WO2017125993A1

WO2017125993A1 - Plant disease control agent containing lignin extract as active ingredient

Info

Publication number: WO2017125993A1
Application number: PCT/JP2016/051216
Authority: WO
Inventors: 利章大原; 義弘鳴坂; 真理鳴坂; 康幸山次; 香代子古藤田
Original assignee: 国立大学法人岡山大学; 株式会社カスケード資源研究所
Priority date: 2016-01-18
Filing date: 2016-01-18
Publication date: 2017-07-27
Also published as: JP6652140B2; JPWO2017125993A1

Abstract

The purpose of the present invention is to provide a plant disease control agent which has little environmental impact and is useful against a broad range of pathogens. The invention disclosed in the present specification provides a plant disease control agent which contains, as an active ingredient, a lignin extract that is extracted from a lignin-containing material by bringing the lignin-containing material and iron ions into contact.

Description

Plant disease control agent comprising lignin extract as an active ingredient

This description relates to a plant disease control agent comprising a lignin extract as an active ingredient.

Material derived from lignocellulosic material, which is a constituent component of plants, is expected as a component having a small environmental load. As such a lignocellulose-derived component, for example, a lignin extract extracted from a lignin-containing material by bringing a metal ion into contact with the lignin-containing material is known. This lignin extract is known to have a wrinkle improving effect and a stain improving effect (Patent Document 1).

Plants are exposed to various infectious pathogens, and disease control is essential for the stable production of agricultural products. Plant disease control agents include resistance inducers based on resistance-inducing activity that promotes the expression of defense response genes inherent in plants. If it is a resistance inducer, it is expected to be used for controlling various pathogens.

JP 2010-30921 A

However, there are still few useful resistance inducers, and development takes time and cost. In recent years, it takes time to evaluate the environmental load and safety of such agricultural chemicals. Therefore, development of this type of drug is not easy.

This specification provides a plant disease control agent that has a low environmental impact and is useful for a wide range of pathogens.

The present inventor has found that a lignin extract derived from lignin, which is a constituent component of a plant, has a controlling action against infectious diseases of plant pathogens. According to the present specification, the following means are provided.

(1) A plant disease control agent comprising, as an active ingredient, a lignin extract extracted by promoting decomposition of lignin in the lignin-containing material by bringing iron ions into contact with the lignin-containing material.
(2) The plant disease control agent according to (1), wherein the lignin extract is extracted from the lignin-containing material by fermenting the lignin material in the presence of iron ions.
(3) The plant disease control agent according to (2), wherein the fermentation is performed using lactic acid bacteria.
(4) The plant disease control agent according to any one of (1) to (3), wherein the lignin-containing material includes herbaceous foliage.
(5) The plant disease control agent according to any one of (1) to (4), which is a resistance inducer.
(6) The plant disease control agent according to any one of (1) to (5), which is used for control against plant disease-causing bacteria.
(7) The plant disease control agent according to (6), wherein the plant disease bacterium is a black spot bacterial bacterium.
(8) The plant disease control agent according to any one of (1) to (5), which is used for control of plant disease-resistant filamentous fungi.
(9) The plant disease control agent according to (8), wherein the plant disease-causing fungus is a vegetable anthracnose fungus.
(10) The plant disease control agent according to any one of (1) to (5), which is used for control of plant disease virus.
(11) The plant disease virus includes tomato mosaic virus (ToMV), psyllium mosaic virus (PIAMV), potato X virus (PVX), tobacco mosaic virus (TMV), potato M virus (PVM) and cucumber mosaic virus (CMV). The plant disease control agent according to (10), which is one or more viruses selected from the group consisting of:
(12) The plant disease control agent according to any one of (1) to (5), which is used for controlling plant disease-causing bacteria, plant disease-causing fungi and plant disease-causing viruses.
(13) Black spot bacteria, vegetable anthrax, tomato mosaic virus (ToMV), plantain mosaic virus (PIAMV), potato X virus (PVX), tobacco mosaic virus (TMV), potato M virus (PVM) and cucumber The plant disease control agent according to (12), which is used for control against mosaic virus (CMV).
(14) A plant growing composition comprising the plant disease control agent according to any one of (1) to (13).
(15) A method for controlling plant diseases using the plant disease control agent according to any one of (1) to (13).
(16) A method for producing a plant by controlling a plant disease using the plant disease control agent according to any one of (1) to (13).

It is a figure which shows the infectious amount of the black spot bacterial pathogen of Arabidopsis thaliana which spread | dispersed the lignin extraction solution. It is a figure which shows the infectious amount of the cruciferous vegetable anthracnose fungus of Arabidopsis thaliana sprayed with the lignin extraction solution. It is a figure which shows the expression level of the resistance related gene of Arabidopsis thaliana sprayed with the lignin extraction solution. It is a figure which shows the evaluation result by the ToMV-Bensamiana tobacco evaluation system of a lignin extraction solution. It is a figure which shows the evaluation result by the ToMV-tomato evaluation system of a lignin extraction solution. It is a figure which shows the relationship between the lignin extract density | concentration in a lignin extract solution, and the infection suppression effect by a ToMV-bensamiana tobacco evaluation system. It is a figure which shows the evaluation result of the infection suppression effect with respect to the virus (PlAMV) of a lignin extraction solution. It is a figure which shows the evaluation result of the infection inhibitory effect with respect to the virus (PVX) of a lignin extraction solution. It is a figure which shows the evaluation result of the infection inhibitory effect with respect to the virus (TMV) of a lignin extraction solution. It is a figure which shows the evaluation result of the infection inhibitory effect with respect to the virus (PVM) of a lignin extraction solution. It is a figure which shows the evaluation result of the infection inhibitory effect with respect to the virus (CMV) of a lignin extraction solution. It is a figure which shows the evaluation result of the infection inhibitory effect of ToMV of the lignin extraction solution derived from sugarcane and bamboo.

The present specification relates to a drug containing, as an active ingredient, a lignin extract that is extracted from a lignin-containing material by bringing the lignin-containing material into contact with iron ions to promote the decomposition of the lignin (hereinafter referred to as “lignin extract”). The present lignin extract has an action of suppressing the plant from being infected with a phytopathogen or causing the plant to exhibit a resistance to phytopathogens. The drug disclosed in the present specification is used as a disease control agent that is a resistance inducer.

According to the present inventors, although the present lignin extract has a low effect of directly controlling pathogenic bacteria and filamentous fungi, it is effective when supplied to a plant body. It has been confirmed that it has the effect of suppressing the infection of bacteria. It has also been confirmed that this lignin extract has no irritation to human skin and eyes and no toxicity. From the above, it can be seen that the present lignin extract has little environmental impact and is effective against a wide range of pathogens.

Although the disclosure of the present specification is not theoretically constrained, the following mechanism is considered as the mechanism of the action of the present lignin extract.

This lignin extract induces resistance to pathogens by supplying it to plants, and can function as a resistance inducer by exerting resistance to pathogens. As will be described later, according to the present lignin extract, it promotes the expression of a plurality of resistance-related genes including chitinase genes (AtChi570, AtChi620) that are known to be involved in infection defense responses. Can do.

Also, iron ions are required for cells to divide, but this lignin extract binds to the iron ions to form a complex and consumes the iron ions. Since iron is also required when pathogenic bacteria such as bacteria and filamentous fungi grow, it is considered that the present lignin extract consumes iron, thereby exerting the effect of inhibiting the growth of pathogenic bacteria.

Also, iron is necessary when a virus is established and the virus propagates. For this reason, this lignin extract is considered to exhibit a virus growth inhibitory action.

Hereinafter, embodiments of the present invention will be described in detail.

(Lignin extract)
The lignin extract, which is an active ingredient of this drug, is extracted from the lignin-containing material by bringing iron ions into contact with the lignin-containing material in the presence of an aqueous medium and promoting the degradation of the lignin in the lignin-containing material. Is done. Hereinafter, the manufacturing method of this lignin extract (henceforth this lignin extract) is demonstrated.

(Method for producing lignin extract)
(Lignin-containing material)
As a lignin containing material, the lignin contained in a plant structure or the derivative | guide_body of the said lignin should just be included. That is, the lignin and the lignin derivative referred to here are substantially free of lignin treated under conditions that promote polycondensation of lignin under strong alkali or strong acid in the pulp production process. Therefore, the lignin-containing material in this specification does not contain black liquor or the like.

Examples of such lignin-containing materials include lignocellulosic material processed products that are processed as they are, or under mild conditions, from plant-derived lignocellulose-based materials. Examples of lignocellulosic materials include whole or part of plants, processed products having a woody part, and the like. Plants include, but are not limited to, conifers, broad-leaved trees, eucalyptus, and other herbs, as well as rice, wheat, corn, sugarcane, kenaf, ghetto, moonfish, and other herbs and bamboo. . Non-use materials of plant-derived lignocellulose materials can also be used. Non-use materials include thinned wood, pruned plant branches and leaves, non-edible fruits such as pine trees, and stalks and leaves after harvesting edible parts. Among these, as lignocellulosic materials, herbaceous foliage such as ghetto can be preferably used. Since these tissues are coarser than woody species, a lignin extract can be efficiently obtained. Moreover, a chlorophyll extract is also contained in a lignin extract by using the leaf part containing a chlorophyll.

The lignin-containing material is preferably crushed to some extent in consideration of extraction efficiency. For example, the lignocellulosic material derived from herbs is preferably cut appropriately, and the lignocellulosic material of woody materials is preferably in the form of chips or powder.

The lignin-containing material may be a material obtained by treating a lignocellulosic material under mild conditions. Examples thereof include lignophenol derivatives described in JP-A-2-233701 and JP-A-9-278904. Moreover, vegetable food wastes such as tea gala and cedar liquor are listed. For example, the essential oil is extracted from Kumazasa by steam distillation, and the distilled water after separation of the essential oil contains polyphenols derived from Kumazasa lignin. Such a distillation residue can also be used as a lignin-containing material. Furthermore, the residue after isolate | separating a cellulose from bagasse which is a residue after squeezing sugarcane, lignocellulose, etc. are mentioned. Such mild conditions are preferably 100 ° C. or lower, more preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and even more preferably 60 ° C. or lower, under weak alkaline to weak acid pH conditions (for example, pH 10 to (About 2) is preferable.

(Iron ion)
The iron ion only needs to be present as a divalent or trivalent ion in the presence of water. In any form, degradation of lignin can be promoted as a result in the presence of water. Such iron ion sources include iron sulfate (II) (FeSO ₄ ), ferric sulfate (III) ((Fe) ₂ (SO ₄ ) ₃ ), so-called iron rust (iron oxide (III) and its hydrates, Iron oxide (II, III) and hydrates thereof, iron hydroxide, and various iron oxyhydroxides). Such iron rust becomes an iron ion source that generates iron ions (II) and iron ions (III) in the presence of water. In addition, when metallic iron rusts, iron ions (Fe (II)) are eluted in the presence of water and pass through iron hydroxide. As a result, iron oxyhydroxide such as iron (III) hydrous oxide ( III) is formed, or iron ions (II) are oxidized by air to iron ions (III), and as a result, iron (III) oxyhydroxide such as iron (III) hydrated oxide can be generated. For this reason, metallic iron or a metallic alloy containing iron can also serve as an iron ion source. Therefore, for example, a mixer or a press used in the extraction process has an iron inner surface and an iron rust on the inner surface is also an iron ion source.

Iron ion (III) is also preferable from the viewpoint of the stability of the extract (anaerobic fermentation (rot)), cost, availability, and the like.

(Extraction process)
The step of generating and extracting the present lignin extract from the lignin-containing material is a step of promoting oxidation of lignin by bringing iron ions into contact with the lignin-containing material. By this step, lignin can be degraded, reduced in molecular weight, and / or slowly modified.

The extraction step is performed in the presence of an aqueous medium. This is because iron ions (II) and (III) are interposed. Examples of the aqueous medium include water and a mixed solution of water and an organic solvent compatible with water. The aqueous medium in the extraction step is supplied as a cell fluid or an intercellular fluid from the lignin-containing material itself, or can be supplied accompanying the lignin-containing material. In addition, the aqueous medium may be separately supplied to the extraction step. It is preferable that the aqueous medium in the extraction step is in such a level that the lignin-containing material can be appropriately contacted with oxygen in the air. This is because the decomposition of lignin is promoted by the gas-liquid interface. In particular, when a herbaceous lignocellulosic material is used, it is not always necessary to add an aqueous medium, but water or the like can be appropriately added in consideration of the concentration of the extract and extraction efficiency. On the other hand, when using woody lignocellulosic materials such as wood powder, it is preferable to use an appropriate amount of water.

In the extraction process, other solvents can be positively added in addition to water. Such a solvent may be one that dissolves or separates water, but a solvent that does not inhibit the decomposition of lignin due to the presence of water can be appropriately selected.

In the extraction step, the lignin-containing material may be allowed to stand as appropriate in a state where metal ions can be present, or may be mixed by stirring or the like. When the lignin-containing material is immersed in an aqueous medium containing metal ions, an extract can be easily obtained. For example, by immersing the lignin-containing material in a metal salt solution used in the extraction process for about 1 to 24 hours, the metal ions and the lignin-containing material can be gently brought into contact with each other. Considering the subsequent fermentation, it is preferable to stand at room temperature or at a temperature lower than that. The lignin-containing material after immersion may be continuously mixed and fermented with the immersion liquid, or the extraction process may be performed by newly bringing the lignin-containing material after immersion into contact with iron ions. The extraction step may be performed, or the lignin-containing material separated from the immersion liquid may be contacted with metal ions again to perform the extraction step.

In the extraction step, the lignin-containing material can be mixed (by stirring or vibration) in an aqueous medium containing metal ions. Although the time of the extraction process accompanied by mixing etc. is not specifically limited, For example, when obtaining a lignin extract from a lignocellulosic material, it should just be performed to such an extent that the restraint state of the cellulose by a lignin is substantially cancelled | released. Although not particularly limited, for example, it can be carried out for several tens of minutes to several hours. In the extraction step, mixing or the like can be stopped as necessary. Moreover, the extraction step may include adjusting the metal ion concentration by adding a metal salt solution as appropriate.

Also, the extraction process can be accompanied by pressing or crushing depending on the form of the lignocellulosic material.

Mixing / stirring and pressing / crushing in the extraction process increase the contact opportunity, contact area and contact time between iron ions and lignin-containing materials, as well as contact between iron ions and lignin-containing materials and decomposition of lignin. It is also meaningful to generate at the gas-liquid interface between gas and liquid. This is because, under these conditions, it is considered that the degradation of lignin is promoted by the Fenton reaction based on the presence of iron ions.

The amount of metal ions present in the extraction process is not particularly limited. When crushed herbaceous foliage is used as a lignin-containing material, the extract is colored due to the presence of a sufficient amount of metal ions. For example, the iron ion is blackened. Therefore, an appropriate metal ion concentration can be set by observing the appearance color of the extract. When iron ions are used as metal ions, a ferric sulfate solution can be typically used. Further, the iron ion concentration is not particularly limited. As an example, a solution of about 0.2 g / l or more and 1 g / l or less can be used as the ferric sulfate solution.

In order to promote the treatment using iron ions, it is preferable to involve fermentation of the lignin-containing material. Although the reason is not clear, the present lignin extract having excellent pathogen infection suppression effect and the like can be obtained. For fermentation, resident bacteria may be used, but lactic acid bacteria are preferably used. Although it does not specifically limit as lactic acid bacteria, The lactic acid bacteria used also for fermented food can be used preferably. As the lactic acid bacteria, for example, known lactic acid bacteria such as Lactobacillus, Bifidobacterium, Enterococcus, Lactococcus, Pediococcus, and Leuconostoc can be appropriately selected and used. For example, Lactobacillus casei strain Shirota, L. casei YIT 9029 and the like are preferable.

Fermentation is preferably performed by aerobic fermentation. The aerobic conditions in the fermentation are not particularly limited, and may be set as appropriate as long as the aerobic fermentation can be maintained and the decomposition of lignin can be promoted. Moreover, although the temperature conditions for fermentation are not specifically limited, it can be about 25 degreeC or more and 40 degrees C or less. Further, the agitation / aeration conditions are not particularly limited, and may be set as appropriate as long as aerobic fermentation can be maintained and decomposition of lignin can be promoted. For example, the agitation culture may be performed for about 24 hours in the beginning, and the stationary culture may be performed for about 72 hours thereafter. In addition, various conditions can be appropriately set by those skilled in the art to ensure good aerobic fermentation. In addition, when extracting with fermentation, such as lactic acid fermentation, depending on the state of the lignin-containing material, it can be about 20 hours to about 80 hours, and it can be continued up to about one week as necessary. You can also.

Prior to the extraction step or prior to fermentation in the extraction step, various operations for promoting the decomposition of lignin or promoting the separation from cellulose can be performed. For example, lignophenol derivatization described in JP-A-2-233701 and JP-A-9-278904, explosion and steaming used for crushing and extracting lignocellulose materials, oxidation treatment, reduction treatment, acid treatment, alkali treatment Examples include treatment, enzyme treatment, microbial treatment, subcritical fluid treatment of water and organic solvents, and supercritical fluid treatment. These treatments are preferably performed prior to the extraction step.

Note that examples of the oxidizing agent for the oxidation treatment include ozone, Fe ³⁺ -HCl, alkali-H ₂ O ₂ and Ce ⁴⁺ . Examples of the reducing agent for the reduction treatment include lithium tetrahydridoaluminate and sodium tetrahydroborate. Among these, sodium tetrahydroborate that selectively reduces a carbonyl group contained in lignin is preferably used. Examples of the alkali treatment chemical include various basic compounds such as sodium hydroxide, potassium hydroxide, ammonia, sodium carbonate, and sodium borate. As the chemical for acid treatment, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, organic acid and the like are preferably used. As the enzyme treatment, a peroxidase that promotes fragmentation of lignin, a saccharifying enzyme that forms a glycoside, a glucuronyltransferase that oxidizes glucuron, and the like are preferably used.

Prior to the extraction step or prior to fermentation in the extraction step, heating may be performed to promote lignin elution and promote binding to metal ions. For example, it is preferable to heat to about 80 ° C. or higher and 100 ° C. or lower. Preferably, it is 80 degrees C or less. Further, although pressurization is not required, pressurization may be performed. These treatments are preferably performed prior to the extraction step.

The extract after the extraction process includes a decomposition product of lignin in the presence of iron ions. In the extract, polymer lignin may exist as a solid content, such as when a lignocellulosic material is used as a lignin-containing material. In this case, if necessary, the liquid portion can be separated as a lignin extract by a known solid-liquid separation technique such as centrifugation or filtration. Moreover, you may remove suitably the contaminating component in an extract according to the kind of used lignin containing material, and the use of a lignin extract.

The extract obtained by the extraction process is usually colored. By adding an extract (typically an extract) extracted with citric acid from acids such as citric acid or other herbs to the extract, the color of the extract can be changed to a lighter color, Brightness can be improved. As such an extract for color tone adjustment, for example, a citric acid extract having a light pink to light purple color such as perilla leaves, hibiscus petals, cherry leaves, etc. can be used. What is necessary is just to set a citric acid concentration suitably. It is preferable to adjust the color tone at as low a temperature as possible.

(This lignin extract)
The present lignin extract is an extract of lignin in the presence of iron ions, and can typically be obtained by the above-described production method disclosed herein. The lignin extract may be in a solid form such as liquid, slurry, paste, powder. For example, the extract obtained by the above method may be used as it is, or may be diluted or concentrated. Further, the extract may be solidified or powdered by drying by freeze drying or the like. This lignin extract has an anti-corruption action and is itself excellent in stability.

The present lignin extract can exert a disease control action on plants. The disease control action includes the action of killing pathogens causing plant diseases, the action of suppressing the growth of pathogens, and the action of suppressing infection of pathogens. Therefore, this lignin extract can be used as an active ingredient of a plant disease control agent. This lignin extract is considered to have an action of inhibiting the supply of iron ions to pathogens by binding to iron ions to form a complex. Therefore, the pathogen in which this lignin extract exhibits a plant disease control action is not particularly limited, and may be any of fungi such as bacteria and filamentous fungi, or viruses, which are the main pathogens of plants. .

Examples of plant diseases caused by bacteria include, for example, rice blight of rice, black rot of wheat, ring rot of potato, common scab, vegetable soft rot, spoilage disease, spot bacterial disease, black spot bacterial disease, Examples include bacterial wilt, tomato scab, leaf knot, carrot root cancer, knot and the like, and black spot bacterial disease is preferred. Plant diseases caused by fungi, which are fungi, include, for example, paddy rice blight and blast, wheat powdery mildew, beans soybean red mold, fruit and vegetable gray mold, white rust, mildew Tomato disease, spot disease, rust disease, anthracnose disease, clubroot disease and the like are preferable, and anthracnose is preferable. Examples of plant diseases caused by viruses include rice atrophy disease, vegetable mosaic disease, and the like, and mosaic disease is preferable.

Examples of bacteria causing plant diseases include, for example, Agrobacterium genus, Clavibacter genus, Erwinia genus, Pseudomonas genus, Ralstonia genus, Corynebacterium genus, Kurtobacterium genus, Burkholderia genus, Xanthomonas genus, Rhizobacter genus And bacteria belonging to the genus Clostridium. Pseudomonas syringae pv. Maculicola, which causes black spot bacterial disease, is preferred.

Examples of filamentous fungi that cause plant diseases include airborne infectious fungi, powdery mildew (Erysiphe, Sphaerotheca, and Leveillula), Botrytis, and Fulvia fulva , Corynespora, Albugo, downy mildew (Pseudoperonospora), Peronospora, Plasmopara, Bremia, Pyricularia, Blast fungus (Pyricularia grisea), sesame leaf blight fungus (Cochliobolus miyabeanus), circospora related fungi (Cercospora spp, Cercosporella spp., Pseudocercospora spp., Paracercospora spp. Mycovellosiella spp.) , Glomerella spp., Rust fungi (Puccinia spp.), Alternaria spp., Sclerotinia spp., Soil-borne fungal root-knot fungi (Pla smodiophoraophbrassicae), Phytophthora genus, Fusarium genus, Verticillium genus, Pythium genus, Rhizoctonia genus. An anthrax fungus is preferable.

Viruses that cause plant diseases are not particularly limited, but include, for example, tobacco mosaic virus (TMV), red pepper mild mottle virus (PMMoV), tomato mosaic virus (ToMV), melon necrotic spot virus (Melon necrotic spot virus) : MNSV), watermelon green spot mosaic virus (Cucumber green mottle mosaic virus: CGMMV), cucumber green spot mosaic virus (Kyuri green mottle mosaic virus: KGMMV), psyllium mosaic virus (PlAMV, potato X virus (PVX), tobacco mosaic virus (TMV), potato mosaic virus (PVM), and cucumber mosaic virus (CMV), preferably various mosaic viruses and potato X virus, wherein the above listed viruses belong to the genus Potexvirus and the tobamovirus genus. Mosquito Is effective likewise the lignin extract also La genus and click spider genus.

The dosage form of the plant disease control agent can take various forms. Specifically, it can be used as a liquid, powder, granule, emulsion, wettable powder, oil, aerosol, flowable and the like. Preferably, it is a wettable powder.

The plant disease control agent containing the present lignin extract may further contain any component other than the present lignin extract. For example, components such as solvents, carriers, pH adjusters, spreading agents for enhancing the spreading power to plants, surfactants for enhancing the permeability to plants, fertilizers such as minerals for enhancing the fertilizing effect Ingredients, agricultural chemical ingredients, binders, extenders and the like can be mentioned.

In addition, about the addition amount of each component, the addition method, and the formulation method, it can follow a method well-known in this technical field. Those skilled in the art can easily prepare the above-mentioned various preparations containing the lignin extract based on the general description and the specific disclosure of the examples or by appropriately modifying or modifying them as necessary. Can be manufactured. The lignin extract content in the preparation is not particularly limited, and is appropriately selected according to the use of the preparation.

Plant disease control agents can be used as so-called pesticides, as well as plant growth compositions such as various fertilizers and plant nutrients, plant insect control compositions, and plant bodies such as leaves for various purposes. It can also be used by adding to various plant compositions such as a composition for partial or whole application, spraying or spraying. That is, as an embodiment of the present disclosure, various plant growth compositions containing the present lignin extract as a plant disease control component can be mentioned.

The plant disease control agent containing the present lignin extract can suppress infection against the above pathogens by contacting with the target plant. The method for bringing a plant disease control agent into contact with a plant is not particularly limited, and can be appropriately selected according to the dosage form and application. For example, it is applied to a part or the whole of a plant body such as a leaf, a stem or a grain. , Spraying or spraying. Moreover, it can also be made to contact with the medium which grows plants, such as a hydroponic liquid and soil in hydroponics, for example, mixing and dispersion | spreading to this cultivation medium are mentioned. Preferably, it is sprayed on the surface of plants such as leaves and stems.

(Plant disease control method and plant production method)
The present specification describes a method for controlling a plant disease using the plant disease control agent disclosed in the present specification, a plant disease control using the plant disease control agent disclosed in the present specification to grow a plant, or Provide a way to produce. As described above, the plant disease control agent is effective against various plant pathogens. Therefore, it is possible to implement a method for producing various crops such as plants for various uses, for example, food and craft (including fuel use). Furthermore, by harvesting all or a part of such a plant, a safe and disease-free plant can be provided.

For applying a plant disease control agent to various plants to grow plants, methods known to those skilled in the art, such as a growing method according to the target food and the application time of the drug, can be applied.

Hereinafter, the present invention will be specifically described with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Preparation of lignin extract)
In this example, as an example of a herbaceous system, an iron crusher having rust as an iron ion source inside the crushed material (3 kilogram units) of the peach (Gentou (sannin)) of the genus Gingeraceae Using the liquid extracted from the plant without adding water, continuous fermentation at 25 ° C to 35 ° C for 72 hours with resident bacteria ( attached to ghetto ) Then, after the 20-25 mm filter treatment, the color was adjusted with a citric acid shiso solution and filtered again with a filter (manufactured by Millipore) having a pore size of 0.45 μm.

(Evaluation of infection control effect against black spot bacteria)
Using the lignin extraction solution prepared in Example 1, the infection inhibitory effect against black spot bacteria was evaluated by the following method. The lignin extract solution to which the spreading agent was added so that the lignin extract solution was 10, 50 and 100% by mass was sprayed on the Arabidopsis thaliana. Two days after the application of the lignin extract solution, Arabidopsis thaliana was spray-inoculated with black spot bacteria (1 × 10 ⁸ cfu / ml). Three days after inoculation, the inoculated leaves are sampled, and the expression level of rpoD gene, a housekeeping gene of black spot bacterial disease infected with Arabidopsis thaliana, is quantified by quantitative real-time PCR (qRT-PCR) method. The amount of infection of Arabidopsis thaliana was quantified. As a control, a solution containing only the spreading agent not containing the lignin extraction solution was sprayed, and the same quantification was performed. The results are shown in FIG.

As shown in FIG. 1, compared with the control, a 50% lignin extract solution showed a significant disease suppression effect. Further, a stronger disease-suppressing effect was observed in the 100% lignin extract solution. From the above, it was found that the lignin extract solution has a disease control effect against phytopathogenic bacteria.

(Evaluation of infection control effect against cruciferous vegetable anthracnose fungi)
Using the lignin extract solution prepared in Example 1, the infection suppression effect against cruciferous vegetable anthracnose fungi was evaluated by the following method. The lignin extract solution was sprayed on the leaves of Arabidopsis thaliana. Two days after the application of the lignin extract solution, Arabidopsis thaliana was spray-inoculated with the cruciferous vegetable anthracnose fungus (5 × 10 ⁵ spores / ml). Five days after the inoculation, the inoculated leaves were sampled, and the expression level of the actin gene, a housekeeping gene of Brassica anthracnose, infected with Arabidopsis thaliana was quantified by qRT-PCR. The amount of infection was quantified. As a control, only the spreading agent not containing the lignin extraction solution was sprayed, and the same quantification was performed. The results are shown in FIG.

As shown in FIG. 2, the disease control effect was significantly observed in the lignin extract solution as compared with the control. From the above, it was found that the lignin extract solution has a disease control effect on plant-borne fungi.

(Evaluation of induction of resistance-related genes)
Using the lignin extraction solution prepared in Example 1, the resistance-inducing activity effect was evaluated by the following method. The lignin extract solution was sprayed on the leaves of Arabidopsis thaliana. After 24 and 48 hours, the leaves sprayed with the lignin extract solution were sampled, and resistance-related genes AtPR1, AtPDF1.2, AtChi570, AtChi620, AtPR2, AtPR3, and AtVSP2 (Narusaka M, Minami T, Iwabuchi) by qRT-PCR method. C, Hamasaki T, Takasaki S, Kawamura K, Narusaka, Y., Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop., PLoS One. 2015 Jan7; 10 (1): e0115864. : 10.1371 / journal.pone.0115864. ECollection 2015. PubMed, PMID: 25565273; PubMed Central PMCID: PMC4286235). As a control, only the spreading agent not containing the lignin extraction solution was sprayed, and the same quantification was performed. The results are shown in FIG.

As shown in FIG. 3, compared to the control, weak expression induction of resistance-related genes was observed in the lignin extract solution. In particular, the expression of chitinase genes (AtChi570, AtChi620) known to be involved in the infection defense response was observed. From the above, it was found that the lignin extract solution controls bacterial diseases and fungal diseases by a mechanism different from existing fungicidal pesticides.

(Evaluation of this lignin extract against ToMV)
The lignin extraction solution prepared in Example 1 was evaluated using the ToMV (Tomato Mosaic Virus) -Bensamiana Tobacco Evaluation System and ToMV-Tomato Evaluation System. That is, the lignin extract solution was sprayed on the leaves of Bensamiana tobacco, and three days later, ToMV virus was inoculated. For virus inoculation, RNA was transcribed using AmpliCap-Max ^™ T7 High Yield Message Maker Kits (cap analogue: GTP = 4: 1) for 2μg of ToMV (GFP expressing virus) plasmid (pTLBN.G3) The transcript was diluted 20 times and applied to 10 μL of Bensamiana tobacco leaves using carborundum. Three days after the virus inoculation, GFP fluorescence spots (corresponding to ToMV infection and growth site) were counted, the virus infection inhibition rate was tested, and the lignin extract solution was evaluated. The results are shown in FIG. The infection suppression rate was calculated from the following formula.

Infection suppression rate (control value)% = 100- (average number of fluorescent spots of treated plants) / (average number of fluorescent spots of untreated plants) × 100

In addition, RNA was extracted from the leaves 6 days after the inoculation, and the infected RNA was quantified by the qRT-PCR method. The results are also shown in FIG. Further, the amount of viral RNA was also measured on the leaves of tomato (sweet heart) in the same manner as described above except that 10 μl of RNA transcript was applied at a 5-fold dilution. The results are shown in FIG. In these evaluations, lentemin (trade name) and ascorbic acid, which are existing drugs, were used as controls.

Furthermore, the infection suppression rate and the amount of viral RNA were measured using the leaves of Bensamiana tobacco in the same manner as described above for the lignin extract solution and the diluted solution (lignin extract concentration 20%, 50%). The results are shown in FIG.

As shown in FIG. 4, the lignin extraction solution showed an effect equivalent to or better than lentemin registered as an agrochemical or a material (ascorbic acid) registered as a virus control agent. In addition, as shown in FIG. 4, the effect superior to that of lentemin was also shown from the viewpoint of the amount of RNA infection. Moreover, as shown in FIG. 5, also in the tomato leaf, the lignin extract solution exhibited an effect equivalent to or better than that of lentemin. Furthermore, as shown in FIG. 6, even when the stock solution of the lignin extraction solution was diluted 5 times, a sufficient infection-inhibiting effect against ToMV infection was observed.

From the above, it was found that the lignin extract solution exhibits an effective control action against viruses.

Using the lignin extraction solution prepared in Example 1 and the moon peach distilled water obtained by distilling the moon peach leaf as a comparative example and lentemin, the control effect on various viruses was evaluated. According to the evaluation system using the leaves of Bensamiana tobacco described in Example 5, the virus infection suppression rate or the amount of viral RNA was evaluated. The viruses targeted for evaluation were PlAMV of the genus Potexvirus (Plant mosaic virus), PVX of the genus Potex virus (Potato X virus), TMV of the Tobamovirus genus, and PVM of the genus Carlavirus (Potato mosaic virus) ) And CMV (cucumber mosaic virus) of the genus Cucumovirus. These results are shown in FIGS.

As shown in FIG. 7 to FIG. 11, the lignin extract solution showed the same superior effect as that of lentemin for all viruses. It was also effective for plant disease viruses that could cause serious damage such as PVX, PVM and CMV.

The lignin extract solution extracted from sugar cane by lactic acid fermentation for 72 hours according to Example 1 was sprayed on foliage of Bensamiana tobacco according to Example 5, and the infection inhibitory effect of the drug against ToMV was evaluated in the same manner as in Example 5. did.

In addition, 250 ml of water was added to bamboo powder (100 g) and lignin extract solution extracted by lactic acid fermentation for 24 hours according to Example 1 was evaluated for drugs against ToMV in the same manner as described above. It was. The results are shown in FIG.

As shown in FIG. 12, both the sugarcane-derived lignin extract solution and the bamboo-derived lignin extract solution exhibited a high infection suppression rate.

Claims

A plant disease control agent comprising, as an active ingredient, a lignin extract extracted by promoting decomposition of lignin in the lignin-containing material by bringing iron ions into contact with the lignin-containing material.
The plant disease control agent according to claim 1, wherein the lignin extract is extracted from the lignin-containing material by fermenting the lignin material in the presence of iron ions.
The plant disease control agent according to claim 2, wherein the fermentation is performed using lactic acid bacteria.
The plant disease control agent according to any one of claims 1 to 3, wherein the lignin-containing material comprises herbaceous foliage.
The plant disease control agent according to any one of claims 1 to 4, which is a resistance inducer.
The plant disease control agent according to any one of claims 1 to 5, which suppresses infection of plant disease-causing bacteria.
The plant disease control agent according to claim 6, wherein the plant disease bacterium is a black spot bacterial bacterium.
The plant disease control agent according to any one of claims 1 to 7, which suppresses infection of plant disease-causing fungi.
The plant disease controlling agent according to claim 8, wherein the plant disease-causing fungus is a vegetable anthracnose fungus.
The plant disease control agent according to any one of claims 1 to 5, which is used for control of plant disease virus.
The plant pathogenic virus comprises tomato mosaic virus (ToMV), psyllium mosaic virus (PIAMV), potato X virus (PVX), tobacco mosaic virus (TMV), potato M virus (PVM) and cucumber mosaic virus (CMV). The plant disease control agent of Claim 10 which is 1 type, or 2 or more types of viruses selected from the group.
The plant disease control agent according to any one of claims 1 to 4, which is used for control against plant disease-causing bacteria, plant disease-causing fungi and plant disease-causing viruses.
Black spot bacteria, vegetable anthrax, tomato mosaic virus (ToMV), psyllium mosaic virus (PIAMV), potato X virus (PVX), tobacco mosaic virus (TMV), potato M virus (PVM) and cucumber mosaic virus ( The plant disease control agent according to claim 12, which is used for control against CMV).
A plant growth composition containing the plant disease control agent according to any one of claims 1 to 13.
A method for controlling plant diseases using the plant disease control agent according to any one of claims 1 to 13.
A method for producing a plant by controlling a plant disease using the plant disease control agent according to any one of claims 1 to 13.