Agent for improving heat resistance or drought tolerance, salt tolerance, or activity of plants

Abstract

The present invention pertains to a plant heat resistance or drought resistance improving agent, salt tolerance improving agent, and activity improving agent containing: an acetic acid or a salt thereof, or a solvate of one of these; and a malic acid or a salt thereof, or a solvate of one of these.

Description

Technical Field

[0001] The present invention relates to an agent for improving heat resistance or drought tolerance, salt tolerance, and activity of plants.

Background Art

[0002] Currently, due to the explosive increase in population, producing sufficient amounts of food plants has become a global issue. In addition, desertification of land due to the reduction of green spaces and the like has also become a problem. Moreover, the rise in surface temperature based on the global warming phenomenon has also become a problem, and the environmental problems in growing plants are increasing. That is, excessive stress based on global environmental factors in plants often causes problems in plant growth.

[0003] One of the stresses on plants is drought stress. Regarding drought stress, attempts have been made to create genetically modified plants with modified drought stress-responsive genes and to apply chemical or biological regulators that improve drought stress tolerance.

[0004] Patent Document 1 discloses a method for improving drought stress tolerance of plants, which includes a step of applying 10 mM or more of acetic acid to the roots of plants by perfusion and growing the plants under drought stress conditions. In addition, Non-Patent Document 1 discloses a network of drought responses in which plants acquire drought tolerance by stimulating the jasmonic acid signaling pathway and triggering a trigger that dynamically converts metabolic flux from glycolysis to acetic acid synthesis.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, it would be advantageous in plant growth if the tolerance performance of plants against drought stress could be further enhanced. Therefore, the present inventors conducted research using as an index whether it was possible to further improve the drought tolerance of plants. In addition, in plant growth, there are also stresses other than drought stress acting on plants. Therefore, the present inventors also conducted research using as an index whether it was possible to confer tolerance on plants against stresses during plant growth in a high-temperature environment. The problem to be solved by the present invention is to provide a means capable of imparting heat resistance, drought tolerance, salt tolerance, or activity to plants.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors found that the application of both acetic acid and malic acid contributes to the good growth of plants against heat stress and / or drought stress, and completed the present invention.

[0009] That is, the present invention is as follows. (1) An agent for improving heat resistance, drought tolerance, salt tolerance, or activity of plants, containing acetic acid or a salt thereof, or a solvate thereof, and malic acid or a salt thereof, or a solvate thereof. (2) An agent for improving heat resistance, drought tolerance, salt tolerance, or activity of plants, containing acetic acid or a salt thereof, or a solvate thereof, for use in combination with malic acid or a salt thereof, or a solvate thereof. (3) An agent for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants, containing malic acid or a salt thereof, or a solvate thereof, for use in combination with acetic acid or a salt thereof, or a solvate thereof. (4) The heat resistance or drought tolerance improver, salt tolerance improver, or activity improver according to any one of (1) to (3), further containing one or more solvents containing at least water. (5) The heat resistance or drought tolerance improver, salt tolerance improver, or activity improver according to (4), having a pH in the range of 3 to 9. (6) A composition for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants, containing acetic acid or a salt thereof, or a solvate thereof, and malic acid or a salt thereof, or a solvate thereof. (7) A composition for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants, containing acetic acid or a salt thereof, or a solvate thereof, for use in combination with malic acid or a salt thereof, or a solvate thereof. (8) A composition for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants, containing acetic acid or a salt thereof, or a solvate thereof, for use in combination with malic acid or a salt thereof, or a solvate thereof. (9) The composition according to any one of (6) to (8), further containing one or more solvents containing at least water. (10) The composition according to (9), having a pH in the range of 3 to 9. (11) A method for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants, including applying acetic acid or a salt thereof, or a solvate thereof, and malic acid or a salt thereof, or a solvate thereof, to plants, materials for applying to plants, or the soil, medium, or culture solution in which plants grow. (12) Obtaining one or more pieces of information regarding plant growth Based on the one or more pieces of information obtained, determining the conditions for applying the heat resistance or drought resistance improver, salt tolerance improver, or activity improver described in any of (1) to (5) or the composition described in any of (6) to (10) to a plant, a material for applying to a plant, or the soil, medium, or culture solution in which the plant grows. A method for managing the growth of a plant, comprising: (13) A method for improving the heat resistance or drought resistance, salt tolerance, or activity of a plant by using acetic acid or a salt thereof, or a solvate thereof, and malic acid or a salt thereof, or a solvate thereof in combination. (14) A method for improving the heat resistance or drought resistance, salt tolerance, or activity of a plant by using acetic acid or a salt thereof, or a solvate thereof, and malic acid or a salt thereof, or a solvate thereof.

Advantages of the Invention

[0010] According to the present invention, it becomes possible to provide a means capable of imparting heat resistance or drought resistance, salt tolerance, and / or activity to a plant.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments and can be implemented with various modifications.

[0013] The present invention is a heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants, containing acetic acid or its salt, or their solvates, and malic acid or its salt, or their solvates. In the present invention, by applying a heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants to plants, the heat resistance and / or drought tolerance, salt tolerance, or activity of the plants can be improved. The heat tolerance or drought tolerance improver for plants of the present invention may be a heat tolerance improver, a drought tolerance improver, or both a heat tolerance improver and a drought tolerance improver. Further, the heat tolerance improver or drought tolerance improver for plants in the present invention may be a heat tolerance improver or a drought tolerance improver for plants. Furthermore, when the heat tolerance improver or drought tolerance improver for plants in the present invention is an agent capable of improving the heat tolerance and / or drought tolerance of plants, it may be a heat and drought tolerance improver. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention can be used as an agricultural chemical or an agrochemical formulation. In the present invention, by applying the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants to plants, it is possible to impart tolerance to plants against stresses during plant growth in an environment such as a high-temperature environment or a saline soil, which has an unfavorable effect on plant growth. In this specification, imparting tolerance to plants against stresses during plant growth does not mean complete tolerance.

[0014] In the present invention, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants contains acetic acid or its salt, or a solvate thereof (hereinafter, sometimes referred to as "acetic acid etc." in this specification). Further, in the present invention, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants contains malic acid or its salt, or a solvate thereof (hereinafter, sometimes referred to as "malic acid etc." in this specification). Here, acetic acid etc., together with malic acid etc., are not particularly limited as long as they exhibit the characteristics as a heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants. However, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants contains acetic acid etc. as an active ingredient. In the present invention, the active ingredient means a component contained in a heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants, which can improve heat resistance or drought tolerance, salt tolerance, or activity as the characteristics of the agent. Acetic acid and the like used in the present invention may be acetic acid and the like for industrial use or acetic acid and the like for food use. As acetic acid, safe and inexpensive acetic acid such as wood vinegar also used for agricultural purposes or brewing acetic acid produced by fermentation or the like may be used. Using these acetic acid and the like as a heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention is suitable because of high safety and low cost.

[0015] As acetic acid and the like used in the present invention, not only acetic acid itself but also salts of acetic acid may be used. The salt of acetic acid is not particularly limited as long as it can supply acetate ions, and examples include salts with cations. Specifically, sodium acetate, potassium acetate, calcium acetate, magnesium acetate, zinc acetate ions, and ammonium acetate etc. are included. In ammonium acetate, instead of ammonium ions, an acetate salt with substituted or unsubstituted ammonium may be used. Among them, as the salt of acetic acid, potassium acetate, sodium acetate, ammonium acetate, magnesium acetate, and calcium acetate can be preferably used. Also, a liquid fertilizer obtained by dissolving eggshells in acetic acid can be used as acetic acid and the like. In the present invention, acetic acid and acetate salts may be used as a mixture. The mixture of acetic acid and acetate salts may be a mixture of acetic acid itself and acetate salts, or a cation source that forms a salt with acetate ions may be added to acetic acid, for example, a mixed solution of acetic acid and acetate salts generated by a neutralization reaction as an aqueous solution. In this case, acetic acid may be completely neutralized, or the cation source may be added in an amount such that a part of acetic acid is neutralized. Examples of the aqueous solution containing acetate salts include acetate buffer solutions etc.

[0016] As the acetic acid or the like used in the present invention, it may be a solvate of acetic acid or a solvate of acetate. The solvent capable of forming a solvate of acetic acid or its salt is not particularly limited, and examples thereof include water and organic solvents such as alcohol, dimethyl sulfoxide (DMSO), ethanolamine, and ethyl acetate. The alcohol may be, for example, a lower alcohol or a higher alcohol. The lower alcohol is not particularly limited, and examples thereof include saturated or unsaturated linear or branched alkyl alcohols having 1 to 6 carbon atoms such as methanol, ethanol, or 2-propanol (isopropyl alcohol). The higher alcohol is not particularly limited, and examples thereof include saturated or unsaturated linear or branched alkyl alcohols having 7 or more carbon atoms such as 1-heptanol or 1-octanol. The solvent for forming the solvate may be a single solvent or two or more solvents. Regarding the solvate, for example, when used as an aqueous solution of the solvate, the form of acetic acid or the like in the aqueous solution is not particularly limited and may not be solvated.

[0017] The acetic acid or the like used in the present invention is acetic acid or its salt, or a solvate thereof, but may be one or more compounds selected from the group consisting of acetic acid or its salt, or a solvate thereof. The compounds included in the group consisting of acetic acid or its salt, or a solvate thereof can be appropriately selected in any combination from the compounds described above for acetic acid, the salt of acetic acid, or a solvate thereof. In the agents, compositions, etc. of the present invention, acetic acid, etc. may be present as acetic acid and / or a salt of acetic acid. Examples of the salt of acetic acid may include potassium acetate, sodium acetate, ammonium acetate, magnesium acetate, and calcium acetate, and may be selected from any combination thereof. However, it may also be potassium acetate, sodium acetate, or ammonium acetate, or potassium acetate and sodium acetate, or magnesium acetate and calcium acetate.

[0018] In the present invention, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants contains malic acid, etc. Malic acid, etc. is not particularly limited as long as it exhibits the characteristics as a heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants. However, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants contains malic acid, etc. as an active ingredient. Malic acid, etc. used in the present invention is not particularly limited and may be malic acid, etc. that can be used in any application, or may be malic acid, etc. for industrial or food applications. Using these malic acid, etc. as the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention is suitable because of its high safety and low cost.

[0019] As the malic acid, etc. used in the present invention, not only malic acid itself but also a salt of malic acid may be used. The salt of malic acid is not particularly limited as long as it can supply malic acid ions, but examples include salts with cations. Specifically, sodium malate, potassium malate, calcium malate, magnesium malate, zinc malate ions, and ammonium acetate, etc. may be mentioned. In ammonium malate, instead of ammonium ions, it may be a salt of malic acid with substituted or unsubstituted ammonium. Among them, as the salts of malic acid, potassium malate, sodium malate, ammonium malate, magnesium malate, and calcium malate can be preferably used. In addition, it is also possible to use a liquid fertilizer obtained by dissolving eggshells in apple vinegar as malic acid or the like. In the present invention, malic acid and malate may be used as a mixture. As the mixture of malic acid and malate, it may be a mixture of malic acid itself and a malate, or a cation source that forms a salt with malate ions may be added to malic acid, and for example, it may be a mixed solution of malic acid and malate produced by a neutralization reaction as an aqueous solution. In this case, malic acid may be completely neutralized, or a cation source may be added in an amount such that a part of malic acid is neutralized. Examples of the aqueous solution containing malate include a malic acid buffer solution.

[0020] As the malic acid or the like used in the present invention, a solvate of malic acid or a solvate of malate may be used. The solvent capable of forming a solvate of malic acid or its salt is not particularly limited, and examples thereof include water and organic solvents such as alcohol, dimethyl sulfoxide (DMSO), ethanolamine, and ethyl acetate. The alcohol may be, for example, a lower alcohol or a higher alcohol. The lower alcohol is not particularly limited, and examples thereof include saturated or unsaturated linear or branched alkyl alcohols having 1 to 6 carbon atoms such as methanol, ethanol, or 2-propanol (isopropyl alcohol). The higher alcohol is not particularly limited, and examples thereof include saturated or unsaturated linear or branched alkyl alcohols having 7 or more carbon atoms such as 1-heptanol or 1-octanol. The solvent forming the solvate may be a single solvent or two or more solvents. Regarding the solvate, for example, when used as an aqueous solution of the solvate, the form of malic acid or the like in the aqueous solution is not particularly limited, and it may not be solvated.

[0021] As the malic acid or the like used in the present invention, it is malic acid or its salt, or a solvate thereof, but it may be one or more compounds selected from the group consisting of malic acid or its salt, or a solvate thereof. As the compounds included in the group consisting of malic acid or its salt, or a solvate thereof, any combination can be appropriately selected from the compounds described above for malic acid, a salt of malic acid, or a solvate thereof. In the agent, composition, etc. of the present invention, malic acid or the like may be present as malic acid and / or a salt of malic acid. As the salt of malic acid, it may be potassium malate, sodium malate, ammonium malate, magnesium malate, calcium malate, and may be selected from any combination thereof, but it may be potassium malate, sodium malate, ammonium malate, or it may be potassium malate, sodium malate, or it may be magnesium malate, calcium malate.

[0022] The salt of acetic acid and the salt of malic acid may have the same cation source, or when using salts of different cation sources respectively, for example, in a solution (preferably an aqueous solution), the cation source may exist in the form of a salt with acetic acid or malic acid in their respective ratios according to their properties (however, if dissociated, it is not recognized as a specific salt).

[0023] In the present invention, as a heat resistance improver, a drying resistance improver, a salt resistance improver, or an activity improver, it may contain acetic acid or the like for use in combination with malic acid or the like, or it may contain malic acid or the like for use in combination with acetic acid or the like. The combined use of acetic acid and malic acid, etc. means that acetic acid and malic acid, etc. may be applied to plants as a single mixture, or a composition containing acetic acid and a composition containing malic acid may be applied to plants simultaneously or separately. The desired effect may be expected by applying acetic acid, etc. to plants and combining it with malic acid, etc. possessed by the plants, or by applying malic acid, etc. to plants and combining it with acetic acid, etc. possessed by the plants.

[0024] In the present invention, "heat resistance improver" and "improving heat resistance" mean that by applying the heat resistance improver for plants of the present invention to a population of plants, heat stress, which is an unfavorable influence on plant growth such as inability to grow (death), poor growth (for example, albino or yellowing of the whole plant or its parts (such as leaves or flowers), reduction of root length or number of leaves, or lodging), reduction of growth rate, or reduction of plant body weight or crop yield, can be substantially reduced. The confirmation of being a "heat resistance improver" or "improving heat resistance" can be confirmed by comparing with a control population of plants to which the heat resistance improver for plants of the present invention is not applied. Usually, it can be confirmed by an improvement in the survival rate of 30% or more, preferably 50% or more, 60% or more, 70% or more, more preferably 80% or more, still more preferably 85% or more, and particularly preferably 90% or more.

[0025] In this specification, "heat stress" means being placed in an environment with a temperature of 60 degrees or less, and the temperature may be an environment of 50°C or less or 45°C or less. Also, usually, considering that the constant temperature is about 25°C, "heat stress" preferably means an environment of 30°C or more, and more preferably an environment of 35°C or more. In the present invention, the confirmation of being a "heat resistance improver" or "improving heat resistance" is not particularly limited, but may be evaluated by the following means, and more specifically, may be evaluated by the method described in the examples. For example, a target plant is grown in a certain amount of a test solution (including water and optionally normal nutrient components) under normal growth conditions, i.e., non-thermal stress conditions. After growing for a certain period, after applying a heat resistance improver, it is grown under heat stress conditions, and then grown under normal growth conditions, i.e., non-thermal stress conditions, and the survival rate of the target plant can be evaluated by measuring it. As the heat stress conditions, it may be a condition of standing still for 30 minutes or more under the temperature conditions of the above-mentioned "heat stress", and the standing time may be set according to the temperature conditions. Under the heat stress conditions, it is preferably a condition of standing still under constant humidity conditions, especially without water supply.

[0026] In the present invention, "drought tolerance improver" and "improve drought tolerance" mean that by applying the drought tolerance improver of the plant of the present invention to a population of plants, growth inability (death), poor growth (for example, albino or yellowing of the whole plant or its part (for example, leaf or flower), reduction of root length or number of leaves, or lodging), reduction of growth rate, or reduction of plant body weight or crop yield, which are unfavorable effects in plant growth, can be substantially reduced. The confirmation of being a "drought tolerance improver" or "improving drought tolerance" can be confirmed by comparing with a control population of plants to which the drought tolerance improver of the plant of the present invention is not applied. Usually, it can be confirmed that the survival rate is improved by 30% or more, preferably 50% or more, 60% or more, 70% or more, more preferably 80% or more, still more preferably 85% or more, and particularly preferably 90% or more.

[0027] In this specification, "drought stress" means being placed in a low humidity environment. Although not particularly limited as the cause of drought stress, in the present invention, it may be drought stress based on temperature conditions, and drought stress accompanied by high temperature without addition of water can be mentioned. Regarding the change in humidity, it affects the change in the amount of water in the plant individual and the soil. Therefore, when the humidity is high, the effect of improving heat resistance and drought tolerance is more exerted. Also, when the humidity is high and heat or dry stress is gradually applied, the effect of mixing malic acid or the like is more exerted. That is, the effect is more exerted at a humidity at which heat and / or dry stress is likely to be applied. In the present invention, the confirmation of being a "drought tolerance improver" or "improving drought tolerance" is not particularly limited, but may be evaluated by the following means, and more specifically, may be evaluated by the method described in the examples. For example, a target plant is grown in a certain amount of a test solution (water and optionally normal nutrient components) under normal growth conditions, that is, under non-drought stress conditions. After growing for a certain period, after applying a drought tolerance improver, it is grown under drought stress conditions, and then grown under normal growth conditions, that is, under non-drought stress conditions, and the survival rate of the target plant is measured for evaluation. As the drought stress conditions, it may be a condition of standing still for 30 minutes or more under the humidity conditions of the above "drought stress", and the standing time may be set according to the type and concentration conditions of the drought tolerance improver. In the drought stress conditions, it is preferably a condition of standing still without particularly supplying water under low humidity conditions.

[0028] In the present invention, the heat tolerance or drought tolerance improver for plants may be a heat tolerance improver for plants, a drought tolerance improver for plants, or both a heat tolerance improver for plants and a drought tolerance improver for plants. In the present invention, the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants may be a composition containing acetic acid or the like and malic acid or the like, and may be a composition for improving the heat tolerance or drought tolerance, salt tolerance, or activity of plants. That is, in this specification, "the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants" can also be understood to have the same meaning as "the composition for improving the heat tolerance or drought tolerance, salt tolerance, or activity of plants".

[0029] In each aspect of the present invention, the effects of the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants may include the effects on the growth of plants themselves, for example, the promotion of growth such as the elongation of the stems and leaves or roots, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the plant body weight or crop yield, greening, or the promotion of tillering.

[0030] The heat tolerance or drought tolerance improver for plants of the present invention may be used for the activation of plants as follows, by utilizing or without utilizing the properties of heat tolerance or drought tolerance. Further, in the present invention, it may be an activity improver for plants that contains acetic acid and the like and malic acid and the like and exhibits the following actions. 1) Promotion of root elongation and improvement of root survival rate 2) Increase in nutrient absorption efficiency 3) Induction of flower buds, promotion of flowering, and increase in fruit set 4) Accumulation of components such as sugars 5) Increase in water-saving effect 6) Inductive effect of callus formation 7) Improvement of the size of the plant body, especially the elongation or hypertrophy of the above-ground part and the underground part 8) Repair of wounds In the present invention, the activity improver for plants may exhibit the actions as described in 1) to 8) above, or may have the growth promotion effects such as the elongation of the stems and leaves or roots, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the plant body weight or crop yield, greening, or the promotion of tillering. That is, in the present invention, by applying acetic acid and the like and malic acid and the like to plants, it is also possible to use them as plant activators or vitality enhancers. As a plant activator or vitality enhancer, it means having advantages in the growth of plants. In the present invention, by applying acetic acid and the like and malic acid and the like to plants, the plants can be given vitality. Further, in the present invention, by applying acetic acid and the like and malic acid and the like to plants, the growth of plants can be promoted, and it may also be used as a growth promoter. In the present invention, it may also be used as a plant salt tolerance improver containing acetic acid and the like and malic acid and the like.

[0031] In the present invention, by applying acetic acid and the like and malic acid and the like to plants, heat resistance and / or drought tolerance can be improved against heat stress and / or drought stress. In the present invention, by applying acetic acid and the like and malic acid and the like to plants, salt tolerance can be improved against salt stress. Furthermore, in the present invention, by applying acetic acid and the like and malic acid and the like to plants, the activity of the plants can be improved. The plant heat resistance or drought tolerance improver, salt tolerance improver, or activity improver in the present invention, or the composition for improving plant heat resistance or drought tolerance, salt tolerance, or activity can be used as an agrochemical formulation or pesticide to promote plant growth.

[0032] In the present invention, the plant heat resistance or drought tolerance improver, salt tolerance improver, or activity improver may be in any form such as a solid (e.g., powder or granule), a liquid (e.g., solution or suspension), or a gas. In the present invention, it is preferable to use the plant heat resistance or drought tolerance improver, salt tolerance improver, or activity improver in the form of a liquid such as a solution or suspension. In the present invention, when the plant heat resistance or drought tolerance improver, salt tolerance improver, or activity improver is used as a solution, it may be in a liquid state or may be used as a liquid adjusted as needed when applied. In the present invention, when used as a heat and drought tolerance improver, the content described as the plant heat resistance or drought tolerance improver of the present invention is equally applicable. The same applies when used as a plant salt tolerance improver or a plant activity improver.

[0033] In the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention, acetic acid and the like, and malic acid and the like may be preferably used alone with acetic acid and malic acid as active ingredients, or may be used in combination with one or more agriculturally acceptable ingredients. It is possible to use acetic acid and the like and malic acid, or acetic acid and malic acid and the like. One or two or more kinds of acetic acid and the like may be used, and one or two or more kinds of malic acid and the like may be used. That is, two or more kinds of acetic acid and the like may be used, two or more kinds of malic acid and the like may be used, acetic acid and one or more kinds of acetic acid and the like other than acetic acid and malic acid and one or more kinds of malic acid and the like other than malic acid may be used, acetic acid and malic acid and one or more kinds of malic acid and the like other than malic acid may be used, acetic acid and one or more kinds of acetic acid and the like other than acetic acid and malic acid may be used, or acetic acid and malic acid may be used. Furthermore, one or more kinds of acetic acid and the like other than acetic acid and one or more kinds of malic acid and the like other than malic acid may be used. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention can be formulated into various dosage forms commonly used in the art according to the desired application method as an agricultural chemical or agrochemical formulation. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention may further contain one or more agriculturally acceptable ingredients in addition to acetic acid and the like and malic acid and the like. Examples of agriculturally acceptable ingredients include solvents or carriers, excipients, binders, solubilizers, stabilizers, thickeners, swelling agents, lubricants, surfactants, oily liquids, buffers, bactericides, antifreezes, defoamers, colorants, antioxidants, additives, fertilizers, and further drugs. Examples of agriculturally acceptable solvents or carriers include water, mineral oil fractions such as kerosene or diesel oil, oils derived from plants or animals, cyclic or aromatic hydrocarbons (e.g., paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, or alkylated benzenes or their derivatives), alcohols (e.g., methanol, ethanol, propanol, butanol, ethylene glycol, glycerol or cyclohexanol), ketones (e.g., cyclohexanone), or amines (e.g., N-methylpyrrolidone), or agriculturally acceptable solvents or liquid carriers such as mixtures thereof. More preferably, it contains at least one solvent containing water. As fertilizers, organic fertilizers such as oil cakes or cow dung, or inorganic fertilizers such as ammonium sulfate, calcium cyanamide or fused phosphorus are preferred.

[0034] When the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention further contains at least one solvent containing water, the pH of the solution of the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention is preferably in the range of 3 to 9. Within this range, the lower limit value of the pH may be 4 or more, 5 or more, 6 or more, and the upper limit value of the pH may be 8.5 or less, 8 or less, 7.5 or less, 7 or less. The pH range is more preferably in the range of 4 to 8, still more preferably in the range of 5 to 7.5, and even more preferably in the range of 5 to 7. The pH range may be 5 to 6 or 6 to 7. The pH of the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants is preferably within the above range at the time of application to the target plants. The pH of the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention may be adjusted with an acid or an alkali. For example, it may be adjusted using an acid, an alkali or a buffer such as hydrochloric acid, nitric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, aqueous ammonia or ammonium acetate. In the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention, it is preferable that the pH is within the above range at the time of application to the target plant. However, even if it is not within the above range at the time of application to the target plant, it may be adjusted to a pH within the above range by utilizing the pH buffering action of the soil, medium, or culture solution to be applied.

[0035] When the heat resistance or drought tolerance improver, salt tolerance improver for plants of the present invention further contains one or more solvents containing at least water, the ratio of acetic acid, etc. to the total volume in the heat resistance or drought tolerance improver, salt tolerance improver for plants of the present invention is preferably in the range of 0.01 to 0.5% by volume. Within this range, the lower limit value of the ratio may be 0.05% by volume or more, 0.075% by volume or more, 0.09% by volume or more, 0.1% by volume or more, and the upper limit value of the ratio may be 0.25% by volume or less, 0.2% by volume or less. The range of the ratio of acetic acid, etc. is more preferably in the range of 0.05 to 0.5% by volume, further preferably in the range of 0.075 to 0.25% by volume, even more preferably in the range of 0.09 to 0.2% by volume, and particularly preferably in the range of 0.1 to 0.2% by volume.

[0036] When the heat resistance or drought tolerance improver, salt tolerance improver for plants of the present invention further contains one or more solvents containing at least water, the concentration of acetic acid, etc. in the heat resistance or drought tolerance improver, salt tolerance improver for plants of the present invention is preferably in the range of 1 to 100 mM. Within this range, the lower limit value of the concentration may be 2 mM or more, 5 mM or more, 7.5 mM or more, 9 mM or more, 10 mM or more, and the upper limit value of the concentration may be 50 mM or less, 40 mM or less, 30 mM or less. The range of the ratio of acetic acid, etc. is more preferably in the range of 1 to 50 mM, further preferably in the range of 7.5 to 50 mM, even more preferably in the range of 9 to 40 mM, and particularly preferably in the range of 10 to 40 mM.

[0037] When the heat resistance or drought tolerance improver or salt tolerance improver for plants of the present invention further contains one or more solvents containing at least water, the concentration of malic acid or the like in the heat resistance or drought tolerance improver or salt tolerance improver for plants of the present invention is preferably in the range of 1 to 100 mM. Within this range, the lower limit value of the concentration may be 2 mM or more, 5 mM or more, 7.5 mM or more, 9 mM or more, 10 mM or more, and the upper limit value of the concentration may be 50 mM or less, 40 mM or less, 30 mM or less. The range of the ratio of malic acid or the like is more preferably in the range of 1 to 50 mM, still more preferably in the range of 7.5 to 50 mM, even more preferably in the range of 9 to 40 mM, and particularly preferably in the range of 10 to 40 mM.

[0038] When acetic acid or the like and malic acid or the like in the present invention are used in combination or as a mixture for plant activation, in addition to the content described as the concentration (volume% or mM) of acetic acid or the like and malic acid or the like when used as a heat resistance or drought tolerance improver or salt tolerance improver for plants, the concentration of malic acid or the like may be in the range of 1 to 100 mM, but may also be a concentration of 1 mM or less. When used for plant activation, the concentration of malic acid or the like may exceed 0 mM and be within the range of 100 mM. The lower limit value may be set from a range exceeding 0 mM to 1 mM or less, or may be the lower limit value described above as a range of 1 mM or more. When the lower limit value of the concentration is in the range of 1 mM or less, the concentration is on the order of 10 -5 of the order of concentration, 10 -4 of the order of concentration, 10 -3 of the order of concentration, 10 -2 of the order of concentration, 10 -1 or may be the lower limit value of the order of concentration.

[0039] When the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention further contains one or more solvents containing at least water, it is preferable that the pH is within the above range and the concentration of acetic acid or the like and malic acid or the like is within the above range. The pH and the concentration can be appropriately selected within the above-described range.

[0040] The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver of the plant of the present invention may contain one or more additional agents. The agent is not particularly limited, and examples thereof include auxin, gibberellin, cytokinin, 2-chloroethylphosphonic acid (trade name: Ethrel (registered trademark)), carbide, benzyladenine, brassinosteroid, strigolactone, and jasmonic acid. Further, the agent may be a plant hormone, a plant chemical regulator, a pesticide, or the like that is usually used in the technical field.

[0041] In the present invention, the target plant is not particularly limited, and for example, it is selected from angiosperms and gymnosperms. The target plant is not particularly limited, and examples thereof include asteraceae plants such as chrysanthemum and gerbera, solanaceae plants such as potato, tomato and eggplant, brassicaceae plants such as rapeseed and cabbage, poaceae plants such as rice, corn, wheat, sugarcane and barley, leguminous plants such as soybean, umbelliferae plants such as carrot, lamiaceae plants such as basil, mint and rosemary, convolvulaceae plants such as morning glory, salicaceae plants such as poplar, euphorbiaceae plants such as cassava, tapioca and jatroph, convolvulaceae plants such as sweet potato, rutaceae plants such as orange and lemon, rosaceae plants such as cherry and rose, orchidaceae plants such as cymbidium, gentianaceae plants such as gentian, primulaceae plants such as cyclamen, violaceae plants such as pansy, liliaceae plants such as lily, chenopodiaceae plants such as sugar beet, vitaceae plants such as grape, cupressaceae plants such as sugi and hinoki, oleaceae plants such as olive and osmanthus, and pinaceae plants such as Japanese red pine. Further, it may be a plant used in the examples. The target plant may be not only the whole plant (i.e., a complete plant body), but also a part of the plant such as a plant tissue or organ (for example, cut flowers, or vegetative propagation organs such as rhizomes, tubers, bulbs or runners), cultured cells and / or callus. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention can be applied to the whole plant or a part thereof (e.g., the whole or a part of seeds, seedlings, or mature plants) at any growth stage including before or after germination of the plant.

[0042] The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention may be applied not only to the plant itself but also to materials for applying to plants or to the soil, medium, or culture solution in which the plant grows. The present invention also relates to a method for improving the heat tolerance or drought tolerance, salt tolerance, or activity of plants, which includes applying acetic acid etc. and malic acid etc., preferably acetic acid and malic acid in an agriculturally effective amount, to plants, materials for applying to plants, or the soil, medium, or culture solution in which the plant grows. In this case, acetic acid etc. and malic acid etc., preferably acetic acid and malic acid in an agriculturally effective amount, may be applied as a mixture. In the method of the present invention, acetic acid etc., malic acid etc. and other aspects to be applied are as described herein as a heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants. The materials for applying to plants are not particularly limited, and examples include various materials commonly used in the art, such as water and fertilizers.

[0043] The dosage form of the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention is not particularly limited and may be a dosage form such as emulsion, wettable powder, liquid agent, aqueous solvent, powder, powder agent, paste agent, or granule, etc., commonly used in the art. In each aspect of the present invention, acetic acid and the like are contained or applied in an agriculturally effective amount. In each aspect of the present invention, the agriculturally effective amount of acetic acid and the like is, for example, in the range of 0.01 to 0.5% by mass, usually in the range of 0.05 to 0.5% by mass, typically in the range of 0.075 to 0.25% by mass, more typically in the range of 0.09 to 0.2% by mass, and particularly in the range of 0.1 to 0.2% by mass, based on the total mass at the time of application. For example, when the heat resistance improver, drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention is in a liquid dosage form, the agriculturally effective amount of acetic acid and the like is, for example, in the range of 0.01 to 0.5% by volume, usually in the range of 0.05 to 0.5% by volume, typically in the range of 0.075 to 0.25% by volume, more typically in the range of 0.09 to 0.2% by volume, and particularly in the range of 0.1 to 0.2% by volume, based on the total volume at the time of application.

[0044] In each aspect of the present invention, malic acid and the like are contained or applied in an agriculturally effective amount. In each aspect of the present invention, the agriculturally effective amount of malic acid and the like is, for example, in the range of 0.01 to 0.5% by mass based on the total mass at the time of application, usually in the range of 0.05 to 0.5% by mass based on the total mass at the time of application, typically in the range of 0.075 to 0.25% by mass based on the total mass at the time of application, more typically in the range of 0.09 to 0.2% by mass based on the total mass at the time of application, and particularly in the range of 0.1 to 0.2% by mass based on the total mass at the time of application. For example, when the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver of the plants of the present invention is in a liquid dosage form, the agriculturally effective amount of malic acid and the like is, for example, in the range of 0.01 to 0.5% by volume based on the total volume at the time of application, usually in the range of 0.05 to 0.5% by volume based on the total volume at the time of application, typically in the range of 0.075 to 0.25% by volume based on the total volume at the time of application, more typically in the range of 0.09 to 0.2% by volume based on the total mass at the time of application, and particularly in the range of 0.1 to 0.2% by volume based on the total mass at the time of application.

[0045] In plant cultivation, based on the growth state of the plants, by appropriately setting the conditions for applying the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver of the plants of the present invention to the plants, the materials for applying to the plants, or the soil, medium or culture solution in which the plants grow, it is possible to stably manage the growth of the plants while improving the heat resistance or drought tolerance, salt tolerance, and activity in the plants. The present invention acquiring one or more pieces of information related to the growth of plants (hereinafter, also referred to as the "information acquisition step"), determining the conditions for applying the heat resistance or drought tolerance improver, salt tolerance improver, or activity improver of the plants of the present invention to the plants, the materials for applying to the plants, or the soil, medium or culture solution in which the plants grow based on the one or more pieces of information acquired (hereinafter, also referred to as the "application condition determination step"), also relates to a method for managing the growth of plants, including

[0046] The one or more pieces of information regarding the growth of plants obtained in the information acquisition step are not particularly limited. For example, under heat stress, drought stress, salt stress conditions, or even in the absence of these conditions, various information regarding the promotion effect of growth such as the elongation of the stems and leaves or roots, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the plant weight or crop yield, greening, or the promotion of tillering, and various information regarding unfavorable effects on plant growth such as growth inability (death), poor growth (for example, albinism or chlorosis of the whole plant or its parts (for example, leaves or flowers), the decrease in root length or the number of leaves, or lodging), the decrease in the growth rate, or the decrease in the plant weight or crop yield can be mentioned. By acquiring the one or more pieces of information exemplified above, the growth state of plants can be evaluated.

[0047] The conditions for applying the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention determined in the application condition determination step are appropriately set so that the heat tolerance or drought tolerance, salt tolerance, or activity of plants can be improved by carrying out the application. The conditions determined in this step are not particularly limited. For example, one or more conditions selected from the group consisting of the composition, pH, application amount, and application time of the heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention, and the content of acetic acid or malic acid contained as an active ingredient can be mentioned. The specific values of these conditions may be appropriately set from the ranges exemplified in this specification.

[0048] In the present invention, in the method for managing plant growth, the number and order of the information acquisition step and the application condition determination step are not particularly limited. For example, the information acquisition step and the application condition determination step may be each carried out once in this order, or the information acquisition step, the application condition determination step, and then a further information acquisition step may be carried out in this order, or a combination of the information acquisition step and the application condition determination step may be repeatedly carried out a plurality of times, such as the first information acquisition step, the first application condition determination step, the second information acquisition step, and the second application condition determination step. In this specification, the application of the heat resistance improver, drought tolerance improver, salt tolerance improver, or activity improver for plants of the present invention can also be understood as replacing it with the application of acetic acid and the like and malic acid and the like. The application of acetic acid and the like and malic acid and the like may be carried out by the method described as "using acetic acid and the like and malic acid and the like in combination" in this specification.

[0049] Further, the present invention may also relate to a method for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants by applying acetic acid and the like and malic acid and the like. Furthermore, the present invention may also relate to acetic acid and the like and malic acid for improving the heat resistance, drought tolerance, salt tolerance, or activity of plants.

Examples

[0050] Hereinafter, the present invention will be described more specifically using examples. However, the technical scope of the present invention is not limited to these examples.

[0051] <Heat and Drought Tolerance Test 1> After germination of Lactuca sativa L. (Sanchu, Asteraceae, Lactuca) using vinyl pots in a simply created incubator, it was grown for 3 weeks under the conditions of a temperature of 22°C and a humidity of 40 - 50%. During the cultivation period, watering was carried out by perfusion of 100 mL / 3 days of water per plant. The one where 50 mL of water was perfused at the base of the plant and absorbed over 24 hours was designated as the water treatment group 1, and the one where 50 mL of a 10 mM acetic acid aqueous solution was perfused at the base of the plant and absorbed over 24 hours was designated as the acetic acid treatment group 1. Subsequently, the vinyl pots were transferred to another tray, without watering, and left standing in an incubator under continuous light, at a temperature of 42°C and a humidity of 40%. The vinyl pots were taken out of the incubator, and the state of the kaki tangerine was observed, and the survival rate of the kaki tangerine was measured. The survival rate was calculated by counting the number of non-withered kaki tangerine seedlings. The results after standing for 5 days are shown in Fig. 1A. The survival rates of both the water treatment group 1 and the acetic acid treatment group 1 after standing for 5 days were 100%. However, as shown in Fig. 1A, in the water treatment group 1, although the plants did not wither, the degree of wilting was clearly more severe compared to the acetic acid treatment group 1. Subsequently, the survival rate after standing for 7 days was 100% in the acetic acid treatment group 1 and 0% in the water treatment group 1.

[0052] <Heat Drying Resistance Test 2> The survival rate of the kaki tangerine was measured in the same manner as in the heat drying resistance test 1. In this test, the conditions were set at a temperature of 50°C and a humidity of 10%. Also, 50 mL of water was poured into the base of the plant and allowed to be absorbed over 24 hours, which was designated as the water treatment group 2. An aqueous solution containing 10 mM acetic acid and 10 mM malic acid was poured into the base of the plant in a volume of 50 mL and allowed to be absorbed over 24 hours, which was designated as the treatment group 2. After standing for 3 days, the vinyl pots were taken out of the incubator, the state of the kaki tangerine was observed, and the survival rate of the kaki tangerine was measured. The survival rate in the treatment group 2 was 100%, and in the water treatment group 2 it was 0%. The results are shown in Fig. 1B. In the following tests as well, the growth of kaki tangerine and tomato was carried out under continuous light. The illuminance in the incubator at a temperature of 42°C was set at approximately 5000 lux, except that it was set at approximately 3300 lux.

[0053] Comparing the results of the water treatment group 1 and the water treatment group 2, since the plants in the water treatment group 2 were completely withered, it can be seen that the conditions in the water treatment group 2 are more severe survival environment conditions for the plants (see Figs. 1A and B). From the results of the acetic acid treatment group 1, it can be seen that the high-temperature drying tolerance performance of the plant body is enhanced by acetic acid treatment. However, from the results of treatment group 2 grown under more severe environmental conditions, it can be seen that by further adding malic acid in addition to acetic acid and applying it, the high-temperature drying tolerance performance of acetic acid is further enhanced.

[0054] <Thermal Drying Tolerance Test 3> In a simply created incubator, using vinyl pots, after tomato (variety: Momotaro, Solanum lycopersicum of the Solanaceae family) germinated, it was grown for 3 weeks under the conditions of a temperature of 22°C and a humidity of 40 - 50%. During the cultivation period, watering was carried out by irrigating 100 mL / 3 days of water per plant. The one where 50 mL of water was irrigated at the base of the plant and absorbed over 24 hours was taken as the water treatment group 3, the one where 50 mL of a 20 mM acetic acid aqueous solution was irrigated at the base of the plant and absorbed over 24 hours was taken as the acetic acid treatment group 3. Also, the one where an aqueous solution containing 10 mM acetic acid and 10 mM malic acid was irrigated at the base of the plant and absorbed over 24 hours was taken as the treatment group 3. After that, the vinyl pots were transferred to another tray, watering was not carried out, and they were left standing in the incubator under the conditions of continuous light, a temperature of 50°C, and a humidity of 10%. After standing for 3 days and 4 days, the vinyl pots were taken out of the incubator and the state of the tomatoes was observed, and the survival rate of the tomatoes was measured. The survival rate was calculated by counting the number of seedlings of the tomatoes that had not withered. The results after standing for 3 days are shown in Figure 2. The survival rate of the water treatment group 3 after standing for 3 days was 0%, and the survival rates of both the acetic acid treatment group 3 and the treatment group 3 were 100%. However, the survival rates of the water treatment group 3 and the acetic acid treatment group 3 after standing for 4 days were 0%, and the survival rate in the treatment group 3 was 100%. It was found that the ability to enhance high-temperature drying tolerance was strengthened in the order of the water treatment group 3, the acetic acid treatment group 3, and the treatment group 3 with acetic acid and malic acid.

[0055] <Activation Test 1> After purchasing Peperomia albovittata (Peperomia albovittata, Piperaceae, Sadazou genus) that was divided into shares during the same period, it was grown for 2 days in a simply constructed incubator under the conditions of a temperature of 22°C and a humidity of 40 - 50%. During the cultivation period, watering was carried out by irrigating 50 mL of water per plant per day. The one where 50 mL of water was irrigated at the base of the plant and absorbed over 24 hours was designated as water treatment group 1, the one where 50 mL of a 20 mM acetic acid aqueous solution was irrigated at the base of the plant and absorbed over 24 hours was designated as acetic acid treatment group 1, and the one where 50 mL of an aqueous solution containing 20 mM acetic acid + 0.075 μM malic acid was irrigated at the base of the plant and absorbed over 24 hours was designated as treatment group 1. After that, it was transferred to a vinyl pot in a separate tray and left standing in the incubator under the conditions of continuous light, a temperature of 22°C, and a humidity of 40%. After standing for 3 weeks, the vinyl pot was taken out of the incubator and the state of the tomato was observed. In each individual Peperomia, the number of flower buds formed at the early flowering stage and the number of flower buds after flowering that had grown to 3 cm or more in length were counted. The results after standing for 3 days are shown in Figure 3. In water treatment group 1 after standing for 3 weeks, the number of flower buds formed before flowering was 3. In acetic acid treatment group 1, the number of flower buds formed before flowering was 5. The number of flower buds after flowering that had grown to 3 cm or more in both water treatment group 1 and acetic acid treatment group 1 was 0. However, in treatment group 1, the number of flower buds formed before flowering was 12, and the number of flower buds after flowering that had grown to 3 cm or more was 6. It was found that treatment group 1 with acetic acid and malic acid had enhanced induction and growth of flower buds compared to each of acetic acid treatment group 1 and water treatment group 1.

[0056] <Activation Test 2> Spinacia oleracea (Spinacia oleracea, Chenopodiaceae, Spinach genus) germinated from direct-sown seeds in a field in a vinyl house was used. During the test period, watering of the plants was carried out twice a day, at 6 am and 4 pm, by an automatic control irrigation system. 50 mL of the test solutions shown below was irrigated at the base of each plant to the seedlings 2 weeks after germination (with 3 - 5 true leaves). 50 mL of the test solution was irrigated again 2 weeks and 4 weeks after the first irrigation treatment (for a total of 3 irrigations). Harvesting was carried out 45 days after the first perfusion treatment, and the wet weights of 20 individuals were measured for each plot. The average weight and standard deviation of the plants in each plot were calculated. The detection of significant differences in wet weight between each plot interval was calculated by Welch's T-test (Welch test). The results are shown in FIGS. 4 and 5. The results of the Welch test in the figures, including the following, mean *: p < 0.05, **: p < 0.01. The test solutions used were as follows. The test solutions prepared in the same manner were also used in the following Activation Tests 3 to 6. Water treatment plot 2 Sterilized distilled water Malic acid treatment plot 2 0.24% (w / w) aqueous malic acid solution Acetic acid treatment plot 2 0.06% (w / w) aqueous acetic acid solution Treatment plot 2 0.24% (w / w) malic acid and 0.06% (w / w) aqueous acetic acid solution Each was adjusted to pH = 6.0 using KOH. No significant difference in wet weight was observed between the water treatment plot 2 and the malic acid treatment plot 2, but a significant increase in wet weight of 122% (p < 0.05) was observed between the water treatment plot 2 and the acetic acid treatment plot 2. A further significant increase in wet weight of 165% (p < 0.01) was observed between the water treatment plot 2 and the treatment plot 2 with acetic acid and malic acid.

[0057] <Activation Test 3> Carrots (Daucus carota subsp. sativus, Apiaceae) germinated from direct-sown seeds in the field were used. During the test period, watering of the plants was by natural rainfall. At two weeks after germination (4 - 5 true leaves), 50 mL of each test solution was perfused at the base of each plant. 50 mL of the test solution was perfused again 3 weeks and 6 weeks after the first perfusion treatment (a total of 3 perfusions were carried out). Harvested 90 days after the first perfusion treatment, the above-ground part (leaf part) was excised and removed to obtain the edible root part, and then the wet weights of 100 individuals were measured for each test plot. The top and bottom 10% of the data were removed respectively, and for 80 individuals, the average weight and standard deviation of the plants in each test plot were calculated. The significant difference in wet weight between each test plot was calculated by Welch's test. No significant difference in wet weight was observed among the three water treatment plots, three acetic acid treatment plots, and three malic acid treatment plots. However, significant differences (p < 0.01) in the root wet weight after harvest were observed between the three water treatment plots and the three plots treated with acetic acid and malic acid, and also between the three acetic acid treatment plots and the three plots treated with acetic acid and malic acid.

[0058] <Activation Test 4> Twenty branches were collected for each test plot from Plectranthus amboinicus (Plectranthus, Lamiaceae) grown in 20-cm pot culture soil, and cut leaving approximately 10 leaves from the shoot tip. Each lower part (stem part) was immersed in 200 mL of each test solution and grown for 2 weeks under natural light in a greenhouse. After 2 weeks, the plants were taken out and the number of roots, root elongation, and root branching were measured respectively. The average values and standard deviations were obtained, and the significant difference between each test plot was calculated by Welch's test. No new root growth was observed in the water treatment plot 4 and acetic acid treatment plot 4, but new root growth was observed in the acetic acid treatment plot 4 and the plot treated with acetic acid and malic acid due to the respective solution treatments. Significant differences were observed in the number of roots, root length, and number of branches between the water treatment plot 4 and the plot treated with acetic acid and malic acid, and also between the acetic acid treatment plot 4 and the plot treated with acetic acid and malic acid. In addition, significant new root growth, elongation, and branching were observed in the plot treated with acetic acid and malic acid compared to the acetic acid treatment plot 4.

[0059] <Activation Test 5> For the field-grown spinach on the day before harvest in a vinyl house, each test solution was applied at 100 mL per plant from the ground surface by watering at the base of the plant using a watering can. After 18 hours, the above-ground part was cut off from the roots with a cutter for harvesting, and wrapped in newspapers of the same area (30 cm x 45 cm) in bundles of 5. One by one, a total of 4 types of test plots (20 individuals in total) were placed in plastic bags (25 cm X 30 m), left with the mouth open and placed vertically, and stored in a refrigerator at 4°C and a humidity of 40%. The weight change of each individual over time was measured with a weighing scale. The weight of each plant at the start of the test was set as 100%, and the weight change of each treatment plot was calculated for each individual. The average and standard deviation of the weight changes of 20 individuals at each time were determined. There was no significant difference in the rate of decrease in wet weight between water treatment plot 5 and malic acid treatment plot 5. However, in acetic acid treatment plot 5 and the treatment plot with acetic acid and malic acid, a significant water retention effect appeared after 12 hours from the start of cold storage, compared with water treatment plot 5 and malic acid treatment plot 5. After the end of the 96-hour experiment, an average of 7.1% reduction in water loss was detected in acetic acid treatment plot 5 compared with water treatment plot 5, and 22% in the treatment plot with acetic acid and malic acid. It was shown that acetic acid treatment plot 5 and the treatment plot with acetic acid and malic acid were effective in maintaining the freshness of the harvested plants.

[0060] <Activation Test 6> North Pole (Leucanthemum paludosum of the Asteraceae family, genus Leucanthemum) grown in 9 cm pots was used. North Pole seedlings that were sown, germinated, and grew at the same time were watered with 100 mL of water every 3 days for 2 weeks for growth. Five seedlings were prepared for each test plot and immersed in 200 mL of each test solution respectively, left for 24 hours, and the solution was absorbed from the bottom of the pot. After the solution treatment, all apical buds were excised (pinched) with scissors. After apical bud excision, the plants were grown in an outdoor greenhouse while being watered with 200 mL of tap water every 4 days, and the number of newly grown apical buds (flower buds) was counted after 3 weeks. There was no significant difference in the number of newly grown flower buds between water treatment plot 6 and malic acid treatment plot 6. However, in acetic acid treatment plot 6 and the treatment plot with acetic acid and malic acid, an increase in the number of flower buds was confirmed compared with water treatment plot 6. A significant difference was also observed between acetic acid treatment plot 6 and the treatment plot with acetic acid and malic acid. Acetic acid can promote the new generation and formation of apical buds and flower buds. Furthermore, it has been revealed that the mixed use of acetic acid and malic acid can promote the new generation and formation of stronger apical buds and flower buds.

Claims

1. A heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants, containing acetic acid or its potassium salt in the range of 1 mM to 50 mM and malic acid or its potassium salt in the range of 1 mM to 50 mM, wherein the improvement of plant activity is the elongation of roots and the improvement of root survival rate the increase in nutrient absorption efficiency the induction of flower buds, the promotion of flowering, and the increase in fruit set the increase in water-saving effect the induction effect of callus formation the improvement of plant size the repair of wounds the promotion of growth, or the maintenance of freshness and moisture after harvest is a heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver for plants.

2. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver according to Claim 1, containing one or more solvents including at least water.

3. The heat tolerance or drought tolerance improver, salt tolerance improver, or activity improver according to Claim 2, having a pH in the range of 3 to 9.

4. A composition for improving the heat tolerance or drought tolerance, salt tolerance, or activity of plants, containing acetic acid or its potassium salt in the range of 1 mM to 50 mM and malic acid or its potassium salt in the range of 1 mM to 50 mM, wherein the improvement of plant activity is the elongation of roots and the improvement of root survival rate the increase in nutrient absorption efficiency the induction of flower buds, the promotion of flowering, and the increase in fruit set the increase in water-saving effect the induction effect of callus formation the improvement of plant size the repair of wounds the promotion of growth, or the maintenance of freshness and moisture after harvest is the composition.

5. The composition according to Claim 4, containing one or more solvents including at least water.

6. The composition according to Claim 5, having a pH in the range of 3 to 9.

7. A method for improving the heat tolerance or drought tolerance, salt tolerance, or activity of plants, including applying acetic acid or its potassium salt in the range of 1 mM to 50 mM and malic acid or its potassium salt in the range of 1 mM to 50 mM to plants, materials for applying to plants, or the soil, medium, or culture solution in which plants grow, wherein the improvement of plant activity is the elongation of roots and the improvement of root survival rate the increase in nutrient absorption efficiency the induction of flower buds, the promotion of flowering, and the increase in fruit set the increase in water-saving effect the induction effect of callus formation the improvement of plant size the repair of wounds the promotion of growth, or the maintenance of freshness and moisture after harvest is the method.

8. Obtaining one or more pieces of information related to plant growth Based on the one or more pieces of information obtained, determining the conditions for applying the heat resistance or drought resistance improver, salt tolerance improver, or activity improver according to any one of claims 1 to 3, or the composition according to any one of claims 4 to 6 to a plant, a material for applying to a plant, or the soil, medium, or culture solution in which the plant grows. A method for managing plant growth, comprising the above.

9. A method for improving the heat resistance or drought resistance, salt tolerance, or activity of a plant, which comprises using acetic acid or its potassium salt in the range of 1 mM to 50 mM and malic acid or its potassium salt in the range of 1 mM to 50 mM in combination, wherein the improvement of the activity of the plant is the elongation of roots and the improvement of root survival rate the increase in nutrient absorption efficiency the induction of flower buds, the promotion of flowering, and the increase in the amount of fruiting the increase in water-saving effect the induction effect of callus formation the improvement of the size of the plant body the repair of wounds the promotion of growth, or the maintenance of freshness and moisture after harvest This is the method.

10. A method for improving the heat resistance or drought resistance, salt tolerance, or activity of a plant, which comprises using acetic acid or its potassium salt in the range of 1 mM to 50 mM and malic acid or its potassium salt in the range of 1 mM to 50 mM, wherein the improvement of the activity of the plant is the elongation of roots and the improvement of root survival rate the increase in nutrient absorption efficiency the induction of flower buds, the promotion of flowering, and the increase in the amount of fruiting the increase in water-saving effect the induction effect of callus formation the improvement of the size of the plant body the repair of wounds the promotion of growth, or the maintenance of freshness and moisture after harvest This is the method.

11. The promotion of plant growth is the elongation of the stem and leaf part or the root part, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the weight of the plant body or the crop yield, greening, or the promotion of tillering. The heat resistance or drought resistance improver, salt tolerance improver, or activity improver according to any one of claims 1 to 3.

12. The promotion of plant growth is the elongation of the stem and leaf part or the root part, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the weight of the plant body or the crop yield, greening, or the promotion of tillering. The composition according to any one of claims 4 to 6.

13. The promotion of plant growth is the elongation of the stem and leaf part or the root part, the increase in the number of leaves, the promotion of flowering or fruiting, the increase in the number of flowers or fruits, the increase in the weight of the plant body or the crop yield, greening, or the promotion of tillering. The method according to any one of claims 7 to 10.

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