Insect lysozyme capable of preventing and treating rice virus diseases and application thereof

Abstract

The invention discloses insect lysozyme capable of preventing and treating rice virus diseases and application of the insect lysozyme. According to the invention, three pieces of lysozyme (RdLYZI1, RdLYZC1 and RdLYZC2) with remarkable inhibitory activity on various rice viruses are innovatively excavated from the body of a natural transmission vector insect of the viruses, and the amino acid sequences of the lysozyme are shown as SEQ ID NO.13, SEQ ID NO.14 and SEQ ID NO.15. The invention further discloses a preparation method of the lysozyme. Experimental verification shows that the lysozyme RdLYZI1, the lysozyme RdLYZC1 and the lysozyme RdLYZC2 can effectively inhibit replication and accumulation of various rice viruses in plants and vector insects, have a remarkable prevention and treatment effect on related virus diseases and relieve plant growth obstacles caused by the viruses. The invention provides a novel biological prevention and control strategy which is environment-friendly and high in targeting property for green prevention and control of rice virus diseases, and has an important application prospect.

Description

Technical Field

[0001] This invention belongs to the field of plant protection and biotechnology, specifically relating to a class of insect lysozymes that can prevent and control rice viral diseases and their applications. Background Technology

[0002] Rice is one of the most important food crops worldwide, and its yield and quality directly affect food security. However, various rice viral diseases seriously threaten rice production, among which diseases caused by Southern Rice Black-Streaked Dwarf Virus (SRBSDV), Rice Gall Dwarf Virus (RGDV), and Rice Stripe Mosaic Virus (RSMV) are particularly prominent. These viruses are mainly transmitted by the white-backed planthopper (SRBSDV). Sogatella furcifera ), electric leafhopper ( Recilia dorsalis Viral diseases are transmitted by vector insects such as stunted insects, with deformed and thickened leaves bearing tumor-like protrusions, delayed heading, and a significant decrease in grain filling rate. In severe cases, they can even cause plant death, resulting in serious yield losses. Currently, field control of these viral diseases mainly relies on chemical pesticides to kill the vector insects and on the breeding and promotion of virus-resistant (tolerant) rice varieties. However, the long-term and large-scale use of chemical pesticides can easily lead to problems such as insect resistance, pesticide residues, and environmental pollution. Furthermore, the breeding of resistant varieties is time-consuming and costly, and their resistance may be lost due to viral mutations.

[0003] Therefore, the development of novel biocontrol agents that are environmentally friendly, target-specific, and unlikely to induce resistance is particularly urgent. Lysozyme is a naturally occurring hydrolytic enzyme widely found in organisms, renowned for its broad-spectrum antibacterial activity, and has mature applications in the medical and food preservation fields. In recent years, its potential antiviral activity has also begun to attract attention. However, current research on lysozyme mainly focuses on vertebrate sources (such as egg white lysozyme), and research on insect-derived lysozyme, especially its application in the control of plant viral diseases, remains lacking. Summary of the Invention

[0004] To address the limitations of existing methods for controlling rice viral diseases, this invention aims to identify and develop a novel type of lysozyme with highly efficient antiviral activity from the insect vector of rice virus, the electric leafhopper, providing new active ingredients and solutions for the green control of rice viral diseases.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an insect lysozyme having any of the following amino acid sequences: (1) Lysozyme RdLYZI1 with an amino acid sequence as shown in SEQ ID NO.13; (2) Lysozyme RdLYZI2 with the amino acid sequence shown in SEQ ID NO.14; (3) Lysozyme RdLYZC1 with the amino acid sequence shown in SEQ ID NO.15; (4) Lysozyme RdLYZC2 with an amino acid sequence as shown in SEQ ID NO.16.

[0006] Secondly, the present invention provides a nucleic acid molecule encoding the above-mentioned insect lysozyme, wherein the nucleotide sequence of the nucleic acid molecule is shown in SEQ ID NO.1~4 in sequence.

[0007] Thirdly, the present invention provides expression cassettes, recombinant vectors, recombinant cells, and recombinant microorganisms containing the above-mentioned nucleic acid molecules.

[0008] Fourthly, the present invention provides a product for preventing and controlling rice viral diseases, the active ingredient of which is the above-mentioned insect lysozyme or the above-mentioned nucleic acid molecule or the above-mentioned expression cassette, recombinant vector, recombinant cell and recombinant microorganism.

[0009] Furthermore, the rice viral diseases include rice gall dwarf virus, rice stripe mosaic virus, and southern rice black-streaked dwarf virus.

[0010] Furthermore, the product can effectively inhibit the replication and accumulation of rice virus in rice plants and virus-carrying insects, and restore rice plant growth disorders caused by rice virus.

[0011] Furthermore, the vector insect is the electric leafhopper or the white-backed planthopper.

[0012] Fifthly, the present invention provides the use of the above-mentioned insect lysozyme, the above-mentioned nucleic acid molecule or the above-mentioned expression cassette, recombinant vector, recombinant cell and recombinant microorganism in the preparation of any of the following products: (1) Products resistant to rice viruses; (2) Products for the prevention and control of rice viral diseases; (3) Products that inhibit the replication of rice viruses in their vector insects.

[0013] Furthermore, the rice viral diseases include rice gall dwarf disease, rice stripe mosaic virus, and southern rice black-streaked dwarf disease, and the vector insects are electric leafhoppers or white-backed planthoppers.

[0014] Furthermore, the product is applied by soaking the roots of infected rice or by soaking rice seedlings before transplanting, wherein the concentration of the product is 0.5~4 mg / mL.

[0015] Compared with the prior art, the present invention has the following significant advantages and beneficial effects: (1) Source innovation: Breaking through the traditional research approach of obtaining lysozyme mainly from vertebrates (such as poultry eggs), it innovatively discovered lysozyme resources with antiviral function from the electric leafhopper, a natural vector of plant viruses, adding a new member to the lysozyme family and expanding its application boundaries.

[0016] (2) Clear function and significant effect: Through in vitro and in vivo functional verification, it was confirmed that the specific lysozymes (RdLYZI1, RdLYZC1, RdLYZC2) provided by the present invention have significant inhibitory effects on a variety of important rice viruses such as RGDV, RSMV and SRBSDV, which can effectively reduce the viral load in host rice and vector insects and alleviate the plant growth obstacles caused by the virus.

[0017] (3) Broad application prospects: The lysozyme, its encoding gene, recombinant vector, and engineered microorganisms provided by this invention can be directly used to develop new biological pesticides, antiviral transgenic rice, or applied as functional molecules in disease control systems. This strategy provides a new and environmentally friendly control option for diseases such as Southern Black-streaked Dwarf Disease, Rice Gall Dwarf Disease, and Rice Stripe Mosaic Disease, which currently lack effective control methods, and meets the requirements of sustainable agricultural development. Attached Figure Description

[0018] Figure 1 Amino acid sequence alignment and conserved catalytic site analysis of four electro-optic leafhopper lysozymes and egg white lysozyme (HEWL).

[0019] Figure 2 Effects of four electro-optic leafhopper lysozyme treatments on the load of rice tumor dwarf virus (RGDV) in rice plants.

[0020] Figure 3 Effects of four electro-optic leafhopper lysozyme treatments on the load of rice stripe mosaic virus (RSMV) in rice plants.

[0021] Figure 4 The effect of four types of electro-optic leafhopper lysozyme treatment on the recovery of plant height in rice plants infected with RGDV.

[0022] Figure 5 The effect of four types of electro-optic leafhopper lysozyme treatment on the recovery of plant height in rice plants infected with RSMV.

[0023] Figure 6 Effects of four lysozyme microinjection treatments on RGDV load in *Electro-optical leafhopper*.

[0024] Figure 7Effects of four lysozyme microinjection treatments on RSMV loading in *Electro-optical leafhopper*.

[0025] Figure 8 Effects of four electro-optic leafhopper lysozyme microinjection treatments on the load of Southern Rice Black-streaked Dwarf Virus (SRBSDV) in the white-backed planthopper. Detailed Implementation

[0026] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0027] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0028] Example 1: Screening, expression, and identification of electro-optic leafhopper lysozyme targeting and inhibiting rice viruses. The electric leafhopper, a typical piercing-sucking pest, primarily damages rice plants by sucking sap from the leaves and leaf sheath phloem, causing stunted growth, yellowing leaves, and in severe cases, overall wilting and death. Furthermore, this insect is a key natural vector for rice dwarf virus (RGDV) and rice stripe mosaic virus (RSMV), playing a significant role in the spread of these diseases in the field.

[0029] In this embodiment, bioinformatics methods were used to systematically screen a batch of potentially functional lysozyme gene sequences from the transcriptome and genome data of the electric leafhopper. Through multiple sequence alignment, domain analysis, and evolutionary relationship assessment, four representative sequences were selected and named RdLYZI1 (sequence shown in SEQ ID NO.1), RdLYZI2 (sequence shown in SEQ ID NO.2), RdLYZC1 (sequence shown in SEQ ID NO.3), and RdLYZC2 (sequence shown in SEQ ID NO.4) as the subjects for subsequent functional verification studies.

[0030] 1. Cloning of the lysozyme gene in the electro-optic leafhopper Specific PCR primers were designed targeting the mature peptide coding regions of the four genes mentioned above (Tables 1 and 2). Total RNA was extracted from adult electric leafhoppers using the Trizol method and reverse transcribed into cDNA, which was then used as a template for PCR amplification. The reaction mixture consisted of 50 μL: 2 μL cDNA template, 1 μL each of 10 μM forward and reverse primers, 25 μL 2 × Primer STAR Mix, and ddH2O to make up the volume. The amplification program was as follows: pre-denaturation at 98℃ for 5 min; followed by 35 cycles (98℃ for 20 s, 60℃ for 30 s, 72℃ for 30 s), and a final extension at 72℃ for 10 min.

[0031] After separation and identification of the PCR products by 1% agarose gel electrophoresis, the target fragment was recovered using a gel extraction kit. The recovered fragment was mixed with the linearized pET-28a vector digested with EcoRI and HindIII, and homologous recombination was performed at 50℃ for 30 min. The ligation product was transformed into E. coli DH5α competent cells, plated on LB agar plates containing kanamycin (50 μg / mL), and incubated upside down at 37℃ for 12 h. Single colonies were picked for PCR identification, and positive clones were sequenced by Sanger sequencing. The sequencing results were compared with the reference sequences in Table 2 to obtain the correct recombinant clones.

[0032] Table 1. Nucleotide sequence of the lysozyme gene of the electro-optic leafhopper

[0033] Table 2 Primers for PCR amplification of the lysozyme gene in the electro-optic leafhopper

[0034] Note: In the primer sequences, lowercase letters indicate homologous multiple arms, italicized and bolded parts are gene-specific sequences, and underlines indicate restriction enzyme sites.

[0035] 2. Lysozyme prokaryotic expression and purification The four recombinant plasmids pET28a-RdLYZI1, pET28a-RdLYZI2, pET28a-RdLYZC1, and pET28a-RdLYZC2, which were verified by sequencing, were transformed into *E. coli* BL21(DE3) competent cells and plated on LB agar plates containing kanamycin (50 μg / mL). The plates were incubated at 37°C with the plates inverted for 12 h. Single positive colonies were picked and inoculated into LB liquid medium containing the corresponding antibiotics and cultured at 37°C with shaking until OD (occurrence limit). 600 =0.6-0.8, the bacterial culture was placed on ice for 5 min to inhibit rapid bacterial proliferation, and isopropyl-β-D-thiogalactoside (IPTG) was added to a final concentration of 1.0 mM. Expression was induced at 37℃ and 160 rpm for 8 h.

[0036] After induction, bacterial cells were collected by centrifugation at 8000 rpm for 10 min at 4°C. The cells were resuspended in pre-cooled (4°C) PBS buffer (pH 7.5), and a final concentration of 1 mM protease inhibitor (PMSF) was added. The cells were then sonicated until the bacterial solution was clear. After centrifugation at 12000 rpm for 10 min at 4°C, the supernatant containing soluble proteins was collected. A portion of the supernatant was mixed with 5×SDS loading buffer, boiled at 99°C for 10 min, and subjected to SDS-PAGE (5% stacking gel, 15% separating gel) gel electrophoresis. Protein expression was detected by Coomassie Brilliant Blue R-250 staining.

[0037] Simultaneously, Western blot was used to verify protein specificity. The protein separated by SDS-PAGE was wet-transferred to a PVDF membrane and blocked with PBST containing 5% skim milk powder (containing 0.05% Tween-20) at room temperature for 2 h. His-tagged monoclonal primary antibody (1:5000 dilution, incubated overnight at 4°C) and HRP-labeled goat anti-mouse secondary antibody (1:10000 dilution, incubated at room temperature for 1 h) were added sequentially. After each antibody incubation, the membrane was washed three times with PBST (5 min each time). Finally, the membrane was developed using an ECL chemiluminescence assay kit. If both Coomassie Brilliant Blue staining and Western blot showed a single, specific band with the correct molecular weight, the target protein was considered successfully expressed.

[0038] Selected positive strains that successfully expressed protein were cultured and expanded. Soluble protein supernatant was prepared according to the method described above. Purification was performed using a His-tagged affinity chromatography column, equilibrated sequentially with 5 column volumes of equilibration buffer (10 mM PBS, 300 mM NaCl, pH 7.5), and incubated at 4°C for 30 min to allow protein binding. Impurities were washed away with 10 column volumes of equilibration buffer. Finally, a gradient elution was performed using elution buffers containing 20, 50, 100, 250, and 500 mM imidazole (10 mM PBS, 300 mM NaCl, pH 7.5), and each fraction was collected.

[0039] Protein purity of the eluted fractions was assessed by SDS-PAGE. Fractions with a purity ≥90% were collected and concentrated and desalted using 3 kDa ultrafiltration tubes (centrifugation at 5000 rpm for 1 h at 4 °C). Protein concentration was determined using the BCA method, and the fractions were aliquoted and stored at -80 °C for later use.

[0040] 3. Lysozyme sequence and enzyme activity site analysis Multiple sequence alignment analysis was performed on the amino acid sequences of four electro-leafhopper lysozymes and the amino acid sequence fragment of the classic C-type lysozyme-egg white lysozyme (HEWL) (Table 3). The results showed that the lysozyme catalyzing residue glutamate (Glu, E) was missing in RdLYZI2 ( Figure 1 (Table 4), while aspartic acid (Asp, D) is highly conserved in all sequences.

[0041] Table 3. Comparison of sequence similarity among different lysozymes (%)

[0042] Table 4. Lysozyme and amino acid sequence of electro-optic leafhopper

[0043] 4. Detection of antiviral ability of lysozyme in infected rice plants Rice gall dwarf virus (caused by RGDV) and rice stripe mosaic virus (caused by RSMV) are serious and damaging diseases in rice-growing areas of southern my country, posing a persistent threat to rice production. Both viruses rely on leafhoppers to sustain their transmission cycle in the field. To evaluate the antiviral effect of lysozyme, rice seedlings were artificially inoculated with infected leafhoppers to transmit the virus, and the resulting infected plants were used as experimental materials for systematic functional verification.

[0044] (1) Experimental materials and treatment Preparation of lysozyme working solution: Take each lysozyme obtained in step (2) of Example 1 and prepare a working solution with a concentration of 1 mg / mL using PBS buffer (pH 7.5).

[0045] Rice seedling cultivation and virus transmission: Rice seedlings were cultivated to a height of 4-6 cm using seedling trays, and each seedling was transplanted into a glass tube with its roots wrapped with absorbent cotton balls. Five electric leafhoppers carrying RGDV or RSMV were introduced into each seedling and placed under conditions of 28℃, 60-70% relative humidity, and 14 h light / 10 h darkness for 7 days to feed and transmit the virus.

[0046] Lysozyme treatment: After inoculation, the roots of rice seedlings were immersed in the corresponding lysozyme working solution for 48 h. Each lysozyme was used in 20 replicates, with PBS buffer (pH 7.5) treatment as a negative control and egg white lysozyme (HEWL) treatment as a reference control. After treatment, the rice seedlings were transferred to Kimura B nutrient solution (Coolaber, Cat# NSP1050) and cultured for another 20 days under the same temperature and light conditions.

[0047] (2) Viral load detection and phenotypic observation Viral load detection: Rice leaf tissue was collected, ground in liquid nitrogen, and total RNA was extracted using the Trizol method. 1 μg of RNA was used for reverse transcription to obtain cDNA. Using rice... Actin The gene was used as an internal control. RT-qPCR was performed on a QuantStudio 5 real-time quantitative PCR instrument using the specific primers listed in Table 5 and SYBR Green Premix as the fluorescent dye. The reaction volume was 20 μL: 1 μL cDNA template, 0.5 μL each of forward and reverse primers (10 μM), 10 μL SYBR Green Master Mix, and sterile water to make up the volume. The amplification program was: 95℃ pre-denaturation for 30 s; followed by 40 cycles (95℃ for 5 s, 60℃ for 30 s); melting curve analysis was performed using the default program. Three technical replicates were set for each sample. Use 2 -ΔΔCt Method for calculating viral genome (RGDV) P8 or RSMVN The relative expression levels of ) were compared with the PBS control group without lysozyme injection, and the differences in viral titers among different treatment groups were compared.

[0048] Phenotypic observation: The plant height of rice seedlings in each treatment group was measured and recorded, and the alleviating effect of lysozyme treatment on virus-induced growth inhibition was analyzed.

[0049] Table 5 Primer sequences for RT-qPCR detection

[0050] RT-qPCR results showed that, against RGDV, compared with the PBS negative control, RdLYZI2, and HEWL treatments, RdLYZI1, RdLYZC1, and RdLYZC2 treatments significantly reduced the viral load in rice. Figure 2 Phenotypic analysis further showed that the rice plant height in the three lysozyme treatment groups was significantly higher than that in the control group, and the growth retardation symptoms caused by RGDV were significantly alleviated. Figure 4 The RT-qPCR results for RSMV were consistent with those for RGDV: RdLYZI1, RdLYZC1, and RdLYZC2 all significantly inhibited RSMV proliferation in rice, and the plant height of the corresponding treatment groups was significantly higher than that of the PBS control, RdLYZI2, and HEWL treatment groups. Figure 3 , Figure 5 The above results indicate that RdLYZI1, RdLYZC1, and RdLYZC all exhibit clear antiviral activity against two serious rice viruses and can simultaneously alleviate growth and development disorders caused by viral infection, providing core experimental support for subsequent field applications.

[0051] Example 2: Detection of antiviral ability of lysozyme from infected electro-optic leafhopper The electric leafhopper is a key vector for the transmission of rice viruses in the field, and the RGDV and RSMV it transmits can replicate and multiply within the insect. Example 1 has already verified the antiviral activity of lysozyme in rice plants. To further clarify the antiviral function of lysozyme within the vector insect, this example uses electric leafhoppers carrying RGDV or RSMV as the research object, and verifies the in vivo antiviral activity of lysozyme through microinjection combined with viral load detection.

[0052] Experimental Materials and Processing Preparation of lysozyme working solution: Take each lysozyme obtained by purification in Example 1 and prepare a working solution with a concentration of 1 mg / mL using PBS buffer (pH 7.5).

[0053] Electro-infected leafhopper treatment: Third-instar nymphs of the electro-infected leafhopper were selected and placed in rearing cages containing rice plants infected with RGDV or RSMV. The nymphs were fed with the virus for 4 days under artificial climate conditions (28℃, relative humidity 60-70%, 14L:10D). After the treatment, the infected leafhoppers were transferred to healthy Taichung No. 1 rice seedlings and reared for another 3 days. The insects were then collected for subsequent experiments.

[0054] Microinjection treatment: After anesthetizing virus-carrying electric leafhoppers with CO2, 46 nL of lysozyme working solution was injected into their thorax using a Nanoject III microinjection system. Each lysozyme treatment group had more than 30 biological replicates, with an equal volume of PBS buffer injected as a negative control and an equal volume of chicken egg white lysozyme (HEWL) injected as a reference control.

[0055] Viral load detection Seventy-two hours after injection, individual *Leechia spp.* from each treatment group were collected, and total RNA was extracted using the TRIzol method. 1 μg of total RNA was used as a template for reverse transcription to obtain cDNA. *Leechia spp.* elongation factor 1 (… EF1 The gene was used as an internal control, and RT-qPCR was performed using the specific primers listed in Table 5. Three technical replicates were set up for each sample, using 2... -ΔΔCt Method for calculating viral genome (RGDV) P8 or RSMV N The relative expression levels of lysozyme were analyzed, using the PBS control group without lysozyme injection as a baseline, to assess the effect of lysozyme treatment on viral replication in the electric leafhopper.

[0056] RT-qPCR results showed that, compared with the PBS and HEWL control groups, injection of RdLYZI1, RdLYZC1, or RdLYZC2 significantly reduced the viral load of RGDV and RSMV in the electric leafhopper; while the viral load in the RdLYZI2 treatment group showed no significant change. Figure 6 , Figure 7 The results showed that RdLYZI1, RdLYZC1, and RdLYZC2 still possessed the activity of inhibiting viral replication in the vector insects.

[0057] Example 3: Detection of antiviral ability of lysozyme from infected white-backed planthoppers To further explore the broad-spectrum resistance of this type of lysozyme to different rice virus-vector insect systems, this example selected Southern Rice Black-Streaked Dwarf Virus (SRBSDV) and its main vector, the White-backed Planthopper, as research subjects, and systematically evaluated the antiviral function of lysozyme in this vector insect.

[0058] (1) Experimental materials and treatment Preparation of lysozyme working solution: Take each lysozyme obtained by purification in Example 1 and prepare a working solution with a concentration of 1 mg / mL using PBS buffer (pH 7.5).

[0059] White-backed planthopper poisoning treatment: Third-instar white-backed planthopper nymphs were selected and placed in rearing cages containing SRBSDV-infected rice plants. They were poisoned for 4 days in an artificial climate chamber (28℃, relative humidity 60-70%, 14L:10D). After poisoning, the infected leafhoppers were transferred to healthy Taichung No. 1 rice seedlings and reared for another 3 days. The insects were then collected for subsequent experiments.

[0060] Microinjection treatment: After anesthetizing virus-carrying white-backed planthoppers with CO2, 46 nL of lysozyme working solution was injected into their thorax using a Nanoject III microinjection system. Each lysozyme treatment group had at least 30 biological replicates, with an equal volume of PBS buffer injected as a negative control and an equal volume of chicken egg white lysozyme (HEWL) injected as a reference control.

[0061] (2) Viral load detection Seventy-two hours after injection, individuals of the white-backed planthopper from each treatment group were collected, and total RNA was extracted using the TRIzol method. 1 μg of total RNA was used as a template for reverse transcription to obtain cDNA. Using the white-backed planthopper... EF1 The gene was used as an internal control, and the Ct value of the SRBSDV P10 gene was detected using the specific primers listed in Table 5. Two [tests were conducted]. -ΔΔCt The relative viral load was calculated using a method to analyze the effect of lysozyme treatment on viral replication in white-backed planthoppers.

[0062] The results are as follows Figure 8 As shown, compared with the PBS and HEWL control groups, injection of RdLYZI1, RdLYZC1, or RdLYZC2 significantly reduced the viral load of SRBSDV in the white-backed planthopper; while the viral load in the RdLYZI2 treatment group showed no significant change. These results indicate that the three lysozymes are effective not only in the RGDV / RSMV-electro-photonic leafhopper system but also possess significant antiviral activity in the SRBSDV-white-backed planthopper system, further confirming the broad-spectrum antiviral function and vector adaptability of these lysozymes.

[0063] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall be covered by the present invention.

Claims

1. An insect lysozyme, characterized in that: The insect lysozyme has any of the following amino acid sequences: (1) Lysozyme RdLYZI1 with an amino acid sequence as shown in SEQ ID NO.13; (2) Lysozyme RdLYZI2 with the amino acid sequence shown in SEQ ID NO.14; (3) Lysozyme RdLYZC1 with the amino acid sequence shown in SEQ ID NO.15; (4) Lysozyme RdLYZC2 with an amino acid sequence as shown in SEQ ID NO.

16.

2. A nucleic acid molecule encoding the insect lysozyme as described in claim 1, characterized in that: The nucleotide sequences of the nucleic acid molecules are shown in SEQ ID NO.1~4 in sequence.

3. Expression cassettes, recombinant vectors, recombinant cells, and recombinant microorganisms containing the nucleic acid molecules as described in claim 2.

4. A product for preventing and controlling rice viral diseases, characterized in that: Its active ingredient is the insect lysozyme of claim 1, or the nucleic acid molecule of claim 2, or the expression cassette, recombinant vector, recombinant cell and recombinant microorganism of claim 3.

5. The product according to claim 4, characterized in that: The rice viral diseases mentioned include rice gall dwarf virus, rice stripe mosaic virus, and southern rice black-streaked dwarf virus.

6. The product according to claim 4, characterized in that: The product can effectively inhibit the replication and accumulation of rice virus in rice plants and virus-carrying insects, and restore rice plant growth disorders caused by rice virus.

7. The product according to claim 6, characterized in that: The vector insect is either the electric leafhopper or the white-backed planthopper.

8. The use of the insect lysozyme of claim 1, the nucleic acid molecule of claim 2, or the expression cassette of the nucleic acid molecule of claim 3, the recombinant vector, the recombinant cell, and the recombinant microorganism in the preparation of any of the following products: (1) Products resistant to rice viruses; (2) Products for the prevention and control of rice viral diseases; (3) Products that inhibit the replication of rice viruses in their vector insects.

9. The application according to claim 8, characterized in that: The rice viral diseases mentioned include rice gall dwarf disease, rice stripe mosaic virus, and southern rice black-streaked dwarf disease, and the vector insects are electric leafhoppers or white-backed planthoppers.

10. The application according to claim 8, characterized in that: The product is applied by soaking the roots of infected rice or by soaking rice seedlings before transplanting, and the concentration of the product is 0.5~4 mg / mL.

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