Compositions with plant growth regulating function, their preparation methods and applications

Abstract

This invention relates to a composition with plant growth regulating function, its preparation method, and its application. The composition comprises compound I and compound II; compound I is (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylenetetrahydrofuran-3,4-diol; and compound II is (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2,5-(dihydroxymethyl)-tetrahydrofuran-3,4-diol; wherein the mass ratio of compound I to compound II is 1:1 to 110:1. The specific proportions of compound I and compound II in the composition result in a better effect on regulating plant growth.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of agricultural technology, and particularly relates to a composition with plant growth regulation function and a preparation method and application thereof. BACKGROUND

[0002] (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylenetetrahydrofuran-3,4-diol and (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2,5-(dihydroxymethyl)-tetrahydrofuran-3,4-diol are homologues produced by Streptomyces. According to the description in the prior art, (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2,5-(dihydroxymethyl)-tetrahydrofuran-3,4-diol has almost no biological activity (R.J. Suhadolnik. Nucleoside Antibiotics [M]. Beijing: Science Press, 1982: 110), and (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylenetetrahydrofuran-3,4-diol is reported to have plant growth regulation activity.

[0003] However, (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2,5-(dihydroxymethyl)-tetrahydrofuran-3,4-diol has a high content in the fermentation broth, and if it can be economically and reasonably utilized, it will help to improve the added value of Streptomyces fermentation for producing (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylenetetrahydrofuran-3,4-diol. SUMMARY

[0004] In order to solve the above technical problems, according to the first aspect of the present application, a composition with plant growth regulation function is provided, which contains compound I and compound II in a specific proportion range, so that it has better effects of regulating plant growth and improving plant stress resistance.

[0005] Optionally, the composition contains compound I and compound II;

[0006] The compound I is (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylenetetrahydrofuran-3,4-diol;

[0007] The compound II is (2R,3R,4S)-2-(6-amino-9H-purin-9-yl)-2,5-(dihydroxymethyl)-tetrahydrofuran-3,4-diol;

[0008] The mass ratio of the compound I and the compound II is 1:1-110:1.

[0009] Optionally, the mass ratio of the compound I and the compound II is 1.1:1-110:1.

[0010] Optionally, the pH value of the composition is 5-9.

[0011] Optionally, the pH value of the composition is 5-8.

[0012] According to a second aspect of the present application, a method for preparing the composition is provided, which is selected from any one of a method of directly extracting from a fermentation broth or a method of mixing the compound I and the compound II.

[0013] Optionally, the method of directly extracting from a fermentation broth comprises:

[0014] (S1) fermenting to obtain a fermentation broth;

[0015] The fermentation broth contains the compound I and the compound II;

[0016] (S2) purifying the fermentation broth to obtain the composition;

[0017] The purifying comprises a macroporous adsorption resin adsorption and an eluent elution step.

[0018] The eluent is an alcohol solution.

[0019] Optionally, the alcohol in the alcohol solution is selected from one or more of C1-C6 alkyl alcohol.

[0020] Optionally, the purifying in (S2) comprises:

[0021] (S2-1) after removing the bacteria from the fermentation broth, adsorbing by a macroporous adsorption resin, removing impurities, eluting by an eluent, and crystallizing;

[0022] (S2-2) repeating the following steps for 0-5 times: dissolving the crystallized product in water, adsorbing by a macroporous adsorption resin, removing impurities, eluting by an eluent, crystallizing, and obtaining the composition;

[0023] The eluent in (S2-1) and (S2-2) is an alcohol solution.

[0024] Optionally, the composition is selected from any one of the compositions of the first aspect.

[0025] According to a third aspect of the present application, a composition obtained by the method of the second aspect is provided.

[0026] According to a fourth aspect of the present application, there is provided a prodrug, a parent drug or a formulation comprising the composition of the first aspect, the composition obtained by the method of the second aspect or the composition of the third aspect.

[0027] Optionally, the dosage form of the formulation is selected from any one of a powder, a granule, a macrogranule, a fine granule, a microgranule, a microcapsule granule, a wettable powder, an oil dispersible powder, a water dispersible granule, a prill, an effervescent granule, a dispersible tablet, an effervescent tablet, a sustained release, a sustained release block, a sustained release tube, a sustained release granule, a soluble powder, a soluble granule, a soluble tablet, a soluble solution, an aqueous solution, a soluble gel, an oil, a spreadable oil, an ultra low volume liquid, an ultra low volume microcapsule suspension, an emulsifiable concentrate, an emulsion, a dispersible liquid, a paste, a thick gel, an aqueous emulsion, an oil emulsion, a microemulsion, a paste, a suspension, a microcapsule suspension, an oil suspension, a suspoemulsion, a seed treatment dispersible powder, a seed treatment soluble powder, a seed treatment liquid, a seed treatment emulsion, a seed treatment suspension, a flowable concentrate, a seed treatment microcapsule suspension.

[0028] According to a fifth aspect of the present application, there is provided the use of the composition of the first aspect, the composition obtained by the method of the second aspect, the composition of the third aspect or the prodrug, the parent drug or the formulation of the fourth aspect in regulating plant growth.

[0029] According to a sixth aspect of the present application, there is provided the use of the composition of the first aspect, the composition obtained by the method of the second aspect, the composition of the third aspect or the prodrug, the parent drug or the formulation of the fourth aspect in the preparation of a plant growth regulator.

[0030] According to a seventh aspect of the present application, there is provided the use of the composition of the first aspect, the composition obtained by the method of the second aspect, the composition of the third aspect or the prodrug, the parent drug or the formulation of the fourth aspect in improving plant stress resistance.

[0031] According to an eighth aspect of the present application, there is provided the use of the composition of the first aspect, the composition obtained by the method of the second aspect, the composition of the third aspect or the prodrug, the parent drug or the formulation of the fourth aspect in the preparation of a product for improving plant stress resistance.

[0032] The positive progress effect of the present application is that:

[0033] (1) Although it is believed in the prior art that compound II has no biological activity, it is unexpectedly found in the composition provided by the present application that compound II can significantly improve the plant growth regulating activity and the ability to improve plant stress resistance of compound I when compound I and compound II are controlled within a certain proportion range, and the performance is better than that of using compound I alone.

[0034] (2) The preparation method of the composition provided in the present application can utilize the different solubilities of Compound I and Compound II in alcohol solvents, and adopt alcohol-containing eluent in the purification process, so that a composition with reasonable proportion of Compound I and Compound II can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 Liquid chromatogram of the composition of Example 1.

[0036] Figure 2 Liquid chromatogram of the composition of Example 3.

[0037] Figure 3 Liquid chromatogram of the composition of Example 4.

[0038] Figure 4 Comparison chart of seedling conditions of seeds treated with the seed soaking treatment of the compositions of Example 2, negative control, Example 4, and Example 9 after being planted in a seedling tray for 7 days. DETAILED DESCRIPTION

[0039] For the purposes of the present application, the terms used in the present application have the following meanings, unless otherwise stated:

[0040] The term "plant growth regulating function" refers to the function of a compound or composition in regulating the development process of a plant, which can cause changes in the growth and development of a plant. Examples thereof include, but are not limited to, promoting or inhibiting germination, rooting, flower bud differentiation, flowering, fruiting, leaf fall, etc.

[0041] The term "improving plant stress resistance" refers to improving the adaptation of a plant to a stressed environment. Examples thereof include, but are not limited to, improving the cold resistance, salt resistance, alkali resistance, and drought resistance of a plant.

[0042] The term "C1-C6 alkyl alcohol" refers to a straight-chain or branched-chain alkyl alcohol containing 1-6 carbon atoms, i.e., a C1-C6 alkyl group having a hydroxyl group (-OH). Examples thereof include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, 2-pentanol, 3-pentanol, n-hexanol, etc.

[0043] The term "alcohol solution" refers to a solution in which alcohol is used as a solute and water is used as a solvent.

[0044] The term "macroporous adsorption resin" is a type of high-molecular adsorption resin that does not contain exchange groups and has a macroporous structure, has a good macroporous network structure and a large specific surface area, and can selectively adsorb organic substances in an aqueous solution through physical adsorption. Examples thereof include, but are not limited to, XDA-6, ADS-8, ADS-21, ADS-4, AB-8, LX-21, etc.

[0045] In one embodiment, the mass ratio of Compound I to Compound II in the composition is 1 : 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.1 : 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.2: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.3: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.4: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.5: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.6: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.7: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.8: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 1.9: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 2.0: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 2.1 : 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 2.2: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 3.5: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 3.8: 1 to 110: 1; preferably, the mass ratio of Compound I to Compound II is 6: 1 to 110: 1.

[0046] In one embodiment, the mass content of Compound I in the composition is > 50% and the mass content of Compound II is < 41%. Preferably, the mass content of Compound I is > 55% and the mass content of Compound II is < 41%; or the mass content of Compound I is > 60% and the mass content of Compound II is < 31%; or the mass content of Compound I is > 65% and the mass content of Compound II is < 31%; or the mass content of Compound I is > 70% and the mass content of Compound II is < 21%; or the mass content of Compound I is > 75% and the mass content of Compound II is < 21%; or the mass content of Compound I is > 85% and the mass content of Compound II is < 11%; or the mass content of Compound I is > 90% and the mass content of Compound II is < 6%; or the mass content of Compound I is > 92% and the mass content of Compound II is < 5%.

[0047] In one embodiment, the mass content of Compound I in the composition is 50% to 98.5% and the mass content of Compound II is 0.90% to 41%.

[0048] In one embodiment, the composition is a solid.

[0049] In one embodiment, the pH of the composition is 5-9, preferably 5-8.

[0050] In one embodiment, the method for preparing the composition is not limited, and can be selected from direct extraction from fermentation broth. The method for extracting from fermentation broth is not limited in the present application, as long as the mass ratio of compound I and compound II in the obtained composition is within the scope of the present application.

[0051] In one embodiment, the composition can be obtained by mixing compound I and compound II. The method for mixing is not limited in the present application, as long as the mass ratio of compound I and compound II in the obtained composition is within the scope of the present application.

[0052] In one embodiment, the strain used for fermentation is not limited, as long as it can produce compound I and compound II. Preferably, it is Streptomyces sp., including but not limited to Streptomyces caniferus NEAU6, Streptomyces sp. Strain 196, Streptomyces angustmyceticus NBRC 3934, Streptomyces decoyicus NRRL 2666, S. angustmyceticus JCM 4053. Or preferably, it is an engineered bacterium containing the synthesis genes of compound I and compound II, including but not limited to an engineered bacterium containing 6 angustmycin A synthesis genes agmDCAEBF derived from S. angustmyceticus JCM 4053.

[0053] In one embodiment, the method for removing the bacterial cells is not limited, and is preferably centrifugation, filtration or extraction, etc.

[0054] In one embodiment, the eluent contains an alcohol, preferably an alcohol or an alcohol solution. The alcohol is selected from C1-C6 alkyl, including but not limited to methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, tert-butyl alcohol, n-pentanol, 2-pentanol, 3-pentanol, n-hexanol, etc.

[0055] In one embodiment, the method for crystallization is not limited, and is preferably any one of cooling crystallization, evaporation crystallization, concentration crystallization, or counter-diffusion crystallization. DETAILED DESCRIPTION:

[0057] The reagents and solvents used in the following examples can be purchased commercially or prepared by conventional methods known to those skilled in the art. All commercially available reagents and solvents were used without further purification.

[0058] 1. The detection of the content of Compound I, Compound II in the composition obtained by direct extraction is carried out as follows:

[0059] (1) Preparation of sample solution

[0060] Accurately weigh 0.1 g of the composition sample into a 100 mL volumetric flask, dissolve and dilute to the mark with the mobile phase, shake well. Take 5 mL of the above solution into a 50 mL volumetric flask, dilute to the mark with the mobile phase, shake well, filter, and reserve.

[0061] (2) Test conditions

[0062] Mobile phase: acetonitrile / 0.1% phosphoric acid water (volume ratio 5:95)

[0063] Chromatographic column: Poroshell 120EC-C18 reversed-phase chromatographic column

[0064] Detection wavelength: 261 nm

[0065] Flow rate: 1.0 mL / min

[0066] Column temperature: 25°C

[0067] Injection volume: 10 μL

[0068] (3) Result calculation

[0069] The content of Compound I, Compound II is calculated by area normalization method.

[0070] 2. The detection of the decomposition rate of Compound I in the composition is carried out as follows:

[0071] (1) Preparation of sample solution

[0072] Prepare 0.1 mg / mL solutions of the composition samples before and after being placed at 50°C for 5 days, and reserve.

[0073] (2) Test conditions

[0074] Mobile phase: acetonitrile / 0.1% phosphoric acid water (volume ratio 5:95)

[0075] Chromatographic column: Poroshell 120EC-C18 reversed-phase chromatographic column

[0076] Detection wavelength: 261 nm

[0077] Flow rate: 1.0 mL / min

[0078] Column temperature: 25 °C

[0079] Injection volume: 10 μL

[0080] (3) Result calculation

[0081] The results were calculated according to the following formula:

[0082] M = (A1-A2) / A1 x 100%

[0083] Wherein:

[0084] M - the decomposition rate of Compound I in the composition after the composition was placed at 50 °C for 5 days;

[0085] A1 - the peak area of Compound I in the composition solution before the composition was placed at 50 °C for 5 days;

[0086] A2 - the peak area of Compound I in the composition solution after the composition was placed at 50 °C for 5 days.

[0087] 3. The average shoot length increase and the average root length increase were calculated according to the following formula:

[0088] Average shoot length increase = (treated average shoot length - negative control average shoot length) / negative control average shoot length x 100%

[0089] Average root length increase = (treated average root length - negative control average root length) / negative control average root length x 100%

[0090] 4. The pH value of the composition was determined according to the national standard GB / T 1601-1993 Pesticide pH Value Determination Method, specifically:

[0091] (1) Reagents and solutions

[0092] Water: freshly boiled and cooled to room temperature distilled water, pH value is 5.5-7.0.

[0093] c(C8H5KO4) = 0.05 mol / L potassium hydrogen phthalate pH standard solution: weigh potassium hydrogen phthalate dried at 105-110 °C to constant weight 10.21 g in a 1000 mL volumetric flask, dissolve and dilute to the mark with water, shake well.

[0094] c(Na2B4O7) = 0.05 mol / L sodium tetraborate pH standard solution: weigh 19.07 g of sodium tetraborate in a 1000 mL volumetric flask, dissolve and dilute to the mark with water, shake well.

[0095] (2) Calibration of pH meter

[0096] Adjust the pointer of the pH meter to zero, adjust the temperature compensation knob to room temperature, calibrate the pH meter with one of the pH standard solutions described above, repeat the calibration until the two readings are the same. Measure the pH of another pH standard solution, the absolute difference between the measured value and the standard value is not greater than 0.02.

[0097] (3) Preparation of sample solution

[0098] Weigh 1 g of sample in a 100 mL beaker, add 100 mL of water, stir vigorously for 1 min, and stand for 1 min.

[0099] (4) Measurement

[0100] Insert the rinsed glass electrode and saturated calomel electrode into the sample solution and measure the pH value. Repeat three times in parallel, the absolute difference between the measured results is less than 0.1, and the arithmetic mean is taken as the pH value of the sample.

[0101] Preparation Examples The compounds I and II in the examples of the composition obtained by mixing are obtained by commercial purchase.

[0102] Preparation of the composition of Example 1

[0103] 1. Preparation of fermentation broth

[0104] Gao's No. 1 agar medium: soluble starch 20 g, NaCl 0.5 g, KNO3 1 g, FeSO4.7H2O 0.01 g, K2HPO4 0.5 g, MgSO4.7H2O 0.5 g, agar 20 g, distilled water 1000 mL, pH 7.2-7.4.

[0105] Seed medium: tryptone 17 g, soybean peptone 3 g, NaCl 5 g, K2HPO4 2.5 g, glucose 2.5 g, distilled water 1000 mL, pH 7.2-7.4.

[0106] Fermentation medium: soluble starch 10 g, glucose 10 g, glycerol 10 g, tryptone 5 g, yeast powder 5 g, CaCO3 3 g, tap water 1000 mL, pH 7.2-7.4.

[0107] Under sterile conditions, scrape the Streptomyces caniferus NEAU6 which has been activated on Gao's No. 1 agar medium into the seed medium, cultivate at 30°C, 200 rpm for 2 days, then inoculate the seed liquid into the fermentation medium at 6% (v / v), cultivate at 30°C, 200 rpm for 5 days.

[0108] 2. Purification

[0109] (1) After the fermentation broth is filtered to remove the bacterial bodies, the XDA-6 macroporous adsorption resin is used for adsorption, and then pure water is used for impurity removal, and then n-pentanol solution (n-pentanol: water = 10:90 by volume) is used for elution, and then the eluate is collected and concentrated for crystallization.

[0110] (2) The crystallization product is dissolved in water, and then the XDA-6 macroporous adsorption resin is used for adsorption, and then pure water is used for impurity removal, and then n-pentanol solution (n-pentanol: water = 10:90 by volume) is used for elution, and then the eluate is collected and concentrated for crystallization. In the obtained composition, the mass content of compound I is 66.5%, and the mass content of compound II is 30.3%, and the liquid chromatogram is as shown in Figure 1

[0111] Thus, a composition containing compound I and compound II with a mass ratio of 66.5:30.3 is obtained.

[0112] Preparation of the composition of Example 2

[0113] 1. Preparation of fermentation broth

[0114] The fermentation broth is obtained in the same manner as in Example 1.

[0115] 2. Purification

[0116] (1) After the fermentation broth is filtered to remove the bacterial bodies, the XDA-6 macroporous adsorption resin is used for adsorption, and then pure water is used for impurity removal, and then n-pentanol solution (n-pentanol: water = 10:90 by volume) is used for elution, and then the eluate is collected and concentrated for crystallization.

[0117] (2) The following steps are repeated 4 times: the crystallization product is dissolved in water, and then the XDA-6 macroporous adsorption resin is used for adsorption, and then pure water is used for impurity removal, and then n-pentanol solution (n-pentanol: water = 10:90 by volume) is used for elution, and then the eluate is collected and concentrated for crystallization. In the obtained composition, the mass content of compound I is 93.7%, and the mass content of compound II is 5.1%.

[0118] Thus, a composition containing compound I and compound II with a mass ratio of 93.7:5.1 is obtained.

[0119] Preparation of the composition of Example 3

[0120] 1. Preparation of fermentation broth

[0121] The fermentation broth is obtained in the same manner as in Example 1.

[0122] 2. Purification

[0123] (1) After the fermentation broth is filtered to remove the bacterial bodies, the XDA-6 macroporous adsorption resin is used for adsorption, and then pure water is used for impurity removal, and then n-pentanol solution (n-pentanol: water = 10:90 by volume) is used for elution, and then the eluate is collected and concentrated for crystallization. ​

[0124] (2) Repeat the following steps 5 times: dissolve the crystalline product in water, adsorb on XDA-6 macroporous adsorption resin, remove impurities with pure water, elute with methanol solution (methanol: water = 10:90 by volume), and collect the eluate to crystallize. The obtained composition contains 98.5% of compound I and 0.9% of compound II by mass, and the liquid chromatogram is shown in Figure 2 .

[0125] Thus, a composition containing compound I and compound II in a mass ratio of 98.5:0.9 is obtained.

[0126] Preparation of the composition of Example 4

[0127] 1. Preparation of fermentation broth

[0128] The fermentation broth was obtained in the same manner as in Example 1.

[0129] 2. Purification

[0130] The fermentation broth was centrifuged to remove the bacterial cells, and the supernatant was extracted with an equal volume of ethyl acetate four times, and then subjected to silica gel column chromatography, gel chromatography, and C-18 column chromatography in this order. The composition obtained after the chromatography contained 99.8% of compound I and no detectable compound II by mass, and the liquid chromatogram is shown in Figure 3 .

[0131] Preparation of the composition of Example 5

[0132] Compound I and compound II were mixed to prepare a composition containing compound I and compound II in a mass ratio of 60:40.

[0133] Preparation of the composition of Example 6

[0134] Compound I and compound II were mixed to prepare a composition containing compound I and compound II in a mass ratio of 70:30.

[0135] Preparation of the composition of Example 7

[0136] Compound I and compound II were mixed to prepare a composition containing compound I and compound II in a mass ratio of 88:12.

[0137] Preparation of the composition of Example 8

[0138] Compound I and compound II were mixed to prepare a composition containing compound I and compound II in a mass ratio of 30:70.

[0139] Preparation of the composition of Example 9

[0140] The compound I and the compound II are mixed to prepare a composition of the compound I and the compound II in a mass ratio of 40:60.

[0141] Effect Examples

[0142] 1. Effect of each composition on germination of rice variety "Bixiang 139"

[0143] The compositions prepared in Examples 1-9 were prepared into aqueous solutions according to the proportions in Table 1 for rice seed soaking of rice variety "Bixiang 139", the soaking conditions were 25°C, soaking for 24h, and the seeds after soaking were dried with clean water for 3 times, and dried with filter paper for standby. Two layers of filter paper were placed in a culture dish (90*15mm), the filter paper was moistened with clean water, and the excess water was drained. The treated rice seeds were placed neatly on the culture dish with 2 layers of filter paper. 6 dishes were set for each treatment, and 15 seeds were placed in each dish. Then the culture dishes were moved into a 30°C, RH 80% artificial weather box for dark culture, and the temperature, moisture and ventilation were checked during germination, and distilled water was added according to the specific circumstances to keep the filter paper moist. Pure water was used as a negative control.

[0144] After 7 days, 50 germinated seeds were randomly selected from each treatment to measure the length of the sprout and the length of the root, and the average length of the sprout and the average length of the root were calculated, and the results are shown in Table 2.

[0145] After 7 days of culture in the seedling tray, the seedlings treated with the compositions of Examples 2, the negative control, Example 4, and Example 9 were compared, and the comparison chart is shown in Figure 4 .

[0146] Table 1. Preparation of aqueous solutions of compositions

[0147]

[0148]

[0149] Table 2. Effect of compositions on germination of rice

[0150]

[0151] Note: The same column of data with different small English letters means significant difference, P<0.05.

[0152] As can be seen from Table 2, the compositions with specific proportions of compound I and compound II (Examples 1-3, 5-7) performed better in plant growth regulation activity than using compound I alone (Example 4), while the compositions with higher content of compound II, the difference in sprout length and root length compared with using compound I alone was not significant (Examples 8 and 9).

[0153] Figure 4The seed treated with the seed coating agent of Example 2, negative control, Example 4, Example 9 composition is planted into the seedling tray and cultured for 7 days, and the seedling conditions are compared. As can be seen from the figure, the composition with specific proportions of compound I and compound II (Example 2) is significantly better than the composition treated with compound I (Example 4) and compound II (Example 9) in terms of both bud length and root length, and is better than the negative control group.

[0154] 2. Use of the composition in improving plant stress resistance

[0155] The compositions of Examples 1-4, 7, and 9 are respectively prepared into a mother liquor with a concentration of 500 mg / L of compound I. The above mother liquor, 5% polyvinyl alcohol as a film forming agent, 2% sodium lignosulfonate as a dispersing agent, 1% xanthan gum as a thickening agent, 1% fatty acid as a wetting agent, and the rest water are used to prepare a seed coating agent with a concentration of 50 mg / L of compound I. The seeds of corn variety Demiya No. 1 with full grains and uniform size are selected, disinfected with 5% sodium hypochlorite for 3 min, washed with distilled water for 3 times, and then coated with the seed coating agent. The seed coating agent without the composition is used as a negative control.

[0156] The treated corn seeds are planted in a plastic box with a layer of wet sand at the bottom, 10 seeds per pot, and covered with about 1 cm of wet sand. The seeds are cultured in a light incubator with a temperature of 15°C. The germination rate is measured after 7 days, and the results are shown in Table 3.

[0157] Table 3. Effect of different compositions on the germination rate of corn variety Demiya No. 1 under low temperature stress

[0158] Sample Germination rate (%) Example 1 78.00±1.63c Example 2 84.50±3.42a Example 3 80.50 ± 1.91 bc Example 4 73.50±1.00d Example 7 83.50 ± 1.91 ab Example 9 74.50±3.42d Negative control 23.00±1.54e

[0159] Note: The lower case English letters after the same column data indicate significant difference, P < 0.05.

[0160] As can be seen from the above, the compositions of Examples 1-3 and 7 containing specific proportions of compound I and compound II can promote the germination of corn variety Demiya No. 1 seeds under low temperature stress, which is significantly better than the negative control, Example 9 with high content of compound II, and Example 4 containing only compound I. Therefore, the composition with specific proportions of compound I and compound II is better than using compound I alone in improving plant stress resistance, and is also significantly better than the composition with high content of compound II.

[0161] 3. Stability experiment

[0162] First, the pH value of the composition of Example 1 is detected, and the method is as described above. The detection result is pH 6.2.

[0163] In order to verify the influence of pH on the stability of the composition, the preparation method of the composition of Example 1 was adopted, and pH adjustment was performed to obtain compositions with pH values of 4, 5, 8, and 9. The compositions with pH values of 4, 5, 6.2, 8, and 9, respectively, were placed at 50°C for 5 days, and the decomposition of Compound I was detected, and the results are shown in Table 4.

[0164] Table 4. Decomposition rate of Compound I in the composition

[0165] Sample Decomposition rate of Compound I Composition at pH 4 55.2％ Composition at pH 5 1.1％ Composition at pH 6.2 0.5％ Composition at pH 8 0.3％ Composition at pH 9 1.8％

[0166] As can be seen from the above table, the compositions with pH values of 5-9 have better stability, and the decomposition rate of Compound I is less than 10% in the stability test, which meets the provisions of NY / T 1860.9-2016 Test Guide for Determination of Pesticide Physicochemical Properties Part 9 on the decomposition rate of the sample under certain pH conditions. The composition with a pH value less than 5 is not stable and is prone to degradation during storage.

[0167] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

[0168] Finally, it should be noted that the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device.

Claims

1. A composition having plant growth regulating function, characterized in that, The composition comprises compound I and compound II; The compound I is (2R, 3R, 4S)-2-(6-amino-9H-purin-9-yl)-2-(hydroxymethyl)-5-methylene tetrahydrofuran-3, 4-diol; The compound II is (2R, 3R, 4S)-2-(6-amino-9H-purin-9-yl)-2, 5-(dihydroxymethyl)-tetrahydrofuran-3, 4-diol; The mass ratio of the compound I and the compound II is 1.5:1-110:

1.

2. The composition of claim 1, wherein, The pH value of the composition is 5-9.

3. The composition of claim 1, wherein, The pH value of the composition is 5-8.

4. A method for preparing a composition having a plant growth regulating function according to any one of claims 1 to 3, characterized by, The method is selected from any one of a method of directly extracting from a fermentation liquor or a method of mixing the compound I and the compound II.

5. The method of claim 4, wherein, The method of directly extracting from a fermentation liquor comprises: (S1) fermentation to obtain a fermentation liquor; The fermentation liquor contains the compound I and the compound II; (S2) purifying the fermentation liquor to obtain the composition; The purifying comprises a macroporous adsorption resin adsorption and an eluent elution step; The eluent is an alcohol solution; The alcohol in the alcohol solution is selected from one or more of C1-C6 alkyl alcohol.

6. The method of claim 5, wherein, The purifying in (S2) comprises: (S2-1) after removing the bacteria from the fermentation liquor, adsorbing by a macroporous adsorption resin, removing impurities, eluting by an eluent, and crystallizing; (S2-2) repeating 0-5 times the following steps: dissolving the crystalline product in water, adsorbing by a macroporous adsorption resin, removing impurities, eluting by an eluent, crystallizing, and obtaining the composition; The eluent in (S2-1) and (S2-2) is an alcohol solution.

7. The composition obtained by the method according to any one of claims 4-6.

8. An original drug, parent drug or formulation, characterized in that, The original drug, the parent drug or the preparation contains the composition according to any one of claims 1-3 or the composition obtained by the method according to any one of claims 4-6, or the composition according to claim 7.

9. The original drug, parent drug, or preparation according to claim 8, characterized by, The dosage form of the preparation is selected from any one of a powder, a granule, an aqueous agent, an oil agent, an emulsion, a latex, a paste, a water emulsion, an oil emulsion, a microemulsion, a grease, a suspension, a suspoemulsion.

10. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a large granule, a fine granule, a microgranule.

11. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a wettable powder, an oil dispersible powder, a water dispersible granule, a dispersible tablet, a dispersible liquid.

12. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a microcapsule granule, a thick gum, a microcapsule suspension, a latex granule, an effervescent granule, an effervescent tablet, an oil suspension.

13. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is a sustained release agent.

14. The original drug, parent drug or preparation according to claim 8, characterized by, The dosage form of the preparation is selected from any one of a sustained release block, a sustained release tube, a sustained release granule.

15. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of an ultra-low volume liquid, an ultra-low volume microcapsule suspension.

16. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a soluble powder, a soluble granule, a soluble tablet, a soluble liquid, a soluble gum, an expanded film oil.

17. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a seed treatment suspension, a seed treatment dispersible powder, a seed treatment soluble powder, a seed treatment liquid.

18. The prodrug, parent drug, or formulation of claim 8, wherein, The dosage form of the preparation is selected from any one of a seed treatment emulsion, a suspension seed coating agent, a seed treatment microcapsule suspension.

19. Use of a composition according to any one of claims 1 to 3, a composition obtained according to the method of any one of claims 4 to 6, a composition according to claim 7, a technical material, a plant growth regulator or a formulation according to any one of claims 8 to 18 for regulating the growth of a plant.

20. Use of a composition according to any one of claims 1 to 3, a composition obtained according to the method of any one of claims 4 to 6, a composition according to claim 7 or a technical material, a plant growth regulator or a formulation according to any one of claims 8 to 18 for the manufacture of a plant growth regulator.

21. Use of a composition according to any one of claims 1 to 3, a composition obtained according to the method of any one of claims 4 to 6, a composition according to claim 7 or a technical material, a plant growth regulator or a formulation according to any one of claims 8 to 18 for increasing the stress tolerance of a plant.

22. Use of a composition according to any one of claims 1 to 3, a composition obtained according to the method of any one of claims 4 to 6, a composition according to claim 7 or a technical material, a plant growth regulator or a formulation according to any one of claims 8 to 18 for the manufacture of a product for increasing the stress tolerance of a plant.

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