Application of taf12b gene or homologous gene in antiviral

Abstract

The application belongs to the technical field of biology and particularly relates to functions of a TAF12b gene and a protein coded by the TAF12b gene and application of the TAF12b gene in plant antiviral activity. Overexpression of the TAF12b gene or a homologous gene thereof can increase the antiviral activity of a plant. The TAF12b gene or the homologous gene thereof includes a NbTAF12b gene derived from Nicotiana benthamiana, a homologous gene SlTAF12b derived from Solanum lycopersicum and a homologous gene OsTAF12b derived from Oryza sativa. The application finds that overexpression of the TAF12b gene can effectively resist viral infection and significantly reduce the viral accumulation in a plant by introducing the TAF12b gene into a target plant such as the Nicotiana benthamiana and the Solanum lycopersicum.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to the function of the TAF12b gene and its encoded protein and its application in plant antiviral therapy. Background Technology

[0002] Plant viruses are a large class of pathogens that are extremely harmful to grain and oil crops such as corn, rice, wheat, and soybeans, as well as cash crops such as vegetables, tomatoes, tobacco, cotton, pumpkins, and waxberries, and medicinal plants such as *Trifolium repens*, *Paris polyphylla*, *Solanum nigrum*, and *Solanum lyratum*. Because of their rapid spread and the difficulty in controlling once infection occurs, they are often referred to as the "cancer" of plants. Plants infected with viruses often exhibit symptoms such as yellowing, mosaic patterns, necrotic spots, necrosis, stunting, and deformities.

[0003] Currently, the control of viral diseases in agricultural production mainly relies on chemical methods such as pesticides. However, the large-scale spraying of pesticides not only increases production costs but also pollutes the ecological environment and harms health, which is inconsistent with the concept of green, environmentally friendly, healthy, and sustainable development. Utilizing antiviral functional genes to cultivate antiviral varieties is one of the most economical and effective strategies for controlling plant viral diseases, but the discovery and utilization of antiviral functional genes are still very limited.

[0004] TAFs (TATA-box binding protein associated factors) are important subunits of the universal transcription factor TFIID complex, widely distributed in plants and animals. Current limited research indicates that TAFs play important roles in plant growth and development and responses to abiotic stress, but their role in plant virus infection remains unclear. Reports show that TAF12b can participate in hormone signaling pathways and unfolded protein responses; in patent CN116479009A, the TAF12b gene was found to regulate the size of plant fruits and seeds. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an application of the TAF12b gene or its homologous gene and its encoded protein in antiviral therapy.

[0006] To address the aforementioned technical problems, this invention provides the application of the TAF12b gene or its homologous gene in plant antiviral activity.

[0007] As an improvement to the application of this invention: overexpression of the TAF12b gene or its homologous gene can increase the antiviral properties of plants.

[0008] As a further improvement to the application of the present invention: the TAF12b gene or its homologous gene includes:

[0009] The NbTAF12b gene from Nicotiana benthamiana, the SlTAF12b homolog from tomato, and the OsTAF12b homolog from rice (preferably the NbTAF12b and SlTAF12b genes).

[0010] The nucleotide sequences of the TAF12b gene or its homologs have been published in patent application CN116479009A. The nucleotide sequence of the OsTAF12b gene is shown in SEQ ID NO:1 or SEQ ID NO:3; the nucleotide sequence of the SlTAF12b gene is shown in SEQ ID NO:5; and the nucleotide sequence of the NbTAF12b gene is shown in SEQ ID NO:7.

[0011] As a further improvement to the application of the present invention:

[0012] The virus in question is a plant virus;

[0013] The plants mentioned are grain and oil crops, economic crops, and medicinal plants, including dicotyledonous or monocotyledonous plants.

[0014] As a further improvement to the application of the present invention:

[0015] The plant viruses mentioned are tomato yellow leaf curl virus (TYLCV) (preferred), Chinese tomato yellow leaf curl virus (TYLCCNV), New Delhi tomato leaf curl virus (ToLCNDV), etc.

[0016] Grain and oil crops include corn, rice, wheat, and soybeans; cash crops include tomatoes (preferred), tobacco, cotton, pumpkin, and bayberry; and medicinal plants include trifoliate orange, Paris polyphylla, Solanum nigrum, and Solanum lyratum.

[0017] This invention also provides the application of the protein encoded by the TAF12b gene (i.e., the TAF12b protein) in plant antiviral activity:

[0018] The TAF12b protein includes highly homologous proteins such as NbTAF12b protein and SlTAF12b protein, or proteins that have the same function by conserved substitution and / or deletion and / or addition of one or more amino acid residues in the amino acid sequence of homologous proteins such as NbTAF12b protein and SlTAF12b protein.

[0019] The amino acid sequence of the TAF12b protein has been published in patent application CN116479009A. The amino acid sequence of the protein encoded by the OsTAF12b gene is shown in SEQ ID NO:2 or SEQ ID NO:4; the amino acid sequence of the protein encoded by the SlTAF12b gene is shown in SEQ ID NO:6; and the amino acid sequence of the protein encoded by the NbTAF12b gene is shown in SEQ ID NO:8.

[0020] This invention also provides the application of recombinant vectors or recombinant host strains containing the TAF12b gene or homologous genes in plant antiviral activity.

[0021] The present invention also provides a method for cultivating virus-resistant TAF12b transgenic plants: using the TAF12b gene or its homologous gene as the target gene, constructing an overexpression vector of the target gene, transforming it into a plant, and cultivating the plant; thereby obtaining virus-resistant TAF12b transgenic plants.

[0022] An improvement to the method of cultivating the virus-resistant TAF12b transgenic plant of the present invention: Overexpression of the TAF12b gene in tobacco or tomato can significantly reduce the infection of viruses such as tomato yellow leaf curl virus (TYLCV).

[0023] The present invention is as follows:

[0024] In a first aspect, the present invention provides the application of the Nicotiana benthamiana NbTAF12b gene and its encoded protein in plant antiviral activity. The nucleotide sequence of the NbTAF12b gene and the amino acid sequence of the protein encoded by the gene have been published in patent application with publication number CN116479009A.

[0025] This invention also provides a method for cultivating virus-resistant TAF12b transgenic plants: the NbTAF12b gene of Nicotiana benthamiana is introduced into the target plant through Agrobacterium-mediated transformation to obtain NbTAF12b gene overexpressing plants.

[0026] This invention also provides the application of the tobacco NbTAF12b gene and its encoded protein in regulating plant antiviral resistance. The plants include, but are not limited to, *Nicotiana benthamiana*. The viruses are plant viruses, including but not limited to tomato yellow leaf curl virus (TYLCV). This application, through overexpression of the *Nicotiana benthamiana* NbTAF12b gene in target plants, can significantly resist viral infection and reduce diseases caused by viral infection.

[0027] Secondly, this invention provides the application of the tomato SlTAF12b gene and its encoded protein in plant antiviral activity. The nucleotide sequence of the SlTAF12b gene and the amino acid sequence of the protein encoded by the gene have been published in patent application with publication number CN116479009A.

[0028] This invention also provides a method for cultivating virus-resistant TAF12b transgenic plants: the tomato SlTAF12b gene is introduced into the target plant through Agrobacterium-mediated transformation to obtain SlTAF12b gene overexpressing plants.

[0029] This invention also provides the application of the tomato SlTAF12b gene and its encoded protein in regulating plant antiviral resistance. The plant includes, but is not limited to, tomato. The virus is a plant virus, including but not limited to Tomato Yellow Leaf Curl Virus (TYLCV). This application, through overexpression of the tomato SlTAF12b gene in target plants, can significantly resist viral infection and alleviate symptoms caused by viral infection.

[0030] It should be emphasized that most existing antiviral genes are R genes, possessing a typical TIR / CC-NBS-LRR domain; however, the TAF12b gene in this invention is a universal transcription factor cofactor and lacks the aforementioned domain. Therefore, existing technologies cannot provide technical guidance for this invention. The antiviral function of TAF12b and its homologs discovered in this invention can provide new gene resources for crop disease resistance breeding.

[0031] The purpose of this invention is to provide a TAF12b gene for crop antiviral breeding and its application in plant antiviral activity. This invention provides an application of the TAF12b gene and its encoded protein in plant antiviral activity. The TAF12b gene includes either the NbTAF12b gene derived from Nicotiana benthamiana or the homologous gene SlTAF12b derived from tomato.

[0032] To date, there have been no reports on the function of the TAF12b gene in plant antiviral processes. This invention reveals for the first time the function of the TAF12b gene in plant antiviral processes, providing new ideas and a new gene source for a deeper understanding of plant antiviral mechanisms and the improvement of plant antiviral traits.

[0033] This invention is the first to discover that the plant TAF12b gene is a novel antiviral gene. Overexpression of the TAF12b gene can significantly improve plant resistance to viruses, providing a theoretical basis and new gene resources for molecular design to improve crop disease resistance. It has great application value in the field of plant disease resistance breeding.

[0034] The NbTAF12b gene of Nicotiana benthamiana and the SlTAF12b gene of tomato provided by this invention can significantly reduce virus symptoms and enhance the antiviral function of plants.

[0035] In summary, this invention relates to the application of a novel plant antiviral gene, TAF12b, and its encoded protein in plant antiviral activity. By introducing the TAF12b gene into target plants such as Nicotiana benthamiana and tomato, this invention found that overexpression of TAF12b effectively resists viral infection and significantly reduces virus accumulation in plants. This invention is the first to discover that the TAF12b gene enhances plant antiviral function, providing a scientific basis and genetic resources for crop genetic improvement and the creation of new antiviral crop materials. Attached Figure Description

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] Figure 1 This is a schematic diagram of the construction of the pCV-NbTAF12b-3Flag overexpression vector in Example 1 of the present invention.

[0038] Figure 2 This is for the identification of the transgenic Nicotiana benthamiana plants overexpressing NbTAF12b in Example 1 of the present invention;

[0039] Figure 2 middle:

[0040] (A) Phenotype of NbTAF12b overexpressing transgenic lines, (B) qRT-PCR detection of the relative expression level of NbTAF12b gene in each line, (C) identification of NbTAF12b overexpressing transgenic lines using Flag-specific antibody, Rubisco is used to indicate consistent loading levels.

[0041] Among them, WT is wild-type Nicotiana benthamiana, while NbTAF12b-OE-L6 and NbTAF12b-OE-L33 are two different NbTAF12b transgenic lines.

[0042] Figure 3 This study analyzes the resistance of the NbTAF12b transgenic Nicotiana benthamiana to Tomato Yellow Leaf Curl Virus (TYLCV) in Example 1 of the present invention.

[0043] Figure 3 (A) Symptoms of TYLCV-inoculated wild-type and NbTAF12b transgenic Nicotiana benthamiana plants, with red arrows indicating TYLCV disease symptoms; (B) qRT-PCR analysis of virus accumulation in TYLCV-inoculated wild-type and NbTAF12b transgenic Nicotiana benthamiana plants.

[0044] Among them, WT is wild-type Nicotiana benthamiana, while NbTAF12b-OE-L6 and NbTAF12b-OE-L33 are two different NbTAF12b transgenic lines.

[0045] Figure 4 This is a schematic diagram of the construction of the pCV-SlTAF12b-3Flag overexpression vector in Example 2 of the present invention.

[0046] Figure 5 This study analyzes the resistance of transgenic tomato plants overexpressing SlTAF12b in Example 2 of the present invention to Tomato Yellow Leaf Curl Virus (TYLCV).

[0047] Figure 5 (A) Symptoms of TYLCV-inoculated wild-type and SlTAF12b transgenic tomatoes; (B) qRT-PCR detection of the relative expression level of the SlTAF12b gene in wild-type and SlTAF12b transgenic tomatoes; (C) qRT-PCR analysis of virus accumulation in TYLCV-inoculated wild-type and SlTAF12b transgenic plants.

[0048] Among them, WT is a wild-type tomato (Ailsa Craig), and SlTAF12b-OE-L1 and SlTAF12b-OE-L2 are two different SlTAF12b transgenic tomato lines. Detailed Implementation

[0049] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0050] Example 1: Overexpression of NbTAF12b gene enhances resistance of Nicotiana benthamiana to virus.

[0051] 1.1 Construction of NbTAF12b transgenic vector

[0052] 0.1g of tobacco leaves were collected, and RNA was extracted using the Trizol method. After removing genomic DNA, oligo(dT) was used. 18(5'-TTT TTT TTT TTT TTT TTT-3') primers were used for reverse transcription to obtain cDNA. Then, using this cDNA as a template, PCR amplification was performed using primer pairs NbTAF12b-F (GAC TCT AGA CCC CTG GGA TCC ATG GCG GAA ATT CCA TCT T) and NbTAF12b-R (TCC AAG GGC GAA TTG GTC GAC AAA TTT TGT CAT CTC ATG C) to obtain the full-length NbTAF12b gene (as shown in SEQ ID NO:7 of patent 2023103537258). Figure 1 As shown, the NbTAF12b gene was constructed into the binary transformation vector pCV-3Flag-N1 fused with a Flag tag using homologous recombination, resulting in the pCV-NbTAF12b-3Flag recombinant overexpression vector.

[0053] The above pCV-3Flag-N1 comes from the reference "Guo LM, Li J, Qi PP, Wang JB, Ghanem H, QingL*, Zhang HM*. The TATA-box binding protein-associated factor TAF12bfacilitates the degradation of type-B response regulators to negativelyregulate cytokinin signaling.Plant Communications. 2024, DOI: https: / / doi.org / 10.1016 / j.xplc.2024.101076.

[0054] 1.2 Agrobacterium-mediated genetic transformation of Nicotiana benthamiana

[0055] The recombinant overexpression vector pCV-NbTAF12b-3Flag constructed in step 1.1 was introduced into Agrobacterium GV3101 using electroporation to prepare OD. 600 A resuspension of Agrobacterium at a concentration of 0.2 was used; then, Nicotiana benthamiana was transformed using a conventional Agrobacterium-mediated transformation method; the specific transformation process is as follows:

[0056] Seed disinfection and sowing: Nitralium benzoate seeds were disinfected with 75% alcohol for 40 seconds, rinsed with sterile water for 1 minute, and then disinfected with 2% sodium hypochlorite for 3-5 minutes, rinsing three times with sterile water, 1 minute each time. The disinfected seeds were sown on germination medium and cultured at 25℃ for 16 hours / 8 hours under light / dark conditions for 4-5 weeks.

[0057] Explant preparation and pre-culture: Leaves of germinated sterile Nicotiana benthamiana seedlings were taken out, cut into small pieces with a scalpel and inoculated into pre-culture medium. They were pre-cultured at 25℃ for 16h / 8h light / dark for 2d.

[0058] Agrobacterium infection and co-culture: using OD 600 Agrobacterium resuspension at 0.2 mg / L was used to place explants that had been cultured for 2 days in the Agrobacterium suspension for 15 minutes. After removing the explants and air-drying them, they were cultured in the dark in a co-culture medium for 2-3 days.

[0059] Callus induction: The co-cultured explants were transferred to the induction medium to induce callus formation. They were cultured at 25°C for 10 days under 16h / 8h light / dark conditions until callus tissue grew.

[0060] Screening and differentiation: Select callus tissues with good growth and inoculate them into resistance screening medium and culture them at 25℃, 16h / 8h light / dark for 20-30 days; Inoculate vigorous positive callus tissues into differentiation medium, 5-8 callus per dish, and culture them at 25℃, 16h / 8h light / dark for 20-30 days.

[0061] Rooting and transplanting: When the seedlings to be differentiated grow to about 2-3 cm, they are cut from the callus tissue and inoculated into rooting medium. They are cultured at 25℃ under 16h / 8h light / dark conditions for 15-20 days. After the rooted tobacco seedlings are washed with water to remove the medium, they are transplanted into soil for culture. NbTAF12b overexpressing transgenic tobacco is obtained.

[0062] 1.3 Identification of NbTAF12b overexpression transgenic plants

[0063] DNA was extracted from transgenic tobacco leaves using the CTAB method, and PCR identification was performed using primer pairs Hyg-F (CTATTT CTT TGC CCTCGG AC) and Hyg-R (CCT GAC CTATTG CAT CTC CC).

[0064] The PCR identification system consisted of 10 μL 2×Taq Master Mix, 0.3 μL Hyg-F, 0.3 μL Hyg-R, 1 μL DNA template, and water added to a final volume of 20 μL. The PCR program was as follows: 94℃ pre-denaturation for 5 min, 94℃ denaturation for 30 s, 56℃ annealing for 30 s, 72℃ extension for 30 s, and 72℃ final extension for 5 min.

[0065] Phenotypic observation of NbTAF12b transgenic overexpression lines that were positive by PCR revealed no significant difference in growth and development status between NbTAF12b transgenic tobacco and wild-type. Figure 2 A). Subsequently, RNA was extracted from transgenic plants using the Trizol method, and cDNA was obtained by reverse transcription. Using primer pairs q-NbTAF12b-F (AGC GTT TGG ATG TGA TAC GT) and q-NbTAF12b-R (GTC ATC TCA TGC AGC ATT TGT G) as templates, qRT-PCR was performed to detect and analyze the expression level of NbTAF12b in transgenic plants. Figure 2 As shown in Figure B, the relative transcription level of the NbTAF12b gene in the NbTAF12b overexpressing tobacco lines NbTAF12b-OE-L6 and NbTAF12b-OE-L33 was significantly higher than that in the wild-type control. Furthermore, total protein was extracted from the transgenic plants, and Western blot analysis using a Flag antibody confirmed the expression of the NbTAF12b-Flag fusion protein in both transgenic lines, indicating high-level expression of the NbTAF12b-Flag fusion protein in transgenic Nicotiana benthamiana. Figure 2 C).

[0066] 1.4 Analysis of antiviral characteristics in plants overexpressing the NbTAF12b gene

[0067] Four-week-old transgenic Nicotiana benthamiana plants (i.e., NbTAF12b-OE-L6 and NbTAF12b-OE-L33) and wild-type Nicotiana benthamiana were inoculated with TYLCV and then cultured according to standard methods; virus symptoms were observed 7 days after inoculation, such as... Figure 3 As shown in A: NbTAF12b-OE-L6 and NbTAF12b-OE-L33 are two strains of NbTAF12b transgenic Nicotiana benthamiana; while the wild-type Nicotiana benthamiana is Nicotiana benthamiana.

[0068] Overexpression of the NbTAF12b gene significantly enhances tobacco resistance to TYLCV, manifested as delayed disease onset and reduced symptoms. Figure 3A). qPCR detection was performed using primer pairs q-TYLCV-F (CCC TCAAAG CTC TAT GGC AAT CGG) and q-TYLCV-R (CAGTGA CGT CTG TGG AAC CCT C). The results showed that the virus accumulation in both NbTAF12b transgenic lines was significantly lower than that in the wild-type control. Figure 3 B). These results indicate that overexpression of the NbTAF12b gene can significantly enhance resistance to the virus in Nicotiana benthamiana.

[0069] Note: TYLCV is a common tomato yellow leaf curl virus. Symptoms include slow plant growth and leaf curling.

[0070] In summary, the TAF12b gene has antiviral function and can inhibit viral infection. This gene can serve as an important target for molecular regulation of viral resistance and has great application prospects in molecular design breeding of plant disease resistance.

[0071] Example 2: Overexpression of the SlTAF12b gene enhances the virus resistance of tomatoes.

[0072] 2.1 Construction of the SlTAF12b gene overexpression vector

[0073] 0.1g of tomato leaves were collected, and RNA was extracted using the Trizol method. After removing genomic DNA, oligo(dT) was used. 18 (5'-TTT TTT TTT TTT TTT TTT-3') primers were used for reverse transcription to obtain cDNA. Then, using this cDNA as a template, PCR amplification was performed using primer pairs SlTAF12b-F (GAC TCT AGA CCC CTG GGA TCC ATG GCT GAA ATT CCG TCG T) and SlTAF12b-R (TCC AAG GGC GAA TTG GTC GAC AAA CCT TGT CAT CTC ATG C) to obtain the SlTAF12b gene (as shown in SEQ ID NO:5 of patent 2023103537258). Figure 4 As shown, the SlTAF12b gene was constructed into the binary transformation vector pCV-3Flag-N1 fused with a Flag tag using homologous recombination, resulting in the pCV-SlTAF12b-3Flag recombinant vector.

[0074] 2.2 Agrobacterium-mediated genetic transformation of tomato

[0075] The recombinant overexpression vector pCV-SlTAF12b-3Flag constructed in step 2.1 was introduced into Agrobacterium GV3101 using electroporation to prepare OD.600 Agrobacterium resuspension at 0.2 g / mL was used; and tomato AC (Ailsa Craig) was transformed using the conventional Agrobacterium-mediated transformation method. The specific transformation process is as follows:

[0076] Seed disinfection and sowing: Tomato seeds were disinfected with 75% alcohol for 1 minute, soaked in 5% sodium hypochlorite solution for 5-8 minutes, and rinsed with sterile water 3 times, 10 minutes each time; the disinfected seeds were sown in germination medium and cultured at 25℃ under 16h / 8h light / dark conditions for 4-5 days.

[0077] Explant preparation and pre-culture: After the cotyledons of tomato seedlings have fully expanded, the cotyledon petioles and cotyledon tips are removed with a scalpel, leaving the middle part, which is cut into two sections and inoculated into the pre-culture medium. The seedlings are pre-cultured at 25℃ for 16h / 8h light / dark for 2 days.

[0078] Agrobacterium infection and co-culture: using OD 600 Agrobacterium resuspension at 0.2 g / L; infect for 10 min, then place the dried explants in a co-culture medium and incubate in the dark at 25°C for 2-3 days;

[0079] Screening and differentiation: The co-cultured explants were transferred to the screening medium and cultured at 25℃ under 16h / 8h light / dark conditions for 20-30 days; the selected callus was then inoculated into the differentiation medium and cultured at 25℃ under 16h / 8h light / dark conditions for 30-40 days.

[0080] Rooting and transplanting: When the seedlings to be differentiated grow to about 2-3 cm, they are cut from the callus tissue and inoculated into rooting medium. They are cultured at 25℃ under 16h / 8h light / dark conditions for 15-20 days. After the rooted tomato seedlings are washed with water to remove the medium, they are transplanted into soil for further culture. This yields SlTAF12b overexpressing transgenic tomatoes.

[0081] 2.3 Identification of SlTAF12b overexpressing transgenic plants

[0082] DNA was extracted from transgenic tomato leaves using the CTAB method, and PCR identification was performed using primer pairs Hyg-F (CTATTT CTT TGC CCTCGG AC) and Hyg-R (CCT GAC CTATTG CAT CTC CC). RNA was extracted from transgenic positive plants using the Trizol method, and qRT-PCR was performed using primer pairs q-SlTAF12b-F (TGG TTT CAC AGG TGG ATG C) and q-SlTAF12b-R (AGATTT CCG ATG CTT CGC) to detect and analyze the expression level of SlTAF12b in transgenic plants. Figure 5As shown in B, the transcription level of the SlTAF12b gene in the SlTAF12b overexpressing tomato lines SlTAF12b-OE-L1 and SlTAF12b-OE-L2 was significantly higher than that in the wild-type control.

[0083] 2.4 Analysis of antiviral characteristics in plants overexpressing the SlTAF12b gene

[0084] The obtained SlTAF12b transgenic tomato lines and wild-type tomatoes, which were in the three-week-old growth stage, were inoculated with TYLCV. Virus symptoms were observed 10 days after inoculation, such as... Figure 5 As shown in Figure A, SlTAF12b-OE-L1 and SlTAF12b-OE-L2 are two lines of SlTAF12b transgenic tomatoes; the wild-type tomato is Ailsa Craig. Compared with the wild-type control, both SlTAF12b overexpression transgenic tomato lines SlTAF12b-OE-L1 and SlTAF12b-OE-L2 showed delayed disease onset and milder symptoms. Further DNA was extracted from diseased leaves, and qPCR was performed using primers q-TYLCV-F (CCC TCAAAG CTC TAT GGCAAT CGG) and q-TYLCV-R (CAG TGACGT CTG TGG AAC CCT C). The results showed that the virus accumulation in both SlTAF12b overexpression transgenic tomato lines was significantly lower than that in the wild-type control. Figure 5 C). These results indicate that overexpression of the SlTAF12b gene can significantly enhance the resistance of tomatoes to TYLCV.

[0085] In conclusion, the tomato SlTAF12b gene has antiviral function and can inhibit viral infection. This gene can serve as an important target for molecular regulation of disease resistance and has great application prospects in molecular design breeding of disease-resistant crops such as tomatoes.

[0086] The present invention describes in detail the application of the TAF12b gene and its encoded protein in plant antiviral activity in the embodiments described above. The application of the TAF12b gene in antiviral activity is not limited to Nicotiana benthamiana and tomato as illustrated in the examples; it can be applied to all plants, especially important food and oil crops, medicinal plants, and economic crops such as vegetables.

[0087] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. The application of the TAF12b gene or its homologous gene in plant antiviral activity, characterized in that... The TAF12b The gene or its homolog is derived from Nicotiana benthamiana. NbTAF12b Genes derived from tomatoes SlTAF12b Gene; The nucleotide sequence of the SlTAF12b gene is shown in SEQ ID NO:5; the nucleotide sequence of the NbTAF12b gene is shown in SEQ ID NO:

7. Overexpression of the NbTAF12b gene can enhance the resistance of Nicotiana benthamiana to the virus; overexpression of the SlTAF12b gene can enhance the resistance of tomatoes to the virus. The virus in question is Tomato Yellow Leaf Curl Virus (TYLCV).

2. TAF12b The application of proteins encoded by genes in plant antiviral activity is characterized by: The TAF12b protein is either NbTAF12b protein or SlTAF12b protein; The amino acid sequence of the protein encoded by the SlTAF12b gene is shown in SEQ ID NO:6; the amino acid sequence of the protein encoded by the NbTAF12b gene is shown in SEQ ID NO:

8. Overexpression of the NbTAF12b gene can enhance the resistance of Nicotiana benthamiana to the virus; overexpression of the SlTAF12b gene can enhance the resistance of tomatoes to the virus. The virus in question is Tomato Yellow Leaf Curl Virus (TYLCV).

3. Contains TAF12b The application of a gene or its homologous gene in a recombinant vector or recombinant host strain in plant antiviral activity, characterized by: The TAF12b The gene or its homolog is derived from Nicotiana benthamiana. NbTAF12b Genes derived from tomatoes SlTAF12b Gene; The nucleotide sequence of the SlTAF12b gene is shown in SEQ ID NO:5; the nucleotide sequence of the NbTAF12b gene is shown in SEQ ID NO:

7. Overexpression of the NbTAF12b gene can enhance the resistance of Nicotiana benthamiana to the virus; overexpression of the SlTAF12b gene can enhance the resistance of tomatoes to the virus. The virus in question is Tomato Yellow Leaf Curl Virus (TYLCV).

4. A method for cultivating a virus-resistant TAF12b transgenic plant, characterized in that: Using the TAF12b gene or its homologous gene as the target gene, an overexpression vector of the target gene is constructed, transformed into plants, and the plants are cultivated to obtain virus-resistant TAF12b transgenic plants; TAF12b The gene or its homolog is derived from Nicotiana benthamiana. NbTAF12b Genes derived from tomatoes SlTAF12b Gene; Overexpression in tobacco NbTAF12b Genes may be overexpressed in tomatoes SlTAF12b The gene can significantly reduce the infection of Tomato Yellow Leaf Curl Virus (TYLCV); The nucleotide sequence of the SlTAF12b gene is shown in SEQ ID NO:5; the nucleotide sequence of the NbTAF12b gene is shown in SEQ ID NO:7.

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