Plant stress tolerance inducer and plant stress tolerance induction method

Abstract

This plant stress tolerance inducer 1a comprises a compound 11 and a lipid 12. The compound 11 is at least one compound selected from the group consisting of nucleosides and modified nucleosides. The lipid 12 is at least one selected from the group consisting of fatty acids having 10-20 carbon atoms and acylglycerols including fatty acid residues having 10-20 carbon atoms.

Description

Plant stress tolerance inducer and method for inducing plant stress tolerance

[0001] The present disclosure relates to a plant stress tolerance inducer and a method for inducing plant stress tolerance.

[0002] BACKGROUND ART Agents for imparting stress tolerance to plants have been known.

[0003] For example, Patent Document 1 describes an agent for imparting resistance to external stresses, which contains a peptide (A) having two to three constituent amino acids, including glutamic acid (Glu) and proline (Pro). The external stress is at least one selected from the group consisting of salt, temperature, oxidation, and drought. The peptide is produced by culturing a specific Escherichia coli strain, harvesting the cells, and ultrasonically disrupting the harvested cells.

[0004] Patent Document 2 describes a composition for inducing environmental stress tolerance in plants. The composition contains (A) an abscisic acid-like substance and (B) an amino acid and / or an amino acid derivative. Examples of environmental stresses include drought stress, low temperature stress, freezing stress, high temperature stress, and high salt concentration stress.

[0005] Non-Patent Document 1 describes that heat tolerance can be increased without suppressing plant growth by pretreating Arabidopsis thaliana with low concentrations of ethanol.

[0006] JP 2019-006774 A JP 2023-106651 A

[0007] Akihiro Matsui et al. Ethanol induces heat tolerance in plants by stimulating unfolded protein response. Plant Molecular Biology. Plant Mol. Biol. 110, 131-145.

[0008] The techniques described in the above documents need to be reconsidered from the viewpoint of effectively imparting stress tolerance to plants. Therefore, the present disclosure provides a novel plant stress tolerance inducer that is advantageous from the viewpoint of effectively imparting stress tolerance to plants.

[0009] The present disclosure provides a plant stress tolerance inducer comprising: at least one compound selected from the group consisting of nucleosides and modified nucleosides; and at least one lipid selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing a fatty acid residue having 10 to 20 carbon atoms.

[0010] The plant stress tolerance inducer of the present disclosure is advantageous from the viewpoint of effectively imparting stress tolerance to plants.

[0011] FIG. 1 is a schematic diagram showing a plant stress tolerance inducer according to the present embodiment. FIG. 2A is a graph showing the relationship between the cotyledon expansion rate of spinach irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. FIG. 2B is a graph showing the relationship between the cotyledon expansion rate of pansies irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. FIG. 2C is a graph showing the relationship between the cotyledon expansion rate of pansies irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. FIG. 3A is a graph showing the relationship between the cotyledon expansion rate of spinach irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. FIG. 3B is a graph showing the relationship between the cotyledon expansion rate of pansies irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. FIG. 4A is a graph showing the relationship between the cotyledon expansion rate of pansies irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. Fig. 4B is a graph showing the relationship between the cotyledon expansion rate of Arabidopsis thaliana irrigated with water or a plant stress tolerance inducer according to an Example and the number of days elapsed since sowing. Fig. 5A is a graph showing the fresh weight of tomatoes irrigated with water or a plant stress tolerance inducer according to an Example. Fig. 5B is a graph showing the plant height of tomatoes irrigated with water or a plant stress tolerance inducer according to an Example.

[0012] (Findings that form the basis of the present disclosure) Abnormal environmental stress caused by global warming can reduce the quality and yield of agricultural crops. For this reason, there is a demand for the development of technologies that impart environmental stress resistance to plants. In particular, in recent years, from the perspective of preventing global warming and reducing environmental impact, there has been a demand for the use of substances that consume less fossil energy in their manufacturing process and that impose a low environmental impact when applied to plants (hereinafter also referred to as application or use).

[0013] As described in Patent Document 1, it is conceivable to use microorganisms such as Escherichia coli to produce agents for imparting stress tolerance to plants. However, agents for imparting stress tolerance to plants obtained using microorganisms may have different effects of imparting stress tolerance depending on the combination of the target plant type and soil properties, and are therefore lacking in versatility. As a result, the effect of imparting stress tolerance is likely to be unstable. It is not easy to consistently achieve high stress tolerance imparting effects using naturally derived substances, and users may be concerned about cost-effectiveness.

[0014] Therefore, the present inventors have conducted extensive research and have newly discovered that an agent containing a specific component can effectively impart stress tolerance to plants. Based on this new finding, the present inventors have completed the plant stress tolerance inducer of the present disclosure.

[0015] (Embodiments of the Present Disclosure) Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, process orders, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts will be described as optional components. Note that each figure is a schematic diagram and is not necessarily an exact illustration. In each figure, substantially identical components are assigned the same reference numerals, and duplicated explanations may be omitted or simplified.

[0016] (Embodiments) Hereinafter, embodiments will be specifically described with reference to Figure 1. Information regarding base sequences or amino acid sequences referred to in this specification is published, for example, on the website of the National Center for Biotechnology Information (NCBI) and can be referenced at any time.

[0017] FIG. 1 is a schematic diagram illustrating a plant stress tolerance inducer according to the present embodiment. As shown in FIG. 1 , plant stress tolerance inducer 1a contains compound 11 and lipid 12. Compound 11 is at least one compound selected from the group consisting of nucleosides and modified nucleosides. Lipid 12 is at least one compound selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing fatty acid residues having 10 to 20 carbon atoms. In plant stress tolerance inducer 1a, the fatty acid may exist as a free fatty acid or as a fatty acid residue contained in acylglycerol. Since plant stress tolerance inducer 1a contains compound 11 and lipid 12, applying plant stress tolerance inducer 1a to plants tends to effectively confer stress tolerance to the plants. Therefore, a method for inducing plant stress tolerance can be provided, which includes using plant stress tolerance inducer 1a, compound 11, and lipid 12 in plants.

[0018] The stress tolerance induced by the plant stress tolerance inducer 1a is not limited to a specific stress tolerance. The plant stress tolerance inducer 1a can induce, for example, at least one tolerance selected from the group consisting of high temperature tolerance and high light tolerance. In this case, tolerance to stresses associated with global warming can be effectively imparted to the plant. The high temperature tolerance of a plant can be evaluated, for example, by cultivating the plant so that the plant's environmental temperature includes a period of time at or above 40°C. The high light tolerance of a plant can be evaluated, for example, by cultivating the plant in an environment including light conditions in which the plant is irradiated with a white light source at an illuminance of 10,000 lux or more.

[0019] Compound 11 is not limited to a specific compound as long as it is at least one selected from the group consisting of nucleosides and modified nucleosides. Compound 11 contains, for example, at least one selected from the group consisting of N-methyl-2-deoxyadenosine, guanosine, and cytidine. In this case, when the plant stress tolerance inducer 1a is used in plants, stress tolerance is more effectively imparted to the plants.

[0020] The fatty acid contained in the lipid 12 is not limited to a specific fatty acid as long as it has a carbon number of 10 or more and 20 or less. The fatty acid contained in the lipid 12 includes, for example, at least one selected from the group consisting of hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid. In this case, when the plant stress tolerance inducer 1a is used on a plant, stress tolerance is more likely to be imparted to the plant more effectively.

[0021] The plant stress tolerance inducer 1a preferably contains N-methyl-2-deoxyadenosine, guanosine, and cytidine as compound 11. In addition, the plant stress tolerance inducer 1a preferably contains hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid. In this case, when the plant stress tolerance inducer 1a is applied to a plant, stress tolerance is more likely to be imparted to the plant more effectively.

[0022] N-methyl-2-deoxyadenosine content C in plant stress tolerance inducer 1a A , guanosine content C G , and cytidine content C C The relationship between the above is not limited to a specific relationship. In the plant stress tolerance inducer 1a, for example, C G >C C >C A In this case, when the plant stress tolerance inducer 1a is applied to a plant, stress tolerance is more likely to be imparted to the plant more effectively.

[0023] Hexadecanoic acid content C in plant stress tolerance inducer 1a H , octadecanoic acid content C OThe content of C9 and the content of 9-octadecenoic acid are not limited to a specific relationship. For example, in the plant stress tolerance inducer 1a, C H >C O >C9 is satisfied. In this case, when the plant stress tolerance inducer 1a is applied to a plant, stress tolerance is more likely to be imparted to the plant more effectively.

[0024] 1 , the plant stress tolerance inducer 1a may further include, for example, an electrolyte 20. The electrolyte 20 includes at least one selected from the group consisting of inorganic nitrogen, inorganic phosphorus, and potassium. The inorganic nitrogen may be contained in a nitrate compound or a nitrite compound. The inorganic phosphorus may be contained in a phosphate compound.

[0025] The plant stress tolerance inducer 1a may be, for example, in a liquid form, and may be supplied to the soil for plant cultivation or to the plant. For example, the plant stress tolerance inducer 1a may be absorbed into or attached to plant seeds, or may be attached to plant leaves. The plant stress tolerance inducer 1a may be sprayed onto plants or may be foliar sprayed onto plants. In the plant stress tolerance inducer 1a, the compound 11 and the lipid 12 are dissolved or dispersed. The plant stress tolerance inducer 1a contains a solvent such as water. The liquid plant stress tolerance inducer 1a may be provided as a solid containing the compound 11 and the lipid 12, and this solid may be dispersed in water for use.

[0026] The plant stress tolerance inducer 1a may be produced, for example, by a method involving the cultivation of a microorganism or fermentation using a microorganism, or by purification from an organism by a method such as solvent extraction, etc. An example of the microorganism is a cyanobacterium, and a cyanobacterium genetically modified to secrete a predetermined lipid component may also be used.

[0027] (Additional Notes) The above disclosure discloses the following technologies. (Technology 1) A plant stress tolerance inducer comprising at least one compound selected from the group consisting of nucleosides and modified nucleosides, and at least one lipid selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing a fatty acid residue having 10 to 20 carbon atoms. (Technology 2) The plant stress tolerance inducer according to Technology 1, wherein the plant stress tolerance inducer induces at least one tolerance selected from the group consisting of high temperature tolerance and high light tolerance. (Technology 3) The plant stress tolerance inducer according to Technology 1 or 2, wherein the compound comprises at least one selected from the group consisting of N-methyl-2-deoxyadenosine, guanosine, and cytidine. (Technology 4) The plant stress tolerance inducer according to any one of Technology 1 to 3, wherein the fatty acid comprises at least one selected from the group consisting of hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid. (Technology 5) The plant stress tolerance inducer according to any one of Technologies 1 to 4, wherein the compound comprises N-methyl-2-deoxyadenosine, guanosine, and cytidine, and the fatty acid comprises hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid. (Technology 6) The plant stress tolerance inducer according to any one of Technologies 1 to 5, further comprising an electrolyte having at least one selected from the group consisting of inorganic nitrogen, inorganic phosphorus, and potassium. (Technology 7) A method for inducing stress tolerance in plants, comprising applying to a plant at least one compound selected from the group consisting of nucleosides and modified nucleosides, and at least one lipid selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing a fatty acid residue having 10 to 20 carbon atoms.

[0028] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0029] (Production of Plant Stress Tolerance Inducer) The plant stress tolerance inducer according to Example 1 was produced using cyanobacteria according to the following procedure. -2 PCC 6803 strain was cultured with shaking for 5 days at 30°C while irradiating with light using a white LED under the conditions of 1. The collected cyanobacteria were subjected to Promega's Wizard (registered trademark) Genomic DNA Purification Kit to extract chromosomal DNA from the cells.

[0030]

[0031] Using the above chromosomal DNA as a template, the promoter region of the petE gene, known to be a copper-inducible promoter, was amplified by PCR using Primer 1 (see SEQ ID NO: 1) and Primer 2 (see SEQ ID NO: 2). Toyobo's KOD One® PCR Master Mix -Blue- was used for PCR. The DNA fragment amplified in this manner was designated Fragment 1. Next, two DNA sequences in the upstream region of the slr0688 gene were amplified by PCR using Primer 3 (see SEQ ID NO: 3) and Primer 4 (see SEQ ID NO: 4), as well as Primer 5 (see SEQ ID NO: 5) and Primer 6 (see SEQ ID NO: 6). The DNA fragment amplified using Primer 3 and Primer 4 was designated Fragment 2. The DNA fragment amplified using Primer 5 and Primer 6 was designated Fragment 3. Next, E. coli harboring the pSL2680 plasmid was cultured in LB medium, and the pSL2680 plasmid was extracted. The LB medium contained 1% by mass of triptone, 0.5% by mass of yeast extract, and 1% by mass of NaCl. Using the pSL2680 plasmid as a template, the kanamycin resistance gene was amplified by PCR using primer 7 (see SEQ ID NO: 7) and primer 8 (see SEQ ID NO: 8). The DNA fragment thus amplified was designated as fragment 4.

[0032] The four fragments were ligated together in the following order: 5'-Fragment 2-Fragment 4-Fragment 1-Fragment 3-3' using Clontech's In-Fusion® Snap Assembly Master Mix. Plasmid DNA containing the ligated DNA fragments was transformed using Takara Bio's E. coli HST08 Premium Competent Cells by heat shock. The resulting E. coli was cultured in the presence of 50 μg / mL ampicillin, and the plasmid was extracted using Promega's Wizard® Plus SV Minipreps DNA Purification System to obtain the peptE-slr0688 plasmid used for gene modification.

[0033] Synechocystis sp. PCC6803 cultured as described above was mixed with 3 μg of the peptE-slr0688 plasmid, suspended, and transformed by natural transformation. The resulting culture was applied to a Merck Millipore Immobilon-NC Triton-free MCE 0.45 μm 82 mm disc membrane filter and grown on BG11 agar medium for 2 days. The culture was then transferred to agar medium containing 20 μg / mL kanamycin and grown for 7 days. The resulting mutant colonies were purified to single colonies on BG11 agar medium containing 20 μg / mL kanamycin. This transformation is believed to have resulted in the insertion of the petE gene promoter and kanamycin resistance gene upstream of the slr0688 gene on the chromosomal DNA of the mutant by homologous recombination. The corresponding sequence was amplified from the mutant chromosomal DNA by PCR and confirmed by DNA sequencing. In this way, Synechocystis PpetE-slr0688 strain, which is a mutant strain of Synechocystis sp. PCC6803 strain, was obtained.

[0034] When cultured in the absence of copper ions, the Synechocystis PpetE-slr0688 strain produces a plant stress tolerance inducer. Therefore, the Synechocystis PpetE-slr0688 strain was cultured according to the following procedure to obtain the plant stress tolerance inducer of the present example.

[0035] 100 μmol photons m inside a flask containing 200 mL of BG11 medium -2 The Synechocystis PpetE-slr0688 strain was cultured with shaking at 30°C for 5 days while irradiating it with light using a white LED under the conditions of 1. The cells were removed by centrifugation at 20,000 × g for 5 minutes, and the supernatant was filtered through a polyvinylidene fluoride membrane filter with a pore size of 0.22 µm to obtain a culture supernatant that is a plant stress tolerance inducer according to the example.

[0036] (Composition Analysis of Plant Stress Tolerance Inducer) 5 mL of the plant stress tolerance inducer according to the present invention was lyophilized, and then a solution with a mass ratio of water, chloroform, and methanol of 1:1.5:2 was added and mixed thoroughly. The chloroform layer was then collected and dried under a nitrogen gas spray to obtain a dried product. The dried product was then processed using a Nacalai Tesque fatty acid methylation kit and a methylated fatty acid purification kit. The culture supernatant was then analyzed using a Shimadzu GCMS-QP2010SE gas chromatography / mass spectrometry (GC / MS) system. The GC / MS analysis used an InertCap Pure WAX ​​(GL Sciences) column with a linear velocity of 30 cm / min. The column temperature was programmed to hold at 50°C for 1 minute after sample injection, then increase to 250°C at a heating rate of 8°C / min, and then hold at 250°C for 30 minutes. The results are shown in Table 2. Table 2 shows the area ratio of the detected peak of each fatty acid to the area value of the detected peak of 9-octadecenoic acid. Note that no types of fatty acids other than those listed in Table 2 were detected.

[0037]

[0038] To 80 μL of the plant stress tolerance inducer according to the example, 20 μL of an aqueous solution containing an internal standard adjusted to a concentration of 1000 μM (mol / L) was added, stirred, and the resulting mixture was ultrafiltered to prepare a liquid sample. This liquid sample was subjected to capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS). Metabolites contained in the plant stress tolerance inducer according to the example were searched for based on the mass-to-charge ratio (m / z) and migration time values ​​obtained by CE-TOFMS. The detected nucleic acid metabolites are shown in Table 3.

[0039]

[0040] (Evaluation of Plant Stress Tolerance Inducers) Spinach (variety: Mirage) and pansy (variety: Nature series) seeds were sown in rock wool at a depth of 2 cm and 1 cm intervals. The spinach and pansies were cultivated in an environment where the room temperature was 40°C and a 6-hour light condition with irradiation at an illuminance of 40,000 lux using a white light source was alternated with an 18-hour dark condition. The temperature in the dark condition was 20°C. In the cultivation of spinach and pansies, the number of individuals in which cotyledon expansion was confirmed after sowing was counted daily, and the cotyledon expansion rate was calculated by dividing the number of individuals by the total number of seeds sown.

[0041] In rock wool in which six spinach seeds were sown, 1 mL of the plant stress tolerance inducer according to the example was applied per three spinach seeds at the time of sowing. In another rock wool in which six spinach seeds were sown, 1 mL of water was applied per three spinach seeds. The relationship between the cotyledon expansion rate of the spinach in this case and the number of days since sowing is shown in Figure 2A.

[0042] In rock wool in which six pansy seeds were sown, 1 mL of the plant stress tolerance inducer according to the example was irrigated for every three pansy seeds. In another rock wool in which six pansy seeds were sown, 1 mL of water was irrigated for every three pansy seeds. The relationship between the cotyledon expansion rate of the pansies and the number of days since sowing in this case is shown in Figure 2B.

[0043] Pansies were grown using rock wool under the same cultivation conditions as above, except that the room temperature under light conditions was changed to 20°C and the illuminance was changed to 6,000 lux. In rock wool sown with six pansy seeds, 1 mL of the plant stress tolerance inducer according to the example was irrigated per three pansy seeds. In another rock wool sown with six pansy seeds, 1 mL of water was irrigated per three pansy seeds. The relationship between the cotyledon expansion rate of the pansies and the number of days since sowing in this case is shown in Figure 2C.

[0044] As shown in Figures 2A and 2B, the cotyledon expansion rates of spinach and pansy grown in rock wool irrigated with the plant stress tolerance inducer according to the example were higher than those of spinach and pansy grown in rock wool irrigated with water. This suggests that the use of the plant stress tolerance inducer according to the example can confer high temperature tolerance and high light tolerance to plants. Figure 2C shows that there is almost no difference in the cotyledon expansion rate of pansies under mild temperature and light conditions.

[0045] Commercially available culture soil was placed in a 36-hole cultivation cell tray, and one spinach (variety: Mirage) seed was sown per cell. A 128-hole cultivation cell tray was filled with soil prepared in a ratio of peat moss volume: perlite volume: vermiculite volume: Akadama soil volume = 6:2:1:1, and pansy (variety: Nature Series) seeds were sown. Spinach and pansies were cultivated at room temperature of 40°C under alternating 6-hour light conditions with 40,000 lux illuminance from a white light source and 18-hour dark conditions. The temperature in the dark conditions was 20°C. For spinach and pansy cultivation, the number of individuals with confirmed cotyledon expansion after sowing was counted daily, and the cotyledon expansion rate was calculated by dividing the number by the total number of seeds sown.

[0046] In a cell in which six spinach seeds were sown, 1 mL of the plant stress tolerance inducer according to the example was irrigated per spinach seed. In another cell in which six spinach seeds were sown, 1 mL of water was irrigated per spinach seed. The relationship between the cotyledon expansion rate of the spinach and the number of days since sowing in this case is shown in Figure 3A.

[0047] In a cell in which 10 pansy seeds were sown, 1 mL of the plant stress tolerance inducer according to the example was irrigated per pansy seed. In another cell in which 10 pansy seeds were sown, 1 mL of water was irrigated per pansy seed. The relationship between the cotyledon expansion rate of the pansies and the number of days since sowing in this case is shown in Figure 3B.

[0048] 3A and 3B, the cotyledon expansion rate of spinach and pansy was higher when the plant stress tolerance inducer was irrigated than when water was irrigated, suggesting that the use of the plant stress tolerance inducer according to the examples can confer high temperature tolerance and high light tolerance to plants.

[0049] Ten pansy seeds (variety: Nature Series) sterilized with hypochlorous acid and 25 Arabidopsis seeds (variety: Col-0) sterilized with hypochlorous acid were sown on Murashige-Skoog (MS) agar medium. Pansies and Arabidopsis were grown under alternating 13-hour light and 11-hour dark conditions. The 13-hour light conditions included 3 hours of illumination at 6,000 lux using a white light source at a room temperature of 25°C, 5 hours of illumination at 10,000 lux using a white light source at a room temperature of 40°C, and 5 hours of illumination at 8,000 lux using a white light source at a room temperature of 30°C. The temperature during the dark conditions was 25°C. In the cultivation of pansies and Arabidopsis thaliana, the number of individuals in which cotyledon expansion was confirmed after sowing was counted daily, and the cotyledon expansion rate was calculated by dividing the number of individuals by the total number of seeds sown.

[0050] Ten sterilized pansy seeds were imbibed with 1 mL of the plant stress tolerance inducer according to the present invention and then sown on MS agar medium. Another ten sterilized pansy seeds were imbibed with 1 mL of water and then sown on MS agar medium. The relationship between the cotyledon expansion rate of the pansies and the number of days since sowing is shown in Figure 4A.

[0051] Twenty-five sterilized Arabidopsis seeds were imbibed with the plant stress tolerance inducer according to the present invention and then sown on MS agar medium. Another 25 sterilized Arabidopsis seeds were imbibed with water and then sown on MS agar medium. The relationship between the cotyledon expansion rate of Arabidopsis and the number of days since sowing is shown in Figure 4B.

[0052] 4A and 4B, the cotyledon expansion rate of pansy and Arabidopsis was higher when the seeds were imbibed with the plant stress tolerance inducer than when the seeds were imbibed with water. This suggests that the use of the plant stress tolerance inducer according to the example can confer high temperature tolerance and high light tolerance to plants.

[0053] A 36-well cultivation cell tray was filled with soil prepared in a ratio of peat moss volume: perlite volume: vermiculite volume: Akadama soil volume = 6:2:1:1, and three tomato (variety: Momotaro) seeds were sown per cell. The tomatoes were grown under alternating 13-hour light and 11-hour dark conditions. The 13-hour light conditions included 3 hours of illumination at 6,000 lux using a white light source at a room temperature of 25°C, 5 hours of illumination at 10,000 lux using a white light source at a room temperature of 40°C, and 5 hours of illumination at 8,000 lux using a white light source at a room temperature of 30°C. The temperature during the dark conditions was 25°C. Thirty-five days after the start of cultivation, the fresh weight and plant height of the tomatoes were measured.

[0054] In 18 cells in which 54 tomato seeds were sown, 1 mL of the plant stress tolerance inducer according to the example was irrigated for every three tomato seeds in each cell. In another 18 cells in which 54 tomato seeds were sown, 1 mL of water was irrigated for every three tomato seeds in each cell. The fresh weight and plant height of the tomatoes in this case 35 days after the start of cultivation are shown in Figures 5A and 5B, respectively.

[0055] 5A and 5B, the fresh weight and plant height of the tomatoes irrigated with the plant stress tolerance inducer were higher than those irrigated with water, suggesting that the use of the plant stress tolerance inducer according to the example can confer high temperature tolerance and strong light tolerance to plants.

[0056] The plant stress tolerance inducer of the present disclosure can effectively confer stress tolerance to plants.

Claims

1. A plant stress tolerance inducer comprising at least one compound selected from the group consisting of nucleosides and modified nucleosides, and at least one lipid selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing a fatty acid residue having 10 to 20 carbon atoms.

2. The plant stress tolerance inducer according to claim 1, which induces at least one tolerance selected from the group consisting of high temperature tolerance and high light tolerance.

3. The plant stress tolerance inducer according to claim 1, wherein the compound comprises at least one selected from the group consisting of N-methyl-2-deoxyadenosine, guanosine, and cytidine.

4. The plant stress tolerance inducer according to claim 1, wherein the fatty acid comprises at least one selected from the group consisting of hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid.

5. The plant stress tolerance inducer according to claim 1, wherein the compound comprises N-methyl-2-deoxyadenosine, guanosine, and cytidine, and the fatty acid comprises hexadecanoic acid, octadecanoic acid, and 9-octadecenoic acid.

6. The plant stress tolerance inducer according to claim 1, further comprising an electrolyte having at least one selected from the group consisting of inorganic nitrogen, inorganic phosphorus, and potassium.

7. A method for inducing stress tolerance in plants, comprising applying to a plant at least one compound selected from the group consisting of nucleosides and modified nucleosides, and at least one lipid selected from the group consisting of fatty acids having 10 to 20 carbon atoms and acylglycerols containing a fatty acid residue having 10 to 20 carbon atoms.

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