Method for reducing accumulation of herbicide in plant body

Abstract

The invention discloses a method for reducing accumulation of herbicides in plants. The glycine betaine is used for treating plants poisoned by herbicides, and it is found that the glycine betaine can relieve elongation reduction, dry weight reduction, chlorophyll reduction and lipid peroxidation caused by oxyfluorfen and reduce accumulation of oxyfluorfen in rice. Betaine can be used for promoting the degradation of oxyfluorfen and reducing the threat of polluted crops to human health.

Description

Technical Field

[0001] The present invention relates to the technical field of herbicide toxicity to plants, and more specifically, to a method for reducing herbicide accumulation in plants. Background Art

[0002] Some varieties of diphenyl ether herbicides are soil sealing agents, mainly used to control the young shoots of annual weeds. After application, they are strongly adsorbed by soil colloids and are difficult to move in the soil. They have a long lasting effect, so they will cause residue accumulation in the environment and crops, causing harm to organisms.

[0003] There are 747 diphenyl ether herbicide products with valid registration in my country, involving 6 major varieties, of which oxyfluorfen accounts for 29.85% of the total number of registered diphenyl ether herbicides.

[0004] Oxyfluorfen (OFF) is a selective diphenyl ether herbicide with high weed control ability. It is mainly used to control broadleaf weeds and sedges in soybeans, corn, cotton, peanuts, vegetable gardens, orchards, etc. The application of oxyfluorfen can cause lipid peroxidation of weeds. At the same time, it inhibits the synthesis of protoporphyrinogen oxidase (PPO) and thus inhibits the synthesis of chlorophyll, thereby controlling weeds. With the large-scale use of oxyfluorfen, it continues to accumulate in the environment.

[0005] Oxyfluorfen is well adsorbed into most soils, especially in soils with high organic matter and clay content, where its binding force is the highest. Its degradation in soil is mainly through photolysis, hydrolysis and microbial degradation, and its half-life in soil is 72 to 150 days. Due to its poor biodegradability, oxyfluorfen is easily left in soil and aquatic systems, causing serious environmental pollution and triggering food security and other issues. In addition, studies have found that a small amount of fluorinated diphenyl ether herbicides remaining in the soil can cause phytotoxicity to subsequent sensitive crops (such as corn, sorghum, rice, etc.).

[0006] Moreover, oxyfluorfen can enter the food chain through plant absorption, further exacerbating its accumulation in the ecosystem. Its accumulation in the ecosystem can cause serious harm to the growth and development of animals, such as damage to the reproduction of earthworms and the livers of fish or the thyroids of rats. Long-term exposure to oxyfluorfen may also lead to transverse limb defects or skull fractures in newborns. Consuming water sources or agricultural products contaminated with oxyfluorfen poses a potential threat to human health. The US Environmental Protection Agency has even listed oxyfluorfen as a potential human carcinogen. A study once found up to 0.106 mg / kg of oxyfluorfen in rice in India, seriously exceeding the international standard of 0.05 mg / kg for the safe residue of pesticides (PMID: 37248026). In addition, oxyfluorfen has also been detected in various environmental media, undoubtedly posing a safety hazard to environmental organisms and even human health.

[0007] Finding a method to reduce the content of oxyfluorfen in crops is crucial for reducing environmental pollution and food security caused by oxyfluorfen. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for reducing the accumulation of herbicides in plants.

[0009] The first purpose of the present invention is to provide a method for reducing the accumulation of herbicides in plants.

[0010] The second purpose of the present invention is to provide a method for improving the herbicide stress resistance of plants.

[0011] The third purpose of the present invention is to provide a method for reducing the negative impact of herbicides on plants.

[0012] The fourth purpose of the present invention is to provide a method for promoting the growth of plants affected by herbicides.

[0013] The fifth purpose of the present invention is to provide the application of betaine in reducing the accumulation of herbicides in plants or in the preparation of drugs for reducing the accumulation of herbicides in plants.

[0014] The sixth purpose of the present invention is to provide the application of betaine in improving the herbicide stress resistance performance of plants or in the preparation of drugs for improving the herbicide stress resistance performance of plants.

[0015] The seventh purpose of the present invention is to provide the application of betaine in reducing the negative impact of herbicides on plants or in the preparation of drugs for reducing the negative impact of herbicides on plants.

[0016] To achieve the above purposes, the present invention is realized through the following technical solutions:

[0017] Betaine (GB) is an alkaloid with the chemical name N,N,N-trimethylglycine. Its chemical structure is similar to that of amino acids and belongs to the quaternary ammonium base class of substances. The molecular formula is C5H 11 NO2.

[0018] The present invention claims protection for the following applications:

[0019] A method for reducing the accumulation of herbicides in plants, which comprises applying betaine to plants that have accumulated herbicides in their bodies.

[0020] A method for improving the herbicide stress resistance performance of plants, which comprises applying betaine to plants that are under herbicide stress.

[0021] A method for reducing the negative impact of herbicides on plants, which comprises applying betaine to plants that are negatively affected by herbicides.

[0022] Preferably, the application used is root application.

[0023] Preferably, the plant is a crop.

[0024] More preferably, the crop is rice.

[0025] Preferably, the negative impact is growth inhibition, reduction in dry weight, reduction in chlorophyll, increase in MDA content, and / or oxidative damage.

[0026] More preferably, the growth inhibition is growth inhibition of the above-ground part and / or the underground part.

[0027] Preferably, the herbicide is a diphenyl ether herbicide.

[0028] More preferably, the herbicide is oxyfluorfen.

[0029] And, a method for promoting the growth of plants affected by herbicides, which comprises applying betaine to plants affected by herbicides.

[0030] Preferably, the application used is root application.

[0031] Preferably, the plant is a crop.

[0032] More preferably, the crop is rice.

[0033] Preferably, the herbicide is a diphenyl ether herbicide.

[0034] More preferably, the herbicide is oxyfluorfen.

[0035] Preferably, the herbicide impact is growth inhibition, reduction in dry weight, reduction in chlorophyll, increase in MDA content, and / or oxidative damage.

[0036] Preferably, the promotion of the growth of plants affected by herbicides is to promote the root elongation, the elongation of the above-ground part, the dry weight of the roots, the dry weight of the above-ground part, and the total chlorophyll content.

[0037] The present invention also claims the following methods:

[0038] The application of betaine in reducing the accumulation of herbicides in plants or in preparing a drug for reducing the accumulation of herbicides in plants.

[0039] The application of betaine in improving the herbicide stress resistance of plants or in preparing a drug for improving the herbicide stress resistance of plants.

[0040] The application of betaine in reducing the negative impact of herbicides on plants or in preparing a drug for reducing the negative impact of herbicides on plants.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention uses betaine to treat plants poisoned by herbicides and finds that betaine can alleviate the reduction of elongation, the decrease of dry weight, the reduction of chlorophyll, and lipid peroxidation caused by oxyfluorfen, and reduce the accumulation of oxyfluorfen in rice. Betaine can be applied to promote the degradation of oxyfluorfen and reduce the threat to human health caused by contaminated crops. Description of the Drawings

[0043] Figure 1 Effects of betaine on the growth changes of rice seedlings under oxyfluorfen stress: Oxyfluorfen at concentrations of 0, 0.05, 0.1, 0.15, 0.2, and 0.25 mg / L was added to 10-day-old rice seedlings for 6 days; A shows the phenotypes of rice seedlings treated with OFF for 6 days. From left to right, they are: CK, CK + GB 175 mg / L, OFF 0.05 mg / L, OFF 0.05 mg / L + GB175 mg / L, OFF 0.1 mg / L, OFF 0.1 mg / L + GB 175 mg / L, OFF 0.15 mg / L, OFF 0.15 mg / L + GB175 mg / L, OFF 0.2 mg / L, OFF 0.2 mg / L + GB 175 mg / L, OFF 0.25 mg / L, and OFF 0.25 mg / L + GB175 mg / L; B shows the elongation of the roots and above-ground parts of rice; C shows the dry weights of the roots and above-ground parts of rice; D shows the total chlorophyll (Chl) concentration in rice leaves; E shows the malondialdehyde (MDA) concentration in the roots and above-ground parts of rice; vertical bars represent the standard deviations of three biological replicates.

[0044] Figure 2Effect of betaine on rice under oxyfluorfen stress; A is the SOD activity of roots and shoots, B is the APX activity of roots and shoots, C is the GST activity of roots and shoots, D is the P450 activity of roots and shoots; E is the MATE activity of roots and shoots.

[0045] Figure 3 Effect of betaine on the accumulation of oxyfluorfen in roots and shoots of rice under oxyfluorfen stress. Detailed implementation mode

[0046] The present invention will be further elaborated in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0047] Example 1 Cultivation of rice and betaine treatment

[0048] I. Cultivation of rice

[0049] 1. Seed disinfection

[0050] Surface disinfect the rice seeds with 3% hydrogen peroxide solution, and rinse them repeatedly with distilled water 3 - 5 times after 15 minutes.

[0051] 2. Germination acceleration

[0052] Put the disinfected rice seeds in a petri dish lined with neutral filter paper, and add an appropriate amount of distilled water for germination acceleration.

[0053] 3. Seedling raising

[0054] After germination, select rice seeds with roughly the same germination degree and evenly place them on a net floating board, and put them into a modified 1 / 2 strength Hoagland rice nutrient solution. Incubate them in a constant temperature incubator at a day / night temperature of 30 / 25 °C, a photoperiod of 14 h, a light intensity of 200 μmol / m 2 s, and a relative humidity of 70% for about five days. Select rice seedlings with consistent growth trends and transplant them into small pots containing rice nutrient solution, with 20 seedlings per pot, and acclimatize them for 1 - 2 days.

[0055] II. Betaine treatment

[0056] The 10-day-old rice seedlings after cultivation and domestication were divided into 2 groups (18 pots in each group). In one group, oxyfluorfen was added to the rice nutrient solution at gradient concentrations (0, 0.05, 0.1, 0.15, 0.2, and 0.25 mg / L, 3 pots for each concentration), and in the other group, which served as the control group, oxyfluorfen at gradient concentrations (0, 0.05, 0.1, 0.15, 0.2, and 0.25 mg / L, 3 pots for each concentration) and betaine (175 mg / L, and it has been confirmed through preliminary experiments that the optimal treatment concentration of betaine is 175 mg / L) were added to the rice nutrient solution. The rice nutrient solution was changed every 2 days.

[0057] Example 2 Effect of Betaine Treatment on Physiological Indexes of Rice under Oxyfluorfen Stress

[0058] I. Cultivation of Rice

[0059] Six days after the treatment of the rice in Example 1, the phenotypes of the rice before and after the addition of betaine were photographed and recorded, and the elongation, dry weight, malondialdehyde (MDA) content of the roots and above-ground parts of the rice seedlings, and the chlorophyll content of the leaves were measured.

[0060] Among them, the detection methods of chlorophyll and malondialdehyde (MDA) can be found in the prior art: Chen, Z.J., Qiao, Y., Zhang, N., Yang, H., Liu, J. 2023. Acetyltransferase OsACE2 acts as a regulator to reduce the environmental risk of oxyfluorfen to rice production. Science of The Total Environment, 867, 161599.

[0061] II. Experimental Results

[0062] The results are as Figure 1 shown that the physiological indexes of the rice seedlings after the addition of betaine are better than those of the rice seedlings only under oxyfluorfen stress.

[0063] Compared with the rice seedlings only under the stress of 0, 0.05, 0.1, 0.15, 0.2, and 0.25 mg / L OFF, the exogenous betaine increased the elongation of the roots of the rice seedlings by 5.1%, 3.4%, 4.2%, 6.2%, 5.4%, and 5.3% respectively;

[0064] the dry weights increased by 112.6%, 66.9%, 70.1%, 76.6%, 73.4%, and 68.4% respectively;

[0065] Exogenous betaine increased the elongation of the above-ground parts of rice seedlings by 6.1%, 4.6%, 6.7%, 8.2%, 7.5% and 7.0% respectively;

[0066] the dry weight increased by 64.9%, 54.8%, 61.5%, 64.1%, 62.8% and 57.0% respectively;

[0067] the chlorophyll content in the leaves increased by 10.2%, 5.7%, 6.2%, 15.3%, 13.9% and 11.5% respectively ( Figure 1 A to D in

[0068] Compared with rice seedlings under only 0, 0.05, 0.1, 0.15, 0.2 and 0.25 mg / L OFF stress, after applying exogenous betaine, the MDA content in the roots of rice seedlings decreased by 15.3%, 17.0%, 18.9%, 20.3%, 18.5% and 17.6% respectively; the MDA in the above-ground parts of rice seedlings also decreased by 9.5%, 8.8%, 11.5%, 19.3%, 14.5% and 12.8% respectively ( Figure 1 E in

[0069] These results indicate that exogenous betaine treatment can promote the growth of rice seedlings, reduce lipid peroxidation under OFF treatment and reduce phytotoxicity.

[0070] Example 3 Effect of Betaine Treatment on Enzyme Activities of Rice under Oxyfluorfen Stress

[0071] I. Experimental Method

[0072] Six days after the treatment of the rice in Example 1, the activities of five enzymes in the roots and above-ground parts of rice seedlings were measured: superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione S-transferase (GST), cytochrome P450 (P450) and multidrug and toxic compound extrusion transporter (MATE).

[0073] The method for measuring SOD activity is shown in: Chen, Z.J., Lv, Y., Zhai, X.Y., Yang, H., 2021. Comprehensive analyses of degradative enzymes associated with mesotrione-degraded process in rice for declining environmental risks. Sci. Total Environ. 758, 143618.756

[0074] The methods for measuring APX and GST activities are described in: Chen, Z.J., Qiao, Y.X., Zhang, N., Liu, J.T., Yang, H., 2021. Insight into metabolism pathways of pesticide fomesafen in rice: Reducing cropping and environmental risks. Environ. Pollut. 283, 117128.

[0075] The methods for measuring P450 and MATE activities are described in: Sun, J., Yu, X., Xu, H., Yang, Y., Liu, M., Zhang, Y., et al., 2023. Post-Emergence Water-Dispersal Application Provides Equal Herbicidal Activity against Echinochloa crus-galli and Rice Safety as Foliar Spraying of Penoxsulam. Plants-Basel. 12, 2223-7747.

[0076] II. Experimental Results

[0077] The results are as Figure 2 shown. The results show that after exogenous addition of betaine, the activities of SOD, APX, GST, P450, and MATE in rice treated with different concentrations of OFF increased to varying degrees.

[0078] When the OFF concentration was 0.25 mg / L -1 , the SOD activities in the roots and above-ground parts of rice seedlings after adding betaine were 1.5 times and 2.9 times that of the SOD activity under OFF stress alone.

[0079] After exogenous betaine treatment, the APX activities in the roots and above-ground parts of rice seedlings were 1.4 times and 1.5 times that of the APX activity under OFF stress alone; the GST and P450 activities in the roots and buds of rice seedlings were 2.1 times and 1.8 times, 1.3 times and 1.5 times that of the 0.25 mg / L OFF treatment alone, respectively; the MATE activities in the roots and above-ground parts of rice seedlings were 1.3 times and 1.4 times that of the MATE activity under OFF stress alone.

[0080] In summary, exogenous betaine application can enhance the antioxidant and detoxification defense enzyme activities of rice seedlings by reducing excessive ROS and OFF, and reduce the oxidative damage caused by OFF to rice seedlings. Exogenous betaine application reduces the negative effects caused by OFF.

[0081] Example 4 Effect of Betaine Treatment on the Accumulation of Oxyfluorfen in Rice under Oxyfluorfen Stress

[0082] I. Experimental Method

[0083] Six days after the treatment of the rice in Example 1, the accumulation amounts of OFF in the roots and above-ground parts of the rice seedlings were measured.

[0084] The specific method is as follows: Weigh 4 g of roots or above-ground parts, successively add 5 mL of deionized water and 15 mL of acetonitrile, adjust the pH to 2 - 3 with formic acid, shake and extract for 1 h, add a certain amount of sodium chloride, vortex for 5 min, centrifuge at 4000 rpm for 5 min, take 11 mL of the supernatant, transfer it to a 50 mL round-bottom flask, rotary evaporate until nearly dry, add 1.5 mL of acetonitrile for volume fixation. After volume fixation, transfer the solution to a 2 mL centrifuge tube containing 50 mg of PSA, 50 mg of C18, and 10 mg of GCB, vortex for 1 min, centrifuge at 4000 rpm for 10 min, filter through a membrane, load it into an injection vial, and perform HPLC detection on the machine.

[0085] HPLC conditions: Mobile phase: Acetonitrile: 0.05% phosphoric acid aqueous solution by volume = 66:34 (volume ratio), flow rate is 1 mL / min, wavelength is 215 nm, column temperature is 30 °C, chromatographic column: XDB-C18.

[0086] II. Experimental Results

[0087] The results are as Figure 3 shown. After 6 days of OFF treatment, the accumulation amount of OFF in the rice seedlings after adding betaine decreased.

[0088] After 6 days of treatment with 0.25 mg / L OFF, the accumulation amount of OFF in the roots and above-ground parts of the rice was the highest. The OFF concentration in the roots of the rice was 15.3 mg / kg, and the OFF concentration in the stems was 1.1 mg / kg. Exogenous betaine treatment effectively reduced the accumulation of OFF. Compared with the treatment with 0.25 mg / L OFF alone, the accumulation amount of OFF in the roots of the rice seedlings treated with exogenous betaine decreased by 44.5%, and the accumulation amount of OFF in the above-ground parts of the rice seedlings decreased by 51.0%.

[0089] In summary, exogenous betaine can alleviate cell damage related to oxidative stress, improve the activities of antioxidant and detoxifying enzymes, and improve the developmental performance of rice seedlings. Exogenous betaine also has a significant reducing effect on the accumulation of OFF in the above-ground parts and roots of rice seedlings.

Claims

1. A method for reducing the accumulation of herbicides in plants, characterized in that: Apply betaine to plants that have accumulated herbicides.

2. A method for improving the ability of plants to resist herbicide stress, characterized in that: Betaine is applied to plants stressed by herbicides.

3. A method for reducing the negative impact of herbicides on plants, characterized in that: Apply betaine to plants that are negatively affected by herbicides.

4. The method according to any one of claims 1 to 3, characterized in that: The application used was root application.

5. The method according to any one of claims 1 to 3, characterized in that: The plants are crops.

6. The method according to any one of claim 5, characterized in that: The crop is rice.

7. A method for promoting the growth of plants affected by herbicides, characterized in that: Apply betaine to plants affected by herbicides.

8. Use of betaine in reducing the accumulation of herbicides in plants or in preparing drugs for reducing the accumulation of herbicides in plants.

9. Use of betaine in improving the ability of plants to resist herbicide stress or in preparing a drug for improving the ability of plants to resist herbicide stress.

10. Use of betaine in reducing the negative effects of herbicides on plants or in preparing a medicament for reducing the negative effects of herbicides on plants.

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