Application of TAF12b gene or homologous gene thereof in virus resistance

Abstract

The invention belongs to the technical field of biology, and particularly relates to a TAF12b gene, functions of encoding protein of the TAF12b gene and application of the TAF12b gene in antivirus of plants. The TAF12b gene or the homologous gene thereof is overexpressed, so that the antiviral performance of the plant can be improved; the TAF12b gene or the homologous gene of the TAF12b gene comprises an NbTAF12b gene from nicotiana benthamiana, a homologous gene SlTAF12b from tomato, and a homologous gene OsTAF12b from rice. The TAF12b gene is introduced into target plants, such as nicotiana benthamiana and tomato, so that the over-expressed TAF12b can effectively resist virus infection and obviously reduce the virus accumulation amount in the plants.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and specifically relates to the function of a TAF12b gene and a protein encoded therein and applications thereof in plant anti-virus. Background Art

[0002] Plant viruses are a large class of pathogens that are extremely harmful to crops such as grain and oil crops such as corn, rice, wheat, and soybeans, cash crops such as vegetables such as tomatoes, tobacco, cotton, pumpkins, and bayberries, as well as medicinal plants such as Tripterygium wilfordii, Paris polyphylla, Solanum nigrum, and Solanum lyratum. Because of its rapid spread and the difficulty in prevention and control once it develops, it is often called the "cancer" of plants. Plants infected by viruses often show symptoms such as yellowing, mosaic, dead spots, necrosis, dwarfing, and deformity. It is estimated that plant viruses cause direct economic losses of tens of billions of yuan to many important grain and oil crops, cash crops, and medicinal plants in my country each year; the direct economic losses caused by viral diseases worldwide are hundreds of billions of yuan each year. Plant viruses seriously restrict the development of the planting industry economy.

[0003] At present, the prevention and control of viral diseases in agricultural production mainly relies on chemical means such as pesticides, but the large-scale spraying of pesticides such as 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. Using antiviral functional genes to cultivate antiviral varieties to control plant viral diseases is one of the most economical and effective strategies, but the current exploration and utilization of antiviral functional genes is still very limited.

[0004] TAFs (TATA-box binding protein associated factors) are important components of the universal transcription factor TFIID complex, which is widely present in animals and plants. At present, limited research results show that TAF factors play an important role in plant growth and development and abiotic stress response, but their role in plant virus infection is still unclear. Reports show that TAF12b can participate in hormone signaling pathways and unfolded protein responses; in the CN116479009A patent, it was found that the TAF12b gene has the function of regulating 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 a TAF12b gene or a homologous gene thereof and a protein encoded therein in antiviral treatment.

[0006] In order to solve the above technical problems, the present invention provides the application of TAF12b gene or its homologous gene in plant antiviral.

[0007] As an improvement of the application of the present invention: overexpression of the TAF12b gene or its homologous gene can increase the antiviral performance of the plant.

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

[0009] NbTAF12b gene from Nicotiana benthamiana, SlTAF12b homologous gene from tomato, OsTAF12b homologous gene from rice (preferably NbTAF12b gene and SlTAF12b gene);

[0010] The nucleotide sequence of the TAF12b gene or its homologous gene has been published in the patent application with publication number 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; the nucleotide sequence of the NbTAF12b gene is shown in SEQ ID NO:7.

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

[0012] The virus is a plant virus;

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

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

[0015] The plant virus is a plant virus such as Tomato Yellow Leaf Curl Virus TYLCV (preferred), Chinese Tomato Yellow Leaf Curl Virus TYLCCNV, New Delhi Tomato Leaf Curl Virus ToLCNDV, etc.;

[0016] The grain and oil crops include corn, rice, wheat, and soybean; the economic crops include tomato (preferred), tobacco, cotton, pumpkin, and bayberry; and the medicinal plants include Tripterygium wilfordii, Paris polyphylla, Solanum nigrum, and Solanum lyratum.

[0017] The present invention also provides the application of the protein encoded by the TAF12b gene (ie, TAF12b protein) in plant antiviral activities:

[0018] The TAF12b protein includes highly homologous proteins such as NbTAF12b protein and SlTAF12b protein, or proteins having the same function as homologous proteins such as NbTAF12b protein and SlTAF12b protein after conservative substitution and / or deletion and / or addition of one or several amino acid residues in the amino acid sequence.

[0019] The amino acid sequence of the TAF12b protein has been published in the patent application with publication number 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; the amino acid sequence of the protein encoded by the NbTAF12b gene is shown in SEQ ID NO:8.

[0020] The present invention also provides the use of a recombinant vector or a recombinant host strain containing the TAF12b gene or a homologous gene in plant anti-virus.

[0021] The present invention also provides a method for cultivating virus-resistant TAF12b transgenic plants: using 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] As an improvement to the method for cultivating virus-resistant TAF12b transgenic plants of the present invention: overexpressing the TAF12b gene in Nicotiana benthamiana or tomato can significantly reduce the infection of viruses such as Tomato Yellow Leaf Curl Virus TYLCV.

[0023] The present invention is specifically as follows:

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

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

[0026] The present invention also provides an 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). The application can significantly resist virus infection and reduce the diseases caused by virus infection by overexpressing the Nicotiana benthamiana NbTAF12b gene in the target plant.

[0027] In a second aspect, the present invention provides the use of tomato SlTAF12b gene and its encoded protein in plant antiviral treatment. The nucleotide sequence of the SlTAF12b gene and the amino acid sequence of the protein encoded by the gene have been published in a patent application with publication number CN116479009A.

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

[0029] The present invention also provides the use of a tomato SlTAF12b gene and its encoded protein in regulating plant resistance to viruses. The plants include but are not limited to tomatoes. The viruses are plant viruses, including but not limited to tomato yellow leaf curl virus TYLCV. The application can significantly resist virus infection and alleviate the symptoms caused by virus infection by overexpressing the tomato SlTAF12b gene in the target plant.

[0030] It should be emphasized that most of the existing antiviral genes are R genes with typical TIR / CC-NBS-LRR domains; while the TAF12b gene in the present invention is a universal transcription factor cofactor without the above domains, so the prior art cannot provide technical inspiration for the present invention. The antiviral function of TAF12b and its homologous genes discovered in the present invention can provide new gene resources for crop disease resistance breeding.

[0031] The purpose of the present invention is to provide a TAF12b gene for crop virus resistance breeding and use it in plant virus resistance. The present invention provides a TAF12b gene and its encoded protein for use in plant virus resistance. The TAF12b gene includes any one of the NbTAF12b gene from Nicotiana benthamiana or the homologous gene SlTAF12b from tomato.

[0032] So far, there has been no report on the function of TAF12b gene in the process of plant antiviral resistance. This invention reveals for the first time the function of TAF12b gene in the process of plant antiviral resistance, providing new ideas and new gene sources for in-depth understanding of plant antiviral mechanism and improvement of plant antiviral traits.

[0033] The present invention discovered for the first time that the plant TAF12b gene is a new type of antiviral gene. Overexpression of the TAF12b gene can significantly improve the plant's resistance to viruses, providing a theoretical basis and new gene resources for molecular design to improve crop disease resistance, and has great application value in the field of plant disease resistance breeding.

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

[0035] In summary, the present invention relates to a new plant antiviral gene TAF12b and the application of its encoded protein in plant antiviral. The present invention introduces the TAF12b gene into target plants such as Nicotiana benthamiana and tomato, and finds that overexpression of TAF12b can effectively resist virus infection and significantly reduce the amount of virus accumulation in plants. The present invention first discovered that the TAF12b gene has the function of improving plant antiviral function, which can provide scientific basis and gene resources for the genetic improvement of crops to create new antiviral crop materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clear, specific implementation modes of the present invention are 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 The invention relates to the identification of 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) Flag-specific antibodies were used to identify NbTAF12b overexpressing transgenic lines, and Rubisco was used to indicate consistent loading levels;

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

[0042] Figure 3 This is an analysis of the resistance of NbTAF12b transgenic Nicotiana benthamiana to Tomato Yellow Leaf Curl Virus (TYLCV) in Example 1 of the present invention;

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

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

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

[0046] Figure 5 This is an analysis of the resistance of the S1TAF12b-overexpressing transgenic tomato plants to Tomato Yellow Leaf Curl Virus (TYLCV) in Example 2 of the present invention;

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

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

[0049] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0050] Example 1: Overexpression of NbTAF12b gene improves the resistance of Nicotiana benthamiana to viruses

[0051] 1.1 Construction of NbTAF12b transgenic vector

[0052] 0.1 g of tobacco leaves were collected and RNA was extracted using the Trizol method. After removing genomic DNA, oligo(dT) was used to 18(5'-TTT TTT TTT TTT TTT TTT-3') primer was used for reverse transcription to obtain cDNA. Then, the cDNA was used as a template and primers 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) were used for PCR amplification to obtain the full-length gene of NbTAF12b (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 the homologous recombination method to obtain 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 by electroporation to prepare OD 600 =0.2 Agrobacterium resuspension; and then transforming Nicotiana benthamiana by conventional Agrobacterium-mediated method; the specific transformation process is as follows:

[0056] Seed disinfection and sowing: Disinfect the seeds of Nicotiana benthamiana with 75% alcohol for 40 seconds, wash with sterile water for 1 minute, disinfect with 2% sodium hypochlorite for 3-5 minutes, and wash with sterile water 3 times, 1 minute each time. Sow the disinfected seeds on the germination medium and culture at 25℃ with 16h / 8h light / dark for 4-5 weeks;

[0057] Explant preparation and pre-culture: Take out the germinated sterile Nicotiana benthamiana seedling leaves, cut them into small pieces with a scalpel, and inoculate them into the pre-culture medium. Pre-culture them at 25°C and 16h / 8h light / dark for 2 days.

[0058] Agrobacterium infection and co-cultivation: using OD 600 = 0.2 Agrobacterium resuspension, place the explants pre-cultured for 2 days in the Agrobacterium suspension for 15 minutes, take out the explants, dry them, and culture them in the co-culture medium in the dark for 2-3 days;

[0059] Callus induction: transfer the co-cultured explants into induction medium to induce callus, culture at 25°C, 16h / 8h light / dark for 10 days, and wait for callus to grow;

[0060] Screening and differentiation: Select callus tissue with good growth, inoculate it into resistance screening medium, and culture it at 25℃, 16h / 8h light / dark for 20-30 days; inoculate the actively growing positive callus tissue into differentiation medium, 5-8 callus / dish, and culture it 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, and cultured at 25°C, 16h / 8h light / dark for 15-20 days; the rooted tobacco seedlings are washed with water to clean the culture medium, and then transplanted into soil for culture; thus, NbTAF12b overexpressing transgenic tobacco is obtained.

[0062] 1.3 Identification of NbTAF12b overexpressing transgenic plants

[0063] The CTAB method was used to extract DNA from transgenic tobacco leaves, 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 was 10uL 2×Taq Master Mix, 0.3uL Hyg-F, 0.3uL Hyg-R, 1uL DNA template, and water was added to 20uL. The program was 94℃ pre-denaturation for 5min, 94℃ denaturation for 30s, 56℃ annealing for 30s, 72℃ extension for 30s, and 72℃ extension for another 5min.

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

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

[0067] The obtained NbTAF12b transgenic N. benthamiana plants (i.e., NbTAF12b-OE-L6 and NbTAF12b-OE-L33) at the four-week-old growth stage and wild-type N. benthamiana were inoculated with TYLCV and then cultivated according to conventional 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; the wild-type tobacco is Nicotiana benthamiana;

[0068] Overexpression of the NbTAF12b gene can significantly enhance tobacco's resistance to TYLCV, as evidenced by delayed disease onset and reduced symptoms ( Figure 3A). qPCR detection was performed using primers 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 viral accumulation in the two 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 the resistance of Nicotiana benthamiana to viruses.

[0069] Description: TYLCV is a common tomato yellow leaf curl virus, and the symptoms are slow plant growth and curled leaves.

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

[0071] Example 2: Overexpression of the SlTAF12b gene improves tomato resistance to viruses

[0072] 2.1 Construction of S1TAF12b gene overexpression vector

[0073] 0.1 g of tomato leaves were collected and RNA was extracted using the Trizol method. After removing genomic DNA, oligo(dT) was used to 18 (5'-TTT TTT TTT TTT TTT TTT-3') primer was used for reverse transcription to obtain cDNA. Then, the cDNA was used as a template and primers 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) were used for PCR amplification 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 to obtain 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 by electroporation to prepare OD600 = 0.2 Agrobacterium resuspension; and transform tomato AC (Ailsa Craig) using conventional Agrobacterium-mediated method, the specific transformation process is as follows:

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

[0077] Explant preparation and pre-culture: When the cotyledons of tomato seedlings are fully expanded, remove the cotyledon petiole and cotyledon tip with a scalpel, keep the middle part, cut it into two sections and inoculate it into the pre-culture medium, and pre-culture it at 25℃, 16h / 8h light / dark for 2 days;

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

[0079] Screening and differentiation: The explants after co-cultivation were transferred to the screening medium and cultured at 25°C and 16h / 8h light / dark conditions for 20-30 days; the selected calli were inoculated into the differentiation medium and cultured at 25°C and 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, and cultured at 25°C, 16h / 8h light / darkness for 15-20 days; the rooted tomato seedlings are washed with water to clean the culture medium, and then transplanted into soil for culture; SlTAF12b overexpressing transgenic tomatoes are obtained.

[0081] 2.3 Identification of SlTAF12b overexpressing transgenic plants

[0082] The CTAB method was used to extract DNA from transgenic tomato leaves, and PCR identification was performed using primers Hyg-F (CTATTT CTT TGC CCTCGG AC) and Hyg-R (CCT GAC CTATTG CAT CTC CC). The Trizol method was used to extract RNA from transgenic positive plants, and qRT-PCR was performed using primers 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 SlTAF12b gene in 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 of plants overexpressing the SlTAF12b gene

[0084] The obtained SlTAF12b transgenic tomato lines and wild-type tomatoes at the three-week-old growth stage were inoculated with TYLCV, and the virus symptoms were observed 10 days after inoculation, such as Figure 5 As shown in 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, the SITAF12b overexpressing transgenic tomato lines SlTAF12b-OE-L1 and SlTAF12b-OE-L2 showed a phenotype of delayed disease onset and milder symptoms. Further extraction of diseased leaf DNA, q-TYLCV-F (CCC TCAAAG CTC TAT GGCAAT CGG) and q-TYLCV-R (CAG TGACGT CTG TGG AAC CCT C) primers were used for qPCR detection. The results showed that the virus accumulation in the two SITAF12b overexpressing 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 tomato to TYLCV.

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

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

[0087] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. Application of TAF12b gene or its homologous gene in plant antiviral activity.

2. The use according to claim 1, characterized in that: Overexpression of the TAF12b gene or its homologous gene can increase the plant's antiviral properties.

3. The use according to claim 1 or 2, characterized in that: The TAF12b gene or its homologous gene includes: The NbTAF12b gene from Nicotiana benthamiana, the homologous gene SlTAF12b from tomato, and the homologous gene OsTAF12b from rice; 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.

4. The use according to claim 3, characterized in that: The virus is a plant virus; The plants are food and oil crops, economic crops, and medicinal plants, including dicotyledonous or monocotyledonous plants.

5. The use according to claim 4, characterized in that: The plant viruses are Tomato Yellow Leaf Curl Virus TYLCV, Chinese Tomato Yellow Leaf Curl Virus TYLCCNV, and New Delhi Tomato Leaf Curl Virus ToLCNDV; The grain and oil crops are corn, rice, wheat, and soybean; the economic crops are tomato, tobacco, cotton, pumpkin, and bayberry; and the medicinal plants are trifoliate green, Paris polyphylla, Solanum nigrum, and Solanum lyratum.

6. Application of the protein encoded by the TAF12b gene in plant antiviral treatment, characterized in that: The TAF12b protein includes highly homologous proteins such as NbTAF12b protein and SlTAF12b protein, or a protein having the same function as homologous proteins such as NbTAF12b protein and SlTAF12b protein after conservative substitution and / or deletion and / or addition of one or more amino acid residues in the amino acid sequence; 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.

7. Application of recombinant vectors or recombinant host strains containing TAF12b gene or homologous gene in plant antiviral activities.

8. A method for cultivating virus-resistant TAF12b transgenic plants, characterized in that: The TAF12b gene or its homologous gene is used as the target gene, an overexpression vector of the target gene is constructed, and the vector is transformed into a plant, and the plant is cultivated, thereby obtaining a virus-resistant TAF12b transgenic plant.

9. The method for cultivating virus-resistant TAF12b transgenic plants according to claim 8, characterized in that: Overexpression of the TAF12b gene in Nicotiana benthamiana or tomato can significantly reduce the infection of viruses such as Tomato Yellow Leaf Curl Virus TYLCV.

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