JP2016039790A - Plant production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a system in which the ability of a plant to adapt to an environment is stimulated by a combination radiation of monochromatic lights under a dark condition, disease damage resistance is enhanced, and simultaneously the growth of the plant is promoted, in order to achieve a safe vegetable cultivation technique by which the reduction of agricultural chemicals used is possible and yield is increased.SOLUTION: The invention relates to a method of comprising irradiating a plant with a green light under a dark condition, and irradiating it with a red light under a dark condition after a given time has elapsed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a plant by combining monochromatic light such as green light, red light and blue light, or by combining them with white light (natural light or artificial light close to nature).

In the production process of plants, it has been studied to irradiate specific proteins and plant hormones by irradiating monochromatic light for the purpose of disease control or increasing yield of fruits and vegetables.
Patent Document 1 discloses a technology for accelerating fruit set and fruit enlargement by irradiating fruit and vegetables with green light in the dark.
Patent Document 2 discloses a technique for inducing plant gene expression by irradiating a plant with green light to increase disease resistance.
Patent Document 3 discloses a technique for increasing pathogenic resistance by irradiating a plant with purple light.
In Patent Document 2, it seems that the induction of jasmonic acid is suggested from the fact that the expression of two enzymes (AOS, LOX) in the biosynthesis pathway of jasmonic acid was confirmed by irradiation with green light under dark conditions. Jasmonic acid has no protective effect against active parasites (Non-Patent Document 4).
Moreover, although jasmonic acid has an inhibitory effect on plant growth, Patent Document 1 states that it contributes to an increase in the yield of fruit vegetables, but the mechanism is not clear.

International Publication WO2011 / 007868 Japanese Patent No. 5028407 International publication WO2013 / 015442

M. Hentrich et.al The jasmonic acid signaling pathway is linked to auxin homeostasis through the modulation of YUCCA8 and YUCCA9 gene expression.The plant journal 2013 74,626-637 Wim Grunewald et.al Expression of the Arabidopsis jasmonate signaling repressorJAZ1 / TIFY10A is stimulated by auxin.EMBO reports Vol10 / NO8 / 2009 Motomu Endo et.al CRYPTCHROME2 in vascular bundles regulates flowering in Arabidopsis.The Plant Cell, Vol. 19: 84-93 January 2007 A. Leon-Reyes et.al salicylate-mediated suppression of jasmonate-responsive gene expression in Arabidopsis is targeted downstream of jasmonate biosynthesis pathway.Planta (2010) 232: 1423-1432 X. Liu et.al Low-Fluence Red Light Increase the transport and Biosynthesis of Auxin Plant physiology, October 2011, Vol.157, pp.891-904 G. Segarra et.al Simultaneous quantitative LC-ESI-MS / MS analyzes of salicylic acid and jasmonic acid in crude extracts of Cucumis sativus under biotic stress. Phytochemistry 67 (2006): 395-401 Z. Cheng et.al A study of Blue-Light Dependent Phosphorylation, Degradation, and Photobody-Formation of Arabidopsis CRY2. Molecular Plant Volume5 Nomber3 726-733 May 2012.

The present invention constructs a system that stimulates the ability of plants to respond to the environment by combined irradiation of monochromatic light under dark conditions, enhances disease resistance, and simultaneously promotes plant growth.
The purpose of this is to realize a safe and yielding plant production method that can reduce the use of pesticides.

The plant production method according to the present invention includes a step of irradiating a plant with green light under dark conditions and a step of irradiating red light under dark conditions after elapse of a predetermined time.
In this case, you may make it have a step which irradiates white light between the step which irradiates green light, and the step which irradiates red light.
Here, white light means not only natural light but also artificial light close to natural light.

Although details will be described later, when the irradiation light is controlled as described above, the following effects are obtained.
Green light is irradiated under dark conditions, and green light is received by cryptochrome 2 which is a blue and green light receptor of the plant, and the effect of promoting flowering by cryptochrome 2 in the phloem associated cells is exhibited.
At the same time, the plant hormone jasmonic acid is expressed.
This jasmonic acid not only induces a protective protein against dead parasites, but also has a protective effect against food damage.
Jasmonic acid also has growth-inhibiting effects such as suppression of root elongation.
Thereafter, red light is irradiated under dark conditions to stimulate phytochrome B, which is a red light receptor, and attract auxin, which is a growth hormone.
Auxin is a plant hormone necessary for fruit enlargement after flowering in fruits and vegetables such as strawberries.

In this invention, you may make it have a step which irradiates blue light instead of the step which irradiates red light.
If it does in this way, it will irradiate with green light on dark conditions, and the flowering promotion effect by the cryptochrome 2 in a phloem accompanying cell will be exhibited as mentioned above, and the plant hormone jasmonic acid is expressed simultaneously.
As described above, this jasmonic acid has a protective effect against feeding damage in addition to inducing a defense protein against dead parasites, but has no protective effect against active parasites, Has growth-inhibiting effects such as flowering inhibition.
Therefore, salicylic acid is expressed by irradiating blue light under the after-dark condition after irradiation with green light.
Salicylic acid has an antagonistic action with jasmonic acid and has a flowering promoting effect.
Salicylic acid also induces a defense response against active parasites.
Therefore, in this system, jasmonic acid and salicylic acid can be attracted alternately to induce defense against both dead and active parasites, and flowering can be greatly promoted.

The present invention stimulates Cryptochrome 2 by irradiating green light under dark conditions, for example, at night, and induces flowering. In addition, after generating jasmonic acid, a growth-inhibiting plant hormone, Pathogens using the so-called homeostasis effect that maximizes the resilience of maintaining plant homeostasis by irradiating with blue or red light and expressing salicylic acid or auxin that has an antagonistic effect on jasmonic acid The present invention provides a method for producing a plant with a high yield while maintaining a high tolerance to water.
The irradiation schedule requires a period of several hours from the irradiation of monochromatic light under dark conditions to the induction of plant hormones, etc., so in plant cultivation using sunlight, monochromatic light irradiation is repeated under dark conditions at night Is reasonable.
In artificial light utilization type plant cultivation, since dark conditions can be set freely, the same effect can be obtained by irradiating green light and red light or blue light in the same dark period set for several hours.
In addition, the irradiation combination of green light, red light, and blue light can be freely combined in consideration of the effect of each monochromatic light, and can also be combined with white light.

In the green light irradiation light source, the red light irradiation light source, and the blue light irradiation light source, it is preferable that the photon flux on the upper surface of the medium can be irradiated at 10 to 55 μmol / m ² / sec with each monochromatic light source.
Green light has a peak at a wavelength of 530 ± 30 nm, red light has a peak at a wavelength of 650 ± 40 nm, and blue light has a peak at a wavelength of 450 ± 30 nm. Other light sources such as cold cathode tube electroluminescence (EL) and laser light can also be used.

Using the method for producing a plant by combined irradiation of monochromatic light according to the present invention, for example, when green light is irradiated for a predetermined time at night and then red light is irradiated for a predetermined time the next night, a plurality of times, As a result of repeated induction of jasmonic acid expression and auxin expression by irradiation with red light, the following effects occur.
Expression of jasmonic acid increases auxin biosynthetic enzyme (YUCCA) (Non-patent Document 1), and auxin production induces a receptor for jasmonic acid synthesis pathway (JAZ1) (Non-patent Document 2). The talk shows that the growth inhibitory hormone jasmonic acid actively promotes the induction of auxin and increases the yield of fruit and vegetables by establishing a system that can always be reversed in cooperation with the growth promoting hormone auxin.

  In addition, when green light irradiation and blue light irradiation are combined, jasmonic acid and salicylic acid are alternately induced to induce resistance to both dead and active parasites. Induction promotes flowering induction.

The investigation results of combined monochromatic light irradiation and strawberry yield ratio are shown. The combined monochromatic light irradiation and strawberry flowering number survey results are shown. The explanatory view of the irradiation pattern of monochromatic light is shown. The investigation result of the relation between irradiation light and spider mite damage in strawberry cultivation is shown. The analysis result of the jasmonic acid content of the strawberry leaf irradiated with each monochromatic light is shown. The analysis result of the salicylic acid content of the strawberry leaf irradiated with each monochromatic light is shown. The flowering rate transition of each mutant of Arabidopsis thaliana is shown.

  Prior to the description of the plant production method according to the present invention, the effects of irradiating the plant with each monochromatic light were confirmed by experiments, which will be described.

Strawberries were cultivated in a glass greenhouse exposed to natural light during the day, and a comparison was made between those irradiated with monochromatic light of green light, red light and blue light under dark conditions and those not irradiated at night.
<Cultivation conditions>
In each ward, 10 seedlings of strawberries and precious fast-growing were planted.
Monochromatic light irradiation in each section was performed under dark conditions for 2 hours at night from 1 am to 3 am on fire, wood, and soil.
The irradiation dose in each section was as follows.
Green light irradiation section: 20.3 to 36.0 μmol / m ² / s
Red light irradiation zone: 11.3 to 27.0 μmol / m ² / s
Blue light irradiation section: 22.5 to 67.0 μmol / m ² / s
Non-irradiation zone: 0 μmol / m ² / s
In addition, only in the case of clouds and rainy weather, the glass greenhouse was supplemented with an incandescent lamp and a light bulb type LED within a range of 12 hours from 8:00 to 20:00.
The intensity of supplemental light was 120 to 150 μmol / m ² / s with supplemental light alone.
<Results of spider mite damage survey>
The occurrence of spider mites was confirmed 80 days after seedling planting.
In order to quantify the amount of damage, the score was divided into 6 levels as shown below and scored.
Score 0: No change.
Score 1: Black spots are attached to the back of the leaves, but there is no yellowing.
Score 2: Yellow spotted pattern on the back of leaf, no change in leaf surface.
Score 3: The entire leaf back is yellow, but the leaf surface is unchanged.
Score 4: The entire leaf back is yellow, and white spots are progressing on the leaf surface.
Score 5: A spider web is stretched on the leaf.
FIG. 4 shows the result of calculating the average damage amount for each stock from the damage score of the fully developed three-leaf sheet and making a graph.
From this result, the green light irradiation section was 1% error level compared to the other sections, and it was significantly less spoiled.
<Results of investigation of jasmonic acid content>
After evaluation of spider mite damage, we removed the spider mites using Baroque Flowable, and after about 2 weeks, we selected the youngest leaves among the three leaves fully developed from each section, collected about 5g, and analyzed the results by LC-MS / MS. Shown in
The analysis of jasmonic acid content was performed according to the method described in Non-Patent Document 6.
As a result, the content of jasmonic acid was increased because the green light irradiation section was 1% more significant than the other sections.
From this, it is presumed that irradiation with green light under dark conditions induced the expression of jasmonic acid, and as a result, the ability to defend against insect damage was improved.
Jasmonic acid is also known to induce defense against necrotrophic diseases.
<Survey result of salicylic acid content>
The salicylic acid content analyzed by LC-MS / MS according to the description of Non-Patent Document 6 is shown in the graph of FIG.
As shown in the graph, the salicylic acid content in the blue light irradiation section is significantly higher than that in the red light irradiation section and the green light irradiation section.
In addition to inducing systemic acquired resistance (SAR) against biotrophic diseases, the generation of salicylic acid has an antagonism that inhibits the action of jasmonic acid by inhibiting the biosynthetic pathway of jasmonic acid.

Next, a monochromatic light irradiation experiment was performed using a plant model, Arabidopsis thaliana.
There are four types of Arabidopsis used in the experiment: wild species (Col-0), cryptochrome 1 deficient mutant (cry1), cryptochrome 2 deficient mutant (cry2), and jasmonate biosynthetic enzyme deficient mutant (jar1). .
The seeds were sown on an MS medium in a glass bottle and cultivated with an artificial weather device, and after 2 weeks germination, transplanted to a soil medium in a 100 ml polypot and returned to the artificial weather device.
As the soil medium, vermiculite: peat moss: perlite = 1: 1: 1 was used.
The artificial meteorograph is set to 18 hours long (5: 00 to 21:00), 6 hours dark condition (21: 00 to 5:00), 23 ° C, 70% relative humidity, green light irradiation zone, Three sections, a blue light irradiation section and a non-irradiation section, were set.
The monochromatic light was irradiated three times a week on Tuesdays, Thursdays and Sundays for 2 hours from 1:00 to 3:00 between dark conditions.
Dose was in medium top green light 29μmol ^{/ m} 2 ^/ s, and blue light 26μmol ^{/ m} 2 ^/ s.
Fig. 7 shows the results of the survey on the flowering rate.
On the 38th day after sowing (DAS38), the jasmonate biosynthetic enzyme-deficient mutant (jar1) flowered first, followed by the cryptochrome 1-deficient mutant (cry1) and the wild species (col-0), followed by cryptochrome. The 2-deficient mutant (cry2) was not yet flowering.
Moreover, although illustration was abbreviate | omitted, the flowering was quick in the green light irradiation section, and there was no significant difference in the flowering between the two sections of the blue light irradiation section and the non-irradiation section.
For this reason, cryptochrome 2 receives light stimulation and promotes flowering.
It can also be seen that flowering is further accelerated if jasmonic acid is not expressed.
Moreover, it is thought that the flowering promotion by stimulating cryptochrome 2 and the pathway of jasmonic acid expression are independent.
Non-Patent Document 3 describes that cryptochrome 2 is a photoreceptor that promotes flowering.

  Based on the preliminary experiments described above, the results of the investigation will be described below with respect to a combination example of monochromatic light which is a plant production method according to the present invention.

<Cultivation conditions for strawberries>
Set a 1m long, 20cm wide medium with rock wool or zeolite on a 1m high table, spray water onto the medium from a liquid tank with liquid manure under the table. Strawberries were cultivated by circulating hydroponics that returned to the tank with a drain circuit.
The liquid fertilizer concentration was adjusted to EC1.5 ± 0.3.
The fluorescent lamp for irradiation was installed 40 cm above the medium.
A monochromatic light irradiation method is shown in FIG.
(A) As a G irradiation method, green light was irradiated 3 times a week on Tuesdays, Thursdays, and nights for 2 hours from 1:00 to 3:00, and was exposed to natural light in the daytime.
(B) As a G-R irradiation method, green light is irradiated 3 times a week for two hours from 10:00 to 3:00 on nights on Tuesdays, Thursdays and Sundays. Irradiated with red light for 2 hours at ~ 3: 00.
In the daytime, natural light was applied.
(C) is a GB irradiation method, which is irradiated with green light for 2 hours from 10:00 to 3:00 on Tuesdays, Thursdays and Fridays three times a week, and at 1:00 on Mondays, Wednesdays and Fridays the following night. Irradiated with blue light for ˜3: 00 for 2 hours.
In the daytime, natural light was applied.
For comparison, a non-irradiation zone where no monochromatic light was irradiated at night was provided.
A partition curtain is provided between each irradiation zone, and the irradiation intensity of monochromatic light on the upper surface of the medium which is not affected by the irradiation of other zones is 10 to 55 μmol / m ^{2 for} green light, red light and blue light. / S.
The fixed number of strawberry treasure seedlings was 5 in the non-irradiated area and 10 in the monochromatic area.
As a cultivation result, FIG. 1 shows the strawberry yield, and FIG. 2 shows the number of flowering.
FIG. 1 shows the yield ratio relative to the non-irradiated zone 1.000. The GR method for expressing auxin the next night after jasmonic acid expression is about twice that for the non-irradiated zone, and about 1. The yield was 7.
FIG. 2 shows the number of flowering with respect to the number of seedlings, and the GB irradiation method in which salicylic acid was expressed with blue light the next night after jasmonic acid expression was the most flowering.
Although the yield of the GB irradiation method does not increase as much as the GR irradiation method from the results shown in FIG. 2, the number of flowering progresses as shown in FIG. It can be used as a means of disease prevention in stages.
Non-patent document 5 reports that phytochrome is stimulated by irradiation with red light under dark conditions in tomato seedlings to induce auxin.
In non-patent document 7, Cryptochrome 2 which is a receptor necessary for inducing flowering is stable to green light irradiation but unstable to continuous irradiation of blue light abundantly in sunlight. It has been reported.
From these non-patent documents and the above experimental results, weak monochromatic light irradiation under dark conditions stimulates photoreceptors such as cryptochrome and phytochrome, and induces plant hormones, which are signal transmitters, to affect plant morphogenesis. It can be seen that

Claims (3)

  A method for producing a plant, comprising: irradiating the plant with green light under dark conditions; and irradiating the plant with red light under dark conditions after a predetermined time has elapsed.   The plant production method according to claim 1, further comprising a step of irradiating white light between the step of irradiating the green light and the step of irradiating the red light.   The plant production method according to claim 1, further comprising a step of irradiating with blue light instead of the step of irradiating with red light.