Plant growth-promoting stress-resistant agent of micromolecular collagen active peptide as well as preparation method and application of plant growth-promoting stress-resistant agent

Abstract

The invention provides a plant growth-promoting stress-resistant agent containing micromolecular collagen active peptide and a preparation method and application thereof, and the plant growth-promoting stress-resistant agent comprises the following raw materials by weight: 5-10% of micromolecular collagen active peptide, 4-8% of soybean peptide-zinc chelate, 3-12% of mineral element, 2-5% of seaweed extract, 1-3% of chitosan oligosaccharide, and the balance of deionized water. The growth-promoting stress-resistant agent disclosed by the invention realizes an integrated function of nutrition supply, efficient trace element delivery and stress-resistant protection through multi-component synergy, can remarkably improve the crop yield and enhance the stress resistance, and is environment-friendly, simple and convenient in process and suitable for various crops and stress planting scenes.

Description

Technical Field

[0001] This invention relates to the field of agricultural biotechnology, and in particular to a plant growth promoter and stress-resistant agent of small molecule collagen active peptides, its preparation method and application. Background Technology

[0002] As agriculture transforms towards green and high-quality development, traditional plant nutrients can no longer meet the comprehensive needs of "improved quality, increased yield, stress resistance, and eco-friendliness." Existing technologies utilize fishery waste to prepare small-molecule collagen peptides as plant nutrients, such as CN101481266B, a patent for a plant nutrient. This patent uses fishery processing waste (fish skin, scales, bones, etc.) as raw materials, and degrades them through a compound enzyme hydrolysis process to prepare small-molecule collagen peptides, which are then used directly as plant nutrients / foliar fertilizers / fertigation. While this achieves improved nutrient supply and yield, it has significant limitations: First, the synergistic effect of promoting growth and stress resistance is insufficient; it can only indirectly resist diseases by enhancing plant immunity, lacking targeted protection against abiotic stresses such as drought and salinity. Second, the delivery efficiency of micronutrients is low; traditional zinc sources (such as zinc sulfate) are prone to precipitation in weakly alkaline soil environments, resulting in insufficient absorption and utilization by plant rhizosphere, and antagonistic effects with other elements. Third, the formulation has a single component, failing to fully utilize the synergistic effect of bioactive substances, leading to limited overall performance.

[0003] Meanwhile, existing zinc-supplemented plant nutrients mostly use the direct addition of inorganic zinc salts, which suffers from poor stability, easy fixation by soil, and low bioavailability. Although some technologies attempt to use peptide-zinc chelates, the preparation process is complex, the chelation rate is low, and they are not effectively combined with other growth-promoting and stress-resistance components, failing to achieve the integrated function of "nutrient supply-efficient delivery-stress protection". In addition, stress-resistance components such as seaweed extracts and chitosan oligosaccharides are mostly simple compound formulations in existing preparations, failing to form a synergistic system with nutrient components, thus significantly reducing their stress-resistance effect.

[0004] Therefore, developing a plant preparation with synergistic components, high micronutrient utilization, and dual effects of promoting growth and resisting stress has become the key to solving the current pain points of green agricultural production. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to overcome the shortcomings of existing plant nutrients, such as limited growth-promoting and stress-resistance functions, low micronutrient utilization, and poor environmental adaptability. This invention provides a plant growth-promoting and stress-resistance agent based on small-molecule collagen active peptides. Through the synergistic effect of multiple components, this formulation can provide plants with complete nutrition, achieve efficient and stable zinc delivery, and enhance the plant's resistance to stresses such as drought, salinity, and pests and diseases. Furthermore, it is non-toxic, residue-free, and can improve soil conditions. The invention also provides a simple, industrially feasible preparation method and a wide range of agricultural applications.

[0006] The technical solution of the present invention: This invention discloses a plant growth promoter and stress-resistant agent of small molecule collagen active peptides. The raw materials of the plant growth promoter and stress-resistant agent, by weight percentage, include: 5-10% small molecule collagen active peptides, 4-8% soybean peptide-zinc chelate, 3-12% mineral elements, 2-5% seaweed extract, 1-3% chitosan oligosaccharide, and the balance being deionized water.

[0007] Furthermore, the molecular weight of the small molecule collagen active peptide is 800-2000 Da, and it is derived from fish scales and fish skin.

[0008] Furthermore, the soybean peptide-zinc chelate is prepared by denaturation, enzymatic hydrolysis and zinc ion chelation of soybean protein isolate.

[0009] Furthermore, the mineral element is selected from one or more of boron, calcium, iron, and manganese.

[0010] Furthermore, the molecular weight of the chitosan oligosaccharide is 500-2000 Da; the alginic acid content in the seaweed extract is ≥30%, and the mannitol content is ≥15%.

[0011] Furthermore, the preparation of the soybean peptide-zinc chelate includes the following steps: S1: Add soy protein isolate to deionized water to prepare a 10% (w / w) soy protein isolate solution; disperse the solution in 0.1 mol / L Tris-HCl buffer and stir magnetically for 25-30 min until the protein is completely dissolved to form a uniform dispersion; place the dispersion in a 45-55℃ constant temperature water bath and incubate for 1.0-1.5 h for reduction; heat the reduced protein solution to 95℃ in a water bath and incubate for 8-10 min to enhance denaturation, then rapidly cool to 40-45℃ to obtain a pretreated protein solution; S2: Add calcium hydroxide solution to the pretreated protein solution to adjust the pH of the system to 8.0-8.5, add alkaline protease, and hydrolyze the enzyme by shaking at 40-45℃ and 150-200 r / min for 20-25 min; continue to add calcium hydroxide solution to adjust the pH of the system to 7.0-7.5, add neutral protease, and then add zinc sulfate powder. Stir while adding the solution at 200 r / min, and maintain the reaction at 42-45℃ for 45-50 min to obtain the enzymatic hydrolysis-chelation mixture. S3: After the reaction is complete, rapidly heat the enzymatic hydrolysis-chelation mixture to 90-95℃ and incubate for 8-10 min to inactivate the protease, then cool to room temperature; transfer the cooled mixture to a disc centrifuge and centrifuge at 5000 r / min for 10 min, discard the undigested protein precipitate at the bottom, and collect the supernatant; filter the supernatant through a 0.22-0.25 μm ceramic microfiltration membrane to remove trace suspended solids and macromolecular impurities, obtaining a clear filtrate; S4: Slowly add anhydrous ethanol to the clarified filtrate, stir well, and place in a cold storage at 2-6℃ for 1.0-1.5h to promote chelate coagulation; introduce the precipitation system into a centrifuge and centrifuge at 4800-5200r / min for 8-12min, discard the supernatant containing free zinc ions and small molecule impurities, and collect the bottom precipitate; wash the precipitate with anhydrous ethanol 1-2 times, centrifuging after each wash; transfer the washed precipitate to a vacuum freeze dryer and dry for 22-26h to constant weight to obtain soybean peptide-zinc chelate.

[0012] Furthermore, the amount of zinc sulfate powder added is 240-400% of the amount of soybean protein isolate.

[0013] Furthermore, the amount of alkaline protease added is 1-1.5% of the soybean protein isolate, and the enzyme activity of the alkaline protease is ≥200,000 U / g.

[0014] Furthermore, the amount of neutral protease added is 2-3.5% of the soybean protein isolate, and the enzyme activity of the neutral protease is ≥100,000 U / g.

[0015] Furthermore, the calcium hydroxide solution has a mass fraction of 8-12%.

[0016] This invention provides a method for preparing a plant growth-promoting and stress-resistant agent of small molecule collagen active peptides, characterized by comprising the following steps: (1) Dilute the small molecule collagen active peptides with deionized water to a concentration of 10-15%, adjust the pH to 6.5-8.5, raise the temperature to 35-45℃, add boric acid first and react for 1-1.5h, then add calcium nitrate and react for 30-40min, and add various mineral elements in sequence and react for 0.5h each. During this period, maintain a stirring rate of 150-200r / min to obtain a small molecule collagen active peptide chelate solution. (2) Keep the temperature at 30-40℃, add soybean peptide-zinc chelate, seaweed extract and chitosan oligosaccharide to the small molecule collagen active peptide chelate solution, stir and react for 1-1.5 hours, adjust the pH to 4-5, let it stand and precipitate for 1.5-2.5 hours and then filter to obtain the plant growth promoter and stress resistant agent of the small molecule collagen active peptide.

[0017] This invention provides an application of a plant growth-promoting and stress-resistant agent of small molecule collagen active peptides, characterized in that the growth-promoting and stress-resistant agent is sprayed on the leaves of crops at a dilution of 800-1500 times, or irrigated at a dilution of 500-800 times; applicable crops include wheat, corn, rice, celery, tomato, cucumber, apple, citrus or strawberry.

[0018] Furthermore, its application scenarios include conventional planting, drought stress, saline-alkali land planting, and continuous cropping obstacles. It can be sprayed during the seedling stage, growth stage, flowering stage, and fruit enlargement stage of crops, once every 7-15 days, for 3-4 consecutive sprays.

[0019] Beneficial effects: 1. Significant Synergistic Effects on Growth and Stress Resistance: The nutrient supply from small molecule collagen active peptides, the efficient delivery of soybean peptide-zinc chelates, the precise supplementation of mineral elements, the stress resistance regulation of seaweed extracts, and the defense induction of chitosan oligosaccharides work synergistically to improve crop germination rate, increase yield, reduce yield decline under drought / salt-alkali stress, and lower the incidence of diseases and pests.

[0020] 2. High utilization rate of trace elements: Soybean peptide-zinc chelate has excellent stability in soil environments with different pH levels. The absorption efficiency of zinc element is improved compared with traditional zinc sulfate, which effectively solves the industry pain point of easy precipitation and low utilization rate of zinc ions, while promoting the absorption of other mineral elements.

[0021] 3. Strong environmental adaptability: The formulation can adapt to acidic, neutral and weakly alkaline (pH 4.0-8.5) soils, and is suitable for various scenarios such as conventional planting, drought stress, saline-alkali land planting, and continuous cropping obstacles, thus broadening the scope of application.

[0022] 4. Eco-friendly and safe: The raw materials are derived from fishery waste and plant protein. The preparation process is free from secondary pollution. The product is non-toxic, residue-free, and pollution-free, meeting the production requirements of AA-grade green food. Long-term use can improve the soil, increase the organic matter content of the soil, and form loose and fertile oily soil.

[0023] 5. Simple process and easy to industrialize: Soybean peptide-zinc chelate adopts a one-step simultaneous enzymatic hydrolysis-chelation process, which is simple to prepare plant growth promoter and stress resistance agent. All parameters are within the industrially achievable range, the production cost is controllable, and it is suitable for large-scale production. Detailed Implementation

[0024] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0025] Unless otherwise specified, all chemical reagents used in this invention are commercially available analytical grade reagents.

[0026] Small molecule collagen active peptides were purchased from Hubei Maidehao Biotechnology Co., Ltd.; fish skin collagen peptide powder with an effective ingredient content of 99%; seaweed extract was purchased from Lanzhou Waterles Biotechnology Co., Ltd.; chitosan oligosaccharide was purchased from Shaanxi Xiazhou Biotechnology Co., Ltd., model AS-01; soy protein isolate was purchased from Xi'an Shilin Biotechnology Co., Ltd., model SD100; alkaline protease and neutral protease were purchased from Leshengyuan Biotechnology (Nanjing) Co., Ltd.

[0027] Example 1 Preparation of soybean peptide-zinc chelate: S1: Weigh 10 kg of soy protein isolate and add 90 kg of deionized water to prepare a 10% (w / w) soy protein isolate solution; disperse the solution in 100 L of 0.1 mol / L Tris-HCl buffer, stir magnetically for 30 min until completely dissolved, and incubate at 48 °C in a water bath for 1.2 h for reduction; raise the temperature to 95 °C and incubate for 9 min to enhance denaturation, and then rapidly cool to 42 °C to obtain the pretreated protein solution; S2: Add a 10% (w / w) calcium hydroxide solution to the pretreated protein solution (calcium hydroxide is added to deionized water and stirred to dissolve, thus obtaining a calcium hydroxide solution), adjust the pH to 8.2, add 0.12 kg of alkaline protease (enzyme activity 200,000 U / g), and hydrolyze at 42℃ and 180 r / min for 22 min with shaking; use a 10% (w / w) calcium hydroxide solution, adjust the pH to 7.2, add 0.3 kg of neutral protease (enzyme activity 100,000 U / g), then add 32 kg of zinc sulfate powder, add while stirring at 200 r / min, react at 43℃ for 48 min, to obtain an enzymatic hydrolysis-chelation mixture; S3: Heat the mixture to 92℃ and hold for 9 min to inactivate it, then cool it to room temperature; centrifuge at 5000 r / min for 10 min and collect the supernatant; filter through a 0.24 μm ceramic microfiltration membrane to obtain a clear filtrate; S4: Add anhydrous ethanol to the filtrate and let it stand at 4℃ for 1.2 h; centrifuge at 5000 r / min for 10 min and collect the precipitate; wash once with anhydrous ethanol, centrifuge and collect the precipitate, then transfer it to a vacuum freeze dryer, pre-freeze at -35℃, and then dry at 50℃ for 24 h under 30 Pa vacuum to obtain the soybean peptide-zinc chelate product; the chelated zinc content / peptide zinc loading was measured to be 286 mg / g. Preparation of plant growth-promoting and stress-resistant agents: (1) Take 8 kg of small molecule collagen active peptides, dilute with deionized water to a concentration of 12%, adjust the pH to 7.5, heat to 40℃, add 1.5 kg of boric acid and react for 1.2 h, then add 2.5 kg of calcium nitrate and react for 35 min, then add 0.8 kg of ferric sodium ethylenediaminetetraacetate and 0.3 kg of manganese sulfate and react for 0.5 h each, stirring at 180 r / min to obtain a chelate solution; (2) Keep the temperature at 35℃, add 6kg soybean peptide-zinc chelate, 3kg seaweed extract and 2kg chitosan oligosaccharide to the chelation solution, stir for 1.2h, adjust the pH to 4.5, let stand for 2h to precipitate and then filter to obtain plant growth promoter and stress resistance agent.

[0028] Example 2 Preparation of soybean peptide-zinc chelate: S1: Weigh 15 kg of soy protein isolate and add 135 kg of deionized water to prepare a 10% (w / w) soy protein isolate solution; disperse the solution in 150 L of 0.1 mol / L Tris-HCl buffer, stir magnetically for 28 min until completely dissolved, and incubate at 52 °C in a water bath for 1.5 h to reduce; raise the temperature to 95 °C and incubate for 10 min to enhance denaturation, and then rapidly cool to 45 °C to obtain the pretreated protein solution; S2: Add 10% calcium hydroxide solution to the pretreated protein solution to adjust the pH to 8.5, add 0.225 kg of alkaline protease (enzyme activity 200,000 U / g), and hydrolyze at 45℃ and 200 r / min for 25 min with shaking; continue to use 10% calcium hydroxide solution to adjust the pH to 7.5, add 0.525 kg of neutral protease (enzyme activity 100,000 U / g), and then add 52.5 kg of zinc sulfate powder. Add while stirring at 200 r / min, and react at 45℃ for 50 min to obtain the enzymatic hydrolysis-chelation mixture; S3: Heat the mixture to 95℃ and keep it at that temperature for 10 min to inactivate it, then cool it to room temperature; centrifuge at 5000 r / min for 10 min and collect the supernatant; filter it through a 0.25 μm ceramic microfiltration membrane to obtain a clear filtrate; S4: Add anhydrous ethanol to the filtrate and let it stand at 6℃ for 1.5h; centrifuge at 5200r / min for 12min and collect the precipitate; wash twice with anhydrous ethanol, centrifuge and collect the precipitate and transfer it to a vacuum freeze dryer, pre-freeze at -32℃, and then dry at 52℃ for 24h under 35Pa vacuum to obtain the soybean peptide-zinc chelate product; the chelated zinc content / peptide zinc loading was measured to be 288mg / g.

[0029] Preparation of plant growth-promoting and stress-resistant agents: (1) Take 10 kg of small molecule collagen active peptides, dilute with deionized water to a concentration of 15%, adjust the pH to 8.0, heat to 45℃, add 2.0 kg of boric acid and react for 1.5 h, then add 3.5 kg of calcium nitrate and react for 40 min, then add 1.2 kg of ferric sodium ethylenediaminetetraacetate and 0.45 kg of manganese sulfate and react for 0.5 h each, stirring at a rate of 200 r / min to obtain a chelate solution; (2) Keep the temperature at 40℃, add 8kg soybean peptide-zinc chelate, 4kg seaweed extract and 2.5kg chitosan oligosaccharide to the chelation solution, stir for 1.5h, adjust the pH to 5.0, let stand for 2.5h to precipitate and then filter to obtain plant growth promoter and stress resistance agent.

[0030] Example 3 Preparation of soybean peptide-zinc chelate: S1: Weigh 8 kg of soy protein isolate and add 72 kg of deionized water to prepare a 10% soy protein isolate solution; disperse the solution in 80 L of 0.1 mol / L Tris-HCl buffer, stir magnetically for 25 min until completely dissolved, and incubate at 45 °C in a water bath for 1.0 h to reduce; raise the temperature to 95 °C and incubate for 8 min to enhance denaturation, and then rapidly cool to 40 °C to obtain the pretreated protein solution; S2: Add 8% calcium hydroxide solution to the pretreated protein solution to adjust the pH to 8.0, add 0.08 kg of alkaline protease (enzyme activity 200,000 U / g), and hydrolyze at 40℃ and 150 r / min for 20 min with shaking; continue to use 8% calcium hydroxide solution to adjust the pH to 7.0, add 0.16 kg of neutral protease (enzyme activity 100,000 U / g), and then add 32 kg of zinc sulfate powder. Add while stirring at 200 r / min, and react at 42℃ for 45 min to obtain the enzymatic hydrolysis-chelation mixture; S3: Heat the mixture to 90℃ and hold for 8 min to inactivate it, then cool it to room temperature; centrifuge at 4800 r / min for 10 min and collect the supernatant; filter through a 0.22 μm ceramic microfiltration membrane to obtain a clear filtrate; S4: Add anhydrous ethanol to the filtrate and let it stand at 2℃ for 1.0 h; centrifuge at 4800 r / min for 8 min and collect the precipitate; wash once with anhydrous ethanol, centrifuge and collect the precipitate and transfer it to a vacuum freeze dryer, pre-freeze at -38℃, and then dry at 48℃ for 26 h under 28 Pa vacuum to obtain the soybean peptide-zinc chelate product; the chelated zinc content / peptide zinc loading was measured to be 282 mg / g.

[0031] Preparation of plant growth-promoting and stress-resistant agents: (1) Take 5 kg of small molecule collagen active peptides, dilute with deionized water to a concentration of 10%, adjust the pH to 6.5, heat to 35℃, add 0.8 kg of boric acid and react for 1.0 h, then add 1.5 kg of calcium nitrate and react for 30 min, then add 0.4 kg of ferric sodium ethylenediaminetetraacetate and 0.2 kg of manganese sulfate and react for 0.5 h each, stirring at 150 r / min to obtain chelate solution; (2) Keep the temperature at 30℃, add 4kg soybean peptide-zinc chelate, 2kg seaweed extract and 1kg chitosan oligosaccharide to the chelation solution, stir for 1.0h, adjust the pH to 4.0, let stand for 1.5h to precipitate and then filter to obtain the plant growth promoter and stress resistance agent product.

[0032] Comparative Example 1 The difference between this preparation and Example 1 is that: Instead of preparing soybean peptide-zinc chelate, soybean peptide-zinc chelate was replaced with food-grade zinc sulfate at a dosage of 6 kg (consistent with the mass of soybean peptide-zinc chelate in Example 1). Comparative Example 2 The difference between this preparation and Example 1 is that: Preparation of soybean peptide-zinc chelate: S1: Weigh 10kg of soy protein isolate, add 90kg of deionized water to prepare a 10% solution, directly heat to 95℃ and keep at that temperature for 9min to denature, then rapidly cool to 42℃ to obtain a pretreated protein solution. S2-S4: Same as Example 1.

[0033] Comparative Example 3 The difference between this preparation and Example 1 is that: Preparation of plant growth-promoting and stress-resistant agents: (1) Same as step (1) in Example 1, to obtain the chelating solution; (2) Keep the temperature at 35℃, add only 6kg soybean peptide-zinc chelate and 2kg chitosan oligosaccharide to the chelation solution, stir for 1.2h, adjust the pH to 4.5, let stand for 2h to precipitate and then filter to obtain plant growth promoter and stress resistance agent.

[0034] The plant growth-promoting and stress-resistant agents containing small molecule collagen active peptides prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to the following tests: Test Design: 1. Test crops and scenarios: Conventional planting scenarios: Wheat (variety: Jimai 22), cucumber (variety: Bomei 8); Saline-alkali land scenario: Tomato (variety: Zhongza 105, soil salinity 0.3%, pH 8.3); Drought stress scenario: Maize (variety: Zhengdan 958, drought treatment is to stop watering for 15 days during the jointing stage). 2. Test Grouping Each group had 3 replicates, with a plot area of ​​10m². Except for the treatment factor, other field management practices (fertilization and weeding) were kept consistent. Experimental group: 0.5 kg of the plant growth promoter and stress resistance agent prepared in Examples 1-3 was diluted 1000 times with water and sprayed on wheat / corn, diluted 600 times and applied as a root irrigation and spraying on tomatoes, diluted 800 times and sprayed on cucumbers, with 0.5 kg of plant growth promoter and stress resistance agent diluted per 10 m². Control groups 1-3: Plant growth-promoting and stress-resistance agents prepared in comparative examples 1-3 (application method is the same as the corresponding experimental groups). Blank control group: water 3. Test Indicators Growth promotion indicators: According to GB / T 3543.4-1995 Crop Seed Inspection Procedures, germination test, the number of germinated plants was counted on the 10th day after sowing, and the germination rate (%) was calculated; plant height was uniformly measured before harvest at maturity to obtain the final plant height (cm); according to GB / T 3543.6-1995 Seed Purity Analysis (Oven Drying Method), at the crop maturity stage, the whole plant was harvested, blanched at 105℃, dried at 65℃ to constant weight, and the biomass per plant (g) was weighed; according to NY / T 1300-2007 Crop Field Yield Measurement Technical Specifications, at the crop full maturity stage, the actual yield (kg / mu) was measured. Stress resistance index: Yield reduction (%) under drought / salt-alkali stress. According to NY / T 1300-2007 Technical Specifications for Field Yield Measurement of Crops, yield reduction is calculated at full maturity after stress treatment throughout the entire growth period. Yield reduction = (Yield of normal group) (Yield of the stressed group) ÷ Yield of the normal group × 100%; Pest and disease incidence (%) is determined according to the general rules of NY / T 1464.1-2021 Field Efficacy Test Guidelines for Pesticides (I), and is investigated during the peak period of pest and disease occurrence, and statistics are completed before harvest; Nutritional utilization index: According to GB 5009.14-2017 National Food Safety Standard, the zinc content (mg / kg) of crops was measured at the crop harvest period, and the biomass and zinc content were measured after drying the whole crop at maturity, and then the zinc absorption efficiency (%) was calculated. Soil improvement index: Soil organic matter content (%) after planting. According to NY / T 1121.6-2006 Soil Testing Part 6: Determination of Soil Organic Matter, soil samples are taken before sowing and after crop harvest.

[0035] Test results: Table 1: Conventional Planting Scenarios (Wheat)

[0036] Table 2: Saline-alkali land scene (tomato)

[0037] Table 3: Drought Stress Scenarios (Maize)

[0038] Results analysis: Growth-promoting effect: The germination rate, plant height, single-plant biomass, and yield of crops in Examples 1-3 were significantly better than those in the comparative and blank controls. Among them, the yield was higher than that of the blank control and higher than that of Comparative Example 1 (zinc sulfate replacement), proving that the synergistic nutrient supply effect of small molecule collagen active peptides and soybean peptide-zinc chelate was significant. Stress resistance effect: In the saline-alkali land scenario, the survival rate of tomatoes in the examples was improved and the incidence of pests and diseases was reduced. In the drought scenario, the yield reduction of corn was less than that of the blank control, while the stress resistance index of Comparative Example 3 (lacking stress-resistant components) was significantly worse, verifying the synergistic stress-resistant function of seaweed extract and chitosan oligosaccharide. Zinc absorption efficiency: The zinc absorption efficiency of the examples reached a certain level, which was higher than that of Comparative Example 1 (traditional zinc sulfate) and higher than that of Comparative Example 2 (without reduction step), proving the high-efficiency zinc delivery advantage of soybean peptide-zinc chelate. The reduction step is crucial to the chelation rate and absorption efficiency. Soil improvement effect: The soil organic matter content after planting in the examples was higher than that of the blank control and significantly better than that of the comparative example, reflecting the eco-friendly and soil-improving characteristics of the formulation.

[0039] In summary, this invention, through a synergistic system of "nutrient supply-efficient delivery-stress protection," demonstrates significant advantages in promoting growth, stress resistance, nutrient utilization, and soil improvement. Moreover, the process is simple and industrializable, fully meeting the needs of green agricultural production.

[0040] This invention can also be implemented in various other ways. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A plant growth-promoting and stress-resistant agent of small molecule collagen active peptides, characterized in that, The raw materials of the plant growth promoter and stress-resistant agent, by weight percentage, include: 5-10% small molecule collagen active peptides, 4-8% soybean peptide-zinc chelate, 3-12% mineral elements, 2-5% seaweed extract, 1-3% chitosan oligosaccharide, and the balance being deionized water.

2. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 1, characterized in that, The small molecule collagen active peptides have a molecular weight of 800-2000 Da and are derived from fish scales and fish skin.

3. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 2, characterized in that, The soybean peptide-zinc chelate is prepared by denaturation, enzymatic hydrolysis and zinc ion chelation of soybean protein isolate.

4. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 3, characterized in that, The mineral elements are selected from one or more of boron, calcium, iron, and manganese.

5. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 4, characterized in that, The molecular weight of the chitosan oligosaccharide is 500-2000 Da; the alginic acid content in the seaweed extract is ≥30%, and the mannitol content is ≥15%.

6. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 5, characterized in that, The preparation of the soybean peptide-zinc chelate includes the following steps: S1: Add soy protein isolate to deionized water to prepare a 10% (w / w) soy protein isolate solution; disperse the solution in 0.1 mol / L Tris-HCl buffer and stir magnetically for 25-30 min until the protein is completely dissolved to form a uniform dispersion; place the dispersion in a 45-55℃ constant temperature water bath and incubate for 1.0-1.5 h for reduction; heat the reduced protein solution to 95℃ in a water bath and incubate for 8-10 min to enhance denaturation, then rapidly cool to 40-45℃ to obtain a pretreated protein solution; S2: Add calcium hydroxide solution to the pretreated protein solution to adjust the pH of the system to 8.0-8.5, add alkaline protease, and hydrolyze the enzyme by shaking at 40-45℃ and 150-200r / min for 20-25min. Continue to add calcium hydroxide solution to adjust the pH of the system to 7.0-7.5, add neutral protease, and then add zinc sulfate powder. Stir while adding the solution at 200r / min, and maintain the reaction at 42-45℃ for 45-50min to obtain the enzymatic hydrolysis-chelation mixture. S3: After the reaction is complete, rapidly heat the enzymatic hydrolysis-chelation mixture to 90-95℃ and incubate for 8-10 min to inactivate the protease, then cool to room temperature; transfer the cooled mixture to a disc centrifuge and centrifuge at 5000 r / min for 10 min, discard the undigested protein precipitate at the bottom, and collect the supernatant; filter the supernatant through a 0.22-0.25 μm ceramic microfiltration membrane to remove trace suspended solids and macromolecular impurities, obtaining a clear filtrate; S4: Slowly add anhydrous ethanol to the clarified filtrate, stir well, and place in a cold storage at 2-6℃ for 1.0-1.5h to promote chelate coagulation; introduce the precipitation system into a centrifuge and centrifuge at 4800-5200r / min for 8-12min, discard the supernatant containing free zinc ions and small molecule impurities, and collect the bottom precipitate; wash the precipitate with anhydrous ethanol 1-2 times, centrifuging after each wash; transfer the washed precipitate to a vacuum freeze dryer and dry for 22-26h to constant weight to obtain soybean peptide-zinc chelate.

7. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 6, characterized in that, The amount of zinc sulfate powder added is 240-400% of the soybean protein isolate.

8. The plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 7, characterized in that, The amount of alkaline protease added is 1-1.5% of the soybean protein isolate, and the enzyme activity of alkaline protease is ≥200,000 U / g. The amount of neutral protease added is 2-3.5% of the soybean protein isolate, and the enzyme activity of the neutral protease is ≥100,000 U / g. The calcium hydroxide solution has a mass fraction of 8-12%.

9. The method for preparing the plant growth-promoting and stress-resistant agent of small molecule collagen active peptides according to claim 8, characterized in that, Includes the following steps: (1) Dilute the small molecule collagen active peptides with deionized water to a concentration of 10-15%, adjust the pH to 6.5-8.5, raise the temperature to 35-45℃, add boric acid first and react for 1-1.5h, then add calcium nitrate and react for 30-40min, and add various mineral elements in sequence and react for 0.5h each. During this period, maintain a stirring rate of 150-200r / min to obtain a small molecule collagen active peptide chelate solution. (2) Keep the temperature at 30-40℃, add soybean peptide-zinc chelate, seaweed extract and chitosan oligosaccharide to the small molecule collagen active peptide chelate solution, stir and react for 1-1.5 hours, adjust the pH to 4-5, let it stand and precipitate for 1.5-2.5 hours and then filter to obtain the plant growth promoter and stress resistant agent of the small molecule collagen active peptide.

10. The application of the small molecule collagen active peptide as a plant growth promoter and stress-resistant agent according to any one of claims 1-8, characterized in that, The growth-promoting and stress-resistant agent is applied to crop leaves at a dilution of 800-1500 times, or diluted 500-800 times and used for root irrigation. Applicable crops include wheat, corn, rice, celery, tomato, cucumber, apple, citrus, or strawberry.

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