Agropyron mongolicum drought-resistant gene AmNAC102-2, application thereof and method for improving drought resistance of plants

Abstract

The invention discloses an agropyron mongolicum drought-resistant gene AmNAC102-2, application thereof and a method for improving drought resistance of plants, and relates to the field of plant genetic breeding, and the nucleotide sequence of the AmNAC102-2 is shown as SEQ ID NO.1. The invention further discloses a method for improving drought resistance of plants. The mongolian wheatgrass AmNAC102-2 gene disclosed by the invention participates in regulating and controlling the drought stress response of mongolian wheatgrass for the first time, the drought resistance of transgenic tobacco and mongolian wheatgrass can be enhanced, and the gene can be used for cultivating new varieties of drought-resistant plants and has potential application value.

Description

Technical Field

[0001] The invention belongs to the field of plant genetic breeding, and in particular relates to a Mongolian wheatgrass drought-resistant gene AmNAC102-2 and an application thereof, and a method for improving plant drought resistance. Background Art

[0002] Mongolian ice grass, Latin name Agropyron mongolicum Keng, formerly known as sand reed grass, is an excellent perennial diploid grass in my country's desert grasslands, 2n=2x=14, cross-pollinated grass of the Poaceae family, with long and dense fibrous roots, loose and upright stems, gray-green leaves, tight leaf sheaths, flat ligules with cilia, short and smooth auricles, no hairs or micro-hairs on the spike axis, and oval seeds. It is widely distributed in Inner Mongolia, Shanxi, Shaanxi, Gansu, Ningxia and other places. Mongolian ice grass has soft stems and leaves, a well-developed root system, early greening, strong tillering ability, good palatability, strong stress resistance and adaptability. It can grow in sandy, arid or desert grassland areas, showing strong drought resistance characteristics. It has important feeding, ecological and breeding value, can be used for pastures and ecological restoration in cold and arid areas, and can also provide superior gene resources for drought-resistant breeding and improvement of forage and wheat crops. However, no genes related to drought resistance of Mongolian ice grass have been found so far. Summary of the invention

[0003] To solve the above problems, the present invention provides a Mongolian wheatgrass drought-resistant gene AmNAC102-2 and its application and a method for improving plant drought resistance, so as to enrich Mongolian wheatgrass drought-resistant related genes and provide gene resources for crop genetic improvement.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention provides a Mongolian wheatgrass drought-resistant gene AmNAC102-2, and the nucleotide sequence of the Mongolian wheatgrass drought-resistant gene AmNAC102-2 is shown in SEQ ID NO.1.

[0006] The amino acid sequence encoded by the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass is shown in SEQ ID NO.2.

[0007] Furthermore, a method for improving drought resistance of plants is provided, comprising: introducing a substance that overexpresses the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass into a plant, so that the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass is overexpressed.

[0008] Preferably, the method of introducing a substance that causes the overexpression of the Mongolian wheatgrass drought-resistant gene AmNAC102-2 into a plant is selected from any one or a combination of S1-S4:

[0009] S1: introducing a plasmid having the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass into the plant;

[0010] S2: introducing into the plant a chemical reagent for increasing the copy number of the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass on the plant chromosome;

[0011] S3: connecting the enhancer to the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass, and introducing the connection product into the plant;

[0012] S4: Introducing an enhancer into plants that overexpresses the drought-resistant gene AmNAC102-2 of Agropyron mongolica.

[0013] Preferably, introducing a plasmid containing the Mongolian wheatgrass drought-resistant gene AmNAC102-2 into a plant means: constructing a recombinant overexpression vector containing the Mongolian wheatgrass drought-resistant gene AmNAC102-2, transforming the recombinant overexpression vector into Agrobacterium, and then infecting plant callus with the transformed Agrobacterium to screen positive transgenic plants.

[0014] Preferably, the starting vector for constructing the recombinant overexpression vector is pCAMBIA1302-AmNAC102-2-EGFP, and the Agrobacterium is LBA4404.

[0015] Preferably, the plant is Mongolian wheatgrass or tobacco.

[0016] The application of the Mongolian wheatgrass drought-resistant gene AmNAC102-2 in drought-resistant plant breeding.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention first reveals that the AmNAC102-2 gene of Mongolian ice grass is involved in regulating the drought stress response of Mongolian ice grass, and can enhance the drought resistance of transgenic tobacco and Mongolian ice grass. This gene is a transcription factor, also known as trans-acting factor, which is an important regulatory gene in plants. There are many types of transcription factors with complex functions. They can specifically bind to cis-acting elements in the promoter region of eukaryotic genes. The transcriptional regulatory region activates or inhibits gene transcription by interacting with the target gene. It can be used to cultivate new varieties of drought-resistant plants and has potential application value.

[0019] (2) The present invention clones the AmNAC102-2 gene and constructs transgenic tobacco and Mongolian wheat grass that overexpress the AmNAC102-2 gene. The properties of the obtained transgenic tobacco and Mongolian wheat grass are analyzed to find that overexpression of the AmNAC102-2 gene improves the drought resistance of tobacco and Mongolian wheat grass. The AmNAC102-2 gene and the protein encoded by the present invention provide valuable resources for breeding new varieties of drought-resistant Mongolian wheat grass, and at the same time lay a theoretical foundation for studying the mechanism of Mongolian wheat grass responding to drought stress and the molecular mechanism of resisting adverse environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 The present invention is an analysis of physiological indexes of wild-type and transgenic AmNAC102-2 tobacco plants under drought stress;

[0022] Figure 1 Among them, A is a comparison chart of catalase activity; B is a comparison chart of peroxidase activity; C is a chart of total SOD activity; D is a chart of proline content;

[0023] Figure 2 The present invention is an analysis of physiological indexes of wild-type and transgenic AmNAC102-2 Mongolian wheatgrass plants under drought stress;

[0024] Figure 2 Among them, A is a comparison chart of catalase activity; B is a comparison chart of peroxidase activity; C is a chart of total SOD activity; D is a chart of proline content;

[0025] Figure 3 is the relative expression level of the AmNAC102-2 gene in the wild-type and transgenic AmNAC102-2 tobacco plants under drought stress of the present invention;

[0026] Figure 4 It is the relative expression amount of the AmNAC102-2 gene in the wild type and the transgenic AmNAC102-2 Mongolian wheatgrass plants under drought stress of the present invention. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] The technical solution of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any form.

[0030] The overexpression vector used in the following examples is the pCAMBIA1302 plasmid, and the bacterial resistance is kanamycin sulfate Kana; the bacterial resistance of the Escherichia coli Top10 competent cells DL1010 and the Agrobacterium tumefaciens LBA4404 competent cells AC1030 are both kanamycin sulfate Kana.

[0031] The main reagents used in the following examples: TRNzol Reagent; FastQuant RTKit; D2000DNAMarker; GXL DNA Polymerase; 2×Taq PCR MasterMix; GeneGreen NucleicAcid Dye; TIANgel Midi Purification Kit; TIANprep Mini Plasmid Kit; 6× DNALoading Buffer; LD 1kb Ladder; DNA Gel / PCR Purification Miniprep Kit; PlantgDNAIsolation Kit DNA; EZgene TM Plasmid Miniprep Kit; Nco I; Spe I; 2,4-D; 6-BA; IAA; KT; Timentin; Kana; DMSO; As; chloroform; glycerol.

[0032] All other chemical reagents used in the examples were imported or domestic analytical grade reagents.

[0033] The primers used in the examples were synthesized by Shanghai Bioengineering Co., Ltd. and commissioned to BGI for sequencing.

[0034] Unless otherwise specified, the examples were performed according to conventional experimental conditions or the conditions recommended by the manufacturer's instructions.

[0035] Table 1 Chinese-English comparison table

[0036]

[0037]

[0038] Example 1: Screening of the drought-resistant gene AmNAC102-2 of Agropyron mongolica

[0039] In order to understand the molecular mechanism of Mongolica's response to drought, 26 members of the NAC family of Mongolica were screened based on transcriptome sequencing data. Bioinformatics methods and evolutionary relationship comparison showed that the AmNAC102-2 transcription factor had a high homology with the known NAC protein with drought resistance function; differential expression analysis found that this gene played a positive regulatory role in drought stress of Mongolica. Therefore, this study used PCR amplification technology to clone the AmNAC102-2 transcription factor gene of Mongolica, and cloned the AmNAC102-2 gene from the transcriptome of Mongolica. The nucleotide sequence of the AmNAC102-2 gene is shown in SEQ ID NO.1, and the amino acid sequence encoded by the AmNAC102-2 gene is shown in SEQ ID NO.2.

[0040] Example 2: Construction and detection of the overexpression vector of the drought-resistant gene AmNAC102-2 of Agropyron mongolica

[0041] (1) According to the sequence analysis of the coding region, primers F and R were designed to amplify the coding region of the gene and ligated to the expression vector pCAMBIA1302 with a 35S promoter. The upstream primer F used is shown in SEQ ID NO.3; the downstream primer R is shown in SEQ ID NO.4.

[0042] (2) The specific method for connecting the AmNAC102-2 gene to the vector pCAMBIA1302 with a 35S promoter is as follows: the total RNA of Mongolica serrata was extracted and reverse transcribed into cDNA. Then, the cDNA was used as a template and AmNAC102-2 was amplified using upstream and downstream primers. The PCR product was connected to the vector pCAMBIA1302. The connection product was named pCAMBIA1302-AmNAC102-2-EGFP and its correctness was verified by sequencing.

[0043] SEQ ID NO.1:

[0044] 5’-TAAGAGCAGCACAAGAGAAGAAGAATTCAGCAGCAGTAGCAGC GTGCGAGCGAGAGAATCACAGTGAGGTTTGTTGGATCGAGGTTCGCGAGGAAGAAGCCGACCGGAGATGAGCGGCGGACAGGAGCTGCATCTGCCGCCGGGCTTCCGGTTCCACCCGACGGACGAGGAGCTGGTGATGCACTACCTCTGCCGCCGCTGCGCCGGCGCGCCCATCGCCGTCCCCATCATCGCCGAGATCGACCTCTACAAGTTCGACCCCTGGCAGCTCCCAAAGATGGCGCTGTACGGCGAGAAGGAGTGGTACTTCTTCTCCCCGCGGGACCGCAAGTACCCCAACGGGTCCAGGCCCAACAGGGCCGCCGGGTCCGGGTACTGGAAGGCGACGGGGGCCGACAAGCCCGTGGGCACGCCCAAGCCGCTGGCCATCAAGAAGGCGCTCGTCTTCTACGCCGGCAAGGCCCCCAAGGGCGAGAAGACCAACTGGATCATGCACGAGTACCGCCTCGCCGACGTCGACCGATCCGCCCGCAAGAAGAACAGCC-3’

[0045] SEQ ID NO.2

[0046] MSGGQELHLPPGFRFHPTDEELVMHYLCRRCAGAPIAVPIIAEIDLYKFDPWQLPKMALYGEKEWYFFSPRDRKYPNGSRPNRAAGSGYWKATGADKPVGTPKPLAIKKALVFYAGKAPKGEKTNWIMHEYRLADVDRSARKKNS

[0047] SEQ ID NO.3:

[0048] 5’-CATGCCATGGTAAGAGCAGCACAAGAGAAGAAG-3’

[0049] SEQ ID NO.4:

[0050] 5’-GGACTAGTGGCTGTTCTTCTTGCGGGC-3’

[0051] Example 3: Construction of transgenic tobacco overexpressing AmNAC102-2

[0052] The pCAMBIA1302 vector containing AmNAC102-2 constructed in Example 2 was transformed into Agrobacterium LBA4404, and then infected tobacco leaves to obtain transgenic tobacco seedlings.

[0053] (1) Agrobacterium infection and co-cultivation

[0054] Take 500 μL of the frozen Agrobacterium culture containing the pCAMBIA1302-AmNAC102-2-EGFP recombinant plasmid from a -80°C freezer and place it in liquid LB containing kanamycin sulfate and rifampicin. Incubate overnight at 28°C and 200 rpm. Wait until the spectrophotometer shows an absorbance of OD 0. 600 When the pH is about 0.6, centrifuge at 8000rpm for 5min to collect the cells, discard the supernatant, add an equal amount of liquid 1 / 2MS culture medium, resuspend the cells, add 100mmol of acetosyringone (As) to the resuspended liquid, add it at a volume ratio of 1:1000, and let it stand at room temperature in the dark for 30min. Take the young leaves of sterile tobacco seedlings of about 30 days old, remove the leaf margins and main veins, and cut the leaves into about 0.4cm 2 Pour the resuspended bacterial solution into a triangular flask, clamp the cut leaves into the resuspended solution, shake at 200rpm for 8min, place the infected leaves on sterilized filter paper, absorb the excess bacterial solution in the leaves, place the tobacco leaves face down on the co-culture medium, place in a 28℃ incubator, and culture in the dark for 3d.

[0055] (2) Bud induction and differentiation

[0056] The co-cultured leaves were inoculated onto differentiation medium containing 1 mg / L benzylaminopurine + 300 mg / L timentin + 50 mg / L kanamycin sulfate. The culture medium was exposed to light for 16 h and induced to differentiate and sprout at 25°C. The differentiation medium was replaced every 14 days.

[0057] (3) Rooting culture

[0058] The tobacco seedlings were inoculated into rooting medium, the composition of which was 0.5 mg / L indoleacetic acid + 300 mg / L timentin + 50 mg / L kanamycin sulfate. The roots were induced at 25°C under light for 16 h to obtain resistant regenerated tobacco strains. After 30 days, they were transplanted into nutrient soil and cultured into seedlings.

[0059] Example 4: Construction of transgenic Mongolian wheatgrass overexpressing AmNAC102-2

[0060] The pCAMBIA1302 vector containing AmNAC102-2 constructed in Example 2 was transformed into Agrobacterium LBA4404, and then infected with Agropyron mongolica callus to obtain transgenic Agropyron mongolica seedlings.

[0061] (1) Agrobacterium infection and co-cultivation

[0062] The Agrobacterium containing the target vector was inoculated into LB liquid medium containing antibiotics. The LB liquid medium composition was: 50 mg / mL kanamycin sulfate + 50 mg / mL rifampicin. The culture was placed in a 50 mL shaking tube and cultured overnight at 28°C and 200 rpm until the bacterial solution reached OD 600 At about 0.5, collect the bacteria by centrifugation at 8000rpm for 5min, discard the supernatant, add an equal amount of 1 / 2MS liquid culture medium, resuspend the bacteria, add 100mmol of acetosyringone to the resuspended solution at a volume ratio of 1:1000, let it stand at room temperature and away from light for 30min, pour it into a triangular flask containing Mongolian ice grass callus and infect it for 10min, put the infected Mongolian ice grass callus on a clean sterilized filter paper, blow dry the excess bacterial liquid in an ultra-clean workbench, and then transfer the callus to the co-cultivation medium and invert it in a 28℃ incubator away from light for co-cultivation for 3d.

[0063] (2) Screening of Mongolian wheatgrass callus

[0064] The Mongolian ice grass callus tissue co-cultured for 3 days was washed with sterile ddH2O by shaking for many times, and 500 mg / L cefotaxime sodium, abbreviated as Cef, was added to the sterile ddH2O until the washing solution became clear. The callus tissue was then placed on sterile filter paper to absorb excess water. After absorbing dryness, the Mongolian ice grass callus tissue was transferred to a buffer medium. The buffer medium composition was: 0.5 mg / L 2,4-dichlorophenoxyacetic acid + 1 mg / L benzylaminopurine + 400 mg / L acid hydrolyzed casein + 100 mmol acetosyringone, and cultured in a 28°C incubator for 3 days. Then the strains were transferred to a selective medium with a cephalosporin concentration of 500 mg / L for the first screening. The components of the selective medium were: 0.5 mg / L 2,4-dichlorophenoxyacetic acid + 1 mg / L benzylaminopurine + 400 mg / L acid hydrolyzed casein + 50 mg / L kanamycin sulfate + 500 mg / L cephalosporin. After 20 days of screening, the selective medium with a cephalosporin concentration of 250 mg / L was replaced for the second screening.

[0065] (3) Differentiation of Mongolian ice grass into seedlings

[0066] Select resistant, non-browning Mongolian ice grass callus tissue and transfer it to the differentiation medium. Perform differentiation culture in a 25°C light incubator for 16 hours. After 30 days, the seedlings can grow to 1 cm to 2 cm.

[0067] (4) Rooting and transplanting of Mongolian ice grass

[0068] The differentiated seedlings were transferred to the rooting medium, the composition of which was: 1.0 mg / L naphthaleneacetic acid + 400 mg / L acid hydrolyzed protein. Rooting occurred after 7 days. The medium was changed every 20 days. After 40 days, the seedlings were transplanted to the nutrient soil to form seedlings.

[0069] In this example, an overexpression strain was isolated and PCR amplification was used to detect the expression of the gene.

[0070] (1) Extracting DNA from transgenic strains;

[0071] (2) The primer F1 used for detection is shown in SEQ ID NO.5; the primer R1 is shown in SEQ ID NO.6;

[0072] (3) The reaction system used included: DNA template, 1 μL of upstream and downstream primers, 10 μL of 2*Mix, and 8 μL of ddH2O. The reaction conditions were: pre-denaturation at 94°C for 5 min, denaturation at 94°C for 30 s, annealing at 55°C for 30 s, extension at 72°C for 90 s, extension at 72°C for another 10 min, and cooling at 4°C. The denaturation-extension process required 30 cycles.

[0073] SEQ ID NO.5: 5'-TGAGACTTTTCAACAAAGGGTAATAT-3'

[0074] SEQ ID NO.6: 5'-GGCTGTTCTTTCTTGCGGGC-3'

[0075] Example 5: Effects of drought stress on physiological parameters of transgenic strains overexpressing AmNAC102-2

[0076] The non-drought treatment was CK, and the natural drought treatment for 7 days was Drought. Under the non-drought treatment and natural drought treatment for 7 days, the physiological indices of the leaves of the wild-type WT and the transgenic plants overexpressing AmNAC102-2 were measured. Among them, the two transgenic Mongolian ice grass lines overexpressing AmNAC102-2 were abbreviated as OE6 and OE9, and the two transgenic tobacco lines overexpressing AmNAC102-2 were abbreviated as OE12 and OE15. The proline content was determined using the kit A107-1-1, the catalase activity was determined using the kit A007-1-1, the superoxide dismutase activity was determined using the kit A001-3, and the peroxidase activity was determined using the kit A084-3. The operation steps and sampling were carried out according to the instructions. The kits were purchased from Nanjing Jiancheng Bioengineering Institute. The results are shown in Figure 1 and Figure 2As shown, the superoxide dismutase activity, peroxidase activity, catalase activity and proline content in the leaves of the overexpressing plants under natural drought stress for 7 days were significantly increased, indicating that the drought resistance of the transgenic plants was enhanced.

[0077] Example 6: Drought resistance test of transgenic tobacco overexpressing AmNAC102-2

[0078] The tissue culture seedlings were transplanted into nutrient soil, and the wild-type WT and AmNAC102-2 overexpressing transgenic tobacco lines OE12 and OE15 that had been cultured for 28 days were subjected to natural drought treatment for 7 days. The cDNA obtained by reverse transcription of the leaves was extracted as a template. The cDNA obtained by reverse transcription was diluted 10 times and then used for real-time quantitative PCR using MonAmp SYBR Green qPCR Mix, kit numbered MQ10201S. The reaction system used included: MonAmpTM STBR Green qPCRMix, 10μL; 0.4μL of upstream and downstream primers each; 1.5μL of DNA template, supplemented to 20μL with ddH2O, and after being fully mixed, it was placed in a real-time fluorescence quantitative PCR instrument for three-step PCR amplification. The reaction conditions were: 95℃30s, 95℃10s, 60℃10s, 72℃30s, and 40 cycles. According to The relative expression of genes was calculated by the method, and each sample was amplified simultaneously with Actin as the internal reference gene. Figure 3 As shown, the expression levels in the leaves of the overexpressing plants under natural drought stress for 7 days were significantly higher than those of the wild type, showing drought resistance.

[0079] Example 7: Drought resistance test of transgenic Mongolian wheatgrass overexpressing AmNAC102-2

[0080] The tissue culture seedlings were transplanted into nutrient soil, and the wild-type WT and AmNAC102-2 overexpressing transgenic Mongolian ice grass lines OE6 and OE9 that had been cultured for 40 days were subjected to natural drought treatment for 7 days. The cDNA of the total RNA in the leaves was extracted and reverse transcribed as a template. The qRT-PCR test was performed using the MonAmp SYBR Green qPCR Mix kit. The reaction system used included: MonAmpTMSTBR Green qPCR Mix, 10 μL; 0.4 μL of each upstream and downstream primer; 1.5 μL of DNA template, supplemented to 20 μL with ddH2O, and then fully mixed and placed in a real-time fluorescence quantitative PCR instrument for three-step PCR amplification. The reaction conditions were: 95°C 30s, 95°C 10s, 60°C 10s, 72°C 30s, and 40 cycles. According to The relative expression of genes was calculated by the method, and each sample was amplified simultaneously with Actin as the internal reference gene. Figure 4As shown, the expression levels in the leaves of the overexpressing plants under natural drought stress for 7 days were significantly higher than those of the wild type, showing drought resistance.

Claims

1. A drought-resistant gene AmNAC102-2 of Mongolian wheatgrass, characterized in that: The nucleotide sequence of the drought-resistant gene AmNAC102-2 of Agropyron mongolica is shown in SEQ ID NO.

1.

2. The drought-resistant gene AmNAC102-2 of Mongolian wheatgrass according to claim 1, characterized in that: The amino acid sequence encoded by the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass is shown in SEQ ID NO.

2.

3. A method for improving plant drought resistance, characterized in that: include: A substance that causes the overexpression of the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass according to claim 1 is introduced into the plant, so that the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass is overexpressed.

4. The method for improving plant drought resistance according to claim 3, characterized in that: The method of introducing a substance that causes the overexpression of the Mongolian wheatgrass drought-resistant gene AmNAC102-2 into a plant is selected from any one or a combination of S1-S4: S1: introducing a plasmid having the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass into the plant; S2: introducing into the plant a chemical reagent for increasing the copy number of the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass on the plant chromosome; S3: connecting the enhancer to the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass, and introducing the connection product into the plant; S4: Introducing an enhancer into plants that overexpresses the drought-resistant gene AmNAC102-2 of Agropyron mongolica.

5. The method for improving plant drought resistance according to claim 4, characterized in that: Introducing a plasmid containing the Mongolian wheatgrass drought-resistant gene AmNAC102-2 into a plant means: constructing a recombinant overexpression vector containing the Mongolian wheatgrass drought-resistant gene AmNAC102-2, transforming the recombinant overexpression vector into Agrobacterium, then infecting plant callus with the transformed Agrobacterium, and screening positive transgenic plants.

6. The method for improving plant drought resistance according to claim 5, characterized in that: The starting vector for constructing the recombinant overexpression vector is pCAMBIA1302-AmNAC102-2-EGFP, and the Agrobacterium is LBA4404.

7. The method for improving plant drought resistance according to claim 3, characterized in that: The plant is Mongolian wheatgrass or tobacco.

8. Use of the drought-resistant gene AmNAC102-2 of Mongolian wheatgrass according to claim 1 in drought-resistant plant breeding.

Images