Application of taurine in inducing rice to generate disease resistance, preparing rice resistance inducer and preventing and treating rice diseases

Abstract

The invention relates to application of taurine in inducing rice to generate disease resistance, preparing a rice resistance inducer and preventing and treating rice diseases. According to the application disclosed by the invention, the taurine is used for treating the rice, so that the expression of rice disease resistance related genes can be induced, the content of rice anti-sex hormone salicylic acid and jasmonic acid can be increased, the occurrence of rice blast and cochliobolus miyabeanus can be effectively reduced through foliage spraying, and the occurrence of rice bacterial leaf blight can be effectively reduced through root irrigation treatment.

Description

Technical Field

[0001] The present invention relates to the field of bioengineering, and particularly to the application of taurine in inducing disease resistance in rice, preparing a rice elicitor, and controlling rice diseases. Background Art

[0002] With the rapid growth of the global population, food security has become a key issue that needs to be addressed urgently. It is estimated that by 2050, the global population will increase from 7 billion to 9 billion, which highlights the necessity of increasing rice production to achieve global food security. However, the occurrence of various rice diseases severely restricts the yield and quality of rice. Among them, the occurrence of rice blast is one of the most serious fungal diseases that endanger rice production. The direct loss of rice yield caused by rice blast in China reaches up to 3 billion kilograms every year. When the disease occurs severely, it can cause a 40%-50% reduction in rice yield, and even a complete crop failure. Rice brown spot is a common rice disease caused by the fungus Bipolaris oryzae. This disease is widely distributed in rice-growing areas around the world, especially in fields with poor soil and improper management, where it can cause a 10%-30% reduction in rice yield, and up to more than 50% when the disease is severe. Rice bacterial blight is a bacterial disease caused by Xanthomonas oryzae pv. oryzae (Xoo), and it is one of the important diseases in rice production, especially in rice-growing areas of Asia and Africa, where it can cause a 20%-50% reduction in yield, and even a complete crop failure in severe cases. At present, in order to prevent the occurrence of rice blast, brown spot, and bacterial blight, the strategy of "prevention first, comprehensive control" is widely adopted in production, combining agricultural management, disease-resistant varieties, chemical control, and biological control and other means. In agricultural management, measures such as reasonable crop rotation and fertilizer and water management can be adopted to reduce the primary infection source and improve the immunity of rice; chemical control, as a key measure, often uses methods such as seed disinfection and foliar spraying in production; biological control can be carried out by spraying microbial agents, plant elicitors, etc. In traditional disease control, the long-term use of disease-resistant varieties is easily broken through by pathogens, resulting in a decline in disease resistance, and the unreasonable application of chemical pesticides is likely to cause pathogens to develop drug resistance, and the agricultural problems caused by the residues of chemical fertilizers and pesticides are becoming increasingly prominent. With the improvement of people's requirements for food safety and the gradual enhancement of their awareness of ecological environment protection, vigorously promoting green prevention and control technologies such as agricultural control and biological control has become the mainstream trend in the development of the field of food disease prevention and control in China and even the world.

[0003] Taurine (chemical formula: C2H7NO3S) is a sulfur-containing β-amino acid (not involved in protein synthesis), widely distributed in animals, especially in high concentrations in the brain, heart, muscles, and retina. Taurine is an important organic osmolyte within cells, helping to maintain cell volume stability, and has a wide range of biological functions such as anti-inflammatory, analgesic, and maintaining the osmotic balance of the body. In addition, taurine is an active substance that regulates the normal physiological activities of the body and plays an important role in antioxidant, neuroprotection, cardiovascular health, lipid metabolism, immune regulation, etc. In industrial production, taurine can be prepared by fermentation or chemical synthesis methods and is a stable compound in vitro.

[0004] Elicitors are a class of compounds (such as chitosan, salicylic acid, methyl jasmonate, etc.) that can induce plants to enhance disease resistance and stress tolerance. They enhance resistance by activating the plant immune system and reduce the dependence on chemical pesticides. As an important means of biological control, biogenic elicitors are environmentally friendly and safe for non-target organisms (such as bees and natural enemy insects); they have a long-lasting effect, and the induced systemic resistance can last for several weeks to several months, which is superior to chemical pesticides that directly kill bacteria; elicitors have broad-spectrum properties and can simultaneously enhance resistance to multiple diseases and stresses; since elicitors do not directly act on pathogens, the risk of drug resistance can be reduced. However, at present, the production cost of some biogenic elicitors (such as oligosaccharides) is relatively high. Therefore, using biological sources as materials to develop green and economical biogenic rice elicitors is a new trend in rice disease prevention and control. Summary of the Invention

[0005] The object of the present invention is to provide the application of taurine in inducing disease resistance in rice, preparing rice elicitors, and controlling rice diseases. The present invention discovers that taurine can effectively increase the expression of rice disease resistance-related genes, promote the up-regulation of rice resistance hormones, and enhance the broad-spectrum resistance of rice to rice blast, brown spot, and bacterial blight.

[0006] To achieve the above object, the technical solution adopted by the present invention is: The application of taurine in any one or more of the following: 1) Inducing disease resistance in rice; 2) Preparing rice elicitors; 3) Controlling rice blast; 4) Controlling brown spot of rice; 5) Controlling bacterial blight of rice; Furthermore, the induction of disease resistance in rice is manifested as any one or more of the following: 1) Up-regulating the expression of rice disease resistance-related genes; 2) Increasing the content of endogenous hormone salicylic acid in rice; 3) Increasing the content of endogenous hormone jasmonic acid in rice; 4) Enhance the resistance of rice to rice blast; 5) Enhance the resistance of rice to brown spot; 6) Enhance the resistance of rice to bacterial blight.

[0007] A rice resistance inducer, wherein the rice resistance inducer uses taurine as an active ingredient; Furthermore, the content of taurine in the rice resistance inducer is 400 μg / mL; Furthermore, the preparation form of the rice resistance inducer is a soluble liquid formulation.

[0008] The application of the above-mentioned rice resistance inducer is any one or more of the following: 1) Induce disease resistance in rice; 2) Control rice blast; 3) Control brown spot of rice; 4) Control bacterial blight of rice; Furthermore, the induction of disease resistance in rice is manifested as any one or more of the following: 1) Up-regulate the expression of disease resistance-related genes in rice; 2) Increase the content of endogenous hormone salicylic acid in rice; 3) Increase the content of endogenous hormone jasmonic acid in rice; 4) Enhance the resistance of rice to rice blast; 5) Enhance the resistance of rice to brown spot; 6) Enhance the resistance of rice to bacterial blight.

[0009] The remarkable advantages of the present invention are as follows: The present invention explores the mechanism and application of taurine in enhancing the disease resistance of rice, and finds that treating rice with taurine can induce the expression of disease resistance-related genes in rice, increase the content of resistance hormones salicylic acid and jasmonic acid in rice, and effectively reduce the occurrence of rice blast and brown spot by foliar spraying, and effectively reduce the occurrence of bacterial blight of rice by root irrigation. Description of the Drawings

[0010] Figure 1 After hydroponically treating rice seedlings with a growth period of 15 days with a hydroponic solution containing 400 μg / mL taurine, rice leaves were taken at the 24h and 48h time points, and the expression levels of disease resistance-related genes OsPR1a, OsPR5, OsPAL6, and OsJAMyb in rice were detected by RT-qPCR. Control: Treated with a hydroponic solution without taurine; Taurine: Treated with a hydroponic solution containing taurine.

[0011] Figure 2The contents of the resistance hormones salicylic acid (SA) and jasmonic acid (JA) in rice seedlings grown hydroponically for 15 days in a hydroponic solution containing 400 μg / mL taurine for 48 h. Control: treated with a hydroponic solution without taurine; Taurine: treated with a hydroponic solution containing taurine.

[0012] Figure 3 After spraying the rice leaves with a 0.02% Tween aqueous solution containing 400 μg / mL taurine for 6 h, the incidence and lesion area were statistically analyzed after inoculating with Magnaporthe oryzae. Scale bar = 1 cm. Control: sprayed with a 0.02% Tween aqueous solution; Taurine: sprayed with a 0.02% Tween aqueous solution containing taurine.

[0013] Figure 4 After spraying the rice leaves with a 0.02% Tween aqueous solution containing 400 μg / mL taurine for 4 h, the incidence and lesion area were statistically analyzed after inoculating with Bipolaris oryzae. Scale bar = 1 cm. Control: sprayed with a 0.02% Tween aqueous solution; Taurine: sprayed with a 0.02% Tween aqueous solution containing taurine.

[0014] Figure 5 After irrigating the roots of rice plants grown for 45 days with a hydroponic solution containing 400 μg / mL taurine for 3 days, the incidence, lesion length, and bacterial biomass were statistically analyzed after inoculating with Xanthomonas oryzae pv. oryzae. Scale bar = 1 cm. Control: irrigated with a hydroponic solution without taurine; Taurine: irrigated with a hydroponic solution containing taurine. Detailed implementation manners

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0016] In the following embodiments, the hydroponic solution uses Yoshida rice nutrient solution (0.37 mmol / L CaCl2, 0.17 mmol / L NaH2PO4, 0.47 mmol / L MgSO4, 0.27 mmol / L K2SO4, 0.7 mmol / L (NH4)2SO4, 45 mmol / L Fe-EDTA, 0.40 mmol / L SiO2, 15 mmol / L H3BO3, 4.6 mmol / L MnSO4, 0.1 mmol / L NaMoO4, 0.15 mmol / L ZnSO4, 0.16 mmol / L CuSO4, pH 5.5).

[0017] Example 1 To study the induction effect of taurine on the disease resistance of rice, rice seedlings at 15 days old were hydroponically treated with a hydroponic solution containing 400 μg / mL taurine and a hydroponic solution without taurine (control). The solution was changed after 24 h. Leaf samples of rice were taken at two time points, 24 h and 48 h after treatment. Three individual plants were taken for each treatment, and three leaves were taken from each individual plant. The collected leaves were immediately frozen in liquid nitrogen, ground in a mortar, and total RNA was extracted, reverse transcribed into cDNA. The expression levels of four disease resistance-related genes, OsPR1a (uniprot accession no: Q6YSF8), OsPR5 (EMBL accession no: X68197), OsPAL6 (uniprot accession no: Q7X8V3), and OsJAMyb (uniprot accession no: Q2QZJ8), were detected by RT-qPCR, with the rice OsUbq gene as an internal reference. OsPR1a encodes a typical pathogenesis-related protein (PR protein) in rice, belonging to the PR-1 family. Its expression is strongly induced by the salicylic acid signaling pathway and is a marker gene for plant systemic acquired resistance (SAR). OsPR5 belongs to the PR-5 family and is strongly induced by the salicylic acid signaling pathway, enhancing resistance synergistically with OsPR1a. OsPAL6 encodes the key rate-limiting enzyme in the phenylpropanoid metabolic pathway, belonging to the precursor supply substances of the salicylic acid-benzoic acid synthesis pathway, and can activate the expression of PR genes (OsPR1a / OsPR10). The OsJAMyb gene is closely related to jasmonic acid synthesis and signal transduction and is one of the key transcription factors regulating the JA pathway in rice. The RT-qPCR results showed that after 24 h and 48 h of taurine treatment, the expression levels of these four genes were significantly up-regulated compared with the control ( Figure 1 ). Asterisks represent significant differences (*P < 0.05; **P < 0.01, Student’s t-test).

[0018] Example 2 Rice seedlings at 15 days old were hydroponically treated with a hydroponic solution containing 400 μg / mL taurine and a hydroponic solution without taurine (control). The solution was changed after 24 h. Leaf samples of rice were taken 48 h after treatment. Three individual plants were taken for each treatment, and three leaves were taken from each individual plant. The collected leaves were immediately frozen in liquid nitrogen, ground in a mortar, and after liquid nitrogen sampling, the contents of the resistance hormones salicylic acid (SA) and jasmonic acid (JA) in rice were detected by ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MSMS). The occurrence and development of plant disease resistance depend on different signaling pathways and their signal molecules. Among them, SA and JA play the role of endogenous signal molecules in the plant disease resistance defense response. The disease resistance processes mediated by these two signal molecules are respectively called the basic signal pathways of plant disease resistance defense. Such as Figure 2As shown, after treatment with 400 μg / mL taurine, the SA and JA contents in rice seedlings were significantly increased compared with the control, which was beneficial to enhancing the disease resistance of rice. Asterisks represent significant differences (**P<0.01; ***P<0.001, Student’s t-test).

[0019] Example 3 To explore the control effect of taurine treatment on rice blast, 6 h before spraying conidia of Magnaporthe oryzae on rice seedlings, a 0.02% Tween aqueous solution containing 400 μg / mL taurine was evenly sprayed on the leaf surface of rice seedlings at 0.5 mL / plant, and then the disease incidence was observed 6 days after inoculation with Magnaporthe oryzae. As Figure 3 shown, compared with the control treatment, taurine could effectively reduce the disease area of rice blast, indicating that 400 μg / mL taurine had a good preventive effect on the occurrence of rice blast. Asterisks represent significant differences (*P<0.05, Student’s t-test).

[0020] Example 4 To explore the control effect of taurine on rice brown spot, 4 h before spraying conidia of Bipolaris oryzae on rice seedlings, a 0.02% Tween aqueous solution containing 400 μg / mL taurine was evenly sprayed on rice seedlings at 0.5 mL / plant, and then the disease incidence was observed 3 days after inoculation with Bipolaris oryzae. As Figure 4 shown, compared with the control treatment, taurine could effectively reduce the disease area of rice brown spot, indicating that 400 μg / mL taurine also had a good preventive effect on the occurrence of rice brown spot. Asterisks represent significant differences (*P<0.05, Student’st-test).

[0021] Example 5 To explore the control effect of taurine on rice bacterial blight, rice plants grown for 45 days were irrigated with a hydroponic solution containing 400 μg / mL taurine and a hydroponic solution without taurine (control), respectively. The irrigation treatment was carried out once every 24 h, 50 mL of hydroponic solution was added each time, and it lasted for 3 times. After the third time, the rice was inoculated with Xanthomonas oryzae pv.oryzae with an OD 600 =1.0. The inoculation method was to dip scissors in the bacterial solution of Xanthomonas oryzae pv.oryzae and cut the leaf at one-third of the distance from the tip of the second leaf position of the rice. The disease incidence was observed 15 days after inoculation. As Figure 5As shown, compared with the control treatment, taurine can effectively reduce the lesion expansion of rice bacterial blight and decrease the relative biomass of bacteria carried by leaves, indicating that the root irrigation treatment with 400 μg / mL taurine also has a good preventive effect on the occurrence of rice bacterial blight. Asterisks represent significant differences (*P<0.05, Student’s t-test).

[0022] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the present invention, and any modification or partial replacement without departing from the spirit and scope of the present invention should be covered by the scope of the claims of the present invention.

Claims

1. Application of taurine in any one or more of the following: 1) Inducing disease resistance in rice; 2) Preparing a rice resistance inducer; 3) Controlling rice blast; 4) Controlling brown spot of rice; 5) Controlling bacterial blight of rice.

2. The application according to claim 1, wherein: The induction of disease resistance in rice is manifested as any one or more of the following: 1) Up-regulating the expression of rice disease resistance-related genes; 2) Increasing the content of endogenous hormone salicylic acid in rice; 3) Increasing the content of endogenous hormone jasmonic acid in rice; 4) Enhancing the resistance of rice to rice blast; 5) Enhancing the resistance of rice to brown spot; 6) Enhancing the resistance of rice to bacterial blight.

3. A rice elicitor, characterized in that: The rice resistance inducer has taurine as the active ingredient.

4. The rice resistance inducer according to claim 3, wherein: The content of taurine in the rice resistance inducer is 400 μg / mL.

5. The rice elicitor according to claim 3, wherein: The preparation form of the rice resistance inducer is a soluble liquid agent.

6. The application of the rice elicitor according to any one of claims 3 to 5, characterized in that: It is any one or more of the following: 1) Inducing disease resistance in rice; 2) Controlling rice blast; 3) Controlling brown spot of rice; 4) Controlling bacterial blight of rice.

7. The application according to claim 6, wherein: The induction of disease resistance in rice is manifested as any one or more of the following: 1) Up-regulating the expression of rice disease resistance-related genes; 2) Increasing the content of endogenous hormone salicylic acid in rice; 3) Increasing the content of endogenous hormone jasmonic acid in rice; 4) Enhancing the resistance of rice to rice blast; 5) Enhancing the resistance of rice to brown spot; 6) Enhancing the resistance of rice to bacterial blight.

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