Plant activator for rice paddies

Abstract

To provide a plant activator for rice that has excellent effects in promoting the growth of rice plants. [Solution] A plant activator for rice cultivation comprising oxo fatty acids or their derivatives or salts thereof, terpenes or their derivatives, nucleic acids, and amino acids.

Description

[Technical Field]

[0001] This disclosure relates to a plant activator for rice cultivation. [Background technology]

[0002] Various technologies for regulating plant growth have been developed with the aim of improving the production efficiency of grain plants and horticultural plants. One such method involves using plant stimulants that regulate plant growth through means such as promoting growth, suppressing dormancy, and reducing stress, to revitalize plants.

[0003] Patent Document 1 describes a plant activator containing oxo fatty acids or their derivatives or salts and terpenes as active ingredients. Patent Document 2 describes a plant activator containing an oxo fatty acid or its derivative or salt and a nucleic acid as active ingredients. Patent Document 3 describes a plant activator containing oxo fatty acids or their derivatives or salts and amino acids as active ingredients. Patent Document 4 discloses a plant activator containing fatty acids or their derivatives or salts, nucleic acids, terpenes, amino acids, etc., as active ingredients. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-18664 [Patent Document 2] Japanese Patent Publication No. 2024-19077 [Patent Document 3] Japanese Patent Publication No. 2024-19078 [Patent Document 4] Japanese Patent Publication No. 2001-316204 [Overview of the project] [Problems that the invention aims to solve]

[0005] The plant activators described in Patent Document 2 and Patent Document 3 are for soybeans, and no plant activator for rice is described. Also in Patent Document 1 and Patent Document 4, no specific examination has been made on the effects when the plant activator is applied to rice cultivation. In view of the above circumstances, an object of one embodiment of the present disclosure is to provide a plant activator for rice that has an excellent rice growth promoting effect.

Means for Solving the Problems

[0006] One embodiment of the present disclosure is a plant activator for rice, which contains an oxo fatty acid or its derivative or its salt, a terpene or its derivative, a nucleic acid, and an amino acid. The plant activator of the present disclosure exhibits an excellent rice growth promoting effect.

Modes for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the present disclosure, each component contained in the plant activator may contain a plurality of corresponding substances. When there are a plurality of substances corresponding to each component, the content ratio or content of each component means the total content ratio or content of the plurality of substances contained in the plant activator, unless otherwise specified.

[0008] In the present disclosure, the plant activator for rice may sometimes be simply referred to as "plant activator". In the present disclosure, "activation of plants" means regulating to activate or maintain the growth activities of plants in some form. Specifically, it includes concepts such as promotion of plant growth (expansion of stems or leaves, hypertrophy of tubers or tuberous roots, etc.), suppression of dormancy, induction or imparting of resistance of plants to stress (such as diseases or stress caused by the environment), and suppression of plant aging.

[0009] The plant activator of the present disclosure can impart a growth promoting effect to rice. Specifically, as shown in the examples described later, it can promote an increase in the plant height and mass of rice that has been brought into contact with the plant activator of the present disclosure. Furthermore, as shown in the examples described later, the plant activator of the present disclosure exhibits a growth promoting effect on rice even under conditions of low fertilization amount. This result suggests that the effect of the plant activator is exhibited even in an environment that stresses rice, such as under reduced fertilizer application or mid-season drought. Since the components contained in the plant activator of the present disclosure are naturally occurring compounds, the load on the environment is low and the adverse effects on the plants to which it is applied are few. The plant activator of the present disclosure can bring about a growth promoting effect on rice by simple treatments such as spraying. Therefore, there is no need to prepare special equipment etc., and it is excellent in terms of economy. The plant activator of the present disclosure can bring about a growth promoting effect on rice without artificially modifying the growth environment of the plant (light irradiation intensity, carbon dioxide concentration, etc.). Therefore, it is possible to promote the growth of rice without causing physiological disorders such as tip burn associated with the modification of the growth environment.

[0010] (oxo fatty acid or its derivative or its salt) The plant activator of the present disclosure contains an oxo fatty acid or its derivative or its salt. By including an oxo fatty acid or its derivative or its salt as an active ingredient in the plant activator, it is possible to promote the growth of rice. In the present disclosure, the "oxo fatty acid" means a monovalent carboxylic acid having a hydrocarbon chain to which a carboxy group is bonded and containing one or more oxo groups (=O) bonded to the carbon atoms constituting the hydrocarbon chain.

[0011] When the plant activator contains a derivative of an oxo fatty acid or its salt, there is no particular limitation as long as it is a derivative or salt that is acceptable for agricultural use. Derivatives of oxo fatty acids include esters of oxo fatty acids. Specifically, examples of esters of oxo fatty acids include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, isopentyl esters, and octyl esters. Examples of oxo fatty acid salts include alkali metal salts such as sodium salts and potassium salts, ammonium salts, and alkylammonium salts such as tetramethylammonium salt.

[0012] From the viewpoint of promoting the growth of rice plants, it is preferable that the oxo fatty acids include unsaturated oxo fatty acids, and more preferably that they include polyunsaturated oxo fatty acids. In this disclosure, "unsaturated oxo fatty acid" means an oxo fatty acid containing one or more double bonds in its hydrocarbon chain, and "polyunsaturated oxo fatty acid" means an oxo fatty acid containing two or more double bonds in its hydrocarbon chain. When the oxo fatty acids contained in a plant activator are unsaturated oxo fatty acids, the stimulus to rice plants is suppressed and their growth is less likely to be inhibited compared to when saturated fatty acids such as stearic acid are used. As a result, the growth activity of rice plants is more activated.

[0013] The number of carbon atoms in the hydrocarbon chain constituting the oxo fatty acid (excluding carbon atoms in the carboxyl group) is not particularly limited. From the viewpoint of promoting the growth of rice, the number of carbon atoms in the hydrocarbon chain constituting the oxo fatty acid is preferably 10 to 25, preferably 15 to 20, and more preferably 18.

[0014] The hydrocarbon chains constituting oxo fatty acids may be linear or branched. From the viewpoint of promoting the growth of rice, it is preferable that the hydrocarbon chains constituting oxo fatty acids are linear. The hydrocarbon chain constituting the oxo fatty acid may or may not contain double bonds. From the viewpoint of promoting the growth of rice, it is preferable that the hydrocarbon chain constituting the oxo fatty acid contains double bonds, more preferably two or more double bonds, and even more preferably two double bonds. The hydrocarbon chain constituting the oxo fatty acid preferably contains a conjugated double bond. In this disclosure, "the hydrocarbon chain contains a conjugated double bond" means that the hydrocarbon chain contains a structure in which a single bond is positioned between two double bonds (-CH2=CH2-CH2=CH2-).

[0015] In this disclosure, an oxo fatty acid represented by a given structural formula encompasses all geometric isomers and stereoisomers represented by that structural formula. For example, if an oxo fatty acid contains a double bond, its substituent may be in an E configuration or a Z configuration.

[0016] The number of oxo groups in the oxo fatty acid is not particularly limited. From the viewpoint of promoting the growth of rice, it is preferable that the number of oxo groups be one or two, and more preferable that it be one.

[0017] A suitable example of an oxo fatty acid is ketooctadecadienoic acid. In this disclosure, "ketooctadienoic acid" means an oxo fatty acid containing two double bonds in a hydrocarbon chain having 18 carbon atoms. The two double bonds in ketooctadienoic acid may form a conjugated double bond. Specific examples of ketooctadecadienoic acid include 9-oxo-10,12-octadecadienoic acid (9-oxoODA), 13-oxo-9,11-octadecadienoic acid (13-oxoODA), 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid.

[0018] The oxo fatty acid may contain at least one selected from the oxo fatty acid represented by the following formula (I) and the oxo fatty acid represented by the following formula (II).

[0019] Formula (I): HOOC-(R 1 )-CH=CH-C(=O)-R 2

[0020] In formula (I), R 1 represents a hydrocarbon group having 6 to 12 carbon atoms. R 2 represents a hydrocarbon group having 2 to 8 carbon atoms. The hydrocarbon group having 6 to 12 carbon atoms represented by R 1 may be linear or branched and may be saturated or unsaturated. The hydrocarbon group having 2 to 8 carbon atoms represented by R 2 may be linear or branched and may be saturated or unsaturated.

[0021] Formula (II): HOOC-(R 3 )-C(=O)-CH=CH-R 4

[0022] In formula (II), R 3 represents a hydrocarbon group containing 3 to 10 carbon atoms. R 4 represents a hydrocarbon group having 4 to 11 carbon atoms. The hydrocarbon group having 3 to 10 carbon atoms represented by R 3 may be linear or branched and may be saturated or unsaturated. The hydrocarbon group having 4 to 11 carbon atoms represented by R 4 may be linear or branched and may be saturated or unsaturated.

[0023] From the viewpoint of the rice growth promoting effect, it is preferable that R 1 in formula (I) contains a double bond that forms a conjugated double bond together with the double bond between the α-carbon and the β-carbon of the carbonyl group. From the viewpoint of the rice growth promoting effect, R 3However, it is preferable that the double bond includes a double bond that forms a conjugated double bond together with the double bond between the α-carbon and β-carbon of the carbonyl group.

[0024] From the perspective of promoting the growth of rice, R in equation (I) 1 It is preferable that R is a hydrocarbon group having 9 carbon atoms. 1 The C9 hydrocarbon group represented by preferably contains one double bond, and more preferably contains a double bond that forms a conjugated double bond together with the double bond between the α and β carbons of the carbonyl group (i.e., has the structure -CH3-CH2-CH3-CH2-CH2-CH2-CH2-CH=CH-). From the perspective of promoting the growth of rice, R in equation (I) 2 It is preferably a hydrocarbon group having 5 carbon atoms, and more preferably an alkyl group having 5 carbon atoms. From the viewpoint of promoting the growth of rice, the oxo fatty acid represented by formula (I) is preferably an oxo fatty acid having 18 carbon atoms, more preferably ketooctadecadienoic acid, and even more preferably 13-oxo-9,11-octadecadienoic acid.

[0025] From the perspective of promoting the growth of rice, R in equation (II) 3 It is preferably a hydrocarbon group having 7 carbon atoms, and more preferably an alkylene group having 7 carbon atoms. From the perspective of promoting the growth of rice, R in equation (II) 4 It is preferable that R is a hydrocarbon group having 7 carbon atoms. 4 The C7 hydrocarbon group represented by preferably contains one double bond, and more preferably contains a double bond that forms a conjugated double bond together with the double bond between the α and β carbons of the carbonyl group (i.e., has the structure CH3-CH2-CH2-CH2-CH2-CH=CH-). From the viewpoint of promoting the growth of rice, the oxo fatty acid represented by formula (II) is preferably an oxo fatty acid having 18 carbon atoms, more preferably ketooctadecadienoic acid, and even more preferably 9-oxo-10,12-octadecadienoic acid.

[0026] Oxo fatty acids may be a combination of two or more types of oxo fatty acids. When oxo fatty acids are a combination of two or more types, they may exhibit a superior effect in promoting rice growth. The combination of two or more oxo fatty acids may be a combination of two or more unsaturated oxo fatty acids, or a combination of two or more ketooctadecadienoic acid. A combination of two or more oxo fatty acids may include an oxo fatty acid represented by formula (I) and an oxo fatty acid represented by formula (II).

[0027] The oxo fatty acid may also be a combination containing 13-oxo-9,11-octadecadienoic acid and 9-oxo-10,12-octadecadienoic acid. In this case, it is preferable that the amount of 13-oxo-9,11-octadecadienoic acid is greater than the amount of 9-oxo-10,12-octadecadienoic acid. Specifically, the ratio (A / B) of the mass A of 13-oxo-9,11-octadecadienoic acid to the mass B of 9-oxo-10,12-octadecadienoic acid is preferably in the range of 10 / 10 to 10 / 1.

[0028] The origin of oxo fatty acids or their derivatives or salts used in plant activators is not particularly limited. For example, oxo fatty acids or their derivatives or salts may be chemically synthesized, produced using microorganisms, or obtained by reacting enzymes derived from microorganisms with a substrate such as fatty acids. The plant activator should contain an oxo fatty acid or its derivative or salt thereof at a desired concentration. For example, if the oxo fatty acid or its derivative or salt thereof is a product produced using microorganisms, a mixture containing such product may be included in the plant activator.

[0029] The concentration of oxo fatty acids or their derivatives or salts in the plant activator is not particularly limited and can be set considering the cultivation conditions and growth stage of the rice to which the plant activator is applied, as well as the timing, method, and amount of application of the plant activator. In one embodiment of this disclosure, the concentration of oxo fatty acid or its derivative or salt in the plant activator may be 5 mg / L or less. When the concentration is 5 mg / L or less, the possibility of causing phytotoxicity to rice is reduced. The lower limit of the concentration is not particularly limited, but from the viewpoint of exhibiting a sufficient growth-promoting effect, it is preferably 0.05 mg / L or higher. In a preferred embodiment of this disclosure, the preferred range of the concentration is 0.05 mg / L to 5 mg / L.

[0030] (Terpenes or their derivatives) The plant activators of this disclosure include terpenes or their derivatives. Terpenes or their derivatives function as precursors in the biosynthesis of plant hormones related to promoting plant growth. Therefore, by including terpenes or their derivatives as active ingredients in plant activators, the growth of rice can be further promoted.

[0031] The types of terpenes or their derivatives contained in the plant activator are not particularly limited. Suitable terpenes or their derivatives include monoterpenes, sesquiterpenes, diterpenes, and their derivatives. Among these, monoterpenes such as α-pinene, β-pinene, silvestrene, and limonene, and their derivatives, are more preferred because they act as core substances of plant hormones. Terpineol is an example of a terpene derivative. Terpineol isomers include α-terpineol, β-terpineol, γ-terpineol, and δ-terpineol, with α-terpineol being preferred among them. When a plant activator contains terpineol, the terpineol may be a mixture of two or more isomers, or a mixture of isomers with α-terpineol, which is commonly sold commercially as terpineol, as the main component. The terpenes or their derivatives contained in the plant activator may be one type or a combination of two or more types. As terpenes or their derivatives, pine oil containing at least α-pinene as a main component can be suitably used.

[0032] The amount of terpenes or their derivatives contained in the plant activator is not particularly limited and can be determined considering the cultivation conditions and growth stage of the rice to which the plant activator is applied, as well as the timing, method, and amount of application of the plant activator. In one embodiment of this disclosure, the amount of terpenes or their derivatives contained in the plant activator may be 400 times or less by mass ratio relative to the amount of oxo fatty acids or their derivatives or salts. The lower limit of the amount of terpenes or their derivatives contained in the plant activator is not particularly limited, but it may be 0.5 times or more by mass ratio relative to the amount of oxo fatty acids or their derivatives or salts. In one embodiment of this disclosure, the amount of terpenes or their derivatives contained in the plant activator may be selected from a range of 1 to 200 times by mass ratio relative to the amount of oxo fatty acids or their derivatives or salts.

[0033] (nucleic acid) The plant activator of this disclosure contains nucleic acids. Nucleic acids function as precursors in the biosynthesis of plant hormones related to promoting plant growth. Therefore, by including nucleic acids as an active ingredient in plant activators, the growth of rice plants can be further promoted.

[0034] In this disclosure, nucleic acids mean compounds selected from nucleic acid bases, nucleosides, ribonucleotides formed by esterifying a nucleoside with 1 to 3 phosphate groups, and deoxyribonucleotides formed by substituting a hydrogen atom for the hydroxyl group at position 2 of the ribose contained in a ribonucleotide. The nucleoside may be either a ribonucleoside or a deoxyribonucleoside. There are no particular restrictions on the types of nucleic acids contained in plant activators. Examples of nucleic acid bases include adenine, guanine, thymine, cytosine, and uracil. Examples of nucleosides include adenosine, guanosine, thymidine, cytidine, uridine, and 5-methyluridine. Specific examples of ribonucleotides include AMP (adenosine monophosphate), ADP (adenosine diphosphate), ATP (adenosine triphosphate), GMP (guanosine monophosphate), GDP (guanosine diphosphate), GTP (guanosine triphosphate), TMP (thymidylic acid / thymidine phosphate), TDP (thymidine diphosphate), TTP (thymidine triphosphate), CMP (cytidine monophosphate), CDP (cytidine diphosphate), CTP (cytidine triphosphate), UMP (uridine monophosphate), UDP (uridine diphosphate), and UTP (uridine triphosphate). Examples of deoxyribonucleotides include dAMP, dADP, dATP, dGMP, dGDP, dGTP, dTMP, dTDP, dTTP, dCMP, dCDP, dCTP, dUMP, dUDP, and dUTP. The nucleic acids contained in the plant activator may be a single type or a combination of two or more types.

[0035] The amount of nucleic acid contained in the plant activator is not particularly limited and can be determined considering the cultivation conditions and growth stage of the rice to which the plant activator is applied, as well as the timing, method, and amount of application of the plant activator. In one embodiment of this disclosure, the amount of nucleic acid contained in the plant activator may be 100 times or less by mass ratio to the amount of oxo fatty acid or its derivative or salt thereof. The lower limit of the amount of nucleic acid contained in the plant activator is not particularly limited, but it may be 0.1 times or more by mass ratio relative to the amount of oxo fatty acid or its derivative or salt thereof. In one embodiment of this disclosure, the amount of nucleic acid contained in the plant activator may be selected from a range of 0.5 to 50 times by mass ratio relative to the amount of oxo fatty acid or its derivative or salt thereof.

[0036] (amino acid) The plant activator of this disclosure contains amino acids. Amino acids are the basic building blocks of proteins. Therefore, by including amino acids as an active ingredient in plant activators, nitrogen can be absorbed by rice plants in the form of amino acids, thereby further promoting rice growth.

[0037] There are no particular restrictions on the types of amino acids contained in plant activators. Specifically, examples of amino acids include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, histidine, tyrosine, cysteine, aspartic acid, asparagine, serine, glutamic acid, glutamine, proline, glycine, alanine, and arginine. The amino acids contained in the plant activator may be one type or a combination of two or more types.

[0038] The amount of amino acids contained in the plant activator is not particularly limited and can be determined considering the cultivation conditions and growth stage of the rice to which the plant activator is applied, as well as the timing, method, and amount of application of the plant activator. In one embodiment of this disclosure, the amount of amino acids contained in the plant activator may be 1000 times or less by mass ratio to the amount of oxo fatty acids or their derivatives or salts. The lower limit of the amount of amino acids contained in the plant activator is not particularly limited, but it may be 1 or more by mass ratio to the amount of oxo fatty acids or their derivatives or salts. In one embodiment of this disclosure, the amount of amino acids contained in the plant activator may be selected from a range of 5 to 510 times by mass ratio relative to the amount of oxo fatty acids or their derivatives or salts.

[0039] (Hydroxylated fatty acids) The plant activator of this disclosure may further contain a hydroxylated fatty acid or a derivative thereof or a salt thereof. In this disclosure, "hydroxylated fatty acid" means a monovalent carboxylic acid having a hydrocarbon chain to which a carboxyl group is bonded, and containing one or more hydroxyl groups (-OH) bonded to carbon atoms constituting the hydrocarbon chain.

[0040] If a plant activator contains a derivative or salt of a hydroxylated fatty acid, it is not particularly limited as long as the derivative or salt is agriculturally acceptable. Examples of derivatives of hydroxylated fatty acids include esters of hydroxylated fatty acids. Specifically, examples of esters of hydroxylated fatty acids include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, isopentyl esters, and octyl esters. Examples of hydroxylated fatty acid salts include alkali metal salts such as sodium salts and potassium salts, ammonium salts, and alkylammonium salts such as tetramethylammonium salt.

[0041] The number of carbon atoms in the hydrocarbon chain constituting the hydroxylated fatty acid (excluding carbon atoms in the carboxyl group) is not particularly limited. From the viewpoint of promoting the growth of rice, the number of carbon atoms in the hydrocarbon chain constituting the hydroxylated fatty acid is preferably 10 to 25, preferably 15 to 20, and more preferably 18.

[0042] The hydrocarbon chains constituting hydroxylated fatty acids may be linear or branched. From the viewpoint of promoting the growth of rice, it is preferable that the hydrocarbon chains constituting hydroxylated fatty acids be linear. The hydrocarbon chain constituting the hydroxylated fatty acid may or may not contain double bonds. From the viewpoint of promoting the growth of rice, it is preferable that the hydrocarbon chain constituting the hydroxylated fatty acid contains double bonds, and more preferably that it contains one or more double bonds.

[0043] In this disclosure, a hydroxylated fatty acid represented by a given structural formula encompasses all geometric isomers and stereoisomers represented by that structural formula. For example, if a hydroxylated fatty acid contains a double bond, its substituent may be in an E configuration or a Z configuration.

[0044] The number of hydroxyl groups in the hydroxylated fatty acid is not particularly limited. From the viewpoint of promoting the growth of rice, the number of hydroxyl groups is preferably 1 to 3, and more preferably 3.

[0045] A suitable example of a hydroxylated fatty acid is trihydroxyoctadecenoic acid. Examples of trihydroxyoctadecenoic acid include 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid. Hydroxidized fatty acids may be a combination of two or more types of hydroxylated fatty acids.

[0046] The amount of hydroxylated fatty acids or their derivatives or salts contained in the plant activator is not particularly limited and can be determined considering the cultivation conditions and growth stage of the rice to which the plant activator is applied, as well as the timing, method, and amount of application of the plant activator. In one embodiment of this disclosure, the amount of hydroxylated fatty acid or its derivative or salt contained in the plant activator may be 1.0 times or less by mass ratio relative to the amount of oxo fatty acid or its derivative or salt. The lower limit of the amount of hydroxylated fatty acids or their derivatives or salts contained in the plant activator is not particularly limited, but it may be 0.1 times or more by mass ratio relative to the amount of oxo fatty acids or their derivatives or salts. In one embodiment of this disclosure, the amount of hydroxylated fatty acid or its derivative or salt contained in the plant activator may be selected from a range of 0.1 to 0.8 times by mass ratio relative to the amount of oxo fatty acid or its derivative or salt.

[0047] (Purpose and method of use of plant activators) The plant activators of this disclosure are preferably used to increase at least one of the height and mass of rice plants, to improve the stress tolerance of rice plants to reduced fertilizer use or mid-season drainage, or to increase the yield of rice plants.

[0048] The plant activator disclosed herein is suitably used in rice cultivation when the amount of fertilizer applied is reduced compared to conventional methods. Under such conditions, rice plants tend to lack the nutrients necessary for their growth, resulting in a decrease in yield. The plant activator disclosed herein can exert an effect that promotes the growth of rice plants even under such conditions.

[0049] The plant activator disclosed herein is suitably used when mid-season drainage is implemented in rice cultivation. While mid-season drainage has the effect of suppressing the amount of methane discharged from paddy fields, it tends to stress rice plants and reduce yields. The plant activator disclosed herein can exert the effect of promoting rice growth even under conditions in which mid-season drainage is implemented. There are no particular restrictions on the length of the mid-season drainage period in rice cultivation. From the viewpoint of effectively suppressing methane discharge from paddy fields, it is preferable that the period be at least 7 days longer than the average number of days of drainage over the most recent two years.

[0050] The plant activator described herein can be applied to rice plants by any method. Specifically, the method of contacting the plant activator with at least a part of the plant body is not particularly limited. The part of the plant body to which the plant activator is applied is not particularly limited and may be selected from roots, stems, leaves, spikes, etc. The method of bringing the plant activator into contact with at least a part of the plant body may be either by applying the plant activator so that it comes into direct contact with the rice plant body (for example, by bringing it into contact with the plant body in the form of a spray or immersion agent), or by bringing it into indirect contact (for example, by applying the plant activator to the cultivation carrier such as soil or growing medium in the form of a soil drenching agent).

[0051] There are no particular restrictions on the application method of plant activators, and they can be selected according to the rice cultivation method, etc. Specific methods for applying plant activators include ground liquid spraying, ground solid spraying, aerial liquid spraying, aerial solid spraying, surface spraying, application within facilities, soil mixing, soil drenching, surface treatment such as coating, application to seedling trays, single flower treatment, and treatment around the base of the plant. In addition to the application methods described above, the plant activator may be mixed with rice fertilizer components and used as a plant fertilizer. Furthermore, the plant activator may be encapsulated in porous structures or capsules, or impregnated into sheets, etc., and used as a sustained-release agent.

[0052] The form of the plant activator is not particularly limited and can be selected according to the rice cultivation method, etc. The plant activator may be in liquid or gel form, or in solid form (block, powder, granules, etc.). The liquid or gel form of the plant activator may be a ready-to-use type or a concentrated type that requires dilution before use.

[0053] There are no particular restrictions on the growth stage of rice to which plant activators are applied; they can be selected according to the rice cultivation method and other factors. The growth stages of rice to which the plant activator is applied may include one or more of the following: the period from sowing to germination, the vegetative growth period from germination to the formation of panicle primordia, the reproductive growth period from the formation of panicle primordia to flowering, and the ripening period from flowering to maturity. From the viewpoint of promoting the growth of rice plants, it is preferable that plant activators be applied to rice plants at least during the vegetative growth period.

[0054] In recent years, research on plant factories has been active, and cultivation methods that promote plant growth by increasing light intensity and carbon dioxide concentration within the factory have been attempted. However, under conditions of increased light intensity and carbon dioxide concentration, plants, especially leafy vegetables, may exhibit physiological disorders (so-called tip burn) in which the leaf margins and sepal tips of new leaves turn brown and die as if burned. At least one compound selected from oxo fatty acids or their derivatives or salts, and hydroxylated fatty acids or their derivatives or salts, contained in the plant activator of this disclosure contributes to the prevention or suppression of the tip burn phenomenon.

[0055] Furthermore, at least one compound selected from oxo fatty acids or their derivatives or salts, and hydroxylated fatty acids or their derivatives or salts, contained in the plant activator of this disclosure contributes to improving photosynthetic rate and stomatal conductance. Stomatal conductance, also called stomatal conductivity, is an indicator of how easily gases pass through the stomata. Generally, a high measurement value indicates that the stomata are open and photosynthesis is actively taking place. Photosynthetic rate and stomatal conductance can be measured using a portable photosynthetic transpiration measurement system.

[0056] The plant activators of this disclosure include the following embodiments: <1> A plant activator for rice cultivation comprising oxo fatty acids or their derivatives or salts, terpenes or their derivatives, nucleic acids, and amino acids. <2> The aforementioned oxo fatty acid includes an unsaturated oxo fatty acid. <1> A plant activator for rice cultivation as described above. <3> The aforementioned oxo fatty acid contains ketooctadecadienoic acid. <1> or <2> A plant activator for rice cultivation as described above. <4> The oxo fatty acid comprises at least one selected from the group consisting of 9-oxo-10,12-octadecadienoic acid, 13-oxo-9,11-octadecadienoic acid, 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid. <1> ~ <3> A plant activator for rice cultivation described in any one of the following. <5> The oxo fatty acid comprises at least two types of oxo fatty acids. <1> ~ <4> A plant activator for rice cultivation described in any one of the following. <6> The oxo fatty acid comprises at least one selected from the oxo fatty acid represented by the following formula (I) and the oxo fatty acid represented by the following formula (II). <1> ~ <5> A plant activator for rice cultivation described in any one of the following. Equation (I): HOOC-(R 1 )-CH=CH-C(=O)-R 2 Formula (II):HOOC-(R 3 )-C(=O)-CH=CH-R 4 [In formula (I), R 1 This represents a hydrocarbon group with 6 to 12 carbon atoms, R 2 R represents a hydrocarbon group having 2 to 8 carbon atoms. In formula (II), R 3 This indicates a hydrocarbon group with 3 to 10 carbon atoms, and R 4 This indicates a hydrocarbon group with 4 to 11 carbon atoms. <7> R in equation (I) above 1 However, it includes a double bond that forms a conjugated double bond together with the double bond between the α-carbon and β-carbon of the carbonyl group, and R in formula (II) 3 However, it includes a double bond that forms a conjugated double bond together with the double bond between the α-carbon and β-carbon of the carbonyl group. <6> A plant activator for rice cultivation as described above. <8> In the above equation (I), R 1 is a hydrocarbon group with 9 carbon atoms, R 2 is a hydrocarbon group having 5 carbon atoms, and in the above formula (II), R 3 It is a hydrocarbon group with 7 carbon atoms, R 4 It is a hydrocarbon group with 7 carbon atoms. <6> or <7> A plant activator for rice cultivation as described above. <9> The oxo fatty acid includes the oxo fatty acid represented by formula (I) and the oxo fatty acid represented by formula (II). <6> ~ <8> A plant activator for rice cultivation described in any one of the following. <10> The oxo fatty acid represented by formula (I) contains 13-oxo-9,11-octadecadienoic acid, and the oxo fatty acid represented by formula (II) contains 9-oxo-10,12-octadecadienoic acid. <9> A plant activator for rice cultivation as described above. <11> The terpene includes a monoterpene. <1> ~ <10> A plant activator for rice cultivation described in any one of the following. <12> Further comprising hydroxylated fatty acids, derivatives of hydroxylated fatty acids, or salts of hydroxylated fatty acids, <1> ~ <11> A plant activator for rice cultivation described in any one of the following. <13> The hydroxylated fatty acid comprises at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid. <12> A plant activator for rice cultivation as described above. <14> To increase at least one of the height and mass of paddy rice plants, <1> ~ <13> A plant activator for rice cultivation described in any one of the following. <15> To improve stress tolerance of rice to reduced fertilizer use or mid-season drainage, <1> ~ <13> A plant activator for rice cultivation described in any one of the following. <16> To increase the yield of rice, <1> ~ <13> A plant activator for rice cultivation described in any one of the following. <17> These are spray agents, dipping agents, or soil drenching agents. <1> ~ <16> A plant activator for rice cultivation described in any one of the following. [Examples]

[0057] Embodiments of the present disclosure will be described below based on examples. However, embodiments of the present disclosure are not limited to these examples.

[0058] [Example 1] (1) Preparation of plant activators As a raw material containing fatty acids, 90% pure linoleic acid (manufactured by NOF Corporation) was used. To 580g of linoleic acid, potassium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (216g), dipotassium hydrogen phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (280g), and distilled water (13000mL) were added to prepare the test solution. The pH of the test solution was 9.0.

[0059] 40 mg of lipoxygenase (Nacalai Tesque Co., Ltd., derived from soybeans) was added to the test solution, and the reaction was carried out at 15°C for 3 hours while aerating with oxygen and stirring. After that, the reaction mixture was placed in a 90°C water bath for 90 minutes. The resulting reaction solution was designated as Solution A.

[0060] A portion of Solution A (6500 mL) was mixed with phosphoric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (35 mL) to adjust the pH to 7.0. The pH-adjusted Solution A was aerated with oxygen and reacted at 50°C for 22 hours while stirring. The reaction mixture was then placed in a 90°C water bath for 2 hours. The resulting reaction solution was designated as Solution B.

[0061] The entire amount of Solution A that was not used in the preparation of Solution B was mixed with the entire amount of Solution B to obtain a mixture. The obtained mixture was subjected to quantitative analysis by MS2 spectral analysis and LC-MS (liquid chromatography-mass spectrometry). The following reference materials were used: 13-oxoODA (13-oxo-9,11-octadecadienoic acid, Cayman Chemicals), 9oxoODA (9-oxo-10,12-octadecadienoic acid, Cayman Chemicals), 9,10,13-trihydroxy-11-octadecenoic acid (La Rhodan Fine Chemicals), and 9,12,13-trihydroxy-10-octadecenoic acid (La Rhodan Fine Chemicals). The two types of ketoocdadecadienoic acid (13-oxoODA and 9-oxoODA) were quantified using the absolute calibration curve method at a detection wavelength of UV210nm.

[0062] Quantitative analysis revealed a yield of 3.7% for 13-oxoODA and 1.7% for 9-oxoODA. The combined yield of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid was 1.2% (peaks could not be separated by LC-MS), and the recovery rate of linoleic acid was 84.1%. The above yields are the combined yields of isomers such as (E,E isomer) and (E,Z isomer). The yield (%) was calculated based on the following formula. Yield (%) = (Mass of 13-oxoODA, 9-oxoODA, 9,10,13-trihydroxy-11-octadecaenoic acid or 9,12,13-trihydroxy-10-octadecaenoic acid produced) / (Initial mass of linoleic acid used as raw material)

[0063] The mixture of solutions A and B obtained above (0.081 mL) was diluted with deionized water to 2000 mL to prepare the standard solution. The concentration of 13-oxoODA in the standard solution was 0.055 ppm by mass, the concentration of 9-oxoODA was 0.025 ppm by mass, and the total concentration of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid was 0.018 ppm by mass.

[0064] Plant activator 1 was prepared by adding the following materials 1 (6.8 mg), 2 (81 mg), and 3 (32 μL) to a standard solution (2000 mL). Material 1: Grinded nucleic acid granules manufactured by Kenko Ouen Dan Co., Ltd. (containing adenine, adenosine, adenosine monophosphate, guanine, guanosine, guanosine monophosphate, thymine, thymidine, thymidine monophosphate, 5-methyluridine, cytosine, cytidine, cytidine monophosphate, uracil, uridine, and uridine monophosphate) Ingredient 2: Ground multi-amino acids manufactured by Fancl Corporation (containing isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, histidine, tyrosine, cysteine, aspartic acid, asparagine, serine, glutamic acid, glutamine, proline, glycine, alanine, and arginine). Ingredient 3: Pine oil manufactured by ease (containing α-pinene, camphene, β-pinene, and limonene as main components)

[0065] (2) Test on the effect of promoting the growth of rice Rice seeds (variety: Nipponbare) were soaked in water for 3 days in an artificial climate chamber (LH-60FL3-DT: manufactured by Nippon Medical Instruments Co., Ltd.) at a temperature of 30°C with the lights off. After soaking, the seeds were sown (4 seeds / cell) in a 72-cell cell tray filled with sterilized seed-starting soil (Takii Seed Co., Ltd.). The seeds were grown in an artificial climate chamber in a cycle (1 day) consisting of a 14-hour period at 28°C with fluorescent lights and a 10-hour period at 23°C with the lights off, until they reached the 1-leaf to 1.5-leaf stage. Eleven days after sowing, plant activator 1 was sprayed onto the leaves of seedlings using a spray bottle (1 mL per plant, 20 plants). The seedlings were then grown in an artificial climate chamber. Seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0066] [Comparative Example 1] Seedlings were grown in the same manner as in Example 1, except that plant activator 1 was not applied. Eighteen days after sowing, the above-ground parts were cut off, and the height and mass of each plant were measured.

[0067] [Comparative Example 2] The mixture of solutions A and B obtained in Example 1 (0.081 mL) was diluted to 2000 mL with deionized water to prepare plant activator 2. Similar to Example 1, plant activator 2 was sprayed onto the leaves of seedlings, and seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0068] [Comparative Example 3] A mixture of solutions A and B obtained in Example 1 (0.081 mL) was diluted to 2000 mL with deionized water, and material 2 (81 mg) was added to prepare plant activator 3. Similar to Example 1, plant activator 3 was sprayed onto the leaves of seedlings, and seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0069] [Comparative Example 4] A mixture of solutions A and B obtained in Example 1 (0.081 mL) was diluted to 2000 mL with deionized water, and material 1 (6.8 mg) was added to prepare plant activator 4. Similar to Example 1, plant activator 4 was sprayed onto the leaves of seedlings, and seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0070] [Comparative Example 5] A mixture of solutions A and B obtained in Example 1 (0.081 mL) was diluted to 2000 mL with deionized water, and material 3 (32 μL) was added to prepare plant activator 5. Similar to Example 1, plant activator 5 was sprayed onto the leaves of seedlings, and seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0071] [Comparative Example 6] Stearic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (100 mg) and POS(20) sorbitan monooleate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (300 mg) were dispersed in water to prepare a 2000 ml aqueous dispersion. To this aqueous dispersion, material 1 (6.8 mg), material 2 (81 mg), and material 3 (32 μL) were added to prepare plant activator 6. Similar to Example 1, plant activator 6 was sprayed onto the leaves of seedlings, and seven days after spraying, the above-ground parts of the seedlings were cut off, and the height and mass of each plant were measured.

[0072] The results of the test are shown in Table 1 below. The values ​​in the table are the arithmetic mean and standard deviation (σ) of the measured values ​​for 20 strains in each group.

[0073] [Table 1]

[0074] As shown in Table 1, Example 1, in which plant activator 1 containing oxo fatty acids, terpenes, nucleic acids, and amino acids was sprayed, showed greater plant height, mass, and mass per cm compared to Comparative Example 1, in which no plant activator was sprayed, and Comparative Examples 2-6, in which plant activators 2-6 containing at least one of oxo fatty acids, terpenes, nucleic acids, and amino acids were sprayed, indicating more promoted seedling growth. Furthermore, in Comparative Example 6, in which stearic acid, a saturated linear fatty acid without >=O, was used instead of oxo fatty acids, the values ​​for plant height, mass, and mass per cm were all smaller than in Example 1, even though the plant activator contained terpenes, amino acids, and nucleic acids. These results suggest that the synergistic effect of these components was achieved because plant activator 1 used in Example 1 contained oxo fatty acids, terpenes, nucleic acids, and amino acids. Furthermore, the mass per centimeter (mass divided by plant height) measured in Example 1 was larger than that in Comparative Examples 1-6. This result suggests that the growth of seedlings treated with plant activator 1 was more significant in mass than in plant height, and that the seedlings were less prone to lodging due to excessive growth.

Claims

1. A plant activator for rice cultivation comprising oxo fatty acids or their derivatives or salts, terpenes or their derivatives, nucleic acids, and amino acids.

2. The plant activator for rice according to claim 1, wherein the oxo fatty acid comprises an unsaturated oxo fatty acid.

3. The plant activator for rice according to claim 1, wherein the oxo fatty acid contains ketooctadecadienoic acid.

4. The plant activator for rice according to claim 1, wherein the oxo fatty acid comprises at least one selected from the group consisting of 9-oxo-10,12-octadecadienoic acid, 13-oxo-9,11-octadecadienoic acid, 5-oxo-6,8-octadecadienoic acid, 6-oxo-9,12-octadecadienoic acid, 8-oxo-9,12-octadecadienoic acid, 10-oxo-8,12-octadecadienoic acid, 11-oxo-9,12-octadecadienoic acid, 12-oxo-9,13-octadecadienoic acid, and 14-oxo-9,12-octadecadienoic acid.

5. The plant activator for rice according to claim 1, wherein the oxo fatty acid comprises at least two types of oxo fatty acids.

6. The plant activator for paddy rice according to claim 1, wherein the oxo fatty acid comprises at least one selected from the oxo fatty acid represented by the following formula (I) and the oxo fatty acid represented by the following formula (II). Formula (I): HOOC-(R １ )-CH=CH-C(=O)-R ２ Formula (II): HOOC-(R ３ )-C(=O)-CH=CH-R ４ [In formula (I), R １ This represents a hydrocarbon group having 6 to 12 carbon atoms, R ２ R represents a hydrocarbon group having 2 to 8 carbon atoms. In formula (II), R ３ R represents a hydrocarbon group having 3 to 10 carbon atoms. ４ This indicates a hydrocarbon group having 4 to 11 carbon atoms.

7. R in the formula (I) １ includes a double bond that forms a conjugated double bond together with the double bond between the α-carbon and the β-carbon of the carbonyl group, and R in the formula (II) ３ includes a double bond that forms a conjugated double bond together with the double bond between the α-carbon and the β-carbon of the carbonyl group, The plant activator for rice according to claim 6.

8. In the above formula (I), R １ is a hydrocarbon group with 9 carbon atoms, R ２ is a hydrocarbon group having 5 carbon atoms, and in formula (II), R ３ is a hydrocarbon group with 7 carbon atoms, R ４ The plant activator for rice according to claim 6, wherein is a hydrocarbon group having 7 carbon atoms.

9. The rice plant activator according to claim 6, wherein the oxo fatty acid comprises an oxo fatty acid represented by formula (I) and an oxo fatty acid represented by formula (II).

10. The plant activator for rice according to claim 9, wherein the oxo fatty acid represented by formula (I) contains 13-oxo-9,11-octadecadienoic acid, and the oxo fatty acid represented by formula (II) contains 9-oxo-10,12-octadecadienoic acid.

11. The plant activator for paddy rice according to claim 1, wherein the terpene comprises a monoterpene.

12. The plant activator for rice according to claim 1, further comprising a hydroxylated fatty acid, a derivative of a hydroxylated fatty acid, or a salt of a hydroxylated fatty acid.

13. The plant activator for rice according to claim 12, wherein the hydroxylated fatty acid comprises at least one selected from the group consisting of 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid.

14. A plant activator for paddy rice according to any one of claims 1 to 13, for increasing at least one of selected from paddy rice height and mass.

15. A plant activator for rice according to any one of claims 1 to 13, for improving the stress tolerance of rice to reduced fertilizer use or mid-season drainage.

16. A plant activator for rice according to any one of claims 1 to 13, for increasing the yield of rice.

17. A plant activator for rice cultivation according to any one of claims 1 to 13, which is a spray agent, a dipping agent, or a soil drenching agent.

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