Application of spiracoside in improving resistance of rice to rice blast and / or sheath blight

Abstract

The present invention discloses the use of spiracoside in improving rice resistance to rice blast and / or sheath blight, and relates to the field of biotechnology. The present invention explores endogenous metabolites that can affect rice resistance to rice blast, and identifies the effects of endogenous metabolites on rice disease resistance in the field through three treatment methods: simultaneous treatment, preventive treatment, and therapeutic treatment. The results show that spiracoside can significantly enhance rice resistance to rice blast. The results show that after spiracoside treatment, the germination of rice blast fungus spores and the formation of appressorium are inhibited. In addition, the present invention also finds that spiracoside has preventive and therapeutic effects on rice sheath blight. The present invention provides a new endogenous metabolite for preventing and controlling rice blast and sheath blight, and has important agricultural application value.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, in particular to application of spiracoside in improving resistance of rice to rice blast and / or sheath blight. Background Art

[0002] Rice is one of my country's staple crops, and rice blast and sheath blight are major rice diseases that can severely reduce rice yields, sometimes even leading to total crop failure. Controlling these diseases has long been a key and challenging area of ​​rice research, crucial for ensuring my country's food security. Currently, breeding disease-resistant rice varieties and using chemical pesticides are common approaches to controlling these diseases. However, resistance mediated by resistance genes (R genes) typically lacks broad-spectrum resistance and can be lost due to shifts in the dominant pathogenic species, leading to large-scale outbreaks. Long-term use of chemical agents can easily lead to the development of resistance in pathogens, and pesticide residues can pose safety risks to humans and the environment. Therefore, research on resistance to rice blast and sheath blight, and exploring new strategies for their control, is crucial.

[0003] Biopesticides have attracted widespread attention due to their low toxicity, high efficacy, diverse target groups, and environmental friendliness. Plant secondary metabolites have become a key avenue for biopesticide research and development due to their non-selective nature, resistance to pathogenic bacteria, low toxicity, easy degradation, and strong specificity. While plant secondary metabolites are generally non-selective against pathogens when enhancing plant defenses, biopesticides derived from secondary metabolites are less likely to induce pathogenic resistance and eliminate the safety risks of pesticide residues. Therefore, screening and identifying key secondary metabolites that enhance disease resistance among metabolites that play a crucial role in combating pathogens has far-reaching implications for enhancing crop resistance, stabilizing grain yields, and ensuring food security. Currently, identified secondary metabolites that affect pathogen growth and development include phytocassane AE, oryzalexin A-E, sakuranetin, osthole, Schima superba saponins, and schizonepeta tenuifolia essential oil. However, given the over 100,000 secondary metabolites involved in plant defense systems, there is still significant potential for identifying key secondary metabolites that can prevent and treat rice blast and sheath blight. This study aims to improve rice resistance to rice blast and sheath blight by identifying endogenous metabolites associated with rice disease resistance. Summary of the Invention

[0004] The present invention aims to provide a method for improving the resistance of rice to rice blast and / or sheath blight, thereby overcoming the problems of the prior art. The present invention has found that spiracoside can significantly enhance the resistance of rice to rice blast and sheath blight, thus having important agricultural application value.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides application of spiracoside in improving resistance of rice to rice blast and / or sheath blight.

[0007] Furthermore, when the spiraea glycoside is used to improve the resistance of rice to rice blast, the spiraea glycoside enhances the resistance of rice to rice blast by inhibiting the spore germination and appressorium formation of the rice blast pathogen.

[0008] The present invention also provides the use of spiracoside in preparing pesticides for preventing and treating rice blast and / or sheath blight.

[0009] The present invention also provides a pesticide for preventing and controlling rice blast and / or sheath blight, wherein the active ingredient includes spiracoside.

[0010] Furthermore, the pesticide also includes pesticide-acceptable excipients.

[0011] Furthermore, the auxiliary materials include emulsifiers, dispersants and / or cosolvents.

[0012] The present invention also provides use of the above pesticide in preventing and controlling rice blast and / or sheath blight.

[0013] The present invention also provides a method for preventing and controlling rice blast and / or sheath blight, comprising the steps of applying spiracoside to rice plants to prevent and control rice blast and / or sheath blight.

[0014] Furthermore, when preventing and controlling rice blast, the application method is foliar spraying; when preventing and controlling sheath blight, the application method is stem spraying.

[0015] Furthermore, the spraying concentration of the spiraea glycoside is 200 μM.

[0016] The present invention discloses the following technical effects:

[0017] The present invention explores endogenous metabolites that can influence rice resistance to rice blast. The effects of these endogenous metabolites on rice resistance were identified in the field using three treatment methods: simultaneous treatment, preventive treatment, and therapeutic treatment. The results revealed that spiraea glycoside significantly enhances rice resistance to rice blast. The results also showed that spiraea glycoside treatment inhibited spore germination and appressorium formation in rice blast fungi. Furthermore, the present invention also found that spiraea glycoside has preventive and therapeutic effects against rice sheath blight. This invention provides a new endogenous metabolite for preventing and controlling rice blast and sheath blight, and has important agricultural applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Representative pictures of leaves infected with rice blast (A) and statistical diagram of the number of lesions (B) under simultaneous treatment;

[0020] Figure 2 Representative images of leaves infected with rice blast under preventive treatment (A) and statistical diagram of the number of lesions (B);

[0021] Figure 3 Representative pictures of leaves infected with rice blast under treatment (A) and statistical diagram of the number of lesions (B);

[0022] Figure 4 The following are the observation diagrams of germination of rice blast fungus spores in different treatment groups (A) and statistical diagrams of germination rate data (B);

[0023] Figure 5 Representative images of stems infected with sheath blight under preventive treatment (A) and statistical graph of lesion length (B);

[0024] Figure 6 Representative pictures of stems infected with sheath blight under treatment (A) and statistical graph of lesion length (B). DETAILED DESCRIPTION

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0027] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0028] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0029] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0030] Spiraside referred to in the present invention is a glycosylated flavonoid compound, the English name is Spireoside, abbreviated as Spi, the CAS number is 20229-56-5, the chemical formula is C 21 H 20 O 12 , MW = 464.38Da, structural formula:

[0031]

[0032] Example 1

[0033] 1. Experimental Materials

[0034] Metabolite: Spi, purchased from Solarbio, product batch number CS30062-69727, was dissolved in dimethyl sulfoxide (DMSO) before use.

[0035] Rice material: Lijiangxintuanheigu (LTH), which is highly susceptible to most physiological races of rice blast fungus. American rice variety Kitaake was used for inoculation with Rhizoctonia solani.

[0036] Pathogen: Magnaporthe grisea race Guy11. Add spores to sterile water to prepare a spore suspension for later use. Rhizoctonia solani race AG-1-1A was cultured on PDA medium containing wood chips for later use.

[0037] 2. Experimental Methods

[0038] 2.1 Effects of Spi on the incidence of rice blast under different treatments (simultaneous, preventive, and therapeutic)

[0039] (1) Simultaneous processing

[0040] Four-leaf-stage LTH rice plants with uniform growth were divided into two groups, and each group was treated as shown in Table 1. Seven days later, the incidence of the DMSO-treated group was set as 100% based on the number of lesions on the leaves after spraying the pathogen, and the incidence of each treatment group was counted.

[0041] Disease incidence = number of lesions in the experimental group / number of lesions in the DMSO-treated group × 100%.

[0042] Table 1 Experimental groups of simultaneous treatments for rice blast

[0043]

[0044] (2) Preventive treatment

[0045] Four-leaf-stage LTH rice plants with uniform growth were divided into two groups, and each group was treated as shown in Table 2. Seven days later, the incidence of the DMSO-treated group was set as 100% based on the number of lesions on the leaves after spraying with the pathogen, and the incidence of each treatment group was counted.

[0046] Table 2 Experimental groups of rice blast prevention treatments

[0047]

[0048] (3) Treatment

[0049] Four-leaf-stage LTH rice plants with uniform growth were divided into two groups, and each group was treated as shown in Table 3. Seven days later, the incidence of the water-treated group was set as 100% based on the number of lesions on leaves after the pathogen spraying, and the incidence of each treatment group was counted.

[0050] Table 3 Experimental groups of rice blast treatments

[0051]

[0052] 2.2 Rice blast fungus spore germination inhibition experiment

[0053] The experiment was divided into three groups: one group treated with a 200 μM Spi (Spi)-containing Guy11 spore suspension; one group treated with a Guy11 spore suspension containing an equal amount of DMSO and lacking Spi as a solvent control; and another group treated with a Guy11 spore suspension as a blank control. Using the five-point method, the Guy11 spore suspensions from each group were placed onto hydrophobic glass slides. The slides were then incubated in an incubator. Spore germination was observed and statistically analyzed using a Zeiss fluorescence microscope at 0, 4, 12, and 24 hours.

[0054] 2.3 Effects of Spi on the incidence of rice sheath blight under different treatments (prevention and treatment)

[0055] (1) Preventive treatment

[0056] Kitaake rice plants of uniform growth during the grain filling stage were divided into two groups and each group was treated as shown in Table 4. Five days later, the incidence of disease in each treatment group was calculated, with the DMSO-treated group set as 100% based on the length of the lesions on the stem after inoculation.

[0057] Incidence rate = lesion length of experimental group / lesion length of DMSO-treated group × 100%.

[0058] Table 4 Experimental groups of rice sheath blight prevention treatments

[0059]

[0060] (2) Treatment

[0061] Kitaake rice plants of uniform growth at the four-leaf stage were divided into two groups and each group was treated as shown in Table 5. Five days later, the incidence of disease in each treatment group was calculated, with the DMSO-treated group set as 100% based on the length of the lesions on the stem after inoculation.

[0062] Table 5 Experimental groups of treatments for rice sheath blight

[0063]

[0064] 3. Experimental Results

[0065] (1) Statistical results of rice blast incidence

[0066] The statistical results of the incidence of rice blast in each group under different treatments are shown in Table 6. The representative pictures of rice blast-infected leaves and the statistical graphs of the number of lesions under simultaneous treatment, preventive treatment and therapeutic treatment are shown in Table 6. Figure 1-Figure 3 The results showed that foliar spraying of Spi could improve the resistance of rice to rice blast, and the incidence of rice blast was significantly reduced.

[0067] Table 6 Statistical results of rice blast incidence under different treatments

[0068] Treatment DMSO 200 μM Simultaneous processing 100％±25.5％ 51.8％±14.6％ Preventive treatment 100％±26.4％ 52.7％±16.8％ Treatment 100％±33％ 57.5％±17.9％

[0069] (2) Results of spore germination inhibition experiment

[0070] The statistical results of Guy11 spore germination rate in each group under different treatments are shown in Table 7. Among them, the representative pictures and statistical data of the effects of spiraea glycosides on spore germination and appressorium formation of rice blast fungus at different time points under water treatment, DMSO treatment and Spi treatment are shown in Figure 4 The results showed that compared with water treatment and DMSO treatment, spore germination of Guy11 was significantly inhibited 4 hours after Spi treatment; appressorium formation was effectively inhibited at 12 hours and 24 hours. This indicates that Spi can enhance rice resistance to rice blast by inhibiting spore germination and appressorium formation, and can be used to prevent and control rice blast.

[0071] Table 7 Statistical results of spore germination rate of Guy11 under different treatments

[0072] time Spore state water DMSO Spi 0h Ungerminated 99.6％±0.6％ 99.2％±1.2％ 99.2％±1.2％ 4h Germ tube tip swelling 82.1％±2.6％ 79.6％±4.6％ 8.3％±5.2％ 12h Appressorium formation 85.8％±4.1％ 86.7％±1.2％ 45.4％±0.6％ 24h Mature appressorium 95.8％±1.6％ 92.5％±2.7％ 45.8％±0.6％

[0073] (3) Statistical results of sheath blight incidence

[0074] The statistical results of the incidence of sheath blight in each group under different treatments are shown in Table 8. The representative pictures of diseased stems and the statistical graphs of lesion length under preventive treatment and therapeutic treatment are shown in Table 8. Figure 5-Figure 6 The results showed that spraying Spi on the stem could improve the resistance of rice to sheath blight.

[0075] Table 8 Statistical results of sheath blight incidence under different treatments

[0076] Treatment DMSO 200 μM Preventive treatment 100％±19.2％ 60％±17.7％ Treatment 100％±20.2％ 72.8％±24.9％

[0077] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. Application of spiraea glycoside in improving the resistance of rice to rice blast and / or sheath blight.

2. The application according to claim 1, characterized in that When the spiraea glycoside is used to improve the resistance of rice to rice blast, the spiraea glycoside enhances the resistance of rice to rice blast by inhibiting the spore germination and appressorium formation of the rice blast pathogen.

3. Use of spiracoside in the preparation of pesticides for preventing and controlling rice blast and / or sheath blight.

4. Use of a pesticide in preventing and controlling rice blast and / or sheath blight, characterized in that: The active ingredients of the pesticide include meadowfoam glycoside; The pesticide also includes pesticide-acceptable excipients; The auxiliary materials include emulsifiers, dispersants and / or cosolvents.

5. A method for preventing and controlling rice blast and / or sheath blight, characterized in that: The method comprises the steps of applying spiracoside to rice plants to prevent and control rice blast and / or sheath blight.

6. The method according to claim 5, characterized in that When controlling rice blast, the application method is foliar spraying; when controlling sheath blight, the application method is stem spraying.

7. The method according to claim 6, characterized in that The spraying concentration of the spiraea glycoside is 200 μM.

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