IbNFYA3 gene of sweet potato and application of IbNFYA3 gene in improvement of plant stress resistance

Abstract

The invention discloses a sweet potato IbNFYA3 gene and application of the sweet potato IbNFYA3 gene in improvement of plant stress resistance, and belongs to the technical field of molecular biology. The amino acid sequence coded by the sweet potato IbNFYA3 gene is shown as SEQ ID NO.2, and the nucleotide sequence of the sweet potato IbNFYA3 gene is shown as SEQ ID NO.1. Constructing a plant expression vector of the IbNFYA3 gene, and transforming arabidopsis thaliana; the result shows that the morphological development of the arabidopsis thaliana plant with the transferred IbNFYA3 gene is normal, and the arabidopsis thaliana seedling with the transferred IbNFYA3 gene at least can resist the stress of 125mM NaCl or 300mM mannitol; the expression of the IbNFYA3 gene in arabidopsis thaliana can significantly improve the high salinity resistance and drought resistance of the arabidopsis thaliana. Therefore, the IbNFYA3 gene has important application value in the cultivation of drought-resistant and salt-tolerant new germplasm.

Description

Technical Field

[0001] The invention belongs to the technical field of molecular biology, and particularly relates to a sweet potato IbNFYA3 gene and an application thereof in improving plant stress resistance. Background Art

[0002] Organisms often face various adverse conditions (such as drought, high salt, low temperature, etc.) in the natural environment; these adverse conditions can inhibit the growth of organisms and even cause the death of organisms. With the continuous deterioration of the environment, stress such as high salt and drought has become a global problem. Breeding new varieties of organisms with multiple stress resistance has become one of the main research goals of breeders.

[0003] Sweet potatoes are moderately drought-resistant and salt-tolerant crops, but their drought and salt tolerance vary at different growth stages. Drought and salt stress will inhibit the growth of sweet potatoes to a certain extent, affect the development of tubers, and cause a decrease in yield. Plant drought resistance and salt tolerance are controlled by multiple genes. Conventional breeding techniques are inefficient and have a long cycle. The rapidly developing genetic engineering technology provides a new way for biological genetic improvement. Genetic transformation using genes that play an important role in drought and salt stress response is an important means to obtain new drought-resistant and salt-tolerant germplasm. Summary of the invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a sweet potato IbNFYA3 gene and its application in improving plant stress resistance.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] The sweet potato IbNFYA3 gene, the amino acid sequence encoded by the gene is shown as SEQ ID NO.2, and the nucleic acid sequence thereof is shown as SEQ ID NO.1.

[0007] The application of the sweet potato IbNFYA3 gene in improving plant stress resistance or preparing products for improving plant stress resistance.

[0008] Based on the above scheme, the stress resistance is at least one of high salt resistance and drought resistance.

[0009] A method for improving plant stress resistance comprises constructing a plant expression vector containing an IbNFYA3 gene, transforming the vector into a plant, overexpressing the IbNFYA3 gene in the plant, and thus improving the plant stress resistance; the amino acid sequence encoded by the IbNFYA3 gene is shown in SEQ ID NO.2.

[0010] Based on the above scheme, the nucleic acid sequence of the IbNFYA3 gene is shown as SEQ ID NO.1.

[0011] Based on the above scheme, the stress resistance is at least one of high salt resistance and drought resistance.

[0012] On the basis of the above scheme, the method of transforming the plant body is one of the following methods: Agrobacterium-mediated method, gene gun method, electric shock method, PEG method, and liposome method.

[0013] Based on the above scheme, the Agrobacterium is Agrobacterium tumefaciens or Agrobacterium rhizogenes.

[0014] A product for improving plant stress resistance is a recombinant expression vector, an expression cassette, a recombinant bacterium, a recombinant virus or a transgenic cell line containing an IbNFYA3 gene sequence; the nucleic acid sequence of the IbNFYA3 gene is shown in SEQ ID NO:1.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention cloned the IbNFYA3 gene from sweet potato, and sequencing results showed that the gene coding sequence contained 1101 nucleotides and the encoded protein contained 366 amino acids.

[0017] 2. Construct the plant expression vector of IbNFYA3 gene and transform Arabidopsis thaliana; the results show that the Arabidopsis thaliana plant morphology developed normally after IbNFYA3 gene was introduced, and the Arabidopsis thaliana seedlings with IbNFYA3 gene could at least resist 125mM NaCl stress or 300mM mannitol stress; the expression of IbNFYA3 gene in Arabidopsis thaliana can significantly improve its high salt tolerance and drought tolerance. Therefore, IbNFYA3 gene has important application value in the cultivation of new germplasm with drought and salt resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 For analysis of IbNFYA3 transcriptional activation activity;

[0019] Figure 2 The expression of IbNFYA3 in Xu 55-2 after being treated with 30% PEG6000, 200mM NaCl and 100μM ABA stress;

[0020] Figure 3 The in vitro phenotypes of drought and salt tolerance of Columbia wild-type Arabidopsis and IbNFYA3 transgenic Arabidopsis;

[0021] Figure 4 Root length and fresh weight of Columbia wild-type Arabidopsis and IbNFYA3 transgenic Arabidopsis after NaCl or mannitol treatment;

[0022] Figure 5 To identify the drought and salt tolerance of wild-type Arabidopsis thaliana and IbNFYA3 transgenic Arabidopsis thaliana in potted plants;

[0023] Figure 6 Expression analysis of stress resistance-related genes in Columbia wild-type Arabidopsis and IbNFYA3 transgenic Arabidopsis under different conditions;

[0024] Figure 7 To analyze the physiological and biochemical indicators of stress resistance of Columbia wild-type Arabidopsis and IbNFYA3 transgenic Arabidopsis under different conditions;

[0025] Figure 8 Analysis of reactive oxygen accumulation in leaves of Columbia wild-type Arabidopsis and IbNFYA3 transgenic Arabidopsis under different conditions. DETAILED DESCRIPTION

[0026] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The present invention will be further described in detail below in conjunction with specific examples and with reference to data. The following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0027] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The experimental materials, reagents, drugs, etc. used in the following examples, unless otherwise specified, can all be purchased through general channels.

[0028] In the following embodiments,

[0029] The sweet potato line “Xu 55-2” is a drought-tolerant sweet potato line preserved by the Sweet Potato Research Center of Qingdao Agricultural University;

[0030] Escherichia coli DH5α was maintained by the Sweet Potato Research Center of Qingdao Agricultural University;

[0031] The pGBKT7 vector was deposited by the Sweet Potato Research Center of Qingdao Agricultural University;

[0032] Y2H yeast cells were maintained by the Sweet Potato Research Center of Qingdao Agricultural University;

[0033] The plant expression vector Super1300 was deposited by the Sweet Potato Research Center of Qingdao Agricultural University;

[0034] Agrobacterium tumefaciens strain GV3101 was purchased from Shanghai Weidi Biotechnology Co., Ltd.;

[0035] The transgenic recipient material was Arabidopsis Columbia wild-type variety provided by the Sweet Potato Research Center of Qingdao Agricultural University.

[0036] Example 1

[0037] Cloning of IbNFYA3 gene

[0038] Using cDNA obtained by reverse transcription of RNA from sweet potato (Xu 55-2) as a template, PCR amplification was performed with primer pair P1 and P2 to obtain the IbNFYA3 gene as shown in SEQ ID NO.1, which contains 1101 nucleotides and encodes a protein containing 366 amino acids, the sequence of which is shown in SEQ ID NO.2.

[0039] SEQ ID NO.1(5'→3'):

[0040]

[0041] SEQ ID NO.2

[0042] MLNFSFSKEGDQTAAQSFTPMSITSSSLWNSTDQPENPLSESADTGQKSAPQRGFCMKQTESQLQDQDNTSTLSTDQSHQTVAAMTPSNCHMPKVGPQPGFATLLSLLISSDMSHSLETQLGRLRSYAEIHERQMKDCSIKPSQPHLDEDCTIHQGQLDFSQSMACLSWTEPYLGRLVATYG PNGIIVVFLKFEQIYPQMVGIVPARMPLPSECAESIPIYVNAKQYRAILRRREIRAKLEAENKVVKVRKPYLHESRHAHALKRARGSGGRFLNKSELQQLKSAASPTHGKNISNQKGGGDISGSQLQHSESGSWGTTSTPSGSDVTSIFSGDGIFQQPEFRVSSSPYHMGVSMHEAENFVRRRT

[0043] The sequences of the PCR amplification primer pair P1 and P2 are as follows:

[0044] P1: 5'-ATGCCTAAATTTCTCATTCTC-3' (SEQ ID NO.3);

[0045] P2: 5'-TCAGGTTCTCTACGCACAA-3' (SEQ ID NO. 4).

[0046] PCR amplification system (50 μL): 25 μL 2× Flash HS PCR Master Mix, 2 μL of 20 μmol / L forward and reverse primers, 500 ng reverse transcription product, supplemented with ddH2O;

[0047] The PCR amplification program was as follows: pre-denaturation at 95°C for 5 min, followed by 35 cycles of reaction, with denaturation at 95°C for 30 s, annealing at 58°C for 30 s, and extension at 72°C for 1 min in each cycle; after the cycle was completed, extension was continued for 10 min.

[0048] Example 2

[0049] Analysis of IbNFYA3 transcriptional activation activity

[0050] Primers were designed according to the IbNFYA3 sequence and conserved domain, and restriction sites (NdeⅠ and SalⅠ) and protective bases (primer sequences such as P3 and P4) were added to both ends of the primers. The full-length gene sequence was amplified and inserted into the multiple cloning site of the pGBKT7 vector (Kan resistance) to obtain the pGBKT7+IbNFYA3 recombinant vector.

[0051] The primers for constructing the IbNFYA3 transcriptional activation activity analysis vector are as follows. The underline indicates the restriction endonuclease recognition sequence:

[0052] P3: 5'-GGAATTC CATATG ATGCTAAAATTTCCATTCTC-3'(NdeI, SEQ ID NO.5);

[0053] P4: 5'-ACGC GTCGAC TCAGGTTCTTCTACGCACAA-3'(SalI, SEQ ID NO.6);

[0054] The recombinant vector pGBKT7+IbNFYA3 was transformed into Y2H yeast cells as follows:

[0055] Yeast Y2H Gold was activated on YPDA solid medium. A single clone yeast plaque was picked and placed in a centrifuge tube. YPDA liquid medium was added for shaking culture. 1 mL of bacterial solution was taken and centrifuged at 5 000 rpm for 1 min. The supernatant was discarded. 500 mL of ddH2O was used to suspend the precipitate. The supernatant was discarded. 50 μL of LiAc (1M), 20 μL of DTT (1M), 6.75 μL of Carrier DNA, and 1 μg of recombinant plasmid were added to the centrifuge tube in sequence. Mix well and add 160 μL of 50% PEG4000. Place in a 42°C water bath for 30 min. Place in a centrifuge at 5 000 rpm for 1 min. The supernatant was discarded. 500 mL of ddH2O was used to suspend the precipitate. The supernatant was discarded. Add 150 μL ddH2O to the centrifuge tube to suspend the precipitate, streak the suspended cells on the solid medium of SD / -Trp / -His / X-α-Gal, culture in a constant temperature incubator at 30°C for 3-5 days, and observe the growth of the colonies. pGBKT7 was used as a negative control and pGAL4 was used as a positive control.

[0056] The results are as follows Figure 1 As shown, the protein encoded by the full-length IbNFYA3 gene does not have transcriptional activation activity.

[0057] Example 3

[0058] Expression of IbNFYA3 in sweet potato after stress treatment

[0059] (1) Treat the seedlings of "Xu 55-2" with Hoagland solution containing 30% PEG6000, 200 mM NaCl or 100 μM ABA, take samples at 0 h, 1 h, 3 h, 6 h, 12 h and 24 h after treatment, freeze them in liquid nitrogen and grind them into powder, and extract RNA using RNA extraction kit. The extracted total RNA is treated with DNase I and purified.

[0060] (2) The samples were reacted on a QuantStudio 3 fluorescence quantitative PCR instrument.

[0061] The 20 μL reaction system included: 10 μL 2×SybrGreen qPCR Master Mix, 0.25 μL each of 20 μmol / L forward and reverse primers, and 20 ng of reverse transcription product.

[0062] The amplification procedure is: first pre-denaturation at 94°C for 2 minutes; then enter 40 cycles of reaction, with denaturation at 94°C for 30 seconds, annealing at 58°C for 30 seconds, and extension at 72°C for 30 seconds in each cycle; after the cycle is completed, slowly increase the temperature to 94°C to prepare the melting curve. Each reaction is set up with 3 replicate wells.

[0063] IbNFYA3 gene quantitative PCR primers are:

[0064] P5: 5'-CGGCTGCTGGAAAATGC-3' (SEQ ID NO.7);

[0065] P6: 5'-AAAGGGCGGTGGAGACA-3' (SEQ ID NO. 8).

[0066] The primer sequence of the internal standard gene Actin is:

[0067] P7: 5'-AGCAGCATGAAGATTAAGGTTGTAGCAC-3' (SEQ ID NO.9);

[0068] P8: 5'-TGGAAAATTAGAAGCACTTCCTGTGAAC-3' (SEQ ID NO. 10).

[0069] The results are as follows Figure 2 As shown, the expression of IbNFYA3 gene was significantly upregulated after 30% PEG6000 and 200 mM NaCl stress treatments and was induced by 100 μM ABA, indicating that it is involved in the ABA-mediated response of sweet potato to drought and salt stress.

[0070] Example 4

[0071] Construction of plant expression vector of IbNFYA3 gene

[0072] Using the cDNA of the sweet potato line "Xu 55-2" as a template, PCR amplification was performed using upstream and downstream primers (P9, P10, underlined to indicate restriction endonuclease recognition sequences) containing KpnI and SalI restriction sites to obtain the coding region sequence of the IbNFYA3 gene containing restriction sites.

[0073] P9: 5'-GG GGTACC ATGCTAAAATTTCCATTCTC-3' (KpnI, SEQ ID NO. 11);

[0074] P10: 5'-ACGC GTCGAC GGTTCTTCTACGCACAA-3'(SalI, SEQ ID NO.12)

[0075] The PCR product was recovered, and the plant expression vector Super1300 was digested with KpnI and SalI. The IbNFYA3 gene coding sequence was cloned into the corresponding restriction sites of the plant expression vector Super1300 to obtain the plant expression vector Super1300-IbNFYA3 of the gene.

[0076] Example 5

[0077] Obtaining Transgenic Arabidopsis thaliana with IbNFYA3 Gene

[0078] (1) Preparation, activation and bacterial liquid preparation of Agrobacterium recombinant strains: The Super1300-IbNFYA3 recombinant plasmid was transformed into competent cells of Agrobacterium strain GV3101 by liquid nitrogen freeze-thaw method, and the recombinant strain containing the recombinant plasmid was screened. A single colony of the recombinant strain was picked and inoculated into LB (rifampicin 50 mg / L, kanamycin 50 mg / L) liquid medium, and cultured at 28°C and 180 rpm until OD600 = 0.5-0.8, then 2 mL of bacterial liquid was transferred to 50 mL LB (rifampicin 50 mg / L, kanamycin 50 mg / L) medium and cultured until OD600 = 0.6-0.8. After the bacterial liquid was centrifuged at 5000 rpm for 15 min, it was suspended with the same volume of liquid 1 / 2MS (0.02% silwet L-77) for later use.

[0079] (2) Planting of Arabidopsis thaliana: Select appropriate Arabidopsis thaliana seeds, soak them in 1% NaClO for 5 min, rinse them with sterile water for 4-6 times, and plant them on the substrate soil.

[0080] (3) Agrobacterium-mediated genetic transformation: Select a robust Arabidopsis plant in the early fruiting stage, and place it upside down with the pot on top of the container containing the Agrobacterium suspension prepared in step 1). Immerse the entire inflorescence in the Agrobacterium suspension for about 20-30 seconds, and make sure that the leaves do not come into contact with the impregnation solution as much as possible. Remove the pot and place it horizontally in a dark box for about 24 hours. Make sure to maintain a certain humidity. After 24 hours, place the treated Arabidopsis plants under light conditions of 22-25°C to allow them to grow normally. Mature seeds are collected after about 3 weeks.

[0081] The transgenic Arabidopsis seeds were inoculated into 20 mL MS (hygromycin 50 mg / L) medium and cultured at 22°C for about 1 week. Bright green and strong Arabidopsis seedlings were selected and transplanted into substrate soil. The transgenic plants were purified to the T3 generation.

[0082] 3. PCR detection of transgenic plants

[0083] The genomic DNA of the transgenic plants was extracted, and the primers were designed using the above vector sequences for PCR amplification. The PCR reaction program was: 95°C, 5min; 95°C, 50s, 55°C, 50s, 72°C, 1min, 32 cycles; 72°C, 10min. After the reaction was completed, the product was detected by electrophoresis, and positive transgenic plants were screened.

[0084] The primers for identifying transgenic plants are:

[0085] P13: 5'-CGCCATTTCGCCTTTTCAGAAATGG-3' (SEQ ID NO. 13);

[0086] P14: 5'-TGGTACAAACGTAGGGCTAGCTG-3' (SEQ ID NO. 14).

[0087] Example 6

[0088] Identification of drought and salt tolerance in transgenic Arabidopsis thaliana

[0089] To analyze the salt and drought tolerance of transgenic Arabidopsis plants at the seedling stage, the transgenic Arabidopsis thaliana with IbNFYA3 gene and wild-type Arabidopsis thaliana seeds were inoculated in 1 / 2MS medium for germination. One week later, the seedlings were transferred to 1 / 2MS medium containing 125mM NaCl or 300mM mannitol. The culture was carried out at 22℃ for about 2 weeks, and the results were observed. Figure 3 and Figure 4 As shown, the results showed that under high salt or mannitol stress conditions, the growth and rooting of transgenic IbNFYA3 Arabidopsis seedlings were better than those of Columbia wild-type Arabidopsis seedlings. Therefore, the salt resistance concentration of transgenic IbNFYA3 Arabidopsis seedlings was 125mM or above, and the drought resistance concentration was 200mM mannitol or above.

[0090] To analyze the salt and drought tolerance of transgenic plants under soil culture conditions, the transgenic IbNFYA3 Arabidopsis and Columbia wild-type Arabidopsis seeds were inoculated in 1 / 2MS culture medium for germination. After 1 week, the seedlings were transferred to culture soil and continued to be cultured for 10 days before treatment. The salt-treated plants were irrigated with 300mM NaCl aqueous solution once every 3 days, and the natural drought-treated plants were not irrigated. After 2 weeks of natural drought, they were rehydrated for 3 days and the results were observed (e.g. Figure 5 The results showed that the growth and rooting of transgenic IbNFYA3 Arabidopsis seedlings were better than those of Columbia wild-type Arabidopsis seedlings under high salt or natural drought stress conditions.

[0091] Example 7

[0092] Induced expression of stress resistance genes in transgenic IbNFYA3 Arabidopsis and Columbia wild-type Arabidopsis under different conditions

[0093] Normal, drought (natural drought for 2 weeks) or high salt (300mM NaCl aqueous solution irrigated for 2 weeks, irrigated once every 3 days) stress IbNFYA3 gene Arabidopsis and Columbia wild-type Arabidopsis plant samples were taken, and RNA was extracted using an RNA extraction kit. The extracted total RNA was treated with DNase I and purified, and fluorescent quantitative primers were designed according to the specific sequence of Arabidopsis stress resistance genes. The samples were reacted on a QuantStudio 3 fluorescent quantitative PCR instrument, and the reaction system was the same as in Example 3, and the data were analyzed.

[0094] AtZEP, gene quantitative PCR primers are:

[0095] P15: 5'-CGGAGCTTTCTTCTTGATGG-3' (SEQ ID NO. 15);

[0096] P16: 5'-TCGATTTCGGAGTTTTCCTG-3' (SEQ ID NO. 16);

[0097] AtLOX2 gene quantitative PCR primers are:

[0098] P17: 5'-CAAACCTCAGAAGACGATGTAAGG-3' (SEQ ID NO. 17);

[0099] P18: 5'-GACCTCTCGACCAAGTTATGCC-3' (SEQ ID NO. 18);

[0100] AtP5CR gene quantitative PCR primers are:

[0101] P19: 5'-AGTTTAGCTTCACAGACCGTTC-3' (SEQ ID NO. 19);

[0102] P20: 5'-GCTCTGTGAGAGCTCGCGGCTTC-3' (SEQ ID NO. 20);

[0103] AtP5CS gene quantitative PCR primers are:

[0104] P21: 5'-ATGATCTTATTTATGTTCTGC-3' (SEQ ID NO. 21);

[0105] P22: 5'-CACTATCTTCCGTCACTAT-3' (SEQ ID NO. 22);

[0106] The primer sequence of the internal standard gene AtActin is:

[0107] P23: 5'-GCACCCTGTTCTTCTTACCGA-3' (SEQ ID NO. 23);

[0108] P24: 5'-AGTAAGGTCACGTCCAGCAAGG-3' (SEQ ID NO. 24).

[0109] The results are as follows Figure 6 As shown in the figure, under normal growth conditions, there was no significant difference in the expression levels of stress-related genes between the transgenic lines and the wild-type lines. Under salt or drought stress, the expression levels of ABA signaling pathway-related genes AtZEP, JA signaling pathway-related genes AtLOX2, and proline synthesis pathway-related genes AtP5CR and AtP5CS in transgenic Arabidopsis were significantly higher than those in wild-type plants. This indicates that IbNFYA3 activated the expression of stress-resistant genes under salt or drought stress.

[0110] Physiological and biochemical indicators related to stress resistance in transgenic Arabidopsis thaliana with IbNFYA3 gene

[0111] (1) Arabidopsis thaliana transgenic with IbNFYA3 and wild-type Arabidopsis thaliana plants were collected under normal stress, drought stress (natural drought for 2 weeks), or high salt stress (irrigation with 300 mM NaCl aqueous solution for 2 weeks, once every 3 days) and the malondialdehyde (MDA) and proline (Pro) contents and the enzyme activities of the key enzymes SOD and POD in the active oxygen scavenging system of Arabidopsis plants under different conditions were determined using a microplate reader.

[0112] The results are as follows Figure 7As shown in the figure, the related indicators of the normally growing IbNFYA3 transgenic lines and the wild-type lines did not show significant differences. Under salt or drought stress, the MDA content of the IbNFYA3 transgenic lines was significantly lower than that of the wild-type lines, and the Pro content and the enzyme activities of SOD and POD were significantly higher than those of the wild-type plants. The results showed that the overexpression of IbNFYA3 could activate the active oxygen scavenging system of transgenic plants under drought or salt stress, enhance the osmotic adjustment ability of transgenic plants, and reduce the damage of stress to the membrane system.

[0113] (2) Leaves of Arabidopsis thaliana with IbNFYA3 gene and wild-type Arabidopsis thaliana under different treatment conditions were taken for NBT staining and DAB staining to analyze the leaf O 2- 2 and H2O accumulation.

[0114] The results are as follows Figure 8 As shown, under stress, Arabidopsis transgenic plants overexpressing IbNFYA3 2- The accumulation of H2O2 in the 100 μg / ml NFYA3 gene was significantly lower than that in the wild-type Arabidopsis. Overexpression of the IbNFYA3 gene reduced the excessive accumulation of reactive oxygen species under drought and high salt stress, and alleviated the damage of high salt and drought stress to the physiological activities of Arabidopsis.

[0115] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. Sweet potato IbNFYA3 gene, characterized in that The amino acid sequence encoded by the gene is shown in SEQ ID NO.

2.

2. The sweet potato IbNFYA3 gene according to claim 1, characterized in that Its nucleic acid sequence is shown in SEQ ID NO.

1.

3. Use of the sweet potato IbNFYA3 gene according to claim 1 or 2 in improving plant stress resistance or preparing products for improving plant stress resistance.

4. The use according to claim 3, characterized in that: The stress resistance is at least one of high salt resistance and drought resistance.

5. A method for improving plant stress resistance, characterized in that: A plant expression vector containing the IbNFYA3 gene is constructed and transformed into a plant body to overexpress the IbNFYA3 gene in the plant, thereby improving the stress resistance of the plant; the amino acid sequence encoded by the IbNFYA3 gene is shown in SEQ ID NO.

2.

6. The method for improving plant stress resistance according to claim 5, characterized in that: The nucleic acid sequence of the IbNFYA3 gene is shown in SEQ ID NO.

1.

7. The method for improving plant stress resistance according to claim 5, characterized in that: The stress resistance is at least one of high salt resistance and drought resistance.

8. The method for improving plant stress resistance according to claim 5, characterized in that: The method of transforming the plant body is one of the following: Agrobacterium-mediated method, gene gun method, electric shock method, PEG method, and liposome method.

9. The method for improving plant stress resistance according to claim 8, characterized in that: The Agrobacterium is Agrobacterium tumefaciens or Agrobacterium rhizogenes.

10. A product for improving plant stress resistance, characterized in that: It is a recombinant expression vector, expression cassette, recombinant bacteria, recombinant virus or transgenic cell line containing the IbNFYA3 gene sequence; the nucleic acid sequence of the IbNFYA3 gene is shown in SEQ ID NO:1.

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