Salt-stress-resistant reliever for crops and preparation method and use method of salt-stress-resistant reliever

Abstract

The invention discloses a salt-stress-resistant alleviator for crops as well as a preparation method and a use method of the salt-stress-resistant alleviator. The salt-stress-resistant alleviator for the crops comprises carotenoid, a polyphenol compound and non-protein amino acid. The alleviator comprises carotenoid, a polyphenol compound and non-protein amino acid, is simple in components, does not contain hormones and pesticide components, is safe and environment-friendly, and is trace and efficient; the survival rate of seedlings of plants can be remarkably improved through foliage spraying, the three components form a synergistic effect, accumulation of osmotic regulation substances is enhanced, the activity of antioxidant enzymes is improved, and the removal capacity of active oxygen is enhanced, so that the salt tolerance of the plants is improved, and the damage of salt stress to the plants is effectively relieved.

Description

Technical Field

[0001] This invention belongs to the field of agricultural technology, and in particular relates to a salt stress relief agent for crops, its preparation method and application method. Background Technology

[0002] Plants are susceptible to various abiotic stresses during their growth and development, with salt stress being one of the major ones. Excessive soil salinity hinders root water absorption, disrupts ion balance, and causes oxidative damage, ultimately leading to leaf yellowing, leaf drop, and even plant death. Therefore, improving crop resistance to salt stress is crucial for their growth and development. Traditional methods for improving plant salt stress primarily involve breeding salt-tolerant varieties and soil improvement. However, breeding salt-tolerant varieties takes a long time (5-8 years), and soil improvement is costly and difficult to implement on a large scale.

[0003] A Chinese patent with publication number CN114027308A discloses a compound agent for alleviating salt stress in rice, which is composed of a certain proportion of humic acid, gibberellin, dimethyl sulfoxide, and Tween 20.

[0004] While the aforementioned compound agents can alleviate salt stress in rice, the excessive use of humic acid can lead to an imbalance in the carbon-nitrogen ratio in the soil, affecting microbial activity, inhibiting plant growth, and causing environmental pollution, which is inconsistent with the development concept of green agriculture. Summary of the Invention

[0005] The purpose of this invention is to provide a salt stress mitigator for crops, its preparation method, and its application method, aiming to solve the technical problem that the large-scale use of existing technologies to alleviate salt stress in crops can lead to environmental pollution.

[0006] To solve the above-mentioned technical problems, the present invention is mainly achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a salt stress reliever for crops, comprising carotenoids, polyphenolic compounds and non-protein amino acids.

[0008] In some embodiments of this application, the salt stress relief agent for crops comprises, by mass percentage, 0.05%~0.2% carotenoids, 0.1%~0.5% polyphenolic compounds, 0.2%~1.0% non-protein amino acids, with the balance being an adhesion promoter.

[0009] In some embodiments of this application, the adhesion aid includes glycerin, Tween 20, anhydrous ethanol, and deionized water.

[0010] In some embodiments of this application, the salt stress relief agent for crops comprises, by mass percentage: 0.1% carotenoids, 0.3% polyphenolic compounds, 0.5% non-protein amino acids, 0.02% glycerol, 0.02% Tween 20, 5% anhydrous ethanol, and the balance being deionized water.

[0011] In some embodiments of this application, the carotenoids include one or more combinations of β-carotene, lutein, astaxanthin, and lycopene.

[0012] In some embodiments of this application, the polyphenolic compound includes one or more combinations of tea polyphenols, moringa polyphenols, eugenol polyphenols, and walnut polyphenols.

[0013] In some embodiments of this application, the non-protein amino acids include one or more combinations of proline, γ-aminobutyric acid, betaine, glutamic acid, arginine, and glycine.

[0014] In a second aspect, the present invention provides a method for preparing a salt stress mitigator for crops as described in any one of the embodiments of the first aspect above, comprising the following steps:

[0015] S1: Preparation of carotenoid stock solution: Mix carotenoids with anhydrous ethanol and stir thoroughly until completely dissolved;

[0016] S2: Preparation of polyphenol compound mother liquor: Mix the polyphenol compound with deionized water and stir thoroughly under heating conditions until completely dissolved;

[0017] S3: Preparation of non-protein amino acid stock solution: Weigh a certain amount of non-protein amino acids and mix them with deionized water, stirring thoroughly until completely dissolved;

[0018] S4: Mix the carotenoid stock solution prepared in step S1, the polyphenol compound stock solution prepared in S2, and the non-protein amino acid stock solution prepared in S3 to obtain mixed solution one.

[0019] S5: Add glycerol and Tween 20 to the mixed solution one, stir thoroughly to obtain the finished product.

[0020] In some embodiments of this application, in step S2, the temperature is heated to 60~70°C.

[0021] In a third aspect, the present invention provides a method of using a salt stress reliever for crops as described in any one of the embodiments of the first aspect above, comprising spraying during the seedling stage, spraying on both sides of the leaves until the liquid is about to drip, spraying once every other day for a total of three times;

[0022] Applicable environmental conditions: Spraying temperature is 5~35℃, and spraying time is before 9:00 am or after 4:00 pm.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] The salt stress alleviator for crops disclosed in this invention comprises carotenoids, polyphenolic compounds, and non-protein amino acids. It has a simple composition, is free of hormones and pesticides, is safe and environmentally friendly, and is highly effective in small doses. Foliar application can significantly improve seedling survival rates. The three components work synergistically to enhance the accumulation of osmotic regulators, increase the activity of antioxidant enzymes, and enhance the scavenging capacity of reactive oxygen species, thereby improving the salt tolerance of plants and effectively alleviating the damage caused by salt stress. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In a first aspect, embodiments of this disclosure provide a salt stress reliever for crops, comprising carotenoids, polyphenolic compounds, and non-protein amino acids.

[0027] The salt stress relief agent for crops disclosed in this embodiment includes carotenoids, polyphenolic compounds, and non-protein amino acids. It has a simple composition, is free of hormones and pesticides, is safe and environmentally friendly, and is highly effective in small doses. Foliar spraying can significantly improve the survival rate of seedlings. The three components work synergistically to enhance the accumulation of osmotic regulators, increase the activity of antioxidant enzymes, and enhance the ability to scavenge reactive oxygen species, thereby improving the salt tolerance of plants and effectively alleviating the damage of salt stress to plants.

[0028] In some embodiments of this application, the salt stress relief agent for crops comprises, by mass percentage, 0.05%~0.2% carotenoids, 0.1%~0.5% polyphenolic compounds, 0.2%~1.0% non-protein amino acids, with the balance being an adhesion promoter.

[0029] Specifically, salt stress leads to the accumulation of superoxide anions and hydrogen peroxide in crop cells, causing damage such as lipid peroxidation of cell membranes and protein denaturation. Carotenoids can directly quench singlet oxygen, scavenge superoxide anions and hydroxyl radicals, and reduce oxidation chain reactions. At the same time, carotenoids can promote abscisic acid synthesis, regulate stomatal opening and closing, reduce water loss, regulate intracellular ion balance, and reduce the accumulation and toxicity of sodium ions.

[0030] Polyphenolic compounds can promote potassium ion absorption and sodium ion efflux, maintain the intracellular potassium / sodium ratio balance, stabilize cell membrane structure, reduce the passive inflow of sodium ions into cells, promote chlorophyll synthesis, and act as photoprotectants, absorbing excess light energy and releasing it as heat energy to prevent chlorophyll photo-oxidation.

[0031] Non-protein amino acids can accumulate in cells, increase intracellular osmotic pressure, maintain water balance, and scavenge reactive oxygen species directly or indirectly.

[0032] Adhesion aids can reduce the surface tension of the mitigating agent, allowing it to spread into a thin film on the leaf surface. This increases the contact area between the mitigating agent and the leaf, improves the amount of mitigating agent adhering, reduces waste caused by the liquid rolling off, and helps improve the utilization efficiency of the mitigating agent.

[0033] In some embodiments of this application, the adhesion aid includes glycerin, Tween 20, anhydrous ethanol, and deionized water.

[0034] In some embodiments of this application, the salt stress relief agent for crops comprises, by mass percentage: 0.1% carotenoids, 0.3% polyphenolic compounds, 0.5% non-protein amino acids, 0.02% glycerol, 0.02% Tween 20, 5% anhydrous ethanol, and the balance being deionized water.

[0035] In some embodiments of this application, the carotenoids include one or more combinations of β-carotene, lutein, astaxanthin, and lycopene.

[0036] In some embodiments of this application, the polyphenolic compound includes one or more combinations of tea polyphenols, moringa polyphenols, eugenol polyphenols, and walnut polyphenols.

[0037] In some embodiments of this application, the non-protein amino acids include one or more combinations of proline, γ-aminobutyric acid (γ-GABA), betaine, glutamic acid, arginine, and glycine.

[0038] In a second aspect, embodiments of this disclosure provide a method for preparing a salt stress mitigator for crops as described in any one of the embodiments of the first aspect above, comprising the following steps:

[0039] S1: Preparation of carotenoid stock solution: Mix carotenoids with anhydrous ethanol and stir thoroughly until completely dissolved;

[0040] S2: Preparation of polyphenol compound mother liquor: Mix the polyphenol compound with deionized water and stir thoroughly under heating conditions until completely dissolved;

[0041] S3: Preparation of non-protein amino acid stock solution: Weigh a certain amount of non-protein amino acids and mix them with deionized water, stirring thoroughly until completely dissolved;

[0042] S4: Mix the carotenoid stock solution prepared in step S1, the polyphenol compound stock solution prepared in S2, and the non-protein amino acid stock solution prepared in S3 to obtain mixed solution one.

[0043] Specifically, the order of S1, S2, and S3 can be set according to actual needs.

[0044] S5: Add glycerol and Tween 20 to the mixed solution one, stir thoroughly to obtain the finished product.

[0045] In some embodiments of this application, in step S2, the temperature is heated to 60~70°C.

[0046] In a third aspect, the present disclosure provides a method of using a salt stress reliever for crops as described in any one of the first aspect embodiments above, including spraying during the seedling stage, spraying on both sides of the leaves until the liquid is about to drip, spraying once every other day for a total of three times;

[0047] Applicable environmental conditions: Spraying temperature is 5~35℃, and spraying time is before 9:00 am or after 4:00 pm.

[0048] The salt stress relief agent for crops provided in this disclosure is suitable for crops such as soybeans, rice, and cucumbers.

[0049] Example 1: Effects of spraying astaxanthin solution on salt-stressed soybean seedlings.

[0050] (1) Material cultivation: Soybean seeds were sown in seedling trays containing peat moss:vermiculite = 3:1 and placed in a greenhouse at 28℃, 60% humidity and 16 / 8h photoperiod for two weeks. Seedlings with uniform growth (three-leaf-one-heart stage and five-leaf-one-heart stage) were selected, with 30 seedlings in each group.

[0051] (2) The specific handling is as follows:

[0052] Control group 1: Foliar spraying with distilled water (containing 0.02% Tween 20 and glycerol by mass percentage).

[0053] Experimental group 1-1: Foliar spraying with a 0.05% astaxanthin solution (containing 0.02% Tween 20 and glycerol, each at 0.02% by mass).

[0054] Experimental groups 1-2: Foliar spraying with a 0.1% astaxanthin solution (containing 0.02% Tween 20 and glycerol in each component).

[0055] Experimental groups 1-3: Foliar spraying with a 0.2% astaxanthin solution (containing 0.02% Tween 20 and glycerol in each group).

[0056] The salt stress treatment was as follows: 24 hours after the first foliar spray, the plants were transferred to Hogland nutrient solution containing 150 mmol / L NaCl for 7 days of stress culture, followed by 3 days of recovery culture; spraying was performed once every 1 day for a total of 3 sprays, and the survival rate was counted.

[0057] The experimental results are expressed as mean ± standard deviation, and the significance of the differences was analyzed using Duncan's new multiple range method (P<0.05).

[0058] (3) The results of the soybean seedling survival rate test are shown in Table 1 below:

[0059] Table 1 shows the effect of spraying astaxanthin solution on the survival rate of soybean seedlings under salt stress.

[0060]

[0061] Table 1 shows that after salt stress treatment, the survival rates of soybean seedlings at the three-leaf stage were 48.6%, 76.9%, and 65.2% after spraying with astaxanthin at concentrations of 0.05%, 0.1%, and 0.2%, respectively, while the survival rate after spraying with distilled water was only 21.3%. This indicates that spraying with astaxanthin significantly improves the survival rate of soybean seedlings at the three-leaf stage, and the survival rate of seedlings sprayed with 0.1% astaxanthin was 2.6 times higher than that of control group 1; (Five-leaf stage...) After salt stress treatment, the survival rates of soybean seedlings at the one-leaf stage were 52.4%, 80.3%, and 68.7% after spraying with astaxanthin at concentrations of 0.05%, 0.1%, and 0.2%, respectively. However, the survival rate after spraying with distilled water was only 25.7%. This indicates that spraying with astaxanthin can significantly improve the survival rate of soybean seedlings at the five-leaf stage. The survival rate of seedlings sprayed with 0.1% astaxanthin was 2.1 times higher than that of the control group 1, and the 0.1% astaxanthin concentration had the best effect.

[0062] (4) Physiological index determination: Seedlings at the five-leaf-one-heart stage were selected and treated with no stress, stress, no stress + spraying with astaxanthin solution, and stress + spraying with astaxanthin solution. The astaxanthin solution was a 0.1% astaxanthin solution (containing 0.02% Tween 20 and glycerol in each solution), sprayed 3 times (once every other day). After 7 days of salt stress culture, samples were taken to detect leaf cell membrane permeability, MDA, H2O2, etc. The results, including the contents of SOD, POD, CAT, Pro, and SS, are shown in Table 2 below.

[0063] Table 2. Effects of astaxanthin application on physiological indicators of soybean seedlings at the five-leaf stage under salt stress.

[0064]

[0065] Cell membrane permeability is a core indicator for measuring cell membrane integrity, directly reflecting the degree of plant damage from abiotic stress. Table 2 shows that cell membrane permeability reached 0.21% under no-salt stress and 0.58% after salt stress, indicating that salt stress causes severe cell membrane damage. Under no-salt stress and after spraying with astaxanthin solution, cell membrane permeability reached 0.19%, and under salt stress and after spraying with astaxanthin solution, cell membrane permeability reached 0.35%. MDA decreased after spraying, indicating that 0.1% astaxanthin solution can significantly reduce cell membrane damage.

[0066] At the same time, after spraying with 0.1% astaxanthin solution, the leaves showed increased reactive oxygen species (H2O2 and H2O2). The content of H2O2 decreased significantly, while the activity of antioxidant enzymes (SOD, POD, CAT) increased, indicating that the efficiency of H2O2 removal in leaf cells was improved. Through osmotic regulation, cell membrane stability was enhanced, and stress resistance was improved.

[0067] In addition, the contents of osmotic regulators (Pro and SS) increased and accumulated after spraying with 0.1% astaxanthin solution, indicating that soybean seedlings gradually adapt to salt stress environment through osmotic regulation mechanism, which can protect the stability of cell membrane structure and improve stress resistance.

[0068] Example 2: Effects of spraying tea polyphenol solution on salt-stressed soybean seedlings.

[0069] (1) Material cultivation: Same as in Example 1.

[0070] (2) The specific handling is as follows:

[0071] Control group 2: Foliar spraying with distilled water (containing 0.02% Tween 20 and glycerol by mass percentage).

[0072] Experimental group 2-1: Foliar spraying with a 0.1% tea polyphenol solution (containing 0.02% Tween 20 and glycerol, both by mass).

[0073] Experimental group 2-2: Foliar spraying with a 0.3% tea polyphenol solution (containing 0.02% Tween 20 and glycerol, respectively).

[0074] Experimental groups 2-3: Foliar spraying with a 0.5% tea polyphenol solution (containing 0.02% Tween 20 and glycerol in each case).

[0075] Salt stress treatment: Same as in Example 1.

[0076] (3) The results of the soybean seedling survival rate test are shown in Table 3 below:

[0077] Table 3 shows the effect of spraying tea polyphenol solution on the survival rate of soybean seedlings under salt stress.

[0078]

[0079] Table 3 shows that after salt stress treatment, the survival rates of soybean seedlings at the three-leaf-one-heart stage, sprayed with 0.1%, 0.3%, and 0.5% tea polyphenols, were 45.2%, 78.5%, and 62.3%, respectively, while the survival rate after spraying with distilled water was only 20.8%. This indicates that spraying with tea polyphenols significantly improves the survival rate of soybean seedlings at the three-leaf-one-heart stage, and the survival rate of seedlings sprayed with 0.3% tea polyphenols was 2.8 times higher than that of the control group; at the five-leaf-one-heart stage... After being treated with salt stress, soybean seedlings were sprayed with 0.1%, 0.3%, and 0.5% tea polyphenols, and the survival rates were 49.6%, 82.1%, and 66.8%, respectively. However, the survival rate after spraying with distilled water was only 24.9%. This indicates that spraying with tea polyphenols can significantly improve the survival rate of soybean seedlings at the five-leaf stage. The survival rate of seedlings sprayed with 0.3% tea polyphenols was 2.3 times higher than that of the control group, and the 0.3% tea polyphenol solution had the best effect.

[0080] (4) Physiological index determination: Seedlings at the five-leaf-one-heart stage were selected and treated with no stress, stress, no stress + spraying with tea polyphenol solution, and stress + spraying with tea polyphenol solution. The tea polyphenol solution was a 0.3% (w / w) tea polyphenol solution (containing 0.02% Tween 20 and glycerol in each solution), sprayed 3 times (once every other day). After 7 days of salt stress culture, samples were taken to detect leaf cell membrane permeability, MDA, H2O2, etc. The results, including the contents of SOD, POD, CAT, Pro, and SS, are shown in Table 4 below.

[0081] Table 4 shows the effects of spraying tea polyphenols on key physiological indicators of soybean seedlings at the five-leaf stage under salt stress.

[0082]

[0083] Table 4 shows that cell membrane permeability was 0.2% under no salt stress and 0.56% after salt stress, indicating that salt stress causes severe cell membrane damage and increases permeability. Under no salt stress, spraying with 0.3% tea polyphenol solution reduced cell membrane permeability to 0.18%, indicating a decrease in permeability. After salt stress, spraying with 0.3% tea polyphenol solution reduced cell membrane permeability to 0.32%. The MDA content decreased by more than 40% compared to the control, indicating that spraying with 0.3% tea polyphenol solution can effectively reduce cell membrane damage caused by salt stress.

[0084] Simultaneously, after spraying with a 0.3% tea polyphenol solution, the leaves showed increased reactive oxygen species (H2O2 and...). The content of H2O2 decreased significantly, while the activity of antioxidant enzymes (SOD, POD, CAT) increased, indicating that the efficiency of H2O2 removal in leaf cells was improved. Through osmotic regulation, cell membrane stability was enhanced, and stress resistance was improved.

[0085] After spraying with a 0.3% tea polyphenol solution, the content of osmotic regulators (Pro and SS) increased significantly, with the Pro content increasing by more than 35%, enhancing antioxidant capacity and osmotic regulation capacity. Therefore, 0.3% was determined to be the optimal concentration of tea polyphenols to alleviate soybean salt stress.

[0086] Example 3: Effects of spraying γ-aminobutyric acid (γ-GABA) solution on salt-stressed soybean seedlings

[0087] (1) The material cultivation is the same as in Example 1.

[0088] (2) The specific handling is as follows:

[0089] Control group 3: Foliar spraying with distilled water (containing 0.02% Tween 20 and glycerol by mass percentage).

[0090] Experimental group 3-1: Foliar spraying with a 0.2% γ-GABA solution (containing 0.02% Tween 20 and glycerol, both by mass).

[0091] Experimental group 3-2: Foliar spraying with a 0.5% γ-GABA solution (containing 0.02% Tween 20 and glycerol, both by mass percentage);

[0092] Experimental group 3-3: Foliar spraying with a 1.0% γ-GABA solution (containing 0.02% Tween 20 and glycerol, both by mass percentage);

[0093] Salt stress treatment was the same as in Example 1.

[0094] (3) The results of the soybean seedling survival rate test are shown in Table 5 below:

[0095] Table 5 shows the effect of spraying γ-GABA solution on the survival rate of soybean seedlings under salt stress.

[0096]

[0097] Table 5 shows that after salt stress treatment, the survival rates of soybean seedlings at the three-leaf stage, sprayed with 0.2%, 0.5%, and 1.0% γ-GABA solutions, were 51.3%, 79.2%, and 68.4%, respectively, while the survival rate after spraying with distilled water was only 21.5%. This indicates that spraying with γ-GABA solution significantly improves the survival rate of soybean seedlings at the three-leaf stage, and the survival rate of seedlings sprayed with 0.5% γ-GABA solution was 2.7 times higher than the control group; the survival rate of seedlings at the five-leaf stage... After salt stress treatment, the survival rates of soybean seedlings sprayed with 0.2%, 0.5%, and 1.0% γ-GABA solutions were 55.7%, 83.5%, and 72.6%, respectively, while the survival rate after spraying with distilled water was only 25.3%. This indicates that spraying with γ-GABA solution can significantly improve the survival rate of soybean seedlings at the five-leaf stage. The survival rate of seedlings sprayed with 0.5% γ-GABA solution was 2.3 times higher than that of the control group, and the 0.5% γ-GABA solution had the best effect.

[0098] (4) Physiological index determination: Seedlings at the five-leaf-one-heart stage were selected and treated with no stress, stress, no stress + spraying with γ-GABA solution, and stress + spraying with γ-GABA solution. The γ-GABA solution was a 0.5% γ-GABA solution (containing 0.02% Tween 20 and glycerol in each solution), sprayed 3 times (once every other day). After 7 days of salt stress culture, samples were taken to detect leaf cell membrane permeability, MDA, H2O2, and other parameters. The results, including the contents of SOD, POD, CAT, Pro, and SS, are shown in Table 6 below.

[0099] Table 6 shows the effects of γ-GABA spraying on key physiological indicators of soybean seedlings at the three-leaf stage under salt stress.

[0100]

[0101] Table 6 shows that cell membrane permeability was 0.2% under no salt stress and 0.59% after salt stress. Salt stress increases cell membrane permeability and causes severe cell membrane damage. Under no salt stress and spraying with 0.5% γ-GABA solution, cell membrane permeability reached 0.18%, and after being subjected to salt stress and spraying with 0.5% γ-GABA solution, cell membrane permeability reached 0.33%, meaning that cell membrane permeability decreased after spraying compared to salt stress treatment. At the same time, MDA content decreased after spraying, indicating that γ-GABA solution can significantly reduce cell membrane damage.

[0102] Spraying can significantly reduce reactive oxygen species (H2O2, H2O2, H2O2) caused by salt stress. The content of SOD, POD, and CAT antioxidant enzymes was reduced by more than 45% compared to the control; at the same time, the activity of SOD, POD, and CAT antioxidant enzymes and the content of Pro osmotic regulators were significantly increased by more than 38%, which can effectively enhance antioxidant defense and osmotic balance capabilities.

[0103] In summary, 0.5% γ-GABA alleviates salt stress through a synergistic effect of "reducing membrane damage, scavenging reactive oxygen species, and enhancing antioxidant capacity." The effect decreases when the concentration is below or above this value. Therefore, 0.5% by mass is determined to be the optimal concentration of γ-GABA for alleviating salt stress in soybeans.

[0104] Example 4: Effect of a salt stress mitigator for crops on salt-stressed soybean seedlings. The mitigator consists of: 0.1% astaxanthin, 0.3% tea polyphenols, 0.5% γ-GABA, 0.02% glycerol, 0.02% Tween 20 by mass percentage, with the balance being deionized water.

[0105] (1) Pot experiment: Soybean seedlings at the three-leaf-one-heart stage were sprayed with distilled water as a control and sprayed with a relief agent as a treatment. Salt stress treatment lasted for 7 days. The treatment at the five-leaf-one-heart stage was the same as in Example 1. Survival rate and physiological indicators were statistically analyzed.

[0106] Field experiment: Spraying a mitigating agent (750 kg per hectare) at the five-leaf stage and subjecting the soil to salt stress (natural saline-alkali soil) for 2 months, growth and physiological indicators were measured.

[0107] (2) The specific handling is as follows:

[0108] Control group 4: Foliar spraying with distilled water (containing 0.02% Tween 20 and glycerol by mass).

[0109] Experimental group 4-1: Foliar spraying of a mitigating agent, namely, 0.1% astaxanthin, 0.3% tea polyphenols, and 0.5% γ-aminobutyric acid mitigating agent (each containing 0.02% Tween 20 and glycerol by mass percentage).

[0110] (3) The survival rate test results of potted soybean seedlings are shown in Table 7 below:

[0111] Table 7 shows the effect of spraying mitigation agents on the survival rate of soybean seedlings under salt stress.

[0112]

[0113] Table 7 shows that after spraying the mitigating agent, the survival rates of soybean seedlings at the three-leaf-one-heart stage and the five-leaf-one-heart stage were both above 90%, while the survival rates of soybean seedlings at the three-leaf-one-heart stage and the five-leaf-one-heart stage without the mitigating agent were 20.6% and 24.8%, respectively. Furthermore, the mitigating agent's effect on alleviating salt stress in soybean seedlings was superior to the single-component treatments in the above examples. In the pot experiment, the survival rates of soybean seedlings at the three-leaf-one-heart stage and the five-leaf-one-heart stage in the field experiment were 3.5 times and 2.9 times higher than the control group 4, respectively, far exceeding the survival rates of the single optimal concentrations of astaxanthin, tea polyphenols, and γ-aminobutyric acid.

[0114] (4) The results of the growth indicators of soybean seedlings in the field are shown in Table 8 below:

[0115] Table 8 shows the effects of spraying mitigation agents on growth indicators of soybean seedlings under salt stress.

[0116]

[0117] As shown in Table 8, after spraying the mitigating agent, the soybean plant height increased by 42%, the root fresh weight increased by 77%, and the number of pods per plant increased by 58%, effectively improving the growth status and yield-related indicators of soybean crops in saline-alkali land.

[0118] (5) Measurement of physiological indicators of soybeans in the field: The results are shown in Table 9 below:

[0119] Table 9 shows the effects of spraying mitigating agents on physiological indicators of soybean seedlings under salt stress.

[0120]

[0121] As shown in Table 9, cell membrane permeability was 0.21% under no salt stress and 0.17% after spraying with the allergen under no salt stress; it was 0.58% after salt stress and 0.28% after spraying with the allergen under salt stress, indicating that the allergen significantly reduced cell membrane permeability. At the same time, MDA was also significantly reduced after spraying, indicating that the allergen can significantly reduce cell membrane damage.

[0122] After spraying the mitigating agent, reactive oxygen species (H2O2 and) The content of antioxidant enzymes (SOD, POD, CAT) and Pro and SS osmotic regulators is significantly increased. The allergen, through the synergistic effect of multiple components, forms a highly efficient antioxidant network and osmotic balance system.

[0123] Specifically, astaxanthin can preferentially remove singlet oxygen produced by photosynthesis in chloroplasts of leaves, protecting the core structure of the photosynthetic system, but it cannot activate enzyme activity. Tea polyphenols, on the other hand, scavenge superoxide anions and hydrogen peroxide in the cytoplasm, while simultaneously enhancing the activity of antioxidant enzymes, thus forming a dual defense of enzymatic and non-enzymatic reactions. γ-GABA can reduce the production of hydroxyl radicals in the cytosolic fluid by chelating metal ions (such as ferrous and copper ions) and activate calcium ion signaling pathways, upregulating the expression of stress-resistance genes. Astaxanthin, tea polyphenols, and γ-GABA form a synergistic effect through complementary antioxidant networks, osmotic regulation, and signaling pathway crossover mechanisms.

[0124] In summary, the salt stress reliever achieves better relief through the synergistic effect of multiple components. Moreover, the formula is free of hormones and pesticides, making it safe, environmentally friendly, and highly effective in small doses, fully validating the scientific validity and field application value of the optimal formula.

[0125] Example 5: Effects of mitigating agents on salt-stressed rice and cucumber seedlings.

[0126] The relieving agent is the same as in Example 4.

[0127] Salt stress treatment solutions: 150 mmol / L NaCl solution was used for salt stress in rice and 150 mmol / L NaCl solution was used for salt stress in cucumber.

[0128] (1) Material cultivation: Rice: After soaking and germinating the seeds, they were sown in seedling pots containing quartz sand and cultured with 1 / 2 Hogland nutrient solution. They were placed in a greenhouse at 26℃, 65% humidity, and a photoperiod of 14h / 10h until they reached the three-leaf and one-heart stage for use.

[0129] Cucumber: Seeds are sown in seedling trays with a peat moss:vermiculite ratio of 2:1 and cultured at 25℃, 70% humidity, and a photoperiod of 16h / 8h until they reach the three-leaf-one-heart stage for use.

[0130] (2) Processing settings:

[0131] Control group 5: Foliar spraying with distilled water containing 0.02% Tween 20 and glycerol.

[0132] Experimental group 5-1: Foliar spraying of compound mitigation agent (spray until the liquid is about to drip from both sides of the leaf).

[0133] (5) Salt stress treatment: 24 hours after foliar spraying, rice was transferred to Hoagland's solution containing 150 mmol / L NaCl for 7 days of stress, and cucumber was transferred to Hoagland's solution containing 150 mmol / L NaCl for 7 days of stress. After the stress period, the survival rate of the two groups of crops was recorded. The survival rate test results are shown in Table 10 below:

[0134] Table 10 shows the effects of the compound mitigating agent on the survival rate of rice and cucumber seedlings under salt stress.

[0135]

[0136] As shown in Table 10, in terms of survival rate, the survival rates of rice and cucumber seedlings treated with the compound mitigation agent increased by 2.8 times and 3.4 times respectively compared with the control group 5. The mitigation agent showed a stable and significant salt tolerance effect on rice and cucumber under salt stress, verifying its cross-crop applicability.

[0137] (6) Measurement of physiological indicators of cucumber: The specific measurement method is the same as in Example 1, and the results are shown in Table 11 below:

[0138] Table 11 shows the effects of the mitigating agents on the physiological indicators of cucumber seedlings under salt stress.

[0139]

[0140] Table 11 shows that the physiological index test results indicate that after salt stress, the cell membrane permeability, MDA, H2O2, and other parameters of cucumber seedlings decreased. Damage indicators were significantly elevated, while the compound treatment group showed a 45%–47.4% reduction in these indicators compared to the control. Simultaneously, the activities of antioxidant enzymes SOD, POD, and CAT increased by 60%, and the activities of osmotic regulators Pro and SS increased by 66.3%–71.6%, consistent with the mechanism of action in soybeans. This demonstrates the stable action mode of the compound agent: "scavenging reactive oxygen species + enhancing antioxidant activity + regulating osmosis." This compound agent is effective in rice, cucumber, and soybeans, has a wide range of applicable crops, is simple to prepare, and convenient to use. It meets the needs of green agriculture for safe, environmentally friendly, and salt-tolerant agents, and has broad application prospects.

[0141] Therefore, compared with the prior art, the salt stress relief agent for crops in this disclosure includes carotenoids, polyphenolic compounds and non-protein amino acids. It has a simple composition, does not contain hormones or pesticides, is safe and environmentally friendly, and is highly effective in small amounts. By foliar spraying, it can significantly improve the survival rate of seedlings, enhance the accumulation of osmotic regulators, increase the activity of antioxidant enzymes, and enhance the ability to scavenge reactive oxygen species, thereby improving the salt tolerance of plants and effectively alleviating the damage of salt stress to plants.

[0142] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0143] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A salt stress relief agent for crops, characterized in that, It includes carotenoids, polyphenolic compounds, and non-protein amino acids.

2. The salt stress reliever for crops according to claim 1, characterized in that, The salt stress relief agent for crops comprises, by mass percentage, 0.05%~0.2% carotenoids, 0.1%~0.5% polyphenolic compounds, 0.2%~1.0% non-protein amino acids, with the balance being an adhesion promoter.

3. The salt stress reliever for crops according to claim 2, characterized in that, The adhesion aids include: glycerin, Tween 20, anhydrous ethanol, and deionized water.

4. The salt stress reliever for crops according to claim 3, characterized in that, The salt stress relief agent for crops comprises, by mass percentage: 0.1% carotenoids, 0.3% polyphenolic compounds, 0.5% non-protein amino acids, 0.02% glycerol, 0.02% Tween 20, 5% anhydrous ethanol, and the balance being deionized water.

5. The salt stress reliever for crops according to claim 1, characterized in that, The carotenoids include β - One or more combinations of carotene, lutein, astaxanthin, and lycopene.

6. The salt stress reliever for crops according to claim 1, characterized in that, The polyphenolic compounds include one or more combinations of tea polyphenols, moringa polyphenols, eugenol polyphenols, and walnut polyphenols.

7. The salt stress reliever for crops according to claim 1, characterized in that, The non-protein amino acids include proline, γ -One or more combinations of aminobutyric acid, betaine, glutamic acid, arginine and glycine.

8. A method for preparing a salt stress mitigating agent for crops as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Preparation of carotenoid stock solution: Mix carotenoids with anhydrous ethanol and stir thoroughly until completely dissolved; S2: Preparation of polyphenol compound mother liquor: Mix the polyphenol compound with deionized water and stir thoroughly under heating conditions until completely dissolved; S3: Preparation of non-protein amino acid stock solution: Weigh a certain amount of non-protein amino acids and mix them with deionized water, stirring thoroughly until completely dissolved; S4: Mix the carotenoid stock solution prepared in step S1, the polyphenol compound stock solution prepared in S2, and the non-protein amino acid stock solution prepared in S3 to obtain mixed solution one. S5: Add glycerol and Tween 20 to the mixed solution one, stir thoroughly to obtain the finished product.

9. The method for preparing a salt stress alleviater for crops according to claim 8, characterized in that, In step S2, heat to 60~70℃.

10. A method of using a salt stress mitigator for crops as described in any one of claims 1 to 7, characterized in that, This includes spraying during the seedling stage, spraying both sides of the leaves until the liquid is about to drip, spraying once every other day, for a total of three times; Applicable environmental conditions: Spraying temperature is 5~35℃, and spraying time is before 9:00 am or after 4:00 pm.

Images