Application of wheat gene TaSNAC11 in improving salt tolerance of plants

Abstract

The invention discloses application of a wheat gene TaSNAC11 in improvement of plant salt tolerance, and belongs to the technical field of functional genomics. Wherein the nucleotide sequence of the wheat gene TaSNAC11 is as shown in SEQ ID NO: 2, and the gene can improve the tolerance of plants to salt stress. The wheat gene TaSNAC11 has the beneficial effects that the wheat gene TaSNAC11 is transformed into the model plant arabidopsis thaliana, the salt tolerance of the arabidopsis thaliana can be obviously improved, if the wheat gene TaSNAC11 is transformed into plants such as wheat, rice, corn and cauliflower, new germplasm with salt tolerance can be possibly obtained, and the new germplasm can be used as a new germplasm. The method is of great significance to cultivation of new varieties of excellent crops and wide application of the new varieties of the excellent crops in production.

Description

Technical Field

[0001] The invention relates to an application of a gene, in particular to an application of a wheat gene TaSNAC11 in improving plant salt tolerance, and belongs to the technical field of functional genomics. Background Art

[0002] Salt stress is a serious adverse environmental factor that can cause osmotic stress, cell ion toxicity, and oxidative stress to crops, which in turn inhibits seed germination, reduces photosynthetic performance, and stagnates growth and development, seriously affecting crop yields. China's land salinization area has reached 100 million hm2. 2 , and is still on the rise. Triticum aestivum ) is an important food crop in my country and occupies an important strategic position in ensuring national food security. Soil salinization has become one of the important unfavorable factors affecting the growth and yield of wheat in my country. Therefore, improving the salt tolerance of wheat is one of the important ways to ensure national food security, and breeding salt-tolerant varieties is an effective measure to improve the salt tolerance of wheat. Further exploration and identification of key salt-tolerant genes is a scientific and reasonable biotechnology means to breed salt-tolerant varieties. Summary of the invention

[0003] The present invention screened and cloned the wheat gene TaSNAC11 from Chinese Spring (CS) wheat, and confirmed that the gene can effectively improve the salt tolerance of Arabidopsis thaliana.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: The invention discloses an application of wheat gene TaSNAC11 in improving plant salt tolerance. The nucleotide sequence of wheat gene TaSNAC11 is shown in SEQ ID NO: 2. The gene can improve plant tolerance to salt stress.

[0005] Preferably, the aforementioned application comprises the following steps: (1) PCR amplification and cloning of wheat gene TaSNAC11; (2) Connecting the cloned wheat gene TaSNAC11 into an expression vector to obtain an overexpression recombinant vector; (3) Transforming the overexpression recombinant vector into Agrobacterium to obtain an overexpression recombinant strain; (4) The overexpression recombinant strain was transformed into plants, and the wheat gene TaSNAC11 overexpression strain was screened and obtained.

[0006] More preferably, the aforementioned expression vector is super1300 (GFP-C); and the aforementioned Agrobacterium is Agrobacterium tumefaciens GV3101.

[0007] The benefit of the present invention lies in that the salt tolerance of Arabidopsis thaliana can be significantly improved by transforming the wheat gene TaSNAC11 into the model plant Arabidopsis thaliana. If the wheat gene TaSNAC11 is transformed into plants such as wheat, rice, corn, and cauliflower, it is possible to obtain new germplasm with salt tolerance, which is of great significance for the cultivation of new varieties of excellent crops and the wide application of new varieties of excellent crops in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of the structure of the destination vector super1300 (GFP-C); Figure 2 is the PCR identification image of TaSNAC11 overexpressing transgenic Arabidopsis lines (OE1 and OE2); Figure 3 It is a statistical diagram of the relative expression level of the gene TaSNAC11 in the TaSNAC11 overexpressing transgenic Arabidopsis lines (OE1, OE2) and the wild type (WT) gene TaSNAC11 in the Columbia ecotype Arabidopsis; Figure 4 It is a statistical graph of the germination rate of transgenic Arabidopsis seeds (OE1, OE2) overexpressing TaSNAC11 and wild-type Arabidopsis seeds (WT) of the Columbia ecotype Arabidopsis after ABA treatment; Figure 5 It is a statistical graph of the germination rate of TaSNAC11 overexpressing transgenic Arabidopsis seeds (OE1, OE2) and wild-type Arabidopsis seeds (WT) of the Columbia ecotype Arabidopsis after salt stress treatment; Figure 6 This is a comparison chart of the root growth of each strain under normal conditions (control group); Figure 7 is the statistical graph of root length of each strain under normal conditions (control group); Figure 8 This is a comparison of the root growth of each strain under salt stress treatment conditions; Fig. 9 is the statistical graph of root length of each strain under salt stress treatment; Fig.10 It is the statistical graph of plant height of each strain under normal conditions and under salt stress treatment conditions; Fig.11 It is the fresh weight statistics of each strain under normal conditions and under salt stress treatment conditions; Fig.12 It is the statistical graph of dry weight of each strain under normal conditions and under salt stress treatment conditions; Fig.13 It is the statistical graph of relative conductivity of each strain under normal conditions and under salt stress treatment conditions; Fig.14It is a statistical graph of chlorophyll content of each strain under normal conditions and under salt stress treatment conditions; Fig.15 It is the statistical graph of SOD activity of each strain under normal conditions and under salt stress treatment conditions; Fig.16 It is a statistical graph of POD activity of each strain under normal conditions and under salt stress treatment conditions. DETAILED DESCRIPTION

[0009] The present invention is described in detail below in conjunction with the accompanying drawings and examples. The reagents, materials and instruments used in the examples are all commercially available unless otherwise specified. The terms used in the examples, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The experimental methods used in the examples are conventional methods unless otherwise specified.

[0010] Example 1: Cloning of wheat gene TaSNAC11 Wheat is an important food crop with a wide planting range. It is also a crop with strong adaptability to harsh external environments. The present invention attempts to screen salt-tolerant genes from wheat, and finally screens a salt-tolerant gene from Chinese Spring (CS) wheat. In the Ensembl Plants database, the gene number of the gene is TraesCS4A02G131000.1, which is located on wheat chromosome 4A, with an ORF (open reading frame) of 1065bp, an mRNA length of 1657bp, and a nucleotide sequence as shown in SEQ ID NO: 2. The size of its encoded product is 354 amino acids, the molecular weight is 38389.46, and the isoelectric point is 9.23. The present invention named the gene TaSNAC11 and cloned it using cloning technology. The specific steps are as follows: Total RNA was extracted from leaves of Chinese spring (CS) wheat grown in water for 7 days using the Trizol method. After purification, cDNA was obtained by reverse transcription using HiScript Ⅲ RT SuperMix for qPCR (+gDNA wiper) reverse transcriptase. The cDNA was used as a template to amplify the gene TaSNAC11 using the upstream primer L1 shown in SEQ ID NO: 3 and the downstream primer R1 shown in SEQ ID NO: 4. The amplified product was sequenced to determine the nucleotide sequence of the target gene.

[0011] The nucleotide sequences of the upstream primer L1 and the downstream primer R1 are shown below: Upstream primer L1: 5′-ATGATCATGTCCGACCCG-3′ (SEQ ID NO: 3); Downstream primer R1: 5′-GAAACGGAGCAGCGTCTG-3′ (SEQ ID NO: 4).

[0012] The PCR reaction system for amplifying the gene TaSNAC11 was: ddH2O 8 μL, 2×Phanta Max Master Mix (Dye Plus) 12.5 μL, upstream primer L1 1 μL, downstream primer R1 1 μL, and cDNA template 2.5 μL.

[0013] The PCR reaction conditions for amplifying the gene TaSNAC11 were as follows: 95°C, 3 min; 95°C, 15 s, 59°C, 15 s, 72°C, 30 s, repeated for 35 cycles; 72°C extension for 5 min, and finally storage at 4°C.

[0014] The obtained PCR amplification products were electrophoresed in 1% agarose gel, and the fragments with a sequence length of about 1062 bp were recovered, and then TM The TA / Blunt-Zero Cloning Kit was connected to pCE2 TA / Blunt-Zero and transformed into E. coli Fast-T1 competent cells, and positive clones were selected for sequencing.

[0015] The sequencing results showed that a DNA fragment with a sequence length of 1062bp was inserted into the pCE2 TA / Blunt-Zero vector. The nucleotide sequence of the DNA fragment is shown in SEQ ID NO: 2, which is consistent with the nucleotide sequence of the gene with gene number TraesCS4A02G131000.1 in the Ensembl Plants database without the termination codon, and was confirmed to be the full-length cDNA sequence of the wheat gene TaSNAC11.

[0016] Example 2: Construction of recombinant expression vector 1. Amplification of target gene XbaI restriction sites were added to the 5' ends of the upstream primer L1 and the downstream primer R1 to obtain the upstream primer L2 and the downstream primer R2. The nucleotide sequences of the upstream primer L2 and the downstream primer R2 are as follows: Upstream primer L2: 5'-ATACACCAAATCGACTCTAGAATGATCATGTCCGACCCG-3' (SEQ ID NO: 5); Downstream primer R2: 5'-CATAGGTACCCGGGCTCTAGAGAAACGGAGCAGCGTCTG-3' (SEQ ID NO: 6).

[0017] PCR amplification was performed using the positive Escherichia coli culture containing the pCE2 TA / Blunt-Zero recombinant vector obtained in Example 1 as a template.

[0018] The PCR reaction system was: ddH2O 8 μL, 2×Phanta Max Master Mix (Dye Plus) 12.5 μL, upstream primer L2 1 μL, downstream primer R2 1 μL, and template 2.5 μL.

[0019] The PCR reaction program was as follows: 95°C, 3 min; 95°C, 15 s, 59°C, 15 s, 72°C, 30 s, repeated for 35 cycles; 72°C extension for 5 min, and finally storage at 4°C.

[0020] The PCR product (target gene) with a sequence length of about 1062 bp was recovered and used for subsequent reactions.

[0021] 2. Vector linearization Using QuickCut TM The target vector super1300 (GFP-C) was linearized by restriction endonuclease XbaI. The structure of the target vector super1300 (GFP-C) is shown in Figure 1 , and obtain the linearized cloning vector.

[0022] Enzyme digestion system: plasmid 1μg, 10×QuickCut Green Buffer 2μL, QuickCut TM XbaI 1 μL, add ddH2O to 20 μL.

[0023] Reaction conditions: incubate at 37°C for 3 h.

[0024] 3. Connect the target gene to the cloning vector The target gene obtained in step 1 was connected to the linearized cloning vector obtained in step 2 using CloneExpress Ⅱ One step Cloning Kit (Vayme) to obtain the recombinant expression vector super1300 (GFP-C)-TaSNAC11.

[0025] The ligation system was as follows: linearized super1300 (GFP-C) 3 μL, target gene 1 μL, 5×CE Ⅱ Buffer 2 μL, Exnase Ⅱ 1 μL, ddH2O 3 μL.

[0026] Reaction conditions: Use a pipette to gently mix the connection system, centrifuge briefly to collect the liquid at the bottom of the tube, and react at 37℃ for 30 minutes.

[0027] 4. Screening and identification of target gene clones The specific steps for screening and identifying target gene clones are as follows: (1) Take 10 μL of the recombination reaction product obtained in step 3 and transform competent cells of Escherichia coli Fast-T1. Incubate at 37°C for 12 h (the culture medium is LB solid medium supplemented with 50 μg / mL kanamycin sulfate). (2) Pick a single clone obtained in step (1) and culture it at 37°C and 180 rpm for 12 h (the culture medium is LB liquid medium supplemented with 50 μg / mL kanamycin sulfate); (3) Using the bacterial solution obtained in step (2) as a template, PCR identification was performed using upstream primer L1 and downstream primer R1; (4) The bacterial solution identified as positive by PCR in step (3) was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing.

[0028] The sequencing result of the TaSNAC11 construct vector is shown in SEQ ID NO: 7. The reference sequence of the TaSNAC11 construct vector is shown in SEQ ID NO: 8. The sequencing result shows that the present invention obtains a recombinant expression vector containing the target gene (TaSNAC11), namely the recombinant expression vector super1300 (GFP-C)-TaSNAC11, and the recombinant expression vector super1300 (GFP-C)-TaSNAC11 is a linearized vector super1300 (GFP-C) with the TaSNAC11 sequence added to the XbaI site.

[0029] The plasmid was extracted from the correctly sequenced bacterial solution and stored at -20°C for subsequent Agrobacterium transformation experiments.

[0030] Example 3: Transformation of wheat gene TaSNAC11 into Arabidopsis 1. Construction of recombinant Agrobacterium The recombinant expression vector super1300 (GFP-C)-TaSNAC11 prepared in Example 2 was transformed into Agrobacterium tumefaciens GV3101 competent cells and screened and cultured at 28° C. in LB solid medium containing 50 μg / mL kanamycin sulfate and 20 μg / mL rifampicin.

[0031] Positive single clones were picked and cultured at 28°C and 180 rpm for 12 h (the culture medium was LB liquid medium supplemented with 50 μg / mL kanamycin sulfate and 20 μg / mL rifampicin).

[0032] Pipette 1 μL of bacterial solution and perform PCR identification using upstream primer L1 and downstream primer R1.

[0033] The bacterial solution that tested positive by PCR was the recombinant Agrobacterium tumefaciens containing the recombinant expression vector super1300 (GFP-C) - TaSNAC11, and the recombinant Agrobacterium tumefaciens was named GV3101 / super1300 (GFP-C) - TaSNAC11.

[0034] 2. Obtaining transgenic Arabidopsis The method for obtaining transgenic Arabidopsis thaliana is as follows: (1) Plant preparation before infection: Wild-type seeds of the Columbia ecotype Arabidopsis thaliana were vernalized at 4°C for 72 hours, sown in MS solid culture medium, and cultured in a culture room at 22°C, 15 h light / 9 h dark, and 60%-70% humidity. When they grew two true leaves, they were transplanted into a planting pot filled with a mixed culture medium (nutrient soil and vermiculite mixed in a mass ratio of 3:1). After the plants bloomed, the tops of the main branches were cut off (to promote the development of lateral branches), and sufficient water was poured on the day before infection. (2) Activation of Agrobacterium: Pour 2 mL of recombinant Agrobacterium tumefaciens GV3101 / super1300 (GFP-C) - TaSNAC11 bacterial solution into a pre-sterilized 250 mL conical flask on a clean bench, add 150 mL of LB liquid medium containing 50 μg / mL kanamycin sulfate and 20 μg / mL rifampicin, and culture in a 28°C full-temperature oscillator for 16 h until the OD 600 When the concentration reaches 0.8, divide the bacterial solution into three 50 mL centrifuge tubes, centrifuge at 5500 g for 20 min, discard the supernatant and keep the bacterial cells; (3) Prepare the resuspension: dissolve 2.5 g sucrose in 50 mL distilled water, then add 10 μL silmet-77; (4) Add the resuspension solution to the activated Agrobacterium cells in batches, 10 mL each time, and measure the OD while adding. 600 Until it reaches 0.8, a resuspended bacterial solution is obtained; (5) Infecting Arabidopsis thaliana by dipping flowers: At 9 a.m. (flowering is most vigorous at this time, which is conducive to infection), use a pipette tip to take 1 mL of the mixed resuspended bacterial solution and drop it on the Arabidopsis inflorescence for infection. After the inflorescence is fully infected, it is immediately kept in the dark for 1 day, and then watered when it is light. A second infection is performed after one week. (6) Harvesting seeds of infected Arabidopsis plants: Cultivating the Arabidopsis plants that have been treated with secondary infection by conventional methods until they are fruitful, and harvesting mature T0 generation seeds; (7) Cultivating T0 positive seedlings: Sterilize T0 seeds and then evenly spread them on MS solid medium containing 60 μL / 100 mL hygromycin. Cultivate until Arabidopsis seedlings grow true leaves, and some seedlings have healthy true leaves and roots that penetrate the medium for a longer period of time (about 14 days). Then obtain T0 positive seedlings. Move the T0 positive seedlings to a planting pot filled with mixed culture medium (nutrient soil and vermiculite mixed in a mass ratio of 3:1) for cultivation. Harvest mature T1 seeds from individual plants. (8) Cultivating the T1 generation seeds into a T1 generation strain with hygromycin resistance according to the method described in step (7); if the ratio of positive seedlings to dead seedlings is approximately 3:1, it is a single copy strain; then culturing the plants in the planting pots until they are fruitful by conventional methods, and harvesting the mature T2 generation seeds produced by each plant in the T1 generation strain; (9) Ten T2 generation seeds were randomly selected for hygromycin resistance using the same method. The strains that no longer showed hygromycin resistance were homozygous strains. Finally, two TaSNAC11 overexpressing T2 generation homozygous strains were obtained. (10) Harvest mature T3 seeds of the TaSNAC11 overexpression T2 homozygous strain (i.e., TaSNAC11 overexpression T3 homozygous transgenic Arabidopsis seeds, denoted as seeds OE1 and seeds OE2, respectively) for the next step of phenotypic identification and analysis.

[0035] The T0 generation refers to the seeds produced by the transformation generation and the plants grown from them; the T1 generation refers to the seeds produced by self-pollination of the T0 generation and the plants grown from them; the T2 generation refers to the seeds produced by self-pollination of the T1 generation and the plants grown from them; the T3 generation refers to the seeds produced by self-pollination of the T2 generation and the plants grown from them; a strain refers to the seeds or plant population produced by self-pollination of the same plant in the previous generation.

[0036] Example 4: PCR identification of homozygous transgenic Arabidopsis thaliana in the T3 generation Seeds OE1 and OE2 obtained in Example 3 were taken and cultured into plants (i.e., TaSNAC11 overexpression T3 generation homozygous transgenic lines, respectively recorded as line OE1 and line OE2) by conventional methods. Leaves of line OE1 and line OE2 were taken respectively, and DNA in the leaves was extracted by the CTAB method. PCR amplification was performed using the upstream primer L1 and the downstream primer R1.

[0037] The results of PCR product electrophoresis are shown in Figure 2 PCR identification results showed that strains OE1 and OE2 were both TaSNAC11 overexpression strains.

[0038] Example 5: Real-time fluorescence quantitative PCR detection of T3 homozygous transgenic Arabidopsis The roots of strains OE1 and OE2 and the wild-type strain of Columbia ecotype Arabidopsis (referred to as strain WT) were photographed, and total RNA was extracted using Trizol method. After purification, cDNA was obtained by reverse transcription using HiScriptⅢRT SuperMix forqPCR (+gDNA wiper) reverse transcriptase. TaSNAC11 was detected by real-time fluorescence quantitative PCR using wheat TaActin gene as internal reference gene using qRT-PCR primers.

[0039] The real-time fluorescence quantitative PCR instrument model is ABI QuantStudio3, using ChamQTMSYBR Color qPCR Master Mix reagent, and the expression level of wheat TaActin gene is used as the internal reference. The result analysis uses the comparative threshold method to quantitatively analyze the real-time fluorescence quantitative PCR results, set the fluorescence threshold value, and determine the cycle number Ct value under the fluorescence threshold value. The C value is calculated based on the Ct value, C=2 -△Ct , △Ct=Ct 目的基因 -Ct 内参基因 Calculate the average of the three replicate C values ​​as the relative expression of the target gene The reaction system was: 2×ChamQ SYBR Color qPCR Master Mix 5μL, 50×ROX ReferenceDye Ⅱ 0.2μL, upstream primer (10μM) 0.2μL, downstream primer (10μM) 0.2μL, first-strand cDNA solution diluted 3 times 0.5μL, and ddH2O 3.9μL.

[0040] The qRT-PCR amplification procedure uses a three-step approach: (1) Pre-denaturation: 95°C for 3 min; (2) Cyclic reaction: 95°C for 15 s, 59°C for 20 s, for a total of 40 cycles; (3) Melting curve: 95℃ for 15s, 60℃ for 60s, and 95℃ for 15s.

[0041] The primer sequences used for real-time fluorescence quantitative PCR in this step are as follows: Actin-L: 5'-TATGCCAGCGGTCGAACAAC-3' (SEQ ID NO: 9); Actin-R: 5'-GGAACAGCACCTCAGGGCAC-3' (SEQ ID NO: 10); qRT-L: 5'-GGTTAGCAGTCGAAGTTATCT-3' (SEQ ID NO: 11); qRT-R: 5'-TTGCGGAGGTAGTGGAGGAT-3' (SEQ ID NO: 12).

[0042] The qRT-PCR amplification results are shown in Figure 3 .Depend on Figure 3 It can be seen that the expression level of the exogenous gene TaSNAC11 in strains OE1 and OE2 is significantly higher than that in strain WT, that is, the expression level of the exogenous gene TaSNAC11 in transgenic Arabidopsis plants is significantly higher than that in wild-type plants.

[0043] Example 6: Phenotypic identification of T3 homozygous transgenic Arabidopsis plants 1. Phenotypic identification of germination rate of homozygous transgenic Arabidopsis thaliana lines overexpressing TaSNAC11 during germination ABA stress treatment medium: add 41.4g MS solid dry powder to 1L distilled water, stir and mix thoroughly, adjust pH to 6.0, sterilize at 121℃ for 15min, add appropriate amount of abscisic acid (ABA) when the medium cools to 40-50℃, make the concentration of ABA to 0.5μM, mix well and pour into a plate (round culture dish) to prepare ABA stress treatment medium with ABA concentration of 0.5μM (0.5μM ABA group). No ABA was added to the control group (CK group).

[0044] Salt stress treatment medium: 41.4g MS solid dry powder and 8.775g NaCl were added to 1L distilled water, stirred thoroughly, the pH value was adjusted to 6.0, and sterilized at 121℃ for 15min. When the medium was cooled to 40-50℃, it was poured into a plate (round culture dish) to prepare a salt stress treatment medium with a NaCl concentration of 150mM (150mM NaCl group). No NaCl was added to the control group (CK group).

[0045] The seeds OE1 and OE2 obtained in Example 3 and wild-type seeds of the Columbia ecotype Arabidopsis thaliana (referred to as seeds WT) were respectively plated on an ABA stress treatment medium containing 0.5 μM ABA or a salt stress treatment medium containing 150 mM NaCl for culture, and a control group (CK group) was set up to observe the germination of seeds in each group, and the germination rate was statistically analyzed after 10 days.

[0046] The germination rate statistics of TaSNAC11 overexpressing T3 homozygous transgenic Arabidopsis seeds OE1 and OE2 and wild-type seeds WT of the Columbia ecotype Arabidopsis under ABA stress are shown in Figure 4 .Depend on Figure 4It can be seen that under normal conditions (CK group), the germination rate of seeds OE1 and seeds OE2 had no significant difference compared with the germination rate of seeds WT; under ABA stress (0.5μM ABA group), the germination rate of seeds OE1 and seeds OE2 was significantly reduced by 12.11% and 9.53% respectively compared with the germination rate of seeds WT.

[0047] The germination rate statistics of TaSNAC11 overexpressing T3 homozygous transgenic Arabidopsis seeds OE1 and OE2 and wild-type seeds WT of the Columbia ecotype Arabidopsis under salt stress are shown in Figure 5 .Depend on Figure 5 It can be seen that under normal conditions (CK group), there was no significant difference in the germination rate of seeds OE1 and seeds OE2 compared with that of seeds WT; under salt stress (150mM NaCl group), the germination rates of seeds OE1 and seeds OE2 were significantly increased by 39.33% and 32.14% respectively compared with that of seeds WT.

[0048] The above results show that the transgenic strains have higher sensitivity to ABA during seed germination and higher tolerance to salt stress.

[0049] 2. Phenotypic identification of TaSNAC11 overexpressing homozygous transgenic Arabidopsis thaliana lines at the seedling stage Square plate salt stress treatment medium: 41.4g MS solid dry powder and 8.775g NaCl were added to 1L distilled water, stirred and mixed thoroughly, the pH value was adjusted to 6.0, and sterilized at 121℃ for 15min. When the medium was cooled to 40-50℃, it was poured into a plate (square plate) to prepare a square plate salt stress treatment medium (NaCl group) with a NaCl concentration of 150mM. No NaCl was added to the control group (CK group).

[0050] The TaSNAC11 overexpressing T3 homozygous transgenic Arabidopsis lines OE1 and OE2 and the wild-type line WT of the Columbia ecotype Arabidopsis were cultured in an incubator under normal conditions for 5 days, and then transferred to a square plate salt stress treatment medium supplemented with NaCl for vertical culture (OE1-NaCl group, OE2-NaCl group, WT-NaCl group). A control group (OE1-CK group, OE2-CK group, WT-CK group) was set up. After 10 days of culture, photos were taken and the root length of the plants was statistically analyzed.

[0051] The root growth of each strain in the control group is shown in Figure 6 , root length statistics are shown in Figure 7 .Depend on Figure 6 and Figure 7 It can be seen that under normal conditions, there is no significant difference in the root length of strains OE1 and OE2 compared with the root length of strain WT.

[0052] The root growth of each strain in the square plate salt stress group is shown in Figure 8 , root length statistics are shown in Fig. 9 .Depend on Figure 8 and Fig. 9 It can be seen that under salt stress, the root length of strains OE1 and OE2 were significantly increased by 39.33% and 43.44% respectively compared with the root length of strain WT.

[0053] 3. Phenotypic identification of TaSNAC11 overexpressing homozygous transgenic Arabidopsis thaliana lines in the adult stage TaSNAC11 overexpression T3 homozygous transgenic Arabidopsis thaliana lines OE1 and OE2 and the wild-type line WT of the Columbia ecotype Arabidopsis thaliana were cultured in round culture dishes under normal conditions for 5 days and then transferred to plastic pots filled with mixed culture matrix (nutrient soil and vermiculite mixed in a mass ratio of 3:1) for culture. They were cultured under normal conditions for 12 days and subjected to NaCl (200 mM) stress treatment (NaCl group) and normal treatment (CK group). The growth of plants in each group was observed and the plant height was measured on the 8th day. The fresh weight, dry weight, relative conductivity, chlorophyll content, and SOD and POD activities of plants in each group were determined on the 12th day.

[0054] The statistical results of plant height of each group are shown in Fig.10 .Depend on Fig.10 It can be seen that under normal conditions, there was no significant difference in the plant height of strains OE1 and OE2 compared with that of strain WT; under salt stress conditions, the plant height of strains OE1 and OE2 was significantly increased by 17.11% and 46.32% respectively compared with that of strain WT.

[0055] The fresh weight statistics of each group of plants are shown in Fig.11 .Depend on Fig.11 It can be seen that under normal conditions, there was no significant difference in the fresh weight of strains OE1 and OE2 compared with that of strain WT; under salt stress conditions, the fresh weight of strains OE1 and OE2 was significantly increased by 121.89% and 193.75% respectively compared with that of strain WT.

[0056] The dry weight statistics of each group of plants are shown in Fig.12 .Depend on Fig.12 It can be seen that under normal conditions, there was no significant difference in the dry weight of strains OE1 and OE2 compared with the dry weight of strain WT; under salt stress conditions, the dry weight of strains OE1 and OE2 showed an upward trend compared with the dry weight of strain WT, among which the dry weight of strain OE1 increased by 34.78% compared with the dry weight of strain WT, and the dry weight of strain OE2 increased significantly by 78.26% compared with the dry weight of strain WT.

[0057] The measurement results of three morphological indices, plant height, fresh weight and dry weight, showed that the transgenic strains had higher tolerance to salt stress.

[0058] The statistical results of relative conductivity of each group of plants are shown in Fig.13 .Depend on Fig.13 It can be seen that under normal conditions, the relative conductivity of strain OE1 was significantly higher than that of strain WT, and there was no significant difference between the relative conductivity of strain OE2 and strain WT; under salt stress, the relative conductivity of strains OE1 and OE2 were significantly reduced by 18.46% and 23.46% respectively compared with that of strain WT.

[0059] When subjected to salt stress, cells are damaged and electrolytes leak out of the cells, which in turn affects life activities, manifested as an increase in relative conductivity. The results showed that under salt stress conditions, transgenic strains were less damaged than wild-type cells, with less electrolyte leaking out of the cells, indicating stronger salt tolerance.

[0060] The statistical results of chlorophyll content of each group of plants are shown in Fig.14 .Depend on Fig.14 It can be seen that under normal conditions, the chlorophyll content of strains OE1 and OE2 had no significant difference compared with strain WT; however, under salt stress conditions, the chlorophyll content of strains OE1 and OE2 was significantly increased by 13.70% and 19.63% respectively compared with strain WT.

[0061] Chlorophyll is an important material basis for plant photosynthesis. Salt stress will accelerate the decomposition of chlorophyll and lead to a decrease in the net photosynthetic rate. The higher chlorophyll content in the TaSNAC11 overexpressing T3 generation homozygous transgenic Arabidopsis lines OE1 and OE2 indicates that their photosynthetic inhibition will be lower, and they can accumulate more photosynthetic assimilates, which in turn show that they are less affected by salt stress.

[0062] The results of SOD activity determination of each group of plants are shown in Fig.15 .Depend on Fig.15 It can be seen that under normal conditions, there was no significant difference in the SOD activity of strains OE1 and OE2 compared with strain WT; however, under salt stress conditions, the SOD activity of strains OE1 and OE2 was significantly increased by 49.64% and 41.00% respectively compared with strain WT.

[0063] The results of POD activity determination of each group of plants are shown in Fig.16 .Depend on Fig.16 It can be seen that under normal conditions, the POD activity of strains OE1 and OE2 had no significant difference compared with strain WT; however, under salt stress conditions, the POD activity of strains OE1 and OE2 increased significantly by 16.95% and 17.85% respectively compared with strain WT. SOD and POD are the main components of the enzymatic antioxidant system that scavenges ROS. Under salt stress, the SOD and POD activities of the TaSNAC11 overexpressing T3 homozygous transgenic Arabidopsis lines OE1 and OE2 were significantly higher than those of the wild-type line WT of the Columbia ecotype Arabidopsis, indicating that they have a stronger ability to scavenging ROS and can effectively reduce the level of membrane lipid peroxidation, thereby alleviating the harm of salt stress to plants.

[0064] In summary, transforming the wheat gene TaSNAC11 into the model plant Arabidopsis thaliana can significantly improve the salt tolerance of Arabidopsis thaliana.

[0065] It should be noted that the above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. Application of wheat gene TaSNAC11 in improving plant salt tolerance, characterized in that: The nucleotide sequence of the wheat gene TaSNAC11 is shown in SEQ ID NO:

2. The gene can improve the tolerance of plants to salt stress.

2. The use according to claim 1, characterized in that: The application comprises the following steps: (1) PCR amplification and cloning of wheat gene TaSNAC11; (2) Connecting the cloned wheat gene TaSNAC11 into an expression vector to obtain an overexpression recombinant vector; (3) Transforming the overexpression recombinant vector into Agrobacterium to obtain an overexpression recombinant strain; (4) The overexpression recombinant strain was transformed into plants, and the wheat gene TaSNAC11 overexpression strain was screened and obtained.

3. The use according to claim 2, characterized in that: The expression vector is super1300 (GFP-C).

4. The use according to claim 2, characterized in that: The Agrobacterium is Agrobacterium tumefaciens GV3101.

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