JP7684452B2 - Plant activators - Google Patents

Description

The present invention relates to a plant activator.

Technologies for regulating plant growth have been developed with the aim of improving the supply efficiency of grain plants and horticultural plants. In addition to measures such as optimizing temperature and sunlight conditions and fertilization, methods have been reported for activating plants using plant activators that have plant growth regulating effects such as promoting growth, suppressing dormancy, and suppressing stress.

Patent Document 1 reports a plant activator that contains an oxo fatty acid derivative or its salt or ester as an active ingredient. The plant activator described in Patent Document 1 has excellent resistance induction and growth promotion effects, but has the problem of being very unstable and quickly decomposing.

The decomposition is believed to be caused by oxidation, but there is no effective way to inhibit this decomposition, and there is a strong need for technology to prevent oxidation.

WO 2018/168860

The plant activator produced by the method described in Patent Document 1 has the problem that it is easily oxidized in the atmosphere. In order to stably exert its effect as a plant activator over the long term, there is a demand for a plant activator that is not easily oxidized and can maintain its effect as a plant activator.

The present invention aims to provide a plant activator that contains an antioxidant to prevent oxidation and has excellent disease resistance and growth promotion effects.

The present invention relates to a composition comprising an oxo fatty acid or a derivative or a salt thereof,
The following formula (I) and/or (II)
HOOC-(R ¹ )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R ² (I)
HOOC-(R ¹ )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R ² (II)
(In the formula,
R ¹ is a linear or branched hydrocarbon group containing 4 to 12 carbon atoms, which may contain one or more double bonds and/or OH groups, and when it contains a double bond, the position of the double bond is not limited;
^R2 is a linear or branched hydrocarbon group containing 2 to 8 carbon atoms, which may contain one or more double bonds and/or OH groups, and when it contains a double bond, the position of the double bond is not limited.
A hydroxylated fatty acid having the structural formula:
The present invention relates to a plant activator comprising at least one member selected from the group consisting of a phenolic antioxidant, ascorbic acid, and tocopherol, wherein R ¹ is preferably —(CH ₂ ) _n — (wherein n is an integer of 4 to 12).

Preferably, the plant activator is characterized in that the phenolic antioxidant is butyl hydroxyanisole.

Preferably, the plant activator contains at least one selected from the phenolic antioxidants, ascorbic acid, and tocopherol in an amount 1/2 to 5 times the amount of the active ingredient by weight.

The plant activator is preferably a hydroxylated fatty acid in which the hydrocarbon group of R ¹ has 6 to 8 carbon atoms and the hydrocarbon group of R ² has 4 to 6 carbon atoms.

The plant activator is preferably a hydroxylated fatty acid in which R ¹ of the hydroxylated fatty acid has a structure of -(CH ₂ ) _n - (n is an integer from 4 to 12) and R ² has a structure of C _n H _2n+1 - (n is an integer from 2 to 8).

The plant activator is preferably a hydroxylated fatty acid in which R ¹ is an alkylene group having 7 carbon atoms (-(CH ₂ ) ₇ --) and R ² is an alkyl group having 5 carbon atoms (CH ₃ CH ₂ CH ₂ CH ₂ CH ₂ --).

Preferably, the hydroxylated fatty acid is hydroxyoctadecenoic acid.

Preferably, the hydroxylated fatty acid is 9,10,13-trihydroxy-11-octadecenoic acid.

Preferably, the plant activator is one in which the hydroxylated fatty acid is 9,12,13-trihydroxy-10-octadecenoic acid.

Note that "octadecaenoic acid" is a conventional notation (for example, JP Patent Publication 3-14539, etc.), and the above-mentioned "9,10,13-trihydroxy-11-octadecenoic acid" is also written as "9,10,13-trihydroxyoctadec-11-enoic acid" or "9,10,13-trihydroxy-11-octadecenoic acid". Similarly, the above-mentioned "9,12,13-trihydroxy-10-octadecenoic acid" is also written as "9,12,13-trihydroxyoctadec-10-enoic acid" or "9,12,13-trihydroxy-10-octadecenoic acid". Note that in the examples, the manufacturer's name is also written in parentheses. The above explanation also applies to all "octadecaenoic acid" used in this specification, claims, drawings, and abstract.

The structural formula of "9,10,13-trihydroxy-11-octadecaenoic acid" is shown in the following structural formula (1).

The structural formula of "9,12,13-trihydroxy-10-octadecenoic acid" is shown in the following structural formula (2).

Preferably, the plant activator is one in which the oxo fatty acid is ketooctadecadienoic acid.

Preferably, the plant activator is one in which the oxo fatty acid is 13-oxo-9,11-octadecadienoic acid.

As the derivatives of the oxo fatty acids and hydroxylated fatty acids, esters of the oxo fatty acids and hydroxylated fatty acids are preferred. As the salts of the oxo fatty acids and hydroxylated fatty acids, sodium salts, potassium salts, ammonium salts, etc. can be used.

It is preferable that the plant activator is a plant activator used as a spray or immersion agent that is brought into contact with the stems, leaves, or roots of a plant, or as a soil drenching agent.

The plant activator is preferably a plant activator used for plants selected from the Brassicaceae, Poaceae, Leguminosae, Solanaceae, Rosaceae, Amaranthaceae, and Malvaceae families.

The plant activator of the present invention has excellent stability of the active ingredient and has excellent disease resistance and growth promotion effects.

Plant activator The plant activator of the present invention is
and a compound represented by the following formula (I) and/or (II):
HOOC-(R ¹ )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R ² (I)
HOOC-(R ¹ )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R ² (II)
(In the formula,
R ¹ is a linear or branched hydrocarbon group containing 4 to 12 carbon atoms, which may contain one or more double bonds and/or OH groups, and when it contains a double bond, the position of the double bond is not limited;
^R2 is a linear or branched hydrocarbon group containing 2 to 8 carbon atoms, which may contain one or more double bonds and/or OH groups, and when it contains a double bond, the position of the double bond is not limited.
A hydroxylated fatty acid having the structural formula:
and at least one selected from the group consisting of a phenolic antioxidant, ascorbic acid, and tocopherol. In particular, R ¹ is preferably -(CH ₂ ) _n - (wherein n is an integer from 4 to 12). The oxo fatty acid and the compound having the structural formula represented by formula (I) and/or (II) above include all geometric isomers and stereoisomers thereof.

In the present invention, "plant activation" means adjusting the plant's growth activity in some way to activate or maintain it, and includes plant growth regulation effects such as growth promotion (a concept that includes the expansion of stems and leaves, and the promotion of tuber and root growth), dormancy suppression, induction and conferring of resistance to plant stress (e.g., disease), and anti-aging.

The plant activator of the present invention contains, as active ingredients for activating plants, an oxo fatty acid or a derivative or a salt thereof, and a hydroxylated fatty acid or a derivative or a salt thereof. For example, an example of an oxo fatty acid is ketooctadecadienoic acid. For example, specific examples of ketooctadecadienoic acids 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, as well as isomers thereof.

The present inventors have confirmed that by inoculating a plant with a hydroxylated fatty acid having the structural formula shown in the above formula (I) and/or (II) or a derivative or a salt thereof, the plant exhibits a significant increase in the length and number of leaves, which are indicators of plant growth, as well as the weight of leaves and plants, an increase in the number of stems per plant, and promotion of tuber or tuberous root growth, as compared to untreated plants, and have found that the hydroxylated fatty acid having the structural formula shown above or a derivative or a salt thereof has an excellent plant activation effect. For example, hydroxylated fatty acids include hydroxyoctadecenoic acid, etc. Specific examples of hydroxyoctadecenoic acid include 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid, as well as their isomers.

In this specification, the term "active ingredient" refers to such oxo fatty acids and hydroxylated fatty acids. Oxo fatty acids such as ketooctadecadienoic acid and hydroxylated fatty acids such as hydroxyoctadecadienoic acid have excellent plant growth activating properties, and therefore, by contacting a part of a plant's stems, leaves, or roots with the plant activator of the present invention, which contains an oxo fatty acid or a derivative or a salt thereof and a hydroxylated fatty acid or a derivative or a salt thereof as active ingredients, a very high plant growth promoting effect can be imparted to the plant.

As the derivatives of the oxo fatty acids and hydroxylated fatty acids, esters are preferred. As the salts of the oxo fatty acids and hydroxylated fatty acids, sodium salts, potassium salts, ammonium salts, etc. can be used.

However, hydroxylated fatty acids are oxidized in the atmosphere. Also, oxo fatty acids are converted to hydroxylated fatty acids when they react with oxygen and water in the atmosphere. Because oxo fatty acids are converted to hydroxylated fatty acids faster than hydroxylated fatty acids are oxidized, the amount of hydroxylated fatty acids increases over time when the two coexist.

At least one selected from the phenolic antioxidant, ascorbic acid, and tocopherol contained in the plant activator of the present invention acts as an antioxidant that inhibits the decomposition of the oxo fatty acid or its derivative or its salt and the hydroxylated fatty acid or its derivative or its salt, which are the active ingredients in the plant activator. As a result, the plant activator of the present invention is stabilized. That is, by containing such an antioxidant, the activation effect and storage stability of the plant activator are prevented from decreasing during processing, distribution, and storage when the plant activator is formulated, and the effectiveness of the plant activator when applied is ensured. For example, preferred examples of antioxidants that contribute to the stabilization of the plant activator are phenolic antioxidants, ascorbic acid (vitamin C), and tocopherol (vitamin E). However, the present invention is not limited to tocopherol, and other vitamin E, such as natural or synthetic vitamin E homologues, and various derivatives and analogues of vitamin E having antioxidant activity, can also be used. In addition, the ascorbic acid (vitamin C) of the present invention includes oxidized forms and isomers of ascorbic acid. In addition, an example of a phenolic antioxidant is butyl hydroxyanisole. However, other phenolic antioxidants that have antioxidant properties can also be used.

The addition of the antioxidant of the present invention does not reduce or destroy the excellent growth-promoting effect of the plant activator containing an oxo fatty acid or a derivative thereof or a salt thereof and a hydroxylated fatty acid or a derivative thereof or a salt thereof. Furthermore, the addition of the antioxidant does not have an adverse effect on the plant body to which it is applied. Therefore, by adding the antioxidant of the present invention, the excellent activating effect of the plant activator containing an oxo fatty acid or a derivative thereof or a salt thereof and a hydroxylated fatty acid or a derivative thereof or a salt thereof remains the same, and by suppressing the decomposition of the active ingredients in the plant activator, it is possible to achieve the maintenance of a stable activating effect of the plant activator over a long period of time.

In the present invention, the antioxidant may be added in a ratio of about 5 times or less by weight relative to the amount of the active ingredient in the plant activator. The preferred concentration of the antioxidant that may be contained in the plant activator of the present invention may depend on the plant species and its condition to which it is applied, but if the ratio exceeds 5 times, there is a risk of causing phytotoxicity to the plant to which it is applied. There is no particular lower limit for the antioxidant concentration, but it is preferably about 1/2 or more by weight relative to the amount of the active ingredient. In a preferred embodiment of the present invention, the ratio of the antioxidant is 1/2 to 5 times by weight relative to the amount of the active ingredient.

The amount of active ingredient in the present invention refers to the total amount of oxo fatty acids and hydroxylated fatty acids or their derivatives or salts contained in the plant activator of the present invention. For example, the amount of active ingredient in the plant activator of the present invention is about 0.2 to 2.0 g/L. The plant activator of the present invention contains an antioxidant in an amount 1/2 to 5 times the amount of the active ingredient by weight. By adding an antioxidant in this amount, decomposition of the active ingredient in the plant activator is significantly suppressed, and the activating effect can be maintained for a long period of time.

The plant activator of the present invention may contain, as necessary, a compatible surfactant and/or diluent or carrier suitable for use as a plant activator. These added components are not particularly limited as long as they are agriculturally acceptable agents. In addition, the plant activator may further contain components other than the surfactant, diluent, and carrier that are typically used in pesticide formulations.

The plant activator of the present invention can be applied to plants by any method. For example, it can be used as a spray or immersion agent that is brought into contact with the stems, leaves, or roots of a plant, or as a soil drenching agent. The plant activator of the present invention may also be contained in a porous structure or capsule, or impregnated in a sheet or the like, and used as a sustained-release agent. The plant activator of the present invention imparts a plant growth-promoting effect to the plant to which it is applied.

The plant to which the plant activator of the present invention can be applied is not particularly limited, and can be used effectively for plants in general, such as plants of the Poaceae, Fabaceae, Solanaceae, Rosaceae, Amaranthaceae, Malvaceae, or Brassicaceae. For example, the growth of the following plants is effectively promoted: Poaceae plants, such as grass, rice, wheat, and corn; Legumes, such as soybeans, broad beans, kidney beans, and licorice; Solanaceae plants, such as tomatoes, eggplants, chili peppers, green peppers, and potatoes; Rosaceae plants, such as strawberries; Amaranthaceae plants, such as spinach; Malvaceae plants, such as cotton and okra; and Brassicaceae plants, such as komatsuna and mizuna. The plants to which the plant activator of the present invention can be applied are not limited to wild-type plants, and may be, for example, mutants or transformants. The varieties of each plant are also not particularly limited.

It has also been found that the plant activator of the present invention can be used as a plant activator that exhibits a strong resistance induction effect, and has been found to exhibit growth promotion effects, fruit yield increasing effects, and disease suppression effects in various plants. Specific examples of disease suppression effects include gray mold disease, vine splitting, vine wilt, and downy mildew in Cucurbitaceae plants such as cucumber, watermelon, melon, and pumpkin; bacterial wilt disease, wilt disease, half-leaf wilt disease, damping-off disease, and brown root rot disease in Solanaceae plants such as tomato, eggplant, and potato; powdery mildew, black spot disease, gray mold disease, and anthracnose in Rosaceae plants such as rose and strawberry; downy mildew in Amaranthaceae plants such as spinach; black rot disease, soft rot disease, bacterial spot disease in Brassicaceae plants such as Chinese cabbage, cabbage, and Komatsuna; Rhizoctonia disease; southern blight in Apiaceae plants such as carrot; and blast disease in Gramineae plants.

The present invention will be described based on examples, but the present invention is not limited to only the examples.

Example 1
Preparation of plant activator As hydroxylated fatty acids, hydroxyoctadecaenoic acids, such as 9,10,13-trihydroxy-11-octadecenoic acid (Larodan Fine Chemicals, 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid (English: 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid), 200 mg/L ethanol solution) and 9,12,13-trihydroxy-10-octadecenoic acid (Larodan Fine Chemicals, 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid (English: 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid), 200 mg/L ethanol solution) were used. An aqueous solution containing hydroxyoctadecaenoic acid was prepared using a mixture of 9(S),10(S),13(S)-trihydroxy-11(E)-octadecenoic acid and 75mL of ethanol solution in 1L of water to a concentration of 15mg/L, and 35mL of ethanol solution of 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid was further dissolved in this aqueous solution to adjust the concentration to 7mg/L. 222mL of 13-oxo-9,11-octadecadienoic acid (13-oxoODA) ((9Z,11E)-13-oxo-9,11-octadecadienoic acid, manufactured by Cayman Chemical Co., Ltd., 100μg/100μL ethanol solution) was added to 778mL of this aqueous solution, and the resulting solution was used as a test plant activator.

Addition of Vitamin C and Vitamin E and Accelerated Testing 680 mg of Vitamin C (Kanto Chemical Co., Ltd.) and 480 mg of Vitamin E (Nacalai Tesque, Inc.) were added to 1 L of the test plant activator obtained above (active ingredient amount 239 mg). The obtained solution was subjected to accelerated testing at 54°C using a Bioshaker (registered trademark) (BR-23UM, Taitec Co., Ltd.) and left for 5 weeks (equivalent to about 2 years at 25°C. See "Stability of Pharmaceuticals" by Sumie Yoshioka). The active ingredient concentration was measured by UV before and after the accelerated testing, and the ratio of the active ingredient concentration after the accelerated testing to the active ingredient concentration before the accelerated testing (active ingredient concentration change %) was calculated from the UV area ratio before and after the accelerated testing.

Example 2
To 1 L of the test plant activator obtained above (active ingredient amount 239 mg), 480 mg of butyl hydroxyanisole (manufactured by Kishida Chemical Co., Ltd.) which is a phenolic antioxidant was added, and this was used as the plant activator of Example 1. The obtained plant activator was subjected to an accelerated test at 54°C using a Bioshaker (registered trademark) (BR-23UM manufactured by Taitec Co., Ltd.) and left for 5 weeks (equivalent to about 2 years at 25°C. See "Stability of Pharmaceuticals" by Sumie Yoshioka). The active ingredient concentration was measured by UV before and after the accelerated test, and the ratio of the active ingredient concentration after the accelerated test to the active ingredient concentration before the accelerated test (change in active ingredient concentration %) was calculated from the UV area ratio before and after the accelerated test.

Example 3
To 1 L of the test plant activator obtained above (active ingredient amount 239 mg), 1110 mg of vitamin C was added. The obtained solution was subjected to accelerated testing at 54°C using a Bioshaker (registered trademark) (BR-23UM manufactured by Taitec Co., Ltd.) and left for 5 weeks (equivalent to approximately 2 years at 25°C. See "Stability of Pharmaceuticals" by Sumie Yoshioka). The active ingredient concentration was measured by UV before and after the accelerated testing, and the ratio of the active ingredient concentration after the accelerated testing to the active ingredient concentration before the accelerated testing (% change in active ingredient concentration) was calculated from the UV area ratio before and after the accelerated testing.

Example 4
To 1 L of the test plant activator obtained above (active ingredient amount 239 mg), 120 mg of vitamin E was added. The obtained solution was subjected to an accelerated test at 54°C using a Bioshaker (registered trademark) (BR-23UM manufactured by Taitec Co., Ltd.) and left for 5 weeks (equivalent to about 2 years at 25°C. See "Stability of Pharmaceuticals" by Sumie Yoshioka). The active ingredient concentration was measured by UV before and after the accelerated test, and the ratio of the active ingredient concentration after the accelerated test to the active ingredient concentration before the accelerated test (% change in active ingredient concentration) was calculated from the UV area ratio before and after the accelerated test.

Comparative Example 1
One liter of the test plant activator obtained above (active ingredient amount 239 mg) was subjected to an accelerated test at 54°C using a Bioshaker (registered trademark) (BR-23UM manufactured by Taitec Co., Ltd.) and left for 5 weeks (equivalent to approximately 2 years at 25°C. See "Stability of Pharmaceuticals" by Sumie Yoshioka). The active ingredient concentration was measured by UV before and after the accelerated test, and the ratio of the active ingredient concentration after the accelerated test to the active ingredient concentration before the accelerated test (% change in active ingredient concentration) was calculated from the UV area ratio before and after the accelerated test.

The results of the percentage change in active ingredient concentration obtained in Examples 1 to 4 and Comparative Example 1 are shown in Table 1 below.

As shown in Table 1, in Comparative Example 1, in which no antioxidant was added, the concentration of oxo fatty acids in the plant activator significantly decreased after 5 weeks of the accelerated test, and it can be seen that the oxo fatty acids were almost completely decomposed after the accelerated test. Accordingly, the concentration of hydroxylated fatty acids increased by about two times after the accelerated test compared to before the accelerated test, and it can be seen that the oxo fatty acids were decomposed and converted to hydroxylated fatty acids. On the other hand, in the plant activators of Examples 1 to 4 in which the antioxidant of the present invention was added, the concentration of oxo fatty acids was well maintained even after 5 weeks of the accelerated test. This shows that in Examples 1 to 4, the decomposition of oxo fatty acids was significantly suppressed by the addition of the antioxidant. In addition, in Examples 1 to 4, only a small increase in the concentration of hydroxylated fatty acids was observed, that is, the decomposition of oxo fatty acids and the conversion to hydroxylated fatty acids were suppressed. From these results, it can be seen that the plant activator containing the antioxidant of the present invention has an excellent effect on stabilizing oxo fatty acids and hydroxylated fatty acids, which are active ingredients for activating plants.

The above results show that the plant activator of the present invention, which contains at least one selected from the group consisting of a phenolic antioxidant, ascorbic acid, and tocopherol, has a remarkable effect on stabilizing the active ingredient.

Claims (5)

Ketooctadecadienoic acid or a salt thereof ;
The following formula (I) and/or (II)
HOOC-(R ¹ )-CH(OH)-CH(OH)-CH=CH-CH(OH)-R ² (I)
HOOC-(R ¹ )-CH(OH)-CH=CH-CH(OH)-CH(OH)-R ² (II)
(In the formula,
R ¹ is an alkylene group having 7 carbon atoms (-(CH ₂ ) ₇ -) ,
^R2 is an _alkyl group _having 5 _{carbon atoms} ( _{CH3CH2CH2CH2CH2CH2-} ) .
or a salt thereof ,
A plant activator comprising at least one member selected from the group consisting of a phenolic antioxidant, ascorbic acid and tocopherol. The plant activator according to claim 1, wherein the phenolic antioxidant is butylhydroxyanisole. 2. The plant activator according to claim 1, wherein the ketooctadecadienoic acid is 13-oxo-9,11-octadecadienoic acid. 4. The plant activator according to claim 1, which is used as a spray or immersion agent to be brought into contact with the stems, leaves or roots of a plant, or as a soil drench agent. The plant activator according to any one of claims 1 to 4 , which is used for a plant selected from the group consisting of Brassicaceae, Poaceae, Leguminosae, Solanaceae, Rosaceae, Amaranthaceae, and Malvaceae.