Preparation method, device and application of polyglutamic acid derivative for promoting root growth

Abstract

The invention discloses a preparation method, device and application of a root-promoting polyglutamic acid derivative, belonging to the field of agricultural technology. The root-promoting polyglutamic acid derivative is modified with indoleacetic acid and phospholipid at the same time, and the preparation method is as follows: after polyglutamic acid is mixed with sodium azide and acetonitrile for reaction, activated HBTU and a mixture of indoleacetic acid and triethylamine are added; after ethylene glycol is mixed with p-nitrophenyl chloroformate for reaction, a mixture of phospholipid and triethylamine is added; the above solutions are mixed for reaction, ultrafiltration is performed after reduced pressure concentration, washing with acetone, filtering, and vacuum freeze drying. The present invention obtains a polyglutamic acid derivative by chemically accessing indoleacetic acid and phospholipid on polyglutamic acid, which can shorten the rooting time, promote plant rooting, and can also provide nitrogen, phosphorus and other elements required by plants at the same time, promote plant growth and development, and improve crop yield and quality.

Description

Technical Field

[0001] The invention relates to a preparation method, a device and application of a root growth-promoting polyglutamic acid derivative, belonging to the technical field of agriculture. Background Art

[0002] Polyglutamic acid, also known as polyglutamic acid, is a biopolymer synthesized by microbial fermentation using glutamic acid as the basic raw material, combined with organic carbon sources, nitrogen sources and minerals. It is one of the only four high-molecular homopolymer amino acids that can be synthesized by microorganisms.

[0003] Polyglutamic acid is an ecological fertilizer adjuvant that can better transport nutrients and water in the soil to plants, form a protective film on the roots, protect the root hairs of plants, and make the plants grow better. In addition, polyglutamic acid can be decomposed into glutamic acid, which is absorbed and utilized by crops without residue, and becomes an amino acid in crops, playing an important role in the growth and development of plants. Therefore, polyglutamic acid is widely used in agricultural production (fertilizers, pesticides), which can play a significant role in water retention, chelating trace elements, increasing synergy and slow release, and improving crop yield and quality.

[0004] Although polyglutamic acid plays an important role in agricultural production, its functional use is still limited. Therefore, based on polyglutamic acid, modified molecules can be added through chemical reactions to obtain polyglutamic acid derivatives with different functions, thereby improving the function of polyglutamic acid and its application range. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for preparing a polyglutamic acid derivative that promotes rooting, a device and application thereof, so as to promote plant rooting and improve crop yield and quality.

[0006] In order to solve the above technical problems, the technical solutions provided by the present invention are as follows:

[0007] The invention discloses a polyglutamic acid derivative for promoting root growth, which is modified with indoleacetic acid and phospholipid at the same time.

[0008] Indoleacetic acid can affect cell division, cell elongation and differentiation, promote plant rooting, accelerate root formation, increase the percentage of plant rooting, and increase crop yields. Phospholipids can activate cells, promote plant root growth, regulate plant metabolism, stimulate crop growth, and enhance immunity and regeneration. At the same time, both can provide crops with absorbable elements, which is beneficial to the growth and development of crops.

[0009] A method for preparing a root-promoting polyglutamic acid derivative: the specific steps are as follows:

[0010] (1) Add polyglutamic acid, sodium azide and acetonitrile to reaction tank I (16), add sulfuric acid to adjust the pH to 4.5-5.0, turn on temperature control device I (14), heat to 10-30°C and stir for reaction for 2-4 hours to obtain solution 1;

[0011] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are mixed evenly in reaction tank II (10), valve I (11) is opened to flow the mixture into reaction tank I (16), and the mixture is reacted at room temperature for 1-2 hours to obtain solution 2;

[0012] (3) Place ethylene glycol, p-nitrophenyl chloroformate and pyridine in reaction tank III (2) and react at room temperature for 2-4 hours to obtain solution 3;

[0013] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 50-60°C and react for 2-3 hours to obtain solution 4;

[0014] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react for 8-10 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0015] (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried to obtain a root-promoting polyglutamic acid derivative.

[0016] Furthermore, in step (1), the mass ratio of polyglutamic acid to sodium azide is 20-25:1-2.

[0017] Furthermore, in step (1), the mass concentration of sulfuric acid is 20-30%. Sulfuric acid, as a catalyst and complexing agent, can promote the reaction. After adding sulfuric acid, the pH of the solution is controlled to be greater than 4. If the pH is too low, polyglutamic acid is easily decomposed.

[0018] Furthermore, in step (2), the mass ratio of the activated HBTU to indoleacetic acid is 0.8-1.2:12-15.

[0019] Furthermore, in step (2), the activated HBTU is mixed with DMF to form a HBTU / DMF complex. HBTU is activated by DMF to form an HBTU-N-oxide intermediate, which can react with a carboxyl group to form an intermediate active ester.

[0020] Furthermore, in step (3), the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 10-15:1-2.

[0021] Furthermore, in step (5), the reaction temperature is 40-60° C. The reaction temperature should not be too high, otherwise the product and unreacted polyglutamic acid will decompose. The purpose of reduced pressure concentration is to remove volatile organic solvents.

[0022] Furthermore, in step (6), the ultrafiltration is performed using a tangential flow ultrafiltration system, the vacuum freeze drying temperature is -40--20°C, and the freeze drying time is 24-48 hours. The purpose of ultrafiltration is to purify the solution and remove small molecule compounds.

[0023] An application of a polyglutamic acid derivative for promoting root growth comprises the following steps:

[0024] (1) dissolving the root growth-promoting polyglutamic acid derivative in water to prepare a solution with a concentration of 100-200 mg / L, performing pretreatment, and then cooling to room temperature;

[0025] (2) Disinfect the cut plants and then soak them in a polyglutamic acid derivative solution for 1-24 hours;

[0026] (3) Cultivate the soaked plants at a temperature of 15-25°C and replenish the solution regularly and quantitatively during the cultivation period.

[0027] Furthermore, in step (1), the concentration of the root-promoting polyglutamic acid derivative solution is 100 mg / L.

[0028] Furthermore, in step (1), the pretreatment is to adjust the pH of the root-promoting polyglutamic acid derivative solution to 6-7 and heat it to 90-100° C. for sterilization. During the pretreatment process, the root-promoting polyglutamic acid derivative may be partially decomposed to produce small molecules, which are beneficial to plant rooting.

[0029] A preparation device for a root-promoting polyglutamic acid derivative comprises a reaction tank I (16), a reaction tank II (10), a reaction tank III (2), a reaction tank IV (5) and a reaction tank V (19) connected by a pipeline, wherein a pH meter (13) and a stirring device I (15) are provided inside the reaction tank I (16) and the temperature is controlled by a temperature control device I (14), and stirring devices are provided inside the reaction tank III (2) and the reaction tank IV (5) and the temperature is controlled by a temperature control device II (6) and a temperature control device III (22) respectively.

[0030] Furthermore, the pipelines between the reaction tanks are all provided with valves. The pipelines connecting the reaction tanks are provided with valves. When the valves are opened, the solution circulates, and the solution can be mixed and reacted. When the valves are closed, the reaction tanks do not interfere with each other, and the reaction can be carried out at the same time, saving time and improving efficiency. In addition, each reaction tank is provided with a feed port, which can be used for the addition of raw materials during the reaction. Stirring can make the sulfuric acid and the solution mix evenly, ensure the uniformity of the solution pH, reduce the degradation of polyglutamic acid, and also improve the reaction efficiency.

[0031] Furthermore, the stirring device I (14) includes a rotating shaft and three stirring blades arranged at equal intervals. A hollow pipe is provided inside the rotating shaft and the stirring blade in the middle position, and sulfuric acid can flow out through the pipe. A valve is provided inside the rotating shaft, and the flow rate of sulfuric acid can be controlled by the valve. The edge end of the stirring blade is provided with multiple small holes to facilitate the uniform distribution of sulfuric acid. After the pH meter detects that the pH of the solution reaches the set value, the valve in the rotating shaft is closed. The sulfuric acid is added by the stirring blade in the middle of the stirring device, and the sulfuric acid and the solution are quickly mixed evenly during stirring to catalyze the reaction. At the same time, sulfuric acid is automatically added, which can save manpower. The program accurately controls the pH value, reduces the waste of sulfuric acid, and reduces the loss of polyglutamic acid in the solution.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention introduces indoleacetic acid and phospholipids by chemical methods to obtain polyglutamic acid derivatives. Indoleacetic acid can affect cell division, cell elongation and differentiation, promote plant rooting and accelerate root formation. Phospholipids can activate cells, promote plant root growth, regulate plant metabolism and stimulate crop growth.

[0034] (2) The root-promoting polyglutamic acid derivatives of the present invention can be continuously degraded into small molecular substances under natural conditions, thereby improving the stress resistance and partial disease resistance of plants. At the same time, they provide nitrogen, phosphorus and other elements required by plants, promote the absorption and utilization of trace elements and nutrients such as phosphorus fertilizers, are beneficial to the growth and development of plants, and improve crop yield and quality.

[0035] (3) The root-promoting polyglutamic acid derivative of the present invention is rich in various elements required by plants and can be slowly degraded in the soil to achieve a slow-release effect. At the same time, the production method of the present invention is simple, which expands the application scope of polyglutamic acid and is suitable for large-scale production.

[0036] (4) The preparation device of the root-promoting polyglutamic acid derivative of the present invention has a valve on the pipeline connecting each reaction tank. When the valve is closed, the reaction tanks do not interfere with each other and can react at the same time, saving time and improving efficiency. After the pH meter detects that the pH of the solution reaches the set value, the valve in the rotating shaft is closed.

[0037] (5) The present invention adds sulfuric acid through the rotating shaft of the hollow pipe and the stirring blade in the middle, and the addition is automatic, which saves manpower. The program accurately controls the pH value, reduces the waste of sulfuric acid, and reduces the loss of polyglutamic acid in the solution. The edge end of the stirring blade is provided with a plurality of small holes to facilitate the uniform distribution of sulfuric acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a preparation device for polyglutamic acid derivatives that promote root growth;

[0039] Among them, 1. Feed port I; 2. Reaction tank III; 3. Pipeline valve II; 4. Feed port II; 5. Reaction tank IV; 6. Temperature control device II; 7. Stirring device III; 8. Feed port III; 9. Stirring device; 10. Reaction tank II; 11. Pipeline valve I; 12. Feed port IV; 13. pH meter; 14. Temperature control device I; 15. Stirring device I; 16. Reaction tank I; 17. Pipeline valve III; 18. Pipeline valve IV; 19. Reaction tank V; 20. Stirring device IV; 21. Pipeline; 22. Temperature control device III.

[0040] Example 1

[0041] (1) Add polyglutamic acid, sodium azide and acetonitrile to a reaction tank I (16), add sulfuric acid to adjust the pH to 4.5, turn on the temperature control device I (14), heat to 10°C and stir to react for 2 hours to obtain a solution 1, wherein the mass ratio of polyglutamic acid to sodium azide is 20:1;

[0042] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are uniformly mixed in reaction tank II (10), valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 2 hours to obtain solution 2, wherein the mass ratio of the activated HBTU to indoleacetic acid is 0.8:12;

[0043] (3) placing ethylene glycol, p-nitrophenyl chloroformate and pyridine in a reaction tank III (2) and reacting at room temperature for 2-4 hours to obtain a solution 3, wherein the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 10:1;

[0044] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 50°C and react for 2 hours to obtain solution 4;

[0045] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react at 40°C for 8 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0046] (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried. The vacuum freeze-drying temperature is -20°C and the freeze-drying time is 48 hours to obtain a root-promoting polyglutamic acid derivative.

[0047] Note: HBTU is 0-(benzotriazole-1-yl)-bis(dimethylamino)carbonium hexafluorophosphate, which belongs to the carbonium salt condensation agent.

[0048] Example 2

[0049] (1) Add polyglutamic acid, sodium azide and acetonitrile to a reaction tank I (16), add sulfuric acid to adjust the pH to 5.0, turn on the temperature control device I (14), heat to 30°C and stir to react for 4 hours to obtain a solution 1, wherein the mass ratio of polyglutamic acid to sodium azide is 25:2;

[0050] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are uniformly mixed in reaction tank II (10), valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 2 hours to obtain solution 2, wherein the mass ratio of the activated HBTU to indoleacetic acid is 1.2:15;

[0051] (3) placing ethylene glycol, p-nitrophenyl chloroformate and pyridine in a reaction tank III (2) and reacting at room temperature for 2-4 hours to obtain a solution 3, wherein the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 15:2;

[0052] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 60°C and react for 3 hours to obtain solution 4;

[0053] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react at 60°C for 10 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0054] (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried. The vacuum freeze-drying temperature is -40°C and the freeze-drying time is 48 hours to obtain a root-promoting polyglutamic acid derivative.

[0055] Example 3

[0056] (1) Add polyglutamic acid, sodium azide and acetonitrile to a reaction tank I (16), add sulfuric acid to adjust the pH to 4.5, turn on the temperature control device I (14), heat to 10°C and stir to react for 4 hours to obtain a solution 1, wherein the mass ratio of polyglutamic acid to sodium azide is 20:2;

[0057] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are uniformly mixed in reaction tank II (10), valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 1.5 hours to obtain solution 2, wherein the mass ratio of the activated HBTU to indoleacetic acid is 0.8:15;

[0058] (3) placing ethylene glycol, p-nitrophenyl chloroformate and pyridine in a reaction tank III (2) and reacting at room temperature for 2-4 hours to obtain a solution 3, wherein the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 10:2;

[0059] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 50°C and react for 3 hours to obtain solution 4;

[0060] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react at 40°C for 10 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0061] (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried. The vacuum freeze-drying temperature is -40°C and the freeze-drying time is 24 hours to obtain a root-promoting polyglutamic acid derivative.

[0062] Example 4

[0063] (1) Add polyglutamic acid, sodium azide and acetonitrile to a reaction tank I (16), add sulfuric acid to adjust the pH to 5.0, turn on the temperature control device I (14), heat to 30°C and stir to react for 2 hours to obtain a solution 1, wherein the mass ratio of polyglutamic acid to sodium azide is 25:1;

[0064] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are uniformly mixed in reaction tank II (10), valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 2 hours to obtain solution 2, wherein the mass ratio of the activated HBTU to indoleacetic acid is 1.2:12;

[0065] (3) placing ethylene glycol, p-nitrophenyl chloroformate and pyridine in a reaction tank III (2) and reacting at room temperature for 4 hours to obtain a solution 3, wherein the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 15:1;

[0066] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 60°C and react for 2 hours to obtain solution 4;

[0067] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react at 60°C for 10 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0068] (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried. The vacuum freeze-drying temperature is -40°C and the freeze-drying time is 48 hours to obtain a root-promoting polyglutamic acid derivative.

[0069] Example 5

[0070] (1) Add polyglutamic acid, sodium azide and acetonitrile to a reaction tank I (16), add sulfuric acid to adjust the pH to 4.7, turn on the temperature control device I (14), heat to 10°C and stir to react for 3 hours to obtain a solution 1, wherein the mass ratio of polyglutamic acid to sodium azide is 23:1.5;

[0071] (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are uniformly mixed in reaction tank II (10), valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 1.5 hours to obtain solution 2, wherein the mass ratio of the activated HBTU to indoleacetic acid is 1.0:15;

[0072] (3) placing ethylene glycol, p-nitrophenyl chloroformate and pyridine in a reaction tank III (2) and reacting at room temperature for 3 hours to obtain a solution 3, wherein the mass ratio of ethylene glycol to p-nitrophenyl chloroformate is 15:1.5;

[0073] (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 55°C and react for 2.5 hours to obtain solution 4;

[0074] (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react at 50°C for 9 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5;

[0075] (6) Solution 5 was ultrafiltered, and the concentrated solution was collected and washed with acetone, filtered, and vacuum freeze-dried. The vacuum freeze-drying temperature was -30°C and the freeze-drying time was 36 h.

[0076] Comparative Example 1

[0077] The steps are the same as those in Example 2, except that indoleacetic acid is not added in step (2).

[0078] Comparative Example 2

[0079] The steps are the same as those in Example 2, except that phospholipids are not added in step (4).

[0080] Comparative Example 3

[0081] The steps are the same as those in Example 2, except that indoleacetic acid is not added in step (2) and phospholipids are not added in step (4).

[0082] Experimental Example 1 Rooting experiment of peach tree cuttings

[0083] Peach cuttings with the same growth potential were selected and divided into 10 groups, each group of 10 peach cuttings, of which one group was immersed in clear water as a control. The polyglutamic acid derivatives of Examples 1-5 and Comparative Examples 1-3 were dissolved in water to prepare a solution with a concentration of 100 mg / L, and 8 groups of peach cuttings were immersed in it for 24 hours, and then placed in a hotbed for cultivation, maintained at a temperature of 20 ° C, and placed in a cool place for cultivation. During the cultivation period, the polyglutamic acid derivative solutions of Examples 1-5 and Comparative Examples 1-3 were supplemented with polyglutamic acid derivatives for root growth at regular intervals and quantitatively, respectively, and recorded as the experimental group. The raw material polyglutamic acid was dissolved in water to prepare a solution with a concentration of 100 mg / L, and one group of peach cuttings was immersed in it for 24 hours. The cultivation method was consistent with the experimental group, and the polyglutamic acid solution was supplemented regularly and quantitatively during the cultivation period. The control group was cultivated under the same conditions, and clear water was supplemented regularly and quantitatively during the cultivation period. The rooting time, average number of roots, average root length and rooting rate were recorded respectively, and the average values ​​were taken respectively. The test results are shown in Table 1.

[0084] Table 1. Rooting of peach cuttings

[0085]

[0086] Through the test, it can be known that the peach tree cuttings soaked in the root-promoting polyglutamic acid derivative solution of Examples 1-5 sprout new roots in 13-14 days, with an average number of 17-18 roots, an average root length of about 2.8 cm, and a rooting rate of more than 94%. The peach tree cuttings soaked in the comparative polyglutamic acid derivative solution sprout new roots as early as 17 days, with an average number of less than 15 roots, an average root length of less than 2.4 cm, and a maximum rooting rate of only 90%. The peach tree cuttings soaked in the polyglutamic acid solution sprout new roots in 17 days, with an average number of 15 roots, an average root length of 2.4 cm, and a rooting rate of 91%. The peach tree cuttings soaked in clean water sprout new roots in 20 days, with an average number of 10 roots, an average root length of 1.8 cm, and a rooting rate of 85%. In addition to clean water, the comparative example 3 has the worst root-promoting effect because the polyglutamic acid raw material is partially degraded after the reaction, and the small molecular substances are removed after ultrafiltration. It can be seen that the rooting of peach cuttings treated with the root-promoting polyglutamic acid derivatives of the present invention is better than that treated with the raw material polyglutamic acid and soaked in water. The polyglutamic acid derivatives prepared by adding phospholipids and indoleacetic acid of the present invention promote the rooting of peach cuttings.

[0087] It is shown that the invention introduces indoleacetic acid and phospholipid to obtain polyglutamic acid derivatives, and treats peach tree cuttings to effectively shorten the rooting time, increase the rooting rate, and promote root growth.

[0088] Experimental Example 2 Rooting of Rose Cuttings

[0089] Select rose cuttings with the same growth potential and divide them into 10 groups, each group has 10 rose cuttings, and one group of rose cuttings is immersed in clean water as a control. The polyglutamic acid derivatives of Examples 1-5 and Comparative Examples 1-3 are dissolved in water to prepare a solution with a concentration of 100 mg / L, and 8 groups of rose cuttings are immersed in it for 2 hours, and then placed in a seedling bag for cultivation, and the temperature is maintained at 20°C. During the cultivation period, the polyglutamic acid derivative solutions of Examples 1-5 and Comparative Examples 1-3 are supplemented with polyglutamic acid derivatives for root growth at regular intervals and quantitatively, which are recorded as experimental groups. The raw material polyglutamic acid is dissolved in water to prepare a solution with a concentration of 100 mg / L, and a group of peach tree cuttings are immersed in it for 24 hours. The cultivation method is consistent with the experimental group, and the polyglutamic acid solution is supplemented regularly and quantitatively during the cultivation period. The control group is cultivated under the same conditions, and clean water is supplemented regularly and quantitatively during the cultivation period. The rooting time, average number of roots, average root length and rooting rate are recorded respectively, and the average values ​​are taken respectively. The test results are shown in Table 2.

[0090] Table 2. Rooting of rose cuttings

[0091]

[0092] Through the test, it can be known that the peach cuttings soaked in the root-promoting polyglutamic acid derivative solution of Examples 1-5 sprout new roots in 9-10 days, with an average number of 24-25 roots, an average root length of 4.3-4.4 cm, and a rooting rate of more than 90%. The peach cuttings soaked in the polyglutamic acid derivative solution of Comparative Examples 1-5 sprout new roots as early as 12 days, with an average number of roots of up to 17, an average root length of up to 3.6 cm, and a rooting rate of up to 85%. The peach cuttings soaked in the polyglutamic acid solution sprout new roots in 12 days, with an average number of 17 roots, an average root length of 3.6 cm, and a rooting rate of 84%. The peach cuttings soaked in clean water sprout new roots in 15 days, with an average number of 14 roots, an average root length of 2.9 cm, and a rooting rate of 79%. It can be seen that the rooting of rose cuttings treated with the root-promoting polyglutamic acid derivatives of Examples 1-5 is better than that of the polyglutamic acid derivatives, raw material polyglutamic acid and water immersion treatments of Comparative Examples 1-3.

[0093] It is shown that the present invention can effectively shorten the rooting time, increase the rooting rate and promote the growth of the root system by treating rose cuttings with root-promoting polyglutamic acid derivatives.

[0094] Experimental Example 3 Rooting of Grape Cuttings

[0095] Select grape cuttings with the same growth potential and divide them into 9 groups, each group has 10 grape cuttings, and one group of grape cuttings is immersed in water as a control. The polyglutamic acid derivatives of Examples 1-5 and Comparative Examples 1-3 are dissolved in water to prepare a solution with a concentration of 100 mg / L, and 8 groups of grape cuttings are immersed in it for 1 hour, and then placed in a hotbed for cultivation, maintaining the temperature at 20°C, and replenishing the root-promoting polyglutamic acid derivative solution regularly and quantitatively during the cultivation period, which is recorded as the experimental group. The raw material polyglutamic acid is dissolved in water to prepare a solution with a concentration of 100 mg / L, and a group of peach tree cuttings are immersed in it for 24 hours. The cultivation method is consistent with the experimental group, and the polyglutamic acid solution is replenished regularly and quantitatively during the cultivation period. The control group is cultivated under the same conditions, and clean water is replenished regularly and quantitatively during the cultivation period. The rooting time, average number of roots, average root length and rooting rate are recorded respectively, and the average values ​​are taken respectively. The test results are shown in Table 3.

[0096] Table 3. Rooting of grape cuttings

[0097]

[0098] Through experiments, it can be known that the grape cuttings soaked in the root-promoting polyglutamic acid derivative solution of Examples 1-5 sprout new roots in 8-9 days, with an average number of 33-34 roots, an average root length of 3.8-4.0 cm, and a rooting rate of more than 95%. The grape cuttings soaked in the polyglutamic acid derivative solution of Comparative Examples 1-3 sprout new roots as early as 12 days, with an average number of roots of up to 29, an average root length of up to 2.7 cm, and a rooting rate of up to 92%. The peach cuttings soaked in the polyglutamic acid solution sprout new roots in 12 days, with an average number of 28 roots, an average root length of 2.7 cm, and a rooting rate of 91%. The grape cuttings soaked in clean water sprout new roots in 16 days, with an average number of 24 roots, an average root length of 2.1 cm, and a rooting rate of 87%. It can be seen that the rooting of grape cuttings treated with the root-promoting polyglutamic acid derivatives of Examples 1-5 is better than that of the grape cuttings treated with polyglutamic acid derivative solutions of Comparative Examples 1-3, better than that of the grape cuttings treated with raw polyglutamic acid solutions, and better than that of the grape cuttings treated with water.

[0099] It shows that by treating grape cuttings with root-promoting polyglutamic acid derivatives, the rooting time can be effectively shortened, the rooting rate can be increased, and root growth can be promoted.

[0100] Experimental Example 4 Wheat Growth and Yield

[0101] A wheat test field with basically the same crop growth was selected and randomly divided into three treatments. Each treatment was randomly divided into 10 groups, each group was 0.5 mu, and a 5m interval belt was set between adjacent groups. Drip irrigation was performed once during the jointing stage of wheat. 8 groups were selected, and the root-promoting polyglutamic acid derivatives of Examples 1-5 and the polyglutamic acid derivatives of Comparative Examples 1-3 were dissolved in water to prepare solutions, and the wheat was drip irrigated separately. One group was drip irrigated with a solution prepared with raw material polyglutamic acid, and 7kg was applied per mu. The remaining group was drip irrigated with clean water as a control. The wheat yield of each group was the average yield of the corresponding group in the three treatments. The test results are shown in Table 4.

[0102] Table 4. Wheat growth and yield

[0103]

[0104] Through experiments, it can be known that when wheat is drip-irrigated with the polyglutamic acid derivative solutions of Examples 1-5 of the present invention, the height of the wheat plant is significantly higher than that of the wheat drip-irrigated with the raw material polyglutamic acid and clean water in Examples 1-3, and the growth is significantly better. When measuring the plant height, it is found that the wheat stalks drip-irrigated with the polyglutamic acid derivative solutions of Examples 1-5 are thicker and the leaves are darker in color, indicating that the lodging resistance and photosynthesis of wheat can be enhanced. The average yield of wheat after drip irrigation with the polyglutamic acid derivative solutions of Examples 1-5 is significantly higher than the average yield of wheat drip-irrigated with the comparative examples 1-3, the raw material polyglutamic acid and clean water, and the wheat grows well after drip irrigation, indicating that the polyglutamic acid derivatives of the present invention can provide plants with the nitrogen, phosphorus and other elements they need, promote plant growth and development, and improve crop yield and quality.

[0105] In summary, after treating branches with the root-promoting polyglutamic acid derivatives of the present invention, the rooting time can be effectively shortened, the rooting rate can be increased, and the root growth can be promoted. At the same time, the nitrogen, phosphorus and other elements required by plants can be provided to promote the growth and development of plants and improve the yield and quality of crops.

Claims

1. A polyglutamic acid derivative for promoting root growth, characterized in that: The root growth-promoting polyglutamic acid derivative is modified with indoleacetic acid and phospholipid at the same time; The preparation method of the root-promoting polyglutamic acid derivative comprises the following specific steps: (1) Add polyglutamic acid, sodium azide and acetonitrile to reaction tank I (16), add sulfuric acid to adjust the pH to 4.5-5.0, turn on temperature control device I (14), heat to 10-30°C and stir for reaction for 2-4 hours to obtain solution 1; (2) After the activated HBTU, indoleacetic acid, triethylamine and acetonitrile are mixed evenly in reaction tank II (10), the pipeline valve I (11) is opened to flow into reaction tank I (16), and the mixture is reacted at room temperature for 1-2 hours to obtain solution 2; (3) Place ethylene glycol, p-nitrophenyl chloroformate and pyridine in reaction tank III (2) and react at room temperature for 2-4 hours to obtain solution 3; (4) Add phospholipid, acetonitrile and triethylamine to reaction tank IV (5), turn on stirring device III (7) to stir evenly, then open pipeline valve II (3) to add solution 3, and at the same time turn on temperature control device II (6) to raise the temperature to 50-60°C and react for 2-3 hours to obtain solution 4; (5) Open pipeline valve III (17) and pipeline valve IV (18) to mix solution 2 and solution 4 in reaction tank V (19), and simultaneously open stirring device IV (20) and temperature control device III (22) to stir and react for 8-10 hours. After the reaction is completed, the mixture flows out through pipeline (21) and is then concentrated under reduced pressure to obtain solution 5; (6) Solution 5 is subjected to ultrafiltration, and the concentrated solution is collected and washed with acetone, filtered, and vacuum freeze-dried to obtain a root-promoting polyglutamic acid derivative.

2. The root growth promoting polyglutamic acid derivative according to claim 1, characterized in that: In step (1), the mass ratio of polyglutamic acid to sodium azide is 20-25:1-2.

3. The root growth promoting polyglutamic acid derivative according to claim 1 or 2, characterized in that: In step (5), the reaction temperature is 40-60°C.

4. The root growth-promoting polyglutamic acid derivative according to claim 3, characterized in that: In step (6), the ultrafiltration is a tangential flow ultrafiltration system, the vacuum freeze drying temperature is -40--20°C, and the freeze drying time is 24-48h.

5. An application of the polyglutamic acid derivative for promoting root growth according to claim 1, characterized in that: The steps include: (1) dissolving the root growth-promoting polyglutamic acid derivative in water to prepare a solution with a concentration of 100-200 mg / L, performing pretreatment, and then cooling to room temperature; (2) Disinfect the cut plants and then soak them in a polyglutamic acid derivative solution for 1-24 hours; (3) Cultivate the soaked plants at a temperature of 15-25°C and replenish the solution regularly and quantitatively during the cultivation period.

6. The use of the polyglutamic acid derivative for promoting root growth according to claim 5, characterized in that: In step (1), the pretreatment is to adjust the pH of the root-promoting polyglutamic acid derivative to 6-7 and heat it to 90-100° C. for sterilization.

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