quantum yield upon single irradiation with 405 nm purple light works as light stress. A test for measuring malondialdehyde (hereinafter referred to as MDA) was conducted. In this test, the experiment was performed twice (experiments 1 and 2). In experiment 1, the light from the light sources AC as shown in FIG. The light from the light sources AC was irradiated for 12 hours (24 hours in total). In Experiment 2, light from light sources A to C was continuously irradiated for 24 hours.
Here, the data regarding the test results are not particularly shown, but according to the test results, Fv / Fm is lower in the 405 nm LED section (light source A) than in the halogen lamp section (light source B). Plant leaves undergo photoinhibition when they receive excessive light in excess of the light required for photosynthesis, and the quantum yield of photosynthesis decreases. That is, the decrease in Fv / Fm was suggested to cause photoinhibition by 405 nm purple single light irradiation rather than halogen lamp light. That is, it was shown that the irradiated object was subjected to oxidative stress more than the halogen lamp light by 405 nm purple light irradiation.

In general, it is known that stress generated in a plant body by light irradiation is strongly influenced by factors such as “high light intensity” and “long irradiation”.
Therefore, when irradiating the plant body with purple light in the present invention, the plant body is irradiated with purple light in a form that is added to the light necessary for the growth of the plant body (for example, natural light or artificially adjusted natural light), It is desirable to intermittently irradiate the plant body with purple light, and more desirably, it is desirable to perform these simultaneously (irradiation with purple light in a form added to natural light or artificially adjusted natural light, and (Purple light irradiation is preferably intermittent irradiation (intermittent irradiation)).
In addition, when violet light is irradiated in the form of adding to natural light or artificially adjusted natural light, natural light or artificially adjusted to suitably induce the expression of pathogen defense response-related genes by purple light irradiation The high intensity of the violet light to be added may be adjusted so that the light intensity is stronger than the violet light included in the natural light.

As described above, the present invention has no possibility of adversely affecting the growth and morphogenesis of the plant body or the photosynthetic action, and does not use a drug in an environment in which natural infection with phytopathogenic bacteria may occur, or , Pathogen-resistant plants that are unlikely to cause disease even if the amount of drug used is reduced, and their fruits and their stems, methods for inducing such pathogen-resistant plants, and plants It is a plant cultivation system that induces the pathogenic resistance of the plant, while bacteriostatically sterilizing the infected phytopathogenic fungi to make the plant difficult to cause disease, and does not adversely affect the human body of the worker It can be used in fields related to agriculture and horticulture.

P ... plant body L ... natural light (visible light) 1 ... pathogen resistant plant body 2 ... leaf 3 ... purple light source 4 ... plant pathogen 5 ... disease spot 6 ... green light source 7 ... dead leaf 8 ... plant growth space 9 ... Medium 10A, 10B ... Plant cultivation system 11 ... Purple light 12 ... Green light

Claims

A pathogen-resistant plant induced by violet light irradiation treatment in which a leaf is irradiated with violet light having a peak between wavelengths of 390-420 nm,
A pathogen defense response-related gene is expressed from a plant of the same species not subjected to the purple light irradiation treatment,
The pathogenic defense response-related gene is a salicylic acid synthesis pathway-related gene or a gene group induced by salicylic acid.
The pathogen-resistant plant according to claim 1, wherein the gene group induced by salicylic acid is a gene group that induces acidic PR protein.
A fruit harvested from the pathogen-resistant plant according to claim 1 or 2.
A leaf stem harvested from the pathogen-resistant plant according to claim 1 or 2.
Induction of a pathogen-resistant plant characterized by performing purple light irradiation treatment in which at least 10% of the total leaf area of the plant is irradiated with purple light having a peak between wavelengths 390-420 nm. Method.
6. The salicylic acid synthesis pathway-related gene or a gene group induced by salicylic acid, which is a pathogen defense response-related gene in the plant body, is expressed by performing the purple light irradiation treatment. Method for Inducing Pathogenic Resistance Plants
A pathogen-resistant plant characterized by being induced by the method according to claim 5 or 6.
A plant growth space capable of directly or indirectly irradiating the plant leaves with outdoor natural light or artificially adjusted natural light; and
A medium or a culture solution for containing the roots of the plant body and supplying nutrients and water necessary for the growth of the plant body;
A violet light source for intermittently irradiating purple light having a peak between wavelengths 390-420 nm to a region of at least 10% of the total leaf area of the plant body;
A plant cultivation system comprising: a control unit that controls turning on and off of the purple light source.
The plant cultivating system according to claim 8, wherein the violet light source can be changed in its mounting position or mounting number, or both the mounting position and the mounting number can be changed.