Brassica napus cold-resistant gene BnERF070 and application thereof

Abstract

The invention discloses a brassica napus cold-resistant gene BnERF070 and an application thereof. The invention discloses an application of a brassica napus BnERF070 gene and an encoded protein thereof in improving stress resistance of plants, the nucleotide sequence of the brassica napus BnERF070 gene is as shown in SEQ ID NO: 1, and the amino acid sequence of the encoded protein is as shown in SEQ ID NO: 2. According to the invention, an AP2 / ERF family transcription factor gene BnERF070 induced by low temperature stress is cloned from brassica napus, and the gene is related to plant stress resistance. By heterologous expression of the gene in arabidopsis thaliana, it is proved that the survival rate of the plant in a low-temperature environment is further improved, the relative conductivity is reduced, the damage degree after low-temperature stress is small, the malonaldehyde content and the superoxide dismutase activity are improved, expression of cold-resistant genes is promoted, and the cold resistance of the plant is improved by transferring the BnERF070.

Description

Technical Field

[0001] This invention relates to the field of plant biotechnology, specifically to the cold-resistant gene BnERF070 in Brassica napus and its applications. Background Technology

[0002] Brassica napus (Brassica napus type) possesses excellent traits such as high yield and lodging resistance in production. Furthermore, its above-ground growth before winter is significantly greater than that of Chinese cabbage (Brassica rapa type), playing a crucial role in increasing surface vegetation cover and reducing dust storms. However, harsh natural conditions such as low temperatures in winter and spring leave a large amount of fallow land in arid and cold regions. The disease-resistant, high-yielding, and high-quality Brassica napus is rarely distributed in northern regions, primarily because it cannot withstand the low temperatures of the north. Low-temperature stress is one of the most significant natural disasters in arid and cold regions. Low-temperature injury easily leads to decreased seed vigor, uneven emergence, and seedling frost damage, severely impacting rapeseed yield and quality. Currently, many scholars have conducted research on methods for identifying rapeseed cold resistance, its physiological and biochemical characteristics, and the discovery of cold-resistant genes. However, the availability of cold-resistant genes and germplasm suitable for production remains scarce, and the progress in improving rapeseed cold resistance is still very limited. The AP2 / ERF family of transcription factors in rapeseed, through synergistic effects with other transcription factors in the plant, respond to adverse conditions such as low temperature and regulate plant growth under stress conditions. However, there are few reports on how the AP2 / ERF gene in rapeseed participates in the regulation of cold resistance in rapeseed. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and to provide the cold-resistant gene BnERF070 of Brassica napus and its application.

[0004] This invention cloned a low-temperature stress-induced AP2 / ERF family transcription factor gene, BnERF070, from Brassica napus and verified its function in cold resistance by heterologous expression of the gene in Arabidopsis thaliana, providing a reference for the innovation of cold-resistant germplasm of rapeseed using this gene.

[0005] The first objective of this invention is to provide the application of the BnERF070 gene of Brassica napus and its encoded protein in improving plant stress resistance.

[0006] A second objective of this invention is to provide a recombinant vector.

[0007] The third objective of this invention is to provide a recombinant engineered bacterium.

[0008] The fourth objective of this invention is to provide a method for improving plant stress resistance.

[0009] The fifth objective of this invention is to provide a method for cultivating stress-resistant plants.

[0010] In order to achieve the above object, the present invention is implemented through the following scheme:

[0011] In a first aspect, the present invention provides the application of the Brassica napus BnERF070 gene and its encoded protein in improving plant stress resistance. The nucleotide sequence of the Brassica napus BnERF070 gene is shown in SEQ ID NO: 1, and the amino acid sequence of its encoded protein is shown in SEQ ID NO: 2.

[0012] Furthermore, the aforementioned resistance includes cold resistance.

[0013] Secondly, the present invention provides a recombinant vector containing the Brassica napus BnERF070 gene.

[0014] Furthermore, the recombinant vector uses the pCambia1300 vector as the backbone vector.

[0015] Thirdly, the present invention provides a recombinant engineered bacterium in which the recombinant vector is expressed.

[0016] Fourthly, the present invention provides a method for improving plant stress resistance by expressing the Brassica napus BnERF070 gene and its encoded protein in plants.

[0017] Furthermore, the recombinant vector was transferred into recipient plants to obtain stress-resistant plants that overexpressed the BnERF070 gene.

[0018] Furthermore, the recombinant vector was transformed into Agrobacterium using an electroporation method to obtain positive Agrobacterium. The positive Agrobacterium was then transferred into recipient plants using a flower dipping method to obtain stress-resistant plants that overexpress the BnERF070 gene.

[0019] In a preferred embodiment of the present invention, the Agrobacterium includes Agrobacterium GV3101.

[0020] Fifthly, the present invention provides a method for cultivating stress-resistant plants by expressing the Brassica napus BnERF070 gene and its encoded protein in the plant.

[0021] Furthermore, the aforementioned resistance includes cold resistance.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention cloned a low-temperature stress-induced AP2 / ERF family transcription factor gene, BnERF070, from Brassica napus, which is associated with plant stress resistance. Through heterologous expression of this gene in Arabidopsis thaliana, it was demonstrated that transformation with BnERF070 further improved plant survival rate in low-temperature environments, reduced relative conductivity, minimized damage after low-temperature stress, increased malondialdehyde content and superoxide dismutase activity, promoted the expression of cold-resistance genes, and thus enhanced plant cold resistance. Attached Figure Description

[0024] Figure 1 for BnERF070 Gene and protein structure analysis. Black rectangles represent coding sequences (CDS); gray rectangles represent uncoding sequences (UTR). Blue rectangles represent... BnERF070 The conserved structural domain AP2 / ERF of the protein.

[0025] Figure 2 Under normal conditions and after low-temperature treatment BnERF070 Gene expression analysis. The white bars represent CK, indicating the expression of genes in the third leaf of Brassica napus (5-6 leaf stage) grown under normal conditions. BnERF070 Relative expression levels; gray bars represent Cold, indicating the expression level in the third leaf of Brassica napus after low-temperature treatment. BnERF070 Relative expression level. BnActin (Gene ID ZS11C01G046950 in version v10) is the internal reference gene. 207, 208, and 209 are three different Brassica napus lines. Results are the means of three biological replicates with calculated standard errors. An asterisk indicates a significant difference between two groups (0.01 < *). P < 0.05; 0.001 < ** P < 0.01; *** P < 0.001; ns indicates no significant difference; unpaired two-tailed t-test).

[0026] Figure 3 For Arabidopsis thaliana BnERF070 The introduction of [a specific substance] promotes its cold resistance. Among them, A represents wild-type Arabidopsis thaliana (Col-0) and [other species]. BnERF070Phenotypic diagrams of two overexpressed transgenic lines (400-9 and 400-10, T3 generation homozygotes, respectively). CK represents the phenotype of Arabidopsis thaliana grown under normal conditions; Cold represents the phenotype of Arabidopsis thaliana grown under normal conditions after low-temperature treatment; Recover represents the phenotype of Arabidopsis thaliana after low-temperature treatment and subsequent return to normal growth conditions for 7 days of culture; B represents the survival rate of wild-type Arabidopsis thaliana and transgenic lines after 7 days of culture following low-temperature treatment and return to normal growth conditions. The results are the means and standard deviations of three biological replicates, each containing 16 plants; C represents the relative electrolytic leakage of wild-type Arabidopsis and transgenic lines under CK and Cold conditions; D represents the soluble sugar content of wild-type Arabidopsis and transgenic lines under CK and Cold conditions; E represents the malondialdehyde (MDA) content of wild-type Arabidopsis and transgenic lines under CK and Cold conditions; F represents the superoxide dismutase (SOD) activity of wild-type Arabidopsis and transgenic lines under CK and Cold conditions; G represents the activity of wild-type Arabidopsis and transgenic lines under CK and Cold conditions. BnERF070 The relative expression levels; H represents the wild-type Arabidopsis and transgenic lines under CK and Cold conditions. AtCBF1 The relative expression levels; I represents the wild-type Arabidopsis and transgenic lines under CK and Cold conditions. AtCBF2 The relative expression levels; J represents the wild-type Arabidopsis and transgenic lines under CK and Cold conditions. AtCBF3 The relative expression levels. AtUBC (AT5G25760) was used as the internal reference gene; the results are the means of three biological replicates with standard errors calculated. An asterisk indicates a significant difference between the two groups (0.01 < *). P < 0.05; 0.001 < ** P < 0.01; *** P < 0.001; ns indicates no significant difference; unpaired two-tailed t-test); different lowercase letters indicate significant differences between data, and the difference analysis method is one-way ANOVA / T multiple comparison method (P < 0.05). Detailed Implementation

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific examples. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available unless otherwise specified.

[0028] Example 1: Detection of BnERF070 gene expression under low temperature stress

[0029] I. Experimental Methods

[0030] BnERF070 is a transcription factor belonging to the AP2 / ERF family, located on chromosome A02 of Brassica napus, specifically at positions 11948157–11948660. The reference sequence is from the BnIR (Brassica napus multi-omics information resource) database (https: / / yanglab.hzau.edu.cn / BnIR / germplasm_info?id=ZS11.v10), with the gene ID ZS11A02G019870 (V10 version). The coding sequence CDS is 504 bp long. The physicochemical properties of the protein include: an amino acid sequence length of 167 aa, a molecular weight of 18588.07 Da, an isoelectric point (pI) of 9.58, a net charge of 12.14 at pH 7.0, an instability index (II) of 48.12 (greater than 40, indicating that the protein is unstable), an aliphatic index of 67.90, and a total average hydrophilicity of -0.654 (less than 0 indicates that the protein is hydrophilic, meaning that the protein is easily soluble in water).

[0031] The nucleotide sequence of the BnERF070 gene is shown in SEQ ID NO: 1, with a full length of 504 bp. This gene contains only one exon and no introns. Its CDS nucleotide sequence is shown in SEQ ID NO: 1, with a full length of 504 bp, encoding 167 amino acids. The amino acid sequence of the protein encoded by the BnERF070 gene is shown in SEQ ID NO: 2. The protein contains a conserved AP2 / ERF domain, see [link to SEQ ID NO: 1]. Figure 1 .

[0032] Plump seeds of Brassica napus (207, 208, and 209, varieties bred by the Cotton Research Institute of Shanxi Agricultural University) were selected for tray seedling cultivation and placed in an artificial climate incubator (light / dark cycle 16 h, 30℃ / 8 h, 28℃; light intensity 6000 μmol·m⁻¹). -2 ·s -1 Germination occurs in the soil. Once the seeds show signs of germination and whitening, transplant them into 10cm x 10cm resin pots (3 parts potting soil to 1 part vermiculite). Plant 3 seedlings per pot. Place the potted plants in a light incubator (temperature: 22℃ / 20℃ day / night; light / dark cycle: 16 h / 8 h; light intensity: 6000 μmol·m⁻¹). -2 ·s -1The plants were cultured; once they reached the 5-6 leaf stage, potted plants with uniform growth were selected and transferred to a pre-cooled low-temperature incubator for -10℃ low-temperature treatment for 1 h. RNA was extracted from leaves of different materials before and after low-temperature treatment. Reverse transcription of the RNA was performed using the HiScript® II 1st Strand cDNA Synthesis Kit (Vazyme, R211-01). The obtained reverse transcription reaction solution was diluted 10-fold with H2O as a template, and the expression levels of each gene were detected using quantitative primers. The primers are shown in Table 1.

[0033] Table 1 Primer Sequences

[0034]

[0035] The quantitative reagent was ChamQ SYBR® qPCR Master Mix (Vazyme, Q311-02). The reaction system consisted of: 5 μL of 2×ChamQ SYBR qPCR Green Master Mixa, 0.5 μL each of forward and reverse primers (100 μM concentration), and 4 μL of template cDNA. Each experiment included 3 sample replicates and 2 technical replicates. The RT-qPCR program (instrument: Bio-Rad CFXDuet) settings are shown in Table 2.

[0036] Table 2 RT-qPCR reaction procedure

[0037]

[0038] After the experiment, the relative expression levels of the target gene were calculated using Excel software, and graphs were generated using GraphPad Prism 8.0.

[0039] 2. Experimental Results

[0040] like Figure 2 As shown, after being treated with a low temperature of -10℃ for 1 h at the 5-6 leaf stage, the expression level of the BnERF070 gene in Brassica napus was significantly upregulated, indicating that the expression of the BnERF070 gene was positively regulated by cold stimulation.

[0041] Example 2: Identification of cold resistance in transgenic Arabidopsis thaliana

[0042] I. Construction of BnERF070 overexpression vector, Arabidopsis transformation and identification of positive plants

[0043] 1. Carrier Construction

[0044] Using cDNA from the Shuang11 gene of Brassica napus as a template, the BnERF070 gene fragment was amplified using a high-fidelity DNA polymerase kit (Phanta Max Super-Fidelity DNA Polymerase, catalog number P505-d1, Nanjing Novizan Biotechnology Co., Ltd.) and primer combinations BnERF-12(+): cagtGGTCTCacaacatgaagcgcatcgtcagaat and BnERF-12(-): cagtGGTCTCatacatcacgcgactcgagcaacgg. The amplification program was as follows: 95℃, 5 min; 95℃, 15 s, 56℃, 15 s, 72℃, 30 s, 35 cycles; 72℃, 5 min; 16℃, 30 min. The amplification system consisted of: 25 μL of 2 × Phanta Max Buffer, 1 μL of 10 mM dNTP Mix, 2 μL each of forward and reverse primers (10 μM), 1 μL of Phanta Max Super-Fidelity DNA Polymerase, 2 μL of template DNA, and 17 μL of ddH2O.

[0045] After amplification, the BnERF070 gene fragment was recovered and digested with the pCambia1300 vector (CAMBIA, http: / / www.cambia.org / ) using Eco31I (BsaI) at 37°C for 1 h. After the reaction, AxyPreP was used... TM The enzyme digestion products were recovered using a PCR Cleanup Kit (AxyGEN, AP-PCR-250) to obtain the target fragment and vector backbone. The target fragment was ligated to the vector backbone using T4 DNA ligase (TransGen, FL101) at 22°C for 1 hour, yielding the pCambia1300-BnERF070 recombinant vector. This pCambia1300-BnERF070 recombinant vector was then transformed into Agrobacterium GV3101 via electroporation to obtain Agrobacterium GV3101 containing the pCambia1300-BnERF070 recombinant vector, which was then used for further processing.

[0046] The specific operating procedure for transforming Agrobacterium tumefaciens by electroporation is as follows:

[0047] (1) Take GV3101 competent cells, thaw them on ice, add 2 μL of recombinant vector containing pCambia1300-BnERF070, mix gently, transfer all of them to an electroporation cup, cool on ice, and cover.

[0048] (2) Place the shock cup into the slot of the shocker and administer the shock.

[0049] (3) After the electric shock, add 1 mL of LB liquid culture medium to the electric shock cup, mix it with a pipette with a 1 mL range, and then transfer all the liquid in the electric shock cup to a 1.5 mL EP tube.

[0050] (4) Incubate at 28℃ and 220 rpm for 3-4 h.

[0051] (5) Take 200 μL of bacterial solution and spread it evenly on an LB solid medium plate containing Rif (100 μg / mL) and Kana (50 μg / mL), and incubate at 28℃ for 2 days until single colonies grow.

[0052] (6) Select well-grown single colonies for plaque PCR identification. Select positive plaques into glass tubes containing 4 mL of liquid LB medium with Rif (100 μg / mL) and Kana (50 μg / mL) resistance, and incubate overnight at 220 rpm in a shaking incubator at 28℃.

[0053] (7) The next day, the positive bacterial solution was preserved with 40% (v / v) glycerol (the bacterial solution and glycerol were mixed at a volume ratio of 1:1) and stored in an ultra-low temperature freezer at -75℃.

[0054] 2. The Arabidopsis thaliana was transformed using the flower-dipping method. The procedure is as follows:

[0055] (1) Take 30 μL of Agrobacterium GV3101 bacterial culture containing the pCambia1300-BnERF070 recombinant vector and transfer it to 4 mL of LB medium with Rif (100 μg / mL) and Kana (50 μg / mL) resistance. Incubate overnight in a shaking incubator (28℃, 220 rpm).

[0056] (2) Add the above bacterial culture to 30 mL of LB medium containing Rif (100 μg / mL) and Kana (50 μg / mL) and incubate overnight in a shaking incubator (28℃, 220 rpm).

[0057] (3) Place in a centrifuge and run at 4,000 rpm for 20 min. Discard the supernatant and collect the bacterial cells.

[0058] (4) Resuspend the bacterial cells (OD) in 5% (w / v) sucrose solution. 600Add Silwet L-77 (0.8%) before dipping the flowers to obtain an Agrobacterium suspension, and transfer it to a 250 mL beaker. For Col-0 background materials, use 0.02% Silwet L-77, and add Silwet L-77 immediately before use.

[0059] (5) Remove the siliques and open flowers from the Arabidopsis thaliana Col-0 plants used for transgenic transformation, and immerse the entire inflorescence in Agrobacterium suspension for 1 min to obtain the plant after flower immersion.

[0060] (6) After soaking the flowers, place the plants horizontally in the dark overnight, then transfer them to a greenhouse under light to grow normally and wait for harvesting.

[0061] 3. Positive identification of transgenic plants

[0062] Seeds were harvested and planted. A 1 / 2 MS medium (Murashige & Skoog Medium) containing 50 μg / L termethin and 50 μg / mL hygromycin was used as the selection medium for positive screening of T0 generation transgenic Arabidopsis thaliana. Positive seedlings were obtained: seeds were sterilized with 10% (v / v) bleach solution for 10 min and washed three times with sterile water to obtain sterilized seeds. The sterilized seeds were spread on 1 / 2 MS medium and vernalized at 4℃ for 3 days to break seed dormancy. The seeds were then transferred to a light incubator with 16 h light / 8 h darkness at 21–22℃ (subsequent culture conditions remained the same). After 10 days of growth on the selection medium, the normally growing seedlings were transplanted into nutrient soil (substrate to vermiculite volume ratio of 2:1). Once the seedlings reached flowering stage, RNA was extracted from their leaves. Two transgenic lines, 400-9 and 400-10, expressing BnERF070 were obtained by qRT-PCR. Homozygous screening was performed on these two lines, and the resulting T3 generation positive homozygous lines were used for evaluating and identifying the cold tolerance of Arabidopsis thaliana. The qRT-PCR primers and methods were the same as those in Tables 1 and 2 of Example 1.

[0063] II. Evaluation and identification of cold resistance in Arabidopsis thaliana

[0064] The steps are as follows: The incubator will be placed in a light-controlled incubator (temperature: day / night 22℃ / 20℃; light / dark cycle 16 h / 8 h; light intensity 6000 μmol·m). -2 ·s -1Wild-type Arabidopsis thaliana (Col-0) and two transgenic lines (400-9, 400-10) were cultured for 30 days and then subjected to low-temperature treatment at -5℃. After 24 hours, the growth status of the plants was observed. Leaves of different materials after low-temperature treatment were taken for subsequent physiological index determination and gene expression analysis. After sampling, the plants were restored to normal growth conditions and cultured for another 7 days. The survival and growth status of the plants were then observed and statistically analyzed.

[0065] III. Experimental Results

[0066] Arabidopsis thaliana plants grown under normal conditions for 30 days were treated at -5℃ for 24 h. Both the wild-type Col-0 and two transgenic lines overexpressing BnERF070 exhibited leaf dehydration and wilting. After being returned to normal conditions for 7 days, some plants withered and died, while others survived, showing withered old leaves but still vibrant new leaves and stem tips. The survival rate of the wild-type plants was 19.8%, while the survival rates of the transgenic lines 400-9 and 400-10 were 52.08% and 47.91%, respectively. The survival rates of the two transgenic lines overexpressing BnERF070 were significantly higher than those of the wild-type plants. Figure 3 A and Figure 3 B).

[0067] Example 3: Determination of physiological indicators in Arabidopsis plants with overexpression of the BnERF070 gene after cold stress

[0068] I. Experimental Methods

[0069] The relative conductivity, soluble sugar, malondialdehyde, and superoxide dismutase content of wild-type Arabidopsis thaliana and transgenic lines (400-9, 400-10) after being treated at -5℃ for 24 h in Example 2 were measured. Wild-type Arabidopsis thaliana and transgenic lines (400-9, 400-10) that had not undergone low-temperature treatment were used as controls.

[0070] The relative conductivity was measured using a DDS-11A conductivity meter (Shanghai Instrument & Electronics Scientific Instruments Co., Ltd.).

[0071] The contents of soluble sugar, malondialdehyde, and superoxide dismutase were detected using a kit from Nanjing Jiancheng Bioengineering Institute. Specifically, the contents of soluble sugar were determined by the anthrone colorimetric method (catalog number A145-1-1), the contents of malondialdehyde were determined by the TBA method (catalog number A003-1), and the contents of superoxide dismutase were determined by the hydroxylamine method (catalog number A001-1).

[0072] 2. Experimental Results

[0073] After low-temperature treatment, the relative electrical conductivity of both wild-type Arabidopsis and transgenic lines (400-9, 400-10) was significantly increased. The relative electrical conductivity of the two transgenic lines was lower than that of wild-type Arabidopsis under both normal conditions and after low-temperature treatment. Figure 3 C) indicates that the transgenic lines suffered less damage to their leaves after cold stress. Under normal conditions and after low-temperature treatment, the soluble sugar content increased in both wild-type Arabidopsis and transgenic lines (C). Figure 3 D), the malondialdehyde content and superoxide dismutase activity of the transgenic lines were higher than those of wild-type Arabidopsis thaliana (D). Figure 3 E and Figure 3 F).

[0074] Example 4: Detection of cold-resistance gene expression levels in Arabidopsis transgenic lines overexpressing the BnERF070 gene

[0075] I. Experimental Methods

[0076] RNA was extracted from wild-type Arabidopsis thaliana and transgenic lines (400-9, 400-10) after being treated at -5℃ for 24 h in Example 2. Wild-type Arabidopsis thaliana and transgenic lines (400-9, 400-10) without refrigeration were used as controls. Reverse transcription of the RNA was performed using the HiScript® II 1st Strand cDNA Synthesis Kit (Vazyme, R211-01). The resulting reverse transcription reaction solution was diluted 10-fold with H2O as a template, and the expression levels of each gene were detected using quantitative primers. The primers are shown in Table 3.

[0077] Table 3 Primer Sequences

[0078]

[0079] The quantitative reagent used was ChamQ SYBR® qPCR Master Mix (Vazyme, Q311-02). The reaction system consisted of: 5 μL of 2×ChamQ SYBR qPCR Green Master Mixa, 0.5 μL each of forward and reverse primers (100 μM concentration), and 4 μL of template cDNA. Each experiment included 3 sample replicates and 2 technical replicates. The RT-qPCR program (instrument: Bio-Rad CFXDuet) settings are shown in Table 2. After the experiment, the relative expression levels of the target gene were calculated using Excel software, and graphs were generated using GraphPad Prism 8.0.

[0080] 2. Experimental Results

[0081] BnERF070 is not expressed in wild-type Arabidopsis thaliana, but it is highly expressed in transgenic lines (400-9, 400-10) under both normal conditions and low-temperature treatment. Figure 3 G); The key genes AtCBF1, AtCBF2, and AtCBF3, which have been reported to be crucial for plant cold resistance in Arabidopsis thaliana, were all highly expressed under low-temperature induction, and the expression level of AtCBF1 in the transgenic line 400-9 was significantly higher than that in wild-type Arabidopsis thaliana (G). Figure 3 H), the expression levels of AtCBF2 and AtCBF3 in transgenic line 400-10 were significantly higher than those in wild-type Arabidopsis thaliana (H). Figure 3 I and Figure 3 The results (J) indicate that overexpression of the BnERF070 gene promotes the expression of the core cold resistance regulator CBF. These indicators all suggest that overexpression of the BnERF070 gene promotes the cold resistance of transgenic Arabidopsis thaliana.

[0082] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that other variations or modifications may be made based on the above descriptions and concepts. It is not necessary and impossible to provide an exhaustive list of all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Application of the Brassica napus BnERF070 gene and its encoded protein in improving plant stress resistance, wherein the nucleotide sequence of the Brassica napus BnERF070 gene is shown in SEQ ID NO: 1, and the amino acid sequence of its encoded protein is shown in SEQ ID NO:

2.

2. The application according to claim 1, characterized in that, The aforementioned resistance includes cold resistance.

3. A recombinant vector, characterized in that, The recombinant vector contains the Brassica napus BnERF070 gene as described in claim 1.

4. The recombinant vector according to claim 3, characterized in that, The recombinant vector uses pCambia1300 as the backbone vector.

5. A recombinant engineered bacterium, characterized in that, The recombinant engineered bacteria express the recombinant vector of claim 3 or 4.

6. A method for improving plant stress resistance, characterized in that, Express the BnERF070 gene and its encoded protein of Brassica napus as described in claim 1 in plants.

7. The method according to claim 6, characterized in that, The recombinant vector described in claim 3 or 4 is transferred into the recipient plant to obtain a stress-resistant plant that overexpresses the BnERF070 gene.

8. The method according to claim 6, characterized in that, The recombinant vector described in claim 3 or 4 is transformed into Agrobacterium by electroporation to obtain positive Agrobacterium. The positive Agrobacterium is then transformed into recipient plants by flower immersion to obtain stress-resistant plants that overexpress the BnERF070 gene.

9. A method for cultivating stress-resistant plants, characterized in that, Express the BnERF070 gene and its encoded protein of Brassica napus as described in claim 1 in plants.

10. The method according to any one of claims 6 to 9, characterized in that, The aforementioned resistance includes cold resistance.

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