Plant growth inhibitor containing zwitterion

Abstract

To provide a novel plant growth inhibitor that can serve as a dwarfing agent effectively inhibiting growth of leaves and / or flower bud formation in plants, a plant growth inhibitor capable of retarding plant growth, or a novel safe and effective plant growth inhibitor applicable as a herbicide.SOLUTION: The present invention provides, for example, a plant growth inhibitor containing a zwitterion as illustrated below.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a zwitterion, a plant growth inhibitor containing the zwitterion, a composition, and a medium. The present invention also relates to a method for inhibiting plant growth and a method for regulating plant growth using the plant growth inhibitor. [Background technology]

[0002] Dwarfing agents (growth inhibitors) and herbicides are widely used in various fields, including agriculture and horticulture.

[0003] Dwarfing agents are chemicals that inhibit plant growth and improve the shape and appearance of plants. Many dwarfing agents exhibit activity similar to plant hormones or inhibit the synthesis of plant hormones. Currently, dwarfing agents in use include paclobutrazol and daminozide. Paclobutrazol is known to inhibit the vegetative growth of plants by inhibiting the biosynthesis of gibberellins. Commercially available products using paclobutrazol include Boundy (registered trademark) Flowable and Ishihara Smarect (registered trademark) Granules. These products are used to inhibit the growth of lawn grass and reduce the labor required for pruning, and to inhibit the growth of rice plants and increase their lodging resistance. A commercially available product using daminozide is Be-Nine Water-Soluble, which is used to inhibit the elongation of internodes in chrysanthemums.

[0004] As herbicides, substances that inhibit photosynthesis, amino acid biosynthesis, fatty acid biosynthesis, or cell division, or substances that disrupt plant growth hormones, such as glyphosate and carbutyrate, are used.

[0005] Meanwhile, zwitterions are compounds that contain both cations and anions in one molecule, and research into the effects of zwitterions (liquid zwitterions) with melting points of 100°C or lower is particularly in progress. For example, Kuroda et al. have reported that liquid zwitterions have low toxicity to cells and are expected to be useful as excipients for various poorly soluble drugs (Patent Document 1, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2018-191623 [Non-patent literature]

[0007] [Non-Patent Document 1] Kosuke Kuroda et al., 2020, communications chemistry, 3:163 Summary of the Invention [Problem to be solved by the invention]

[0008] Conventional dwarfing agents mainly inhibit stem elongation and have little effect on other organs such as leaves or flowers. Furthermore, there are currently no agents that aim to slow plant growth. Furthermore, there is a need for new, safe, and effective herbicides.

[0009] Therefore, an object of the present invention is to provide a novel plant growth regulator that can be used as a dwarfing agent that can effectively inhibit plant leaf growth and / or flower bud formation, to provide a plant growth regulator that can slow plant growth, or to provide a novel safe and effective plant growth regulator that can be used as a herbicide. [Means for solving the problem]

[0010] As a result of extensive research aimed at solving the above problems, the present inventors have found that zwitterions inhibit plant leaf growth and / or flower bud formation. The present inventors have also found that plant growth can be retarded by treating plants with zwitterions and then growing the plants in a medium that does not contain the zwitterions. The present inventors have further found that zwitterions can be used as herbicides. The present invention is based on these findings.

[0011] That is, the present invention includes the following. [1] A plant growth inhibitor containing a zwitterion. [2] The zwitterion is represented by the following formula (1): [ka] (In the formula, R1 is an alkyl group having 1 to 5 carbon atoms, which may contain 1 or 2 oxygen atoms in the molecular chain, R2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R3 is an alkylene group having 3 to 5 carbon atoms, A1 is -SO3 - , -COO - , -OP=O(H)O - , -OP=O(CH3)O - , and -OP=O(OR4)O - an anion selected from the group consisting of R4 is an alkyl group which may contain a heteroatom in the molecular chain. The plant growth inhibitor according to [1], [3] The zwitterion is represented by the following formula (2): [ka] (In the formula, R5 is an alkyl group having 1 to 5 carbon atoms, R6 and R7 are an alkyl group having 1 to 5 carbon atoms, or R6 and R7 together with the N atom to which they are bonded form a 5- or 6-membered heterocycle; R8 is an alkylene group having 3 to 5 carbon atoms; A2 is -SO3 - , -COO - , -OP=O(H)O - , -OP=O(CH3)O - , and -OP=O(OR9)O - an anion selected from the group consisting of R9 is an alkyl group which may contain a heteroatom in the molecular chain. The plant growth inhibitor according to [1], [4] The anion part of the zwitterion is a sulfonate ion -SO3 - The plant growth inhibitor according to any one of [1] to [3], wherein [5] In the formula (1), R1 is an alkyl group having 1 to 5 carbon atoms and not containing an oxygen atom, and A1 is -COO - The plant growth inhibitor according to [2], [6] In formula (2), A2 is -SO3 - The plant growth inhibitor according to [3], [7] The plant growth regulator according to any one of [1] to [6], for use in one or more of the following (i) to (v): (i) inhibiting plant growth without causing plant yellowing, (ii) transiently inhibiting plant growth, (iii) slowing plant growth, (iv) maintaining plant morphology, and (v) slowing plant senescence. [8] The plant growth regulator according to any one of [1] to [6], which is a herbicide. [9] A composition for plant growth inhibition, comprising the plant growth inhibitor according to any one of [1] to [8].

[10] A plant culture medium containing the plant growth inhibitor according to any one of [1] to [8].

[11] The plant culture medium according to

[10] , further comprising one or more of gravel, sand, vermiculite, perlite, rock wool, rice husks, bark, peat moss, coconut shells, polyester, and urethane.

[12] A method for inhibiting plant growth, comprising the step of applying the plant growth regulator according to any one of [1] to [8] to a plant.

[13] A method for regulating plant growth, comprising the steps of applying the plant growth inhibitor according to any one of [1] to [8] to a plant, and growing the plant to which the plant growth inhibitor has been applied in a medium that does not contain the plant growth inhibitor.

[14] The following formula (4) [ka] A zwitterion represented by [Effects of the Invention]

[0012] The plant growth regulator of the present invention can suppress leaf growth and / or flower bud formation. The plant growth regulator of the present invention can also slow plant growth or effectively kill plants such as weeds. [Brief explanation of the drawings]

[0013] [Figure 1] Figure 1 shows photographs showing the morphology of Arabidopsis thaliana plants grown for 10 days on MS medium containing C1imC3S (C1imC3S treatment) and those grown for 10 days on MS medium without C1imC3S (C1imC3S non-treatment). The scale bar indicates 1 cm. [Figure 2] Figure 2 is a graph showing the results of measuring the leaf area of ​​Arabidopsis thaliana plants grown for 10 days in MS medium containing C1imC3S (C1imC3S treatment) and those grown for 10 days in MS medium without C1imC3S (C1imC3S non-treatment). n > 10, *** p < 0.0001. [Figure 3-1] Figure 3 shows photographs showing the morphology of Arabidopsis thaliana plants grown for 10 days on MS medium containing C1imC3S (C1imC3S-treated) and Arabidopsis thaliana plants grown for 10 days on MS medium without C1imC3S (C1imC3S-untreated) when replanted in soil without C1imC3S. A: Morphology of Arabidopsis thaliana 7 days after replanting in soil. B: Morphology of Arabidopsis thaliana 14 days after replanting in soil. C: Morphology of Arabidopsis thaliana 21 days after replanting in soil. D: Morphology of Arabidopsis thaliana 28 days after replanting in soil. E: Morphology of Arabidopsis thaliana 35 days after replanting in soil. F: Morphology of Arabidopsis thaliana 59 days after replanting in soil. The scale bar indicates 5 cm. [Figure 3-2] This is a continuation of Figure 3-1. [Figure 3-3] This is a continuation of Figure 3-2. [Figure 4]Figure 4 is a graph showing the leaf area of ​​Arabidopsis thaliana plants grown for 10 days on MS medium containing C1imC3S (C1imC3S treatment) and those grown for 10 days on MS medium without C1imC3S (C1imC3S non-treatment) when they were replanted in soil without C1imC3S. n > 10, *** p < 0.0001, * p < 0.05, ns: no significant difference. [Figure 5] Figure 5 is a graph showing the bolting rate of Arabidopsis thaliana plants grown for 10 days on MS medium containing C1imC3S (C1imC3S treatment) and those grown for 10 days on MS medium without C1imC3S (C1imC3S non-treatment) when the plants were replanted in C1imC3S-free culture medium and grown thereafter (n = 32). [Figure 6] Figure 6 shows photographs showing the morphology of Arabidopsis plants grown for 10 days on MS medium containing C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N222C3S, or C1pyrrC3S, and Arabidopsis plants grown for 10 days on MS medium without zwitterions (untreated with zwitterions). The scale bar indicates 1 cm. [Figure 7] Figure 7 shows graphs showing leaf area measurements for Arabidopsis plants grown for 10 days on MS medium containing C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N222C3S, or C1pyrrC3S, and for Arabidopsis plants grown for 10 days on MS medium without zwitterions (untreated with zwitterions). a, b, c: Different letters indicate significant differences. n > 10. [Figure 8-1] Figure 8 shows photographs of Arabidopsis thaliana plants grown for 10 days on MS medium containing C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N222C3S, or C1pyrrC3S, and Arabidopsis plants grown for 10 days on MS medium without zwitterions (untreated with zwitterions) were transplanted into zwitterion-free medium and grown thereafter. The number of days on the left side of the photograph indicates the number of days since transplanting into C1imC3S-free medium. [Figure 8-2]This is a continuation of Figure 8-1. [Figure 8-3] This is a continuation of Figure 8-2. [Figure 9] FIG. 9 is a photograph showing the morphology of spinach grown in MS medium containing C1imC3S for 0, 12, and 18 days (C1imC3S-treated) and spinach grown in MS medium not containing C1imC3S for 0, 12, and 18 days (C1imC3S-untreated). [Figure 10] Figure 10 shows photographs of the morphology of spinach plants grown for 18 days on MS medium containing C1imC3S (C1imC3S treatment) and those grown for 18 days on MS medium without C1imC3S (C1imC3S non-treatment) when they were replanted in C1imC3S-free medium. The number of days on the left side of the photograph indicates the number of days since they were replanted in C1imC3S-free medium. [Figure 11] FIG. 11 is a photograph showing the morphology of Chinese chives grown in MS medium containing C1imC3S for 0, 12, and 24 days (C1imC3S-treated) and Chinese chives grown in MS medium not containing C1imC3S for 0, 12, and 24 days (C1imC3S-untreated). [Figure 12] Figure 12 shows photographs of the morphology of Chinese chives grown for 24 days on MS medium containing C1imC3S (C1imC3S treatment) and Chinese chives grown for 24 days on MS medium without C1imC3S (C1imC3S non-treatment) when transplanted into C1imC3S-free medium. The number of days on the left side of the photograph indicates the number of days since transplanting into C1imC3S-free medium. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below.

[0015] The present invention relates to a plant growth regulator containing a zwitterion (hereinafter, may be referred to as "the plant growth regulator of the present invention").

[0016] As used herein, "zwitterion" refers to a compound containing both a cation and an anion in one molecule. Zwitterions include aprotic zwitterions and protic zwitterions, but are particularly aprotic zwitterions. A zwitterion may be a liquid zwitterion. As used herein, "liquid zwitterion" refers to a zwitterion having a melting point of 100°C or less.

[0017] Examples of zwitterions include substances in which an ionic liquid-like cationic moiety and an ionic liquid-like anionic moiety are covalently linked. Preferably, the cationic and anionic moieties of the zwitterion are bonded via one or more alkylene groups having 1 to 15 carbon atoms, which may have one or more heteroatoms in the branched chain. Examples of heteroatoms include oxygen, nitrogen, sulfur, and phosphorus. By limiting the number of carbon atoms in the alkylene group to 1 to 5, the toxicity of the zwitterion to cells can be further reduced.

[0018] Examples of zwitterionic ionic liquid-like cations include phosphonium cations, ammonium cations, imidazolium cations, sulfonium cations, pyrazolium cations, pyridinium cations, pyrrolidinium cations, morpholinium cations, cyclopropenylium cations, and piperidinium cations each having one or more substituents. Among these, ammonium cations, imidazolium cations, and pyrrolidinium cations each having a substituent are preferred. The substituents may be the same or different and may be appropriately selected from, for example, alkyl groups having 1 to 18 carbon atoms and alkoxy groups having 1 to 18 carbon atoms, each of which may have one or more heteroatoms in the molecular chain. In particular, the substituent preferably has one or more alkyl groups having 1 to 5 carbon atoms, each of which may have one or more heteroatoms in the molecular chain. Limiting the number of carbon atoms in the alkyl chain to 1 to 5 can further reduce toxicity to cells. Examples of heteroatoms include oxygen, nitrogen, sulfur, and phosphorus.

[0019] An example of a zwitterionic ionic liquid-like anion is the carboxylate ion -COO - , sulfonate ion -SO3 - , phosphate ion -OP=O(H)O - , -OP=O(CH3)O - ,-OP=O(OR)O - (where R is an alkyl group which may have a heteroatom in the molecular chain). Among them, carboxylate ion -COO - or sulfonate ion -SO3 - , especially sulfonate ions -SO3 - is preferably used.

[0020] More specifically, examples of zwitterions contained in the plant growth inhibitor of the present invention include those represented by the following formula (1): [ka] In formula (1), R1 is an alkyl group having 1 to 5 carbon atoms which may contain one or two oxygen atoms in the molecular chain, R2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R3 is an alkylene group having 3 to 5 carbon atoms, and A1 is -SO3 - , -COO - , -OP=O(H)O - , -OP=O(CH3)O - , and -OP=O(OR4)O - and R4 is an alkyl group which may contain a heteroatom in the molecular chain.

[0021] Specific examples of R1 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, CHOCHCH-, and CHOCHCHOCHCH-. Specific examples of R2 include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Specific examples of R3 include a propylene group, a butylene group, and a pentylene group. Specific examples of R4 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

[0022] The zwitterion contained in the plant growth inhibitor of the present invention also includes a compound represented by the following formula (2): [ka] In formula (2), R5 is an alkyl group having 1 to 5 carbon atoms, R6 and R7 are alkyl groups having 1 to 5 carbon atoms, or R6 and R7 together with the N atom to which they are bonded form a 5- or 6-membered heterocycle, R8 is an alkylene group having 3 to 5 carbon atoms, and A2 is -SO3 - , -COO - , -OP=O(H)O - , -OP=O(CH3)O - , and -OP=O(OR9)O - and R9 is an alkyl group which may contain a heteroatom in the molecular chain.

[0023] Specific examples of R5 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Specific examples of R6 and R7 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Specific examples of the heterocycle formed by R6 and R7 together with the N atom include pyrrolidinium which may have a substituent. Examples of the substituent of pyrrolidinium include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Specific examples of R8 include a propylene group, a butylene group, and a pentylene group. Specific examples of R9 include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

[0024] The zwitterion represented by formula (2) includes the following formula (3): [ka] In formula (3), R5, R8, and A2 are as described in formula (2), and R 10 , R 11 , R12 and R 13 are each independently selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

[0025] Zwitterions represented by formula (1) include, for example, the following compounds: [ka] [ka] [ka] The zwitterion represented by formula (1) also includes a compound represented by the following formula (4): [ka]

[0026] Zwitterions represented by formula (2) include, for example, the following compounds: [ka] [ka]

[0027] The melting point of C1imC3S is 100°C or higher, the melting point of OE2imC3C is 64°C, the melting point of C4imC5C is 100°C or higher, the melting point of C1C1imC3C is 100°C or higher, and N 222 The melting point of C3S is 100°C or higher, and the melting point of C1pyrrC3S is 100°C or higher.

[0028] Although the zwitterions described above are salts, they do not cause salt damage and can therefore be used in plant cultivation. Among the zwitterions described above, C1C1imC3C (the compound represented by formula (4)) is a novel compound. Therefore, the present invention also provides the zwitterions described above, particularly C1C1imC3C.

[0029] The above zwitterions can be synthesized by appropriately employing organic synthesis methods commonly known to those skilled in the art.

[0030] That is, a zwitterion in which the cation is an imidazolium ion and the anion is a carboxylate ion can be obtained, for example, by refluxing 1-alkylimidazole and ethyl bromoalkylate in acetonitrile, washing with diethyl ether, mixing with an anion exchange resin, filtering, and distilling off the solvent under reduced pressure.

[0031] A zwitterion in which the cation is an imidazolium ion and the anion is a sulfonate ion can be obtained, for example, by refluxing 1-alkylimidazole and an alkane sultone in acetonitrile, washing with diethyl ether, and then distilling off the solvent under reduced pressure.

[0032] The alkyl group of the imidazole may contain one or more heteroatoms, such as one or two oxygen atoms. Also, by replacing 1-alkylimidazole with trialkylphosphines, trialkylamines, dialkylsulfones, pyridines, N-alkylpyrrolidines, etc., zwitterions with cations other than the imidazolium cation can be synthesized.

[0033] Alternatively, imidazole having an oligoether chain can be obtained by mixing NaH with tetrahydrofuran and adding imidazole and 1-bromo-2-(2-methoxyethoxy)ethane.

[0034] Similarly, various functional groups such as alkylimidazoles, trialkylphosphines, trialkylamines, dialkylsulfones, pyridines, and N-alkylpyrrolidines can be obtained, and these can be reacted with anionic reagents to obtain the desired zwitterions.

[0035] More detailed synthetic methods are described, for example, in JP 2018-191623 A, Kosuke Kuroda et al., 2017, J. Am. Chem. Soc., 139, 16052-16055, and in Example 2 below.

[0036] As used herein, the term "plant growth regulator" refers to a drug that has the effect of inhibiting plant growth. As used herein, "plant" includes the entire plant body or parts thereof (leaves, stems, roots, flower buds, flowers, flower stalks, etc.), seeds, etc. As used herein, "plant growth inhibition" refers to inhibiting the vegetative growth and / or reproductive growth of a plant, and includes, for example, inhibiting leaf growth, inhibiting stem growth, inhibiting root growth, inhibiting flower bud formation, and inhibiting flower bolting, but preferably refers to inhibiting leaf growth, flower bud formation, and / or flower bolting. "Borting" refers to the formation of flower buds and the extension of flower stalks.

[0037] Whether or not a test substance has a plant growth inhibitory effect can be evaluated, for example, using leaf area as an index. For example, plant seedlings are transplanted into a medium containing the test substance or a medium not containing the test substance, and after growing for a predetermined period (e.g., 10 days), the leaf area is measured. If the leaf area of ​​the plant grown in a medium containing the test substance is 1.5 times or more (e.g., 3 times or more) lower than the leaf area of ​​the plant grown in a medium not containing the test substance, the test substance can be determined to have a plant growth inhibitory effect.

[0038] Whether or not a test substance has a plant growth inhibitory effect can also be evaluated using, for example, the bolting rate as an index. For example, plant seedlings are transplanted into a medium containing the test substance or a medium not containing the test substance, and after growing for a predetermined period (e.g., 10 days), the plants are replanted in a culture medium not containing the test substance and grown until they die. Every 7 days from the time of replanting in the culture medium not containing the test substance until the plants die, the bolting rate is measured as the ratio of the number of plants that have formed flower buds to the total number of plants. If the bolting rate of the plants grown in the medium containing the test substance is 1.5 times or more (e.g., 3 times or more) lower than the bolting rate of the plants grown in the culture medium not containing the test substance on any day from the time of replanting in the culture medium not containing the test substance until the plants die, the test substance can be determined to have a plant growth inhibitory effect.

[0039] In Examples 1 and 2 described below, six zwitterions, C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 It was shown that C3S, C1pyrrC3S, and C1pyrrC3S all have plant growth inhibitory activity. Therefore, in particular, C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 C3S, C1pyrrC3S, and analogous compounds thereof can be used as the active ingredient of the plant growth inhibitor of the present invention.

[0040] The plant to which the plant growth regulator of the present invention is applied may be, for example, an ornamental flowering plant, an agricultural crop such as edible vegetables or fruits, a roadside tree, or turfgrass. The plant to which the plant growth regulator of the present invention is applied may also be either an annual or perennial plant. The plant may also be a terrestrial or aquatic plant, and may also be a herbaceous plant or a woody plant. The plant to which the plant growth regulator of the present invention is applied may be, for example, an annual herbaceous plant.

[0041] Plants to which the plant growth inhibitor of the present invention is applied include, but are not limited to, mosses, ferns, gymnosperms, and angiosperms. Angiosperms include, for example, monocotyledons and dicotyledons. Examples of monocotyledonous plants include plants from the Amaryllidaceae family (e.g., chives, leeks, onions, garlic, and scallions), Liliaceae family (e.g., lilies and tulips), Poaceae family (e.g., rice, wheat, barley, rye, oats, Job's tears, corn, millet, foxtail millet, barnyard millet, finger millet, pearl millet, teff, sugarcane, lawn grass, Zoysiagrass, Bermudagrass, and centipede grass), Bromeliaceae family (e.g., pineapple), Palmaceae family (e.g., coconut palm, oil palm, and date palm), Araceae family (e.g., taro), Dioscoreaceae family (e.g., yams, Chinese yams, and Chinese yams), Zingiberaceae family (e.g., ginger and turmeric), Orchidaceae family (e.g., orchids), and Cannaceae family (e.g., canna). Examples of dicotyledonous plants include Brassicaceae (e.g., rapeseed, cabbage, komatsuna, radish, Chinese cabbage, broccoli), Amaranthaceae (e.g., spinach, beet, Okahijiki), Cucurbitaceae (e.g., gourd, cucumber, pumpkin, watermelon, zucchini), Fabaceae (e.g., soybean, kidney bean, broad bean, sweet pea, black locust), Asteraceae (e.g., lettuce, chrysanthemum, sunflower, cosmos, marigold, daisy, gerbera), Lamiaceae (e.g., perilla, basil, mint), Solanaceae (e.g., eggplant, tomato, potato, tobacco, petunia), Rosaceae (e.g., , strawberry, rose, cherry), Apiaceae (e.g., carrot), Convolvulaceae (e.g., sweet potato, morning glory), Nelumbaceae (e.g., lotus), Violaceae (e.g., pansy, viola), Plantaginaceae (e.g., snapdragon), Campanulaceae (e.g., bellflower), Ranunculaceae (e.g., clematis), Primulaceae (e.g., cyclamen), Caryophyllaceae (e.g., carnation, gypsophila), Salicaceae (e.g., poplar, weeping willow), Ericaceae (e.g., azalea), Malvaceae (e.g., cotton, chiffonier), and Platanaceae (e.g., plane tree).

[0042] The plant to which the plant growth inhibitor of the present invention is applied is preferably a terrestrial plant, more preferably an angiosperm such as a monocotyledonous plant or a dicotyledonous plant, even more preferably a plant of the Amaryllidaceae, Brassicaceae, or Amaranthaceae family, for example, Chinese chive, leek, onion, garlic, shallot, Arabidopsis thaliana, rapeseed, cabbage, komatsuna, radish, Chinese cabbage, broccoli, spinach, beet, or okahijiki.

[0043] The plant growth regulator of the present invention can be used for any one or more of the following (i) to (v): (i) inhibiting plant growth without causing plant yellowing, (ii) transiently inhibiting plant growth, (iii) slowing plant growth, (iv) maintaining plant morphology, and (v) slowing plant senescence.

[0044] Inhibiting plant growth without causing the plant to turn yellow can, for example, extend the period during which the plant can be enjoyed or reduce the effort required to maintain the plant's morphology.

[0045] In general, the longer the growing period of a plant, the higher its yield. Therefore, by temporarily suppressing or slowing plant growth, the growing period from sowing to harvest can be extended, resulting in an increased yield. Furthermore, crops such as vegetables can sometimes be oversupplied due to weather or other factors, causing prices to collapse. However, by temporarily suppressing or slowing plant growth, it becomes possible to harvest crops in line with demand.

[0046] As used herein, "delaying plant growth" means extending the period of time it takes for a plant to grow to a predetermined state, for example, the period from sowing to flower bud formation or bolting, or the period from sowing to harvest. The plant growth regulator of the present invention can delay plant growth by, for example, 10 days, 20 days, 1 month, 2 months, 3 months, or 6 months.

[0047] The plant growth inhibitor of the present invention may be, for example, a dwarfing agent or a herbicide. As used herein, the term "herbicide" particularly refers to an agent that causes plants to wither and die by suppressing plant growth.

[0048] In one embodiment, the plant growth regulator of the present invention comprises a zwitterion.

[0049] The plant growth regulator of the present invention can be applied to a plant by, for example, adding the plant growth regulator of the present invention to a medium in which the plant is grown, or by transplanting the plant into a medium containing the plant growth regulator of the present invention. The plant growth regulator of the present invention can be added to a medium in an amount effective for plant growth inhibition. For example, the plant growth regulator can be added to a medium so that the zwitterion concentration in the medium is 1 mM or more, 10 mM or more, 25 mM or more, 50 mM or more, or 75 mM or more, 10 M or less, 1 M or less, 500 mM or less, 400 mM or less, 300 mM or less, 250 mM or less, 200 mM or less, 150 mM or less, or 125 mM or less, for example, 1 mM to 10 M, 10 mM to 1 M, 10 mM to 500 mM, 25 mM to 250 mM, 75 mM to 125 mM, or 100 mM. The amount of the plant growth regulator of the present invention added to a medium can be appropriately adjusted depending on the intended use of the plant growth regulator of the present invention and the type of zwitterion.

[0050] The plant growth regulator of the present invention may be applied at an appropriate time depending on the intended use, for example, at the seed or seedling stage, during the vegetative growth period, during the reproductive growth period, or a combination thereof.

[0051] The plant to which the plant growth regulator of the present invention has been applied may be continued to grow in a medium containing the plant growth regulator of the present invention, or may be further grown in a medium not containing the plant growth regulator of the present invention. By applying the plant growth regulator of the present invention to a plant and then growing the plant in a medium not containing the plant growth regulator of the present invention, the plant growth can be transiently suppressed and delayed.

[0052] In one embodiment, the zwitterion used in the plant growth inhibitor of the present invention has an anion moiety in which the anion moiety is a sulfonate ion -SO3 - Zwitterions such as C1imC3S, N 222C3S, C1pyrrC3S, or their analogous compounds. C1imC3S, N 222 C3S or a compound similar to C1pyrrC3S is, for example, a zwitterion represented by the above formula (1), in which A1 is -SO3 - or a zwitterion represented by the above formula (2), wherein A2 is -SO3 - is a zwitterion.

[0053] In Examples 1 and 2 described below, zwitterions C1imC3S, N, in which the anion moiety is a sulfonate ion, are used. 222 C3S and C1pyrrC3S significantly inhibited plant growth without causing leaf yellowing. After treatment, plants treated with these zwitterions were initially smaller and bolting was slower than plants not treated with zwitterions, but eventually grew to a size similar to that of plants not treated with zwitterions, and bolting and seed formation occurred normally.

[0054] Therefore, the anion part is a sulfonate ion -SO3 - The plant growth regulator containing the zwitterion represented by the formula (I) can be used, in particular, for one or more of the following purposes (i) to (v): (i) inhibiting plant growth without causing plant yellowing, (ii) transiently inhibiting plant growth, (iii) slowing plant growth, (iv) maintaining plant morphology, and (v) delaying plant senescence.

[0055] In another embodiment, the zwitterion used in the plant growth inhibitor of the present invention is a zwitterion in which the cation moiety is an imidazolium cation substituted with an alkyl group and the anion moiety is a carboxylate ion, such as C4imC5C or C1C1imC3C, or an analogous compound thereof. An analogous compound of C4imC5C or C1C1imC3C is, for example, a zwitterion represented by the above formula (1), in which A1 is -COO - and R1 is an alkyl group having 1 to 5 carbon atoms and not containing an oxygen atom, making it a zwitterion.

[0056] In Example 2 described below, it was shown that C4imC5C and C1C1imC3C significantly inhibit plant growth, and that C4imC5C and C1C1imC3C are highly toxic to plants and cause leaf yellowing. Therefore, a plant growth regulator containing C4imC5C or C1C1imC3C or a compound similar thereto can be used, in particular, as a herbicide.

[0057] As mentioned above, currently, dwarfing agents mainly used are substances that exhibit activity similar to plant hormones or that inhibit the synthesis of plant hormones. However, such substances mainly inhibit stem elongation and have little effect on other organs such as leaves or flowers. Furthermore, application of such substances to plants outside the appropriate concentration range often results in an effect opposite to the desired effect, so the dosage must be strictly controlled.

[0058] In contrast, the plant growth regulator of the present invention can inhibit leaf growth and / or flower bud formation. Furthermore, since the zwitterion, which is the active ingredient of the plant growth regulator of the present invention, is thought to inhibit plant growth by a mechanism of action different from that of plant hormones, it is thought that the amount of the plant growth regulator of the present invention administered to plants can be easily controlled.

[0059] The present invention also provides a composition for plant growth inhibition (hereinafter, sometimes referred to as "the composition of the present invention") containing the plant growth inhibitor described above.

[0060] The composition of the present invention contains a zwitterion contained in a plant growth inhibitor as an essential active ingredient. The zwitterion may be, for example, a zwitterionic liquid. The zwitterion may also be, for example, a zwitterion represented by the above formula (1) or (2).

[0061] The compositions of the present invention may further contain other plant growth regulators or essential elements (such as hydrogen (H), oxygen (O), carbon (C), nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S), iron (Fe), manganese (Mg), zinc (Zn), boron (B), molybdenum (Mo), copper (Cu), chlorine (Cl), and nickel (Ni)).

[0062] The composition of the present invention may further contain agriculturally acceptable additives (for example, carriers (such as solid or liquid carriers), excipients, diluents, disintegrants, binders, coating agents, lubricants, glidants, glidants, emulsifiers, surfactants, solubilizers, suspending agents, preservatives, buffers, pH adjusters), etc.

[0063] The composition of the present invention may be formulated into any dosage form, such as a solid preparation such as a dust, granule, particle, wettable powder, or water-soluble agent; a liquid preparation such as an emulsion, liquid, or oil; an aerosol, paste, or spray.

[0064] The composition of the present invention can be used to inhibit plant growth. The composition of the present invention can also be used for any one or more of the following (i) to (v): (i) inhibiting plant growth without causing plant yellowing, (ii) transiently inhibiting plant growth, (iii) slowing plant growth, (iv) maintaining plant morphology, and (v) delaying plant senescence. The composition of the present invention can be, for example, a dwarfing agent or a herbicide.

[0065] The composition of the present invention can be applied to plants in the same manner as the plant growth inhibitor of the present invention. The content of the zwitterion in the composition of the present invention is not limited, provided that the final concentration of the zwitterion when added to a medium or the like is effective for plant growth inhibition. The concentration of the zwitterion in the composition of the present invention is not limited, and is, for example, 10 mM to 10 M or 100 mM to 1 M. The composition of the present invention can be added to a medium so that the concentration of the zwitterion in the medium is, for example, 1 mM or more, 10 mM or more, 25 mM or more, 50 mM or more, or 75 mM or more, 10 M or less, 1 M or less, 500 mM or less, 400 mM or less, 300 mM or less, 250 mM or less, 200 mM or less, 150 mM or less, or 125 mM or less, e.g., 1 mM to 10 M, 10 mM to 1 M, 10 mM to 500 mM, 25 mM to 250 mM, 75 mM to 125 mM, or 100 mM.

[0066] The plants to which the composition of the present invention is applied are similar to the targets to which the plant growth inhibitor of the present invention is applied as described above, and are preferably terrestrial plants, more preferably angiosperms such as monocotyledons or dicotyledons, and even more preferably plants of the Amaryllidaceae, Brassicaceae, or Amaranthaceae families, such as chives, leeks, onions, garlic, shallots, Arabidopsis thaliana, rapeseed, cabbage, komatsuna, radish, Chinese cabbage, broccoli, spinach, beets, or okahijiki.

[0067] The present invention also provides a plant culture medium (hereinafter, sometimes referred to as "the culture medium of the present invention") containing the plant growth inhibitor of the present invention. As used herein, the term "culture medium" refers to a medium used for growing plants, and includes liquid and solid media. There are no particular limitations on the liquid medium as long as it is suitable for cultivating plants, but it preferably contains essential elements (hydrogen (H), oxygen (O), carbon (C), nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S), iron (Fe), manganese (Mg), zinc (Zn), boron (B), molybdenum (Mo), copper (Cu), chlorine (Cl), nickel (Ni), etc.). Liquid media may contain, for example, inorganic salts (e.g., potassium nitrate, ammonium nitrate, magnesium sulfate, iron sulfate, manganese sulfate, zinc sulfate, copper sulfate, potassium phosphate, sodium molybdate, disodium ethylenediaminetetraacetic acid, boric acid, calcium chloride, cobalt chloride, potassium iodide, etc.), sugars, amino acids, vitamins, etc., and examples thereof include Murashige-Skoog (MS) medium, White's medium, and commercially available Hyponex (registered trademark) solution. Examples of solid media include culture soil, liquid media solidified by adding a gelling agent such as agar, gelatin, gellan gum, or cross-linked polyacrylic acid polymer, gravel, sand, vermiculite, perlite, rock wool, rice husks, bark, peat moss, coconut shells, polyester, and urethane. Liquid media may also be added to solid media for use.

[0068] The present invention also provides a method for inhibiting plant growth (hereinafter, sometimes referred to as "the inhibition method of the present invention"), which comprises the step of applying the plant growth inhibitor of the present invention to a plant.

[0069] The plants to which the suppression method of the present invention is applied are similar to the targets to which the plant growth inhibitor of the present invention is applied as described above, and are terrestrial plants, more preferably angiosperms such as monocotyledons or dicotyledons, and even more preferably plants of the Amaryllidaceae, Brassicaceae, or Amaranthaceae families, such as chives, leeks, onions, garlic, shallots, Arabidopsis thaliana, rapeseed, cabbage, komatsuna, radish, Chinese cabbage, broccoli, spinach, beets, or okahijiki.

[0070] In the suppression method of the present invention, the zwitterion contained as an active ingredient in the plant growth regulator may be, for example, a liquid zwitterion.In the suppression method of the present invention, the zwitterion contained as an active ingredient in the plant growth regulator may also be, for example, a zwitterion represented by the above formula (1) or (2).

[0071] In the suppression method of the present invention, the plant growth inhibitor can be applied, for example, by adding the plant growth inhibitor to a medium in which the plant is growing, or by transplanting the plant into a medium containing the plant growth inhibitor.

[0072] The plant growth inhibitor may be added to the medium in an amount effective for plant growth inhibition. For example, the plant growth inhibitor can be added to the medium so that the concentration of the zwitterion in the medium is 1 mM or more, 10 mM or more, 25 mM or more, 50 mM or more, or 75 mM or more, or 10 M or less, 1 M or less, 500 mM or less, 400 mM or less, 300 mM or less, 250 mM or less, 200 mM or less, 150 mM or less, or 125 mM or less, for example, 1 mM to 10 M, 10 mM to 1 M, 10 mM to 500 mM, 25 mM to 250 mM, 75 mM to 125 mM, or 100 mM.

[0073] In the suppression method of the present invention, the plant growth regulator of the present invention may be applied at an appropriate time depending on the intended use, for example, at the seed or sprout stage, during the vegetative growth period, during the reproductive growth period, or a combination thereof.

[0074] The present invention also provides a method for regulating plant growth (hereinafter sometimes referred to as the "regulating method of the present invention"), which comprises the steps of applying the plant growth inhibitor of the present invention to a plant, and growing the plant to which the plant growth inhibitor has been applied in a medium that does not contain the plant growth inhibitor.

[0075] In the regulation method of the present invention, the step of applying the plant growth regulator of the present invention is the same as in the suppression method of the present invention.

[0076] The zwitterion contained as an active ingredient in the plant growth inhibitor used in the regulation method of the present invention preferably has an anion moiety that is a sulfonate ion -SO3 - Zwitterions such as C1imC3S, N 222 C3S, C1pyrrC3S, or their analogous compounds. C1imC3S, N 222 C3S or a compound similar to C1pyrrC3S is, for example, a zwitterion represented by the above formula (1), in which A1 is -SO3 - or a zwitterion represented by the above formula (2), wherein A2 is -SO3 - is a zwitterion.

[0077] In the regulating method of the present invention, for example, a plant to which a plant growth regulator has been applied may be transplanted into a medium containing no plant growth regulator and the plant may be grown therein. Alternatively, the medium to which a plant growth regulator has been applied may be replaced with a medium containing no plant growth regulator and the plant may be grown therein.

[0078] As used herein, "regulating plant growth" can mean any one or more of transiently suppressing plant growth, slowing plant growth, and slowing plant senescence. [Example]

[0079] The present invention will be described in more detail below using examples, although the technical scope of the present invention is not limited to these examples.

[0080] Example 1: Evaluation of the effect of zwitterion C1imC3S on plant growth using Arabidopsis thaliana Materials and Methods Zwitterions The zwitterion C1imC3S was obtained from the College of Life Science and Technology, Kanazawa University. The synthesis method of C1imC3S is as described in JP 2018-191623 A.

[0081] Zwitterion treatment of Arabidopsis Arabidopsis thaliana (Col-0 strain) seeds were sown on Murashige-Skoog (MS) medium (1x MS medium salt mixture, 0.5 g / L 2-morpholinoethanesulfonic acid, 1x MS vitamin solution, 1% sucrose, 0.4% Gelsang (pH 6.3)). The seeds were then chilled at 4°C in the dark for 2 days and then cultured at 22°C under constant light.

[0082] Arabidopsis plants were transferred to MS medium containing 100 mM C1imC3S 5 days after germination and cultured for 10 days under constant light at 22°C. At the same time, as a control, Arabidopsis plants were transferred to MS medium without C1imC3S 5 days after germination and cultured in the same manner.

[0083] Thereafter, Arabidopsis thaliana was replanted in a 2:1 mixture of vermiculite and Kumiai Nippi horticultural soil (Nihon Hiryo Co., Ltd.) (soil without C1imC3S), and culture was continued at 22°C under constant light conditions.

[0084] Leaf area measurement Starting from the day of transplanting into C1imC3S-free medium (day 0), the first or second leaves of Arabidopsis plants were harvested every 7 days, immersed in a fixative (ethanol:acetic acid = 9:1), and left to stand overnight at 4°C for fixation. The leaves were then photographed using a stereomicroscope (SZX7, Olympus), and the leaf outlines were traced using Image J (NIH), and the leaf area was measured.

[0085] The first and second leaves are the first and second true leaves to form, respectively. The first and second leaves form almost simultaneously and are indistinguishable, so they are generally analyzed together.

[0086] Bolting rate measurement From the day when the Arabidopsis plants were replanted in the C1imC3S-free culture medium (day 0), the plants were visually observed every 7 days, and the percentage of plants that had formed flower buds relative to the total number of plants was calculated as the bolting rate.

[0087] (result) Plant growth inhibition effects of zwitterions The morphology and leaf area measurements of Arabidopsis plants grown for 10 days on MS medium containing or without C1imC3S are shown in Figures 1 and 2, respectively. Compared to untreated Arabidopsis plants, C1imC3S-treated Arabidopsis plants were significantly smaller and had a leaf area that was more than 12-fold reduced. However, the leaves remained green and did not turn yellow. Student's t-test revealed a significant difference in leaf area between C1imC3S-treated and untreated Arabidopsis plants. These results indicate that the zwitterion C1imC3S suppresses plant growth without causing leaf yellowing.

[0088] Plant growth after termination of treatment with zwitterions The morphology of Arabidopsis plants cultured for 10 days on MS medium containing C1imC3S or on MS medium without C1imC3S was shown in Figures 3-1 to 3-3. The C1imC3S-treated Arabidopsis plants were initially smaller and bolting was slower than the untreated plants, but eventually grew to a size comparable to that of the untreated plants, and bolting and seed formation occurred normally.

[0089] The leaf area of ​​Arabidopsis plants cultured for 10 days on MS medium containing C1imC3S or MS medium without C1imC3S was measured and transplanted into soil without C1imC3S. The leaf area of ​​Arabidopsis plants not treated with C1imC3S was approximately 40 mm2 between days 0 and 21 after transplanting into soil without C1imC3S. 2 In contrast, the leaf area of ​​Arabidopsis plants treated with C1imC3S was only 2.6 mm on day 0. 2 However, it gradually increased and reached approximately 40 mm on the 28th day. 2 On the 28th day, the Arabidopsis plants that were not treated with C1imC3S had withered and died, making it impossible to measure the leaf area.

[0090] Student's t-test showed that the leaf areas of C1imC3S-treated Arabidopsis plants on days 0, 7, 14, and 21 were significantly lower than those of untreated Arabidopsis plants on days 0, 7, 14, and 21, respectively (p < 0.0001, p < 0.0001, p < 0.0001, p < 0.0001, p < 0.05, respectively). However, there was no significant difference between the leaf areas of C1imC3S-treated Arabidopsis plants on day 28 and those of untreated Arabidopsis plants on day 21.

[0091] Figure 5 shows the results of measuring the bolting rate when Arabidopsis plants were cultured for 10 days on MS medium containing C1imC3S or on MS medium without C1imC3S and then replanted in C1imC3S-free medium. The bolting rate of Arabidopsis plants not treated with C1imC3S reached over 90% by 14 days after replanting in C1imC3S-free medium. In contrast, the bolting rate of Arabidopsis plants treated with C1imC3S was 0% on day 14 but reached over 90% by day 28. According to the data in Figure 5, the period from sowing to bolting was an average of 28.6 days for Arabidopsis plants not treated with C1imC3S and 40.7 days for Arabidopsis plants treated with C1imC3S.

[0092] These results indicate that plants treated with C1imC3S can resume growth and complete their life cycle after the treatment is terminated.

[0093] Example 2: Evaluation of the effects of various zwitterions on plant growth using Arabidopsis thaliana Materials and Methods Zwitterions Zwitterion C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 C3S and C1pyrrC3S were obtained from the College of Life Science and Technology, Faculty of Science and Technology, Kanazawa University.

[0094] C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, and N 222C3S was synthesized in accordance with the synthesis method described in JP 2018-191623 A or Kosuke Kuroda et al., 2017, J. Am. Chem. Soc., 139, 16052-16055.

[0095] C1pyrrC3S was synthesized by the following method. 1-Methylpyrrolidine (4.26 g, 50 mmol) and 1,3-propane sultone (6.1 g, 50 mmol) were added to acetonitrile (20 mL) under ice cooling, and the mixture was stirred at room temperature for 24 hours. The mixture was washed three times with an excess amount of ethyl acetate to remove unreacted materials, and then dried under reduced pressure to obtain C1pyrrC3S. The structure was confirmed by 1H NMR.

[0096] Zwitterion treatment of Arabidopsis As in Example 1, Arabidopsis seeds were sown on MS medium, subjected to low temperature treatment in a dark room at 4°C for 2 days, and then cultured under constant light conditions at 22°C.

[0097] 100 mM zwitterions C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 Arabidopsis plants were transferred to MS medium containing C3S or C1pyrrC3S 5 days after germination and cultured for 10 days at 22°C under constant light conditions. As a control, Arabidopsis plants were transferred to MS medium without the zwitterions 5 days after germination and cultured in the same manner.

[0098] Thereafter, Arabidopsis thaliana was replanted in a soil mixture of vermiculite and Kumiai Nippi horticultural soil (Nihon Hiryo Co., Ltd.) in a ratio of 2:1 (zwitterion-free soil), and culture was continued at 22°C under constant light conditions.

[0099] (result) Plant growth inhibition effects of various zwitterions C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222The morphology of Arabidopsis plants grown for 10 days on MS medium containing C3S or C1pyrrC3S, or on MS medium without zwitterions, is shown in Figure 6. Consistent with the results of Example 1, Arabidopsis plants treated with C1imC3S were significantly smaller than those not treated with zwitterions. Arabidopsis plants treated with zwitterions other than C1imC3S were also smaller than those not treated with zwitterions, particularly C4imC5C, C1C1imC3C, and N 222 Arabidopsis plants treated with C3S or C1pyrrC3S had similarly small plant bodies as those treated with C1imC3S. C4imC5C and C1C1imC3C were highly toxic to plants, and Arabidopsis plants treated with these compounds showed yellowing of leaves, whereas Arabidopsis plants treated with other zwitterions did not show yellowing of leaves.

[0100] C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 The leaf area measurements of Arabidopsis plants grown for 10 days on MS medium containing C3S or C1pyrrC3S, or on MS medium without zwitterions, are shown in Figure 7. Consistent with the results of Example 1, Arabidopsis plants treated with C1imC3S had a leaf area that was more than seven times lower than that of Arabidopsis plants not treated with zwitterions. Arabidopsis plants treated with zwitterions other than C1imC3S also had lower leaf areas than those not treated with zwitterions, particularly C4imC5C, C1C1imC3C, and N. 222 The leaf area of ​​Arabidopsis plants treated with C3S or C1pyrrC3S was as low as that of Arabidopsis plants treated with C1imC3S.

[0101] One-way ANOVA followed by Tukey's multiple test showed that the zwitterions C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, and N 222 The leaf area of ​​Arabidopsis plants treated with C3S or C1pyrrC3S was significantly lower than that of Arabidopsis plants not treated with zwitterions.

[0102] These results indicate that not only C1imC3S but also various zwitterions inhibit plant growth. 222 It was shown that C3S and C1pyrrC3S can significantly inhibit plant growth without causing leaf yellowing.

[0103] Plant growth after treatment with various zwitterions C1imC3S, OE2imC3C, C4imC5C, C1C1imC3C, N 222 Figures 8-1 to 8-3 show the morphology of Arabidopsis plants grown for 10 days in MS medium containing C3S or C1pyrrC3S, or in MS medium without zwitterions, which were then transplanted into zwitterion-free soil. Consistent with the results of Example 1, Arabidopsis plants treated with C1imC3S were initially smaller and bolting was delayed compared to Arabidopsis plants not treated with zwitterions, but ultimately grew to a size comparable to that of Arabidopsis plants not treated with C1imC3S, and bolting and seed formation occurred normally. OE2imC3C, N 222 Arabidopsis plants treated with C3S or C1pyrrC3S showed similar results to those treated with C1imC3S. On the other hand, Arabidopsis plants treated with C4imC5C and C1C1imC3C resumed growth after being replanted in zwitterion-free medium, with yellowed leaves turning green, and leaf number increasing and bolting. However, leaf size did not increase significantly, and ultimately the plants remained small.

[0104] From the above results, not only plants treated with C1imC3S but also plants treated with OE2imC3C and N 222 Plants treated with C3S, C1pyrrC3S, C4imC5C, or C1C1imC3C were also shown to be able to resume growth and complete their life cycle after the treatment was terminated.

[0105] Example 3: Evaluation of the effects of zwitterions on plant growth using spinach Materials and Methods Zwitterions The zwitterion C1imC3S was obtained from the College of Life Science and Technology, Kanazawa University.

[0106] Zwitterion treatment of spinach Spinach (Spinacia oleracea; cultivar "Krone") seeds were sown on Murashige-Skoog (MS) medium (1x MS medium salt mixture, 0.5 g / L 2-morpholinoethanesulfonic acid, 1x MS vitamin solution, 1% sucrose, 0.4% Gelsang (pH 6.3)). After 2 days of cold treatment at 4°C in the dark, they were cultured at 22°C under constant light.

[0107] Spinach plants 5 days after germination were transferred to MS medium containing 100 mM C1imC3S and cultured for 18 days under constant light at 22°C. At the same time, as a control, spinach plants 5 days after germination were transferred to MS medium without C1imC3S and subjected to the same procedure.

[0108] Thereafter, the spinach was replanted in a soil mixture of vermiculite and Kumiai Nippi horticultural soil (Nihon Hiryo Co., Ltd.) in a ratio of 2:1 (soil not containing C1imC3S), and the culture was continued under constant light conditions at 22°C.

[0109] (result) Plant growth inhibition effects of zwitterions The morphology of spinach grown on MS medium containing C1imC3S or MS medium without C1imC3S is shown in Figure 9. The spinach treated with C1imC3S was significantly smaller than the spinach untreated with C1imC3S, and the leaves in particular hardly grew. These results indicate that zwitterions inhibit the growth of not only Arabidopsis but also various dicotyledonous plants, including spinach.

[0110] Plant growth after termination of treatment with zwitterions The morphology of spinach plants grown on MS medium containing C1imC3S or MS medium without C1imC3S was then transplanted into culture medium without C1imC3S. The morphology of spinach plants treated with C1imC3S was shown in Figure 10. Compared to spinach not treated with C1imC3S, the plants were initially smaller and bolting was slower, but they eventually grew to a size similar to that of spinach not treated with C1imC3S, and bolting occurred normally.

[0111] Example 4: Evaluation of the effects of zwitterions on plant growth using Chinese chive Materials and Methods Zwitterions The zwitterion C1imC3S was obtained from the College of Life Science and Technology, Kanazawa University.

[0112] Zwitterionic treatment of chives Chinese chive (Allium tuberosum; cultivar "Oba Nira") seeds were sown on Murashige-Skoog (MS) medium (1x MS medium salt mixture, 0.5 g / L 2-morpholinoethanesulfonic acid, 1x MS vitamin solution, 1% sucrose, 0.4% Gelsang (pH 6.3)) and incubated at 4°C in the dark for 2 days, then cultured at 22°C under constant light.

[0113] Eight-day-old Chinese chives were transferred to MS medium containing 100 mM C1imC3S and cultured for 24 days under constant light at 22°C. As a control, Chinese chives were transferred to MS medium without C1imC3S and cultured in the same manner.

[0114] The chives were then replanted in a 2:1 mixture of vermiculite and Kumiai Nippi horticultural soil (Nihon Hiryo Co., Ltd.) (soil without C1imC3S), and culture was continued at 22°C under constant light conditions.

[0115] (result) Plant growth inhibition effects of zwitterions The morphology of Chinese chives grown on MS medium containing C1imC3S or without C1imC3S is shown in Figure 11. Chinese chives treated with C1imC3S were significantly smaller than those not treated with C1imC3S, and in particular, their leaves hardly grew. These results indicate that zwitterions inhibit the growth of not only Arabidopsis and spinach, but also monocotyledonous plants, including Chinese chives.

[0116] Plant growth after termination of treatment with zwitterions The morphology of Chinese chives grown on MS medium containing C1imC3S or MS medium without C1imC3S when they were transplanted into culture medium without C1imC3S is shown in Figure 12. The Chinese chives treated with C1imC3S were initially smaller than the Chinese chives not treated with zwitterions, but eventually grew to a size similar to that of the Chinese chives not treated with C1imC3S.

Claims

1. Plant growth regulators containing zwitterions.

2. The zwitterion is represented by the following formula (1): 【Chemical 1】 (In the formula, R 1 is an alkyl group having 1 to 5 carbon atoms, which may contain one or two oxygen atoms in the molecular chain, R 2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R 3 is an alkylene group having 3 to 5 carbon atoms, A 1 -SO 3 - , -COO - , -OP=O(H)O - , -OP=O(CH 3 )O - , and -OP=O(OR 4 )O - an anion selected from the group consisting of R 4 is an alkyl group which may contain a heteroatom in the molecular chain. The plant growth inhibitor according to claim 1, wherein the compound is represented by the formula:

3. The zwitterion is represented by the following formula (2): 【Chemistry 2】 (In the formula, R 5 is an alkyl group having 1 to 5 carbon atoms, R 6 and R 7 is an alkyl group having 1 to 5 carbon atoms, or R 6 and R 7 forms a 5- or 6-membered heterocyclic ring together with the N atom to which it is attached, R 8 is an alkylene group having 3 to 5 carbon atoms, A 2 -SO 3 - , -COO - , -OP=O(H)O - , -OP=O(CH 3 )O - , and -OP=O(OR 9 )O - an anion selected from the group consisting of R 9 is an alkyl group which may contain a heteroatom in the molecular chain. The plant growth inhibitor according to claim 1, wherein the compound is represented by the formula:

4. The anion part of the zwitterion is a sulfonate ion -SO 3 - The plant growth inhibitor according to claim 1, wherein

5. In formula (1), R 1 is an alkyl group having 1 to 5 carbon atoms and not containing an oxygen atom, and A 1 -COO - The plant growth inhibitor according to claim 2, wherein

6. In formula (2), A 2 -SO 3 - The plant growth inhibitor according to claim 3, wherein

7. The plant growth regulator according to any one of claims 1 to 6, for use in one or more of the following (i) to (v): (i) inhibiting plant growth without causing plant yellowing, (ii) transiently inhibiting plant growth, (iii) slowing plant growth, (iv) maintaining plant morphology, and (v) delaying plant senescence.

8. The plant growth regulator according to any one of claims 1 to 6, which is a herbicide.

9. A plant growth inhibitor composition comprising the plant growth inhibitor according to any one of claims 1 to 6.

10. A plant culture medium comprising the plant growth inhibitor according to any one of claims 1 to 6.

11. The plant culture medium according to claim 10, further comprising one or more of gravel, sand, vermiculite, perlite, rock wool, rice husks, bark, peat moss, coconut shells, polyester, and urethane.

12. A method for inhibiting plant growth, comprising the step of applying the plant growth regulator according to any one of claims 1 to 6 to a plant.

13. A plant growth regulation method comprising the steps of applying the plant growth inhibitor according to any one of claims 1 to 6 to a plant, and growing the plant to which the plant growth inhibitor has been applied in a medium that does not contain the plant growth inhibitor.

14. The following formula (4) 【Chemistry 3】 A zwitterion represented by

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