Application of brown planthopper NlP21 protein and coding gene thereof in regulation and control of brown planthopper resistance of plants

Abstract

The invention provides application of brown planthopper NlP21 protein and a coding gene thereof in regulation and control of brown planthopper resistance of plants, and belongs to the technical field of gene engineering. The invention provides a brown planthopper NlP21 protein and a sequence of a coding gene thereof. The gene is of great significance in regulating and controlling the resistance of plants to brown planthoppers and regulating and controlling the growth of the brown planthoppers. The viability of the brown planthopper can be effectively reduced by inhibiting the expression of the NlP21 gene in the brown planthopper, and the resistance of the plant to the brown planthopper can be effectively improved by overexpressing the NlP21 gene in the plant. The nilaparvata lugens NlP21 protein and the coding gene thereof provided by the invention have good application prospects, and have great application values for reducing pesticide use, maintaining ecological balance and realizing sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of genetic engineering, and in particular to application of brown planthopper N1P21 protein and its encoding gene in regulating plant resistance to brown planthopper. Background Art

[0002] Brown planthopper is a long-distance migratory pest with strong explosiveness and harmfulness. It often lives in groups at the base of rice plants, sucking sap, causing the plants to wilt and die, resulting in reduced or even total crop failure, seriously affecting rice yield and quality. It is currently the primary pest in rice production. Brown planthoppers cause a reduction in rice production of approximately 1 to 1.5 billion kilograms each year, equivalent to tens of billions of yuan in economic losses. At present, pesticides are generally used to control brown planthoppers. However, the long-term excessive use of chemical pesticides not only makes the environment worse, but also produces pesticide residues, seriously endangering human health and causing serious environmental pollution. Therefore, it is of great significance to actively carry out research and application of biological control technology for brown planthoppers, implement scientific and effective control of the harm of brown planthoppers, and ensure food security and environmental safety.

[0003] RNA interference (RNAi) refers to a gene silencing phenomenon induced by double-stranded RNA (dsRNA) in molecular biology. Since RNAi technology can specifically eliminate or shut down the expression of specific genes, it has been widely used in the field of exploring gene function and disease treatment. Since its discovery, RNAi technology has developed rapidly and is currently widely used in insect gene research. The method of injecting in vitro synthesized dsRNA into specific parts of insects using a microinjector is called microinjection. Microinjection is one of the most commonly used introduction methods. This method has the advantage of being able to accurately control the injection volume. It can specifically observe the effect of reduced expression of specific genes on single brown planthoppers, which is of great help to the theoretical study of gene function. Using it to study brown planthopper genes is of great significance to ensuring my country's food security and environmental security. Summary of the invention

[0004] In view of the above deficiencies in the prior art, the present invention provides the use of brown planthopper N1P21 protein and its encoding gene in regulating plant resistance to brown planthopper.

[0005] To achieve the above purpose, the specific technical solutions of the present invention are as follows:

[0006] In a first aspect, the present invention provides the use of a brown planthopper N1P21 protein or a gene encoding it or an inhibitor of a gene encoding the brown planthopper N1P21 protein in regulating plant resistance to brown planthoppers, wherein the amino acid sequence of the N1P21 protein is (a) or (b):

[0007] (a) the amino acid sequence shown in SEQ ID NO. 1;

[0008] (b) an amino acid sequence represented by SEQ ID NO. 1 in which one or more amino acids are substituted, deleted and / or added, and which has the same function as the protein composed of the amino acid sequence represented by SEQ ID NO. 1;

[0009] The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by replacing, deleting and / or adding one or more nucleotides, and a nucleotide sequence that expresses the same protein as the nucleotide sequence shown in SEQ ID NO. 2.

[0010] Furthermore, the method of improving the resistance of plants to brown planthoppers comprises: overexpressing the gene encoding the brown planthopper N1P21 protein in the plants.

[0011] In a second aspect, the present invention provides an application of an inhibitor of a gene encoding a N1P21 protein of a brown planthopper in inhibiting the growth of the brown planthopper. The inhibitor of a gene encoding a N1P21 protein of a brown planthopper is a dsRNA capable of inhibiting the expression of a gene encoding a N1P21 protein of a brown planthopper. The nucleotide sequence of the dsRNA is shown in SEQ ID NO.3.

[0012] Furthermore, the method of inhibiting the growth of brown planthoppers comprises inhibiting the expression of a gene encoding the N1P21 protein in brown planthoppers.

[0013] In a third aspect, the present invention provides a dsRNA for inhibiting the expression of a gene encoding a NlP21 protein of brown planthopper, wherein the gene encoding the NlP21 protein comprises a nucleotide sequence as shown in SEQ ID NO. 2; or, comprises a nucleotide sequence as shown in SEQ ID NO. 2 in which one or more nucleotides are replaced, deleted and / or added, and expresses the same protein as the nucleotide sequence as shown in SEQ ID NO. 2;

[0014] The dsRNA comprises the nucleotide sequence shown in SEQ ID NO. 3.

[0015] In a fourth aspect, the present invention provides a method for improving the resistance of rice to brown planthoppers, comprising: overexpressing a gene encoding a brown planthopper NlP21 protein in the rice; the gene encoding the NlP21 protein comprises the nucleotide sequence shown in SEQ ID NO. 2; or, comprises a nucleotide sequence in which the nucleotide sequence shown in SEQ ID NO. 2 is replaced, deleted and / or one or more nucleotides are added, and expresses the same protein as the nucleotide sequence shown in SEQ ID NO. 2.

[0016] In a fifth aspect, the present invention provides a method for preparing transgenic rice with resistance to brown planthoppers, and adopts the method for improving the ability of rice to resist brown planthoppers to cultivate transgenic rice with resistance to brown planthoppers.

[0017] In a sixth aspect, the present invention provides a method for inhibiting the growth of brown planthoppers, comprising: inhibiting the expression of a gene encoding a brown planthopper NlP21 protein in brown planthoppers; the gene encoding the NlP21 protein comprises the nucleotide sequence shown in SEQ ID NO. 2; or, comprises a nucleotide sequence in which the nucleotide sequence shown in SEQ ID NO. 2 is replaced, deleted and / or one or more nucleotides are added, and expresses the same protein as the nucleotide sequence shown in SEQ ID NO. 2.

[0018] Furthermore, the method for inhibiting the growth of brown planthoppers is to inhibit the expression of the gene encoding the brown planthopper NlP21 protein in the brown planthopper by dsRNA; the dsRNA includes the nucleotide sequence shown in SEQ ID NO.3.

[0019] In a seventh aspect, the present invention provides a biological material, which is an expression cassette, a vector or a transgenic cell; the biological material includes a gene encoding the NlP21 protein of the brown planthopper, or includes the dsRNA.

[0020] Compared with the prior art, the present invention is beneficial in that:

[0021] 1. The present invention discloses the nucleotide sequence of the NIP21 gene of brown planthopper for the first time. Currently, there is no relevant report on the function of inhibiting its expression to significantly affect the growth and development of brown planthopper.

[0022] 2. According to the cDNA sequence of the NlP21 gene of brown planthopper, the present invention adopts the RNAi technology of microinjection of dsRNA to silence the NlP21 gene of brown planthopper, resulting in a lethal effect on brown planthopper. As time goes by, the survival rate becomes lower and lower; obviously, the dsRNA of this gene and its corresponding expression cassette, recombinant vector or recombinant bacteria and other products have important application value in the field of brown planthopper control.

[0023] 3. The present invention constructs an overexpression genetic transformation vector for the NlP21 gene of brown planthopper. Experiments show that when the vector is transferred into rice plants that are hosts of brown planthoppers, the rice's resistance to brown planthoppers is greatly improved. After brown planthoppers feed on the transgenic material, the insect weight gain and survival rate of brown planthoppers are reduced, indicating that the vector plays an important role in improving the resistance to brown planthoppers. The present invention is of great significance for cultivating insect-resistant plants, has a good application prospect, and has great application value for reducing the use of pesticides, maintaining ecological balance and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The cloning result of the NlP21 gene provided in Example 1 of the present invention; wherein the first lane is the marker, the second lane is the NlP21 ORF; the third lane represents the NlP21 ORF sequence after the signal peptide is removed;

[0025] Figure 2 The agarose gel electrophoresis diagram of dsNlP21 and dsGFP provided in Example 2 of the present invention;

[0026] Figure 3 The relative expression analysis results of the NlP21 gene after microinjection provided in Example 3 of the present invention; wherein, CK is the uninjected brown planthopper, dsGFP is the brown planthopper injected with dsGFP, and 1-5 are the brown planthoppers injected with NlP21 for different days; different lowercase letters (a, b, c) indicate P<0.05, reaching significant differences;

[0027] Figure 4 The results of the analysis of the survival rate and weight gain of brown planthoppers after microinjection provided in Example 4 of the present invention; wherein, Figure 4 A shows the result of placing brown planthoppers on rice after microinjection and counting the survival rate of brown planthoppers every day; Figure 4 B is the injected brown planthopper, after it emerges into an adult, the weight gain of the female insects is measured within two days;

[0028] Figure 5 The brown planthopper feeding control Nipponbare and Nipponbare provided in Example 6 of the present invention NlP21 Plant phenotypic analysis results; Figure 5 A is wild type Nipponbare and Nipponbare NlP21 Analysis results of NlP21 expression in plants; Figure 5 B is the identification result of the resistance of the NlP21 overexpressing transgenic T2 positive strain to brown planthopper at the seedling stage; Figure 5 C represents brown planthoppers feeding on transgenic plants, including the parent plants Nipponbare and Nipponbare NlP21 The results of insect weight gain analysis of transgenic plants after two days; Figure 5 D shows brown planthoppers feeding on transgenic plants, including the parent plants Nipponbare and NipponbareNlP21 Analysis results of the survival rate of brown planthoppers within ten days after transgenic plants. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In a first aspect, the present invention provides the use of a brown planthopper N1P21 protein or a gene encoding it or an inhibitor of a gene encoding the brown planthopper N1P21 protein in regulating plant resistance to brown planthoppers, wherein the amino acid sequence of the N1P21 protein is (a) or (b):

[0031] (a) the amino acid sequence shown in SEQ ID NO. 1;

[0032] (b) an amino acid sequence represented by SEQ ID NO. 1 in which one or more amino acids are substituted, deleted and / or added, and which has the same function as the protein composed of the amino acid sequence represented by SEQ ID NO. 1;

[0033] The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by replacing, deleting and / or adding one or more nucleotides, and a nucleotide sequence that expresses the same protein as the nucleotide sequence shown in SEQ ID NO. 2.

[0034] In a second aspect, the present invention provides an application of an inhibitor of a gene encoding a N1P21 protein of a brown planthopper in inhibiting the growth of the brown planthopper. The inhibitor of a gene encoding a N1P21 protein of a brown planthopper is a dsRNA capable of inhibiting the expression of a gene encoding a N1P21 protein of a brown planthopper. The nucleotide sequence of the dsRNA is shown in SEQ ID NO.3.

[0035] Example 1

[0036] Cloning of N1P21 gene from Nilaparvata lugens

[0037] Twenty heads of biotype 1 brown planthoppers were taken, total RNA was extracted, and then reversed into cDNA. Primers were designed based on the sequence, and the 5' and 3' RACE kits of TaKaRa were used to obtain the 5' and 3' end sequences of the candidate gene, determine the transcription start site and stop site of the candidate gene, and splice the full-length cDNA sequence of the gene. Primers NlP21-F and NlP21-R were resynthesized based on the full-length cDNA sequence, and the full-length cDNA of NlP21 was amplified and the ORF was predicted. The ORF sequence is shown in the sequence table SEQ ID NO.1 ( Figure 1 ).

[0038] NlP21-F: 5'-ATGGTTACTCAGATCAGTTG-3'; as shown in SEQ ID NO. 4;

[0039] NlP21-R:5'-TTAGGGACACATAACAACGT -3'; as shown in SEQ ID NO. 5.

[0040] Example 2

[0041] Preparation of dsRNA (dsNlP21) for silencing the NlP21 gene of brown planthopper and the green fluorescent protein GFP gene dsGFP for control

[0042] 1. Using the cDNA obtained in Example 1 as a template, PCR amplification was performed using dsNlP21-F and dsNlP21-R as primers to obtain a PCR amplification product.

[0043] dsNlP21-F (forward primer): 5'-TAATACGACTCACTATAGGGAGATTCTGGGCCCGCACCGGTTGC-3'; as shown in SEQ ID NO. 6;

[0044] dsNlP21-R (reverse primer): 5'-TAATACGACTCACTATAGGGAGAGTCCTTGGCGTAGCTGTAGGC-3'; as shown in SEQ ID NO. 7;

[0045] The underlined region is the T7 RNA polymerase promoter sequence.

[0046] 2. Use the plasmid containing GFP as a template and dsGFP-F and dsGFP-R as primers to perform PCR amplification to obtain the PCR amplification product.

[0047] dsGFP-F (forward primer): 5'-TAATACGACTCACTATAGGGCGGACT-3'; as shown in SEQ ID NO. 8;

[0048] dsGFP-R (reverse primer): 5'-TAATACGACTCACTATAGGGCGATGC-3'; as shown in SEQ ID NO. 9;

[0049] The underlined region is the T7 RNA polymerase promoter sequence.

[0050] 3. The amplified product was recovered, A was added, and ligated to the pMD18-T (TAKARA) vector. The positive clone was sent for sequencing. The correct clone was obtained, and the clone plasmid was used as a template for amplification using the above primers. The amplified product was purified and concentrated to a concentration of 1 μg / μL. The product was used as a template for dsRNA synthesis.

[0051] 4. Add the following reagents into a 200 μL centrifuge tube in proportion. The system is as follows:

[0052]

[0053] Flick to mix, centrifuge briefly. Place in PCR, program: 37 ℃, 4 h; 75 ℃, 5 min; store at 16 ℃. Aspirate 1 μL, detect by gel electrophoresis, and proceed to the next step after the target band is detected.

[0054] 5. Add the following reagents to the above centrifuge tube to remove DNA and ssRNA:

[0055]

[0056] Mix thoroughly, centrifuge briefly, and place in a PCR instrument at 37°C for 30 min. Then take out and add 1 μL of EDTA (Fementas), and continue to place back in the PCR instrument at 65°C for 5 min to terminate the reaction. Aspirate 1 μL, dilute 10 times, detect 2 μL by gel electrophoresis, and detect the concentration of 2 μL using a NANOdrop UV spectrophotometer. If the detection band is a single bright band, such as Figure 2 As shown, and OD260 / 280 is between 1.8-2.0, it means that the dsRNA quality is good and the next step: RNA phenol-chloroform extraction can be carried out.

[0057] 6. Perform routine phenol-chloroform extraction to remove proteins, adjust the dsRNA concentration to 5 μg / μL, dispense 10 μL into each tube, and store at -80°C.

[0058] Example 3

[0059] Microinjection of dsNlP21 and dsGFP and effect detection

[0060] 1. Preparation of brown planthoppers: 30 females and 10 males were placed in a cup with TN1 seedlings. After 24 hours, the adults were taken out. After hatching, the fourth-instar nymphs were obtained after 20 days and were used for injection.

[0061] 2. Plate preparation: Weigh 1.5 g of agar powder and add it to 100 mL of water. Bring to a boil and pour into a glass plate. Wait for it to solidify and set aside.

[0062] 3. Injection: Take 5-8 insects of similar growth and place them in a test tube. Anesthetize them with CO2 for 20 seconds. Then pour the insects onto a 1.5% agar plate with the abdomen facing upward. Use Nanoliter 2010 microinjector to perform injection according to the instructions. The injection position is between the anterior and mid-thorax. The injection volume is 46 nL (5μg / μL).

[0063] 4. After the brown planthoppers were injected with dsRNA, sampling was started from the first day after injection, with three samples taken every day for 5 days. At the same time, the brown planthoppers without injection and injected with dsGFP were taken as controls, and the changes in gene expression were verified by qRT-PCR.

[0064] The specific operation is as follows: After sampling, RNA is extracted and reversed according to the instructions of TAKARA's PrimeScript RT reagent Kit with gDNA Eraser (Cat. No. RR047A) to obtain the reversed product. Take 5 μL of the cDNA obtained by reversed, dilute it 10 times with TE, and perform real-time quantitative PCR according to the following operation. The PCR reaction is carried out on the CFX96 TouchTM Real-Time PCRDetection System (Bio-Rad) instrument, following the following reaction system:

[0065]

[0066] Reaction conditions: 95 ℃ pre-denaturation for 2 min, 95 ℃ denaturation for 5-10 s, TM (55-65 ℃) annealing extension for 30 s, repeat the latter two steps for 40 cycles, and finally 65 ℃-95 ℃, increase 0.5 ℃ each step, and make a melting curve for 5 s to determine the specificity of the amplified product. Each sample was repeated 3 times, and the amplification efficiency was calculated for each PCR plate. The results were analyzed using Bio-Rad CFXManager. First, the melting curve, QC (quality control), etc. were analyzed to remove unqualified data. The Gene Study function of the software for gene expression analysis is (1+E) -ΔΔCt Algorithm analysis.

[0067] Primers for internal reference gene actin:

[0068] Actin-F: 5'-GACAGGATGCAGAAGGAAATCA-3'; as shown in SEQ ID NO. 10;

[0069] Actin-R: 5'-GACTCGTCGTACTCCTGCTTTG-3'; as shown in SEQ ID NO. 11;

[0070] NlP21 quantitative primers:

[0071] NlP21-1F: 5'-ATCCAACCGACCAACAACCA-3'; as shown in SEQ ID NO. 12;

[0072] NlP21-1R: 5′-CAGTACAAGTCTCCGCCGAA-3′; as shown in SEQ ID NO. 13.

[0073] 5. Results Figure 3 As shown in the figure, the relative expression of NlP21 gene in the experimental group injected with dsNlP21 was significantly reduced from the first day of injection compared with the uninjected brown planthopper and the control group injected with dsGFP, and there was a significant difference compared with the control (P<0.05). The results showed that microinjection of dsNlP21 could induce RNAi effect of salivary gland secretion gene NlP21 in brown planthopper, resulting in a significant decrease in gene expression.

[0074] Example 4

[0075] Phenotypic detection of brown planthopper after microinjection

[0076] Brown planthopper survival rate experiment: Brown planthoppers were divided into three groups: uninjected, injected with dsGFP, and injected with dsNlP21. After injection, they were allowed to recover and then placed back on the rice. Ten insects were selected each time and repeated 5 times. The results are shown in the figure. Figure 4 As shown in A, the survival rate of brown planthoppers injected with dsNlP21 was significantly lower than that of brown planthoppers injected with dsGFP and without injection from the third day after injection.

[0077] Brown planthopper weight gain experiment: After the injection, the brown planthoppers were placed back on the rice and waited for them to emerge. The brown planthoppers that emerged on the first day were weighed individually and then placed in a wax bag tied to the rice seedlings. After two days, the surviving brown planthoppers were removed and weighed again. The difference between the two weights was recorded as the insect weight gain. Ten insects were tested each time and repeated 5 times. Figure 4 As shown in Figure B, the weight gain of newly emerged brown planthoppers within 48 hours was analyzed, and it was found that the weight gain of the insects decreased after the injection of dsNlP21. The results show that after the injection of dsNlP21, the expression of this gene was reduced, which affected the feeding of brown planthoppers and thus affected the survival rate of brown planthoppers.

[0078] Example 5

[0079] Construction of Genetic Transformation Vector for Overexpression of NlP21 Gene in Brown Planthopper

[0080] 1. ORF sequence amplification (remove the signal peptide segment): use high-fidelity enzyme KOD Plus Neo (TOYOBO) and primer NlP21 -SP -F and NlP21 -SP -R, the template is a plasmid containing the NlP21 gene, and the ORF sequence of the NlP21 gene is amplified.

[0081] NlP21 -SP -F: 5'-ATGGTGAAACTCTCGATAGT-3'; as shown in SEQ ID NO. 14;

[0082] NlP21 -SP -R: 5'-GGGACACATAACAACGTCGT-3'; as shown in SEQ ID NO. 15.

[0083] 2. After PCR is completed, take 2 μL for agarose gel electrophoresis. If the band is single, directly recover it; if there is a miscellaneous band, cut the gel to recover the target size fragment, which is about 0.7 kb. Since there is no A tail at the end of the KOD PLUS NEU amplified fragment, it is necessary to add A before connecting to the vector.

[0084] 3. The pCXUN vector was digested with Xcm I to form a T terminus, which was then connected to the A-added product at 16°C overnight. After transformation, a single clone was selected. The vector primers were UBIS and UBIA. The size of the inserted fragment was verified by PCR. The fragment of about 1 kb was sent to the company for sequencing.

[0085] UBIS: 5'-TGTTTCTTTTGTCGATGCTCACCC-3'; as shown in SEQ ID NO. 16;

[0086] UBIA: 5′-TTCTATCGCGGCTTAACGTAATTCA-3′; as shown in SEQ ID NO. 17.

[0087] 4. The correctly sequenced vector plasmid was transferred into Agrobacterium strain EHA105 by conventional electroporation.

[0088] Example 6

[0089] Functional verification of transgene after NlP21 overexpression

[0090] 1. Obtaining transgenic plants overexpressing NlP21 mediated by Agrobacterium

[0091] The genetic transformation method mediated by Agrobacterium EHA105 (Hiei et al., 1994, Efficient transformation of rice ( Oryza sativa L.)mediated by Agrobacterium and sequence analysis of the boundaries of the T-DNA. Plant Journal 6:271-282) and the above-mentioned NlP21 overexpression genetic transformation vector was introduced into Nipponbare.

[0092] 2. Brown planthoppers feed on Nipponbare NlP21 Phenotypic verification of transgenic plants

[0093] After harvesting the seeds, the T2 generation homozygous transgenic plants Nipponbare NlP21 , Nipponbare NlP21 The expression of NlP21 gene in the culture medium was detected by quantitative PCR, the primers were NlP21-1F, NlP21-1R, the internal reference was Osactin, the primers were Osactin-F, Osactin-R. Figure 5 As shown in A, the NlP21 gene accumulated in large quantities in the transgenic plants.

[0094] NlP21-1F: 5'-ATCCAACCGACCAACAACCA-3'; as shown in SEQ ID NO. 18;

[0095] NlP21-1R: 5'-CAGTACAAGTCTCCGCCGAA-3'; as shown in SEQ ID NO. 19;

[0096] Osactin-F: 5'-GATCACTGCCTTGGCTCCTA-3'; as shown in SEQ ID NO. 20;

[0097] Osactin-R: 5'-GTACTCAGCCTTGGCAATCC-3'; as shown in SEQ ID NO. 21;

[0098] The positive transgenic lines were identified for resistance to brown planthoppers using the seedling group method. Ten days after inoculation with brown planthoppers, the entire control variety Nipponbare died, while the positive transgenic lines carrying the overexpression vector of the gene NlP21 still survived, indicating that the gene NlP21 has the function of enhancing rice resistance to brown planthoppers ( Figure 5 Therefore, the brown planthopper gene NlP21 can be used in rice to breed rice varieties with brown planthopper resistance.

[0099] Twenty second-instar brown planthoppers of biotype I fed on Nipponbare and Nipponbare NlP21 , the survival rate of insects according to the number of days, repeated five times. The results are as follows Figure 5 As shown in C, due to the transgenic plant Nipponbare NlP21 The increased resistance affected the feeding of brown planthoppers, causing a significant decrease in their survival rate on the 10th day.

[0100] The newly emerged female adults of biotype I were reared in Nipponbare NlP21 and Nippon Haru NlP21 Two days later, weigh the worms, 10 each time. Repeat three times. Figure 5 As shown in D, the insect weight of brown planthopper was also significantly reduced. The above results indicate that the gene NlP21 can improve the resistance of rice to brown planthopper.

[0101] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, the technical solution of the present invention can be modified and changed in many simple ways, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. Application of brown planthopper N1P21 protein or its encoding gene in improving rice resistance to brown planthopper, characterized in that: The amino acid sequence of the NlP21 protein is (a) or (b): (a) the amino acid sequence shown in SEQ ID NO. 1; (b) an amino acid sequence represented by SEQ ID NO. 1 in which one or more amino acids are substituted, deleted and / or added, and which has the same function as the protein composed of the amino acid sequence represented by SEQ ID NO. 1; The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by replacing, deleting and / or adding one or more nucleotides, and a nucleotide sequence that expresses the same protein as the nucleotide sequence shown in SEQ ID NO.

2.

2. The use of the brown planthopper N1P21 protein or its encoding gene according to claim 1 in improving the resistance of rice to brown planthopper, characterized in that: The method of improving the resistance of plants to brown planthoppers is: overexpressing the coding gene of the brown planthopper N1P21 protein in the plants.

3. The use of an inhibitor of a gene encoding N1P21 protein of brown planthopper in inhibiting the growth of brown planthopper, characterized in that: The inhibitor of the gene encoding the N1P21 protein of brown planthopper is a dsRNA capable of inhibiting the expression of the gene encoding the N1P21 protein of brown planthopper; the nucleotide sequence of the dsRNA is shown in SEQ ID NO.

3.

4. The use of the inhibitory factor of the gene encoding the N1P21 protein of brown planthopper according to claim 3 in inhibiting the growth of brown planthopper, characterized in that: The method of inhibiting the growth of brown planthoppers comprises inhibiting the expression of the gene encoding the N1P21 protein in brown planthoppers.

5. A dsRNA for inhibiting the expression of a gene encoding N1P21 protein of brown planthopper, characterized in that: The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by substitution, deletion and / or addition of one or more nucleotides, and a nucleotide sequence expressing the same protein as the nucleotide sequence shown in SEQ ID NO. 2; The dsRNA comprises the nucleotide sequence shown in SEQ ID NO.

3.

6. A method for improving the resistance of rice to brown planthoppers, characterized in that: include: Overexpressing a gene encoding a brown planthopper N1P21 protein in the rice; The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by replacing, deleting and / or adding one or more nucleotides, and a nucleotide sequence that expresses the same protein as the nucleotide sequence shown in SEQ ID NO.

2.

7. A method for preparing transgenic rice with resistance to brown planthoppers, characterized in that: The method for improving the resistance of rice to brown planthoppers as claimed in claim 6 is used to cultivate transgenic rice with resistance to brown planthoppers.

8. A method for inhibiting the growth of brown planthopper, characterized in that: include: Inhibit the expression of the gene encoding the NlP21 protein in brown planthoppers; The gene encoding the NlP21 protein includes the nucleotide sequence shown in SEQ ID NO. 2; or, includes the nucleotide sequence shown in SEQ ID NO. 2 by replacing, deleting and / or adding one or more nucleotides, and a nucleotide sequence that expresses the same protein as the nucleotide sequence shown in SEQ ID NO.

2.

9. A method for inhibiting the growth of brown planthopper according to claim 8, characterized in that: The expression of the gene encoding the PIB14 protein of the brown planthopper is inhibited by dsRNA; the nucleotide sequence of the dsRNA is shown in SEQ ID NO.

3.

10. A biomaterial, characterized in that: The biological material is an expression box, a vector or a transgenic cell; the biological material includes a gene encoding the NlP21 protein of the brown planthopper, or includes the dsRNA.

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