Cucumber salt-tolerance gene CsNAC41 and its application

Abstract

The present invention relates to the field of gene engineering technology, and in particular to a cucumber salt-tolerant gene CsNAC41 and an application thereof. Arabidopsis is infected according to the following method: a recombinant expression vector comprising the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 is constructed, the recombinant expression vector is transformed into Agrobacterium, cultured, a recombinant bacterium carrying the recombinant expression vector is obtained, and the recombinant bacterium carrying the recombinant expression vector is used to infect Arabidopsis plants; the empty vector when constructing the recombinant expression vector is an overexpression vector pHB; the Agrobacterium is GV3101; a transgenic Arabidopsis with strong salt tolerance and strong stress resistance can be obtained, and the method of the present invention provides a basis for screening crops with strong stress resistance.

Description

Technical Field

[0001] The invention relates to the technical field of genetic engineering, in particular to a cucumber salt-tolerant gene CsNAC41 and an application thereof. Background Art

[0002] Cucumber (Cucumis sativus L.), also known as cucumber and prickly melon, originated in the southern Himalayas and belongs to the Cucurbitaceae family. It is one of the most widely grown vegetables in China. Cucumber has high nutritional value and economic benefits. The fruit is sweet and crispy, rich in vitamin E, and has the effect of clearing heat and detoxifying. However, during the planting process, cucumber is easily affected by abiotic stresses such as salt, drought and cold. Among them, salt stress can destroy the antioxidant defense system of cucumber plants, inhibit their normal growth and development, and even cause symptoms of whole-plant yellowing, seriously affecting their yield. Therefore, it is particularly important to explore the key salt-tolerant genes of crops such as cucumbers and analyze their molecular mechanisms in salt stress for the cultivation of salt-tolerant crops. Summary of the invention

[0003] The purpose of the present invention is to provide a cucumber salt-tolerant gene CsNAC41 and an application thereof.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides an application of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, comprising the following steps: constructing a recombinant expression vector comprising the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing to obtain a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector;

[0006] The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB;

[0007] The Agrobacterium is GV3101;

[0008] The plant is Arabidopsis thaliana.

[0009] The present invention also provides the use of a protein encoded by the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants. The protein encoded by the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.2.

[0010] The present invention also provides a primer pair for amplifying the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1, and the primer pair is shown in SEQ ID NO.3-4.

[0011] The present invention also provides a primer pair for detecting the expression amount of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, and the primer pair is shown in SEQ ID NO.5-6.

[0012] The present invention also provides an application of a recombinant expression vector in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, wherein the recombinant expression vector comprises the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 and an empty vector;

[0013] The empty vector is the overexpression vector pHB.

[0014] Preferably, the method for using the recombinant expression vector in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants comprises the following steps: transforming the recombinant expression vector into Agrobacterium, culturing to obtain recombinant bacteria carrying the recombinant expression vector, and infecting plant plants with the recombinant bacteria carrying the recombinant expression vector;

[0015] The Agrobacterium is GV3101;

[0016] The plant is Arabidopsis thaliana.

[0017] The present invention also provides an application of a recombinant bacterium in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, wherein the recombinant bacterium comprises the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 or a recombinant expression vector and a host bacterium;

[0018] The recombinant expression vector is the recombinant expression vector described above;

[0019] The host bacteria is Agrobacterium GV3101.

[0020] Preferably, the method for using the recombinant bacteria in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants comprises the following steps: infecting plant plants with the recombinant bacteria;

[0021] The plant is Arabidopsis thaliana.

[0022] The present invention also provides a method for improving plant salt tolerance, comprising the following steps:

[0023] Overexpressing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 in a plant; or constructing a recombinant expression vector containing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing, obtaining a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector;

[0024] The primer pair for amplifying the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.3-4;

[0025] The primer pair for detecting the expression of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.5-6;

[0026] The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB;

[0027] The Agrobacterium is GV3101;

[0028] The plant is Arabidopsis thaliana.

[0029] The present invention also provides a method for cultivating salt-tolerant transgenic plants, comprising the following steps:

[0030] Constructing a recombinant expression vector containing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing to obtain a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector;

[0031] The primer pair for amplifying the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.3-4;

[0032] The primer pair for detecting the expression of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.5-6;

[0033] The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB;

[0034] The Agrobacterium is GV3101;

[0035] The plant is Arabidopsis thaliana.

[0036] The present invention provides a cucumber salt-tolerant gene CsNAC41 and an application thereof. The present invention provides a cucumber salt-tolerant gene CsNAC41, and the nucleotide sequence of the cucumber salt-tolerant gene CsNAC41 is shown in SEQ ID NO.1. The gene sequence of the present invention is 888 bp in length and encodes 295 amino acids. The cucumber salt-tolerant gene CsNAC41 of the present invention has the highest expression level in cucumber fruit, and the expression level of the gene is the highest at 24 hours of salt stress. By transfecting Arabidopsis with the cucumber salt-tolerant gene CsNAC41 of the present invention, transgenic Arabidopsis with strong stress resistance can be obtained, providing a basis for screening plant varieties with strong stress resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The expression of cucumber salt tolerance gene CsNAC41 in different cucumber tissues;

[0038] Figure 2 The expression of cucumber salt-tolerance gene CsNAC41 at different times of salt stress (the horizontal axis represents the time of salt stress, and the vertical axis represents the expression level);

[0039] Figure 3 The expression of cucumber salt tolerance gene CsNAC41 at different times after abscisic acid (ABA) treatment (the horizontal axis represents the time after treatment, and the vertical axis represents the expression level);

[0040] Figure 4 The expression of cucumber salt tolerance gene CsNAC41 in transgenic Arabidopsis strains (the horizontal axis represents the infected plants of different Arabidopsis strains, and the vertical axis represents the expression level);

[0041] Figure 5 The effect of salt stress on the root length of overexpressing Arabidopsis thaliana strains OE3, OE9 and wild-type Arabidopsis thaliana (Figure A is a visual diagram of the control group and salt stress group, and Figure B is a bar graph of root length measurement results);

[0042] Figure 6 The effect of ABA induction on the root length of Arabidopsis thaliana overexpressing OE3, OE9 and wild-type Arabidopsis thaliana (Figure A is a visual diagram of the control group and the ABA-treated group, and Figure B is a bar graph of the root length measurement results);

[0043] Figure 7 The growth of Arabidopsis thaliana OE3 and OE9 overexpressing lines and wild-type Arabidopsis thaliana under salt stress (Figure A shows the phenotype of Arabidopsis thaliana under different treatments, from left to right showing wild-type Arabidopsis thaliana lines, Arabidopsis thaliana OE3 overexpressing lines and Arabidopsis thaliana OE9 overexpressing lines; Figure B shows the total chlorophyll content in Arabidopsis thaliana under different treatments; Figure C shows the relative conductivity of Arabidopsis thaliana under different treatments);

[0044] Figure 8Analysis of antioxidant enzyme activities of different Arabidopsis strains under salt stress conditions (A represents the activity of superoxide dismutase SOD; B represents the activity of peroxidase POD);

[0045] Fig. 9 Figure 2 shows the expression of genes related to salt stress response under salt stress conditions (Figure A shows the expression of AtRD22, Figure B shows the expression of AtRbohF, and Figure C shows the expression of AtP5CS). DETAILED DESCRIPTION

[0046] In the present invention, the nucleotide sequence of the cucumber salt tolerance gene CsNAC41 is shown as SEQ ID NO.1; SEQ ID NO.1: ATGGCCTCCGATTTGCAGTTACCGCCGGGATTTAGGTTTCATCCAACTGACGACGAGCTTGTGACGCATTATTTGTGTCGTAAATGTGCGTCGCAGCCGATTTCGGTGCCGATTATTGCTGAAATCGATCTTTACAAATATAATCCATGGGATTTGCCTGAAAGGGCTTTGTATGGAGAGAAAGAGTGGTATTTCTTTTCACCGAGAGACCGGAAGTATCCGAACGGTTCGAGGCCGAACCGGTCGGCTGGGAGTGGATATTGGAAGGCGACCGGAGCTGATAAACCGATAGGAAGGCCGAAGGCGGTTGGGATTAAGAAGGCTTTGGTTTTTTATTCTGGGAAAGCTCCTAAGGGTGAGAAAACCAATTGGATCATGCACGAGTACCGGCTCGCTGATGTGGACCGCTCGGCTCGAAAGAAGAATAGTCTAAGGCTAGACGATTGGGTACTTTGTCGCATATACAACAAAAAGGGGGCAATCGAGAAACAGAACCCGCCGGAGATGAACACGATTGGGTTCTTTGAAAATGAGGAACAAGAGGAAAAGCCCGAAATTCTGAATGACAGAGCAATTTCTGGGCGAATCCCGCCGGCATCACCTTTGCAAGGTCCGCCATCGTCCGGCGTAGTCAACGATTACGTATACTTTGACCCCTCAGATTCGATTCCTCGTCTTCACGCGGACTCGAGCTGCTCGGAGCACGTGGTGTCATCGGAGTTCACGAGCGAAGTACAGAGTGAGCCTAGACTGAAAGAAGAGTACTGTGGATTAGGATTTCAGTATAATTACACGGACAGTTCATTGGAAAGCGCATTCTGTGCTCAATTTCCGTCGTTACATCAGATGTCGCCATTGCAGGATATGTTCATGTACAAGCCATTTTGA。

[0047] In the present invention, the amino acid sequence of the protein encoded by the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.2; SEQ ID NO.2: MASDLQLPPGFRFHPTDDELVTHYLCRKCASQPISVPIIAEIDLYKYNPWDLPERALYGEKEWYFFSPRDRKYPNGSRPNRSAGSGYWKATGADKPIGRPKAVGIKKALVFYSGKAPKGEKTNWIMHEYRLADVDRSARKKNSLRLDDWVLCRIYNKKGAIEKQNPPEMNTIGFFENEEQEEKPEILNDRAISGRIPPASPLQGPPSSGVVNDYVYFDPSDSIPRLHADSSCSEHVVSSEFTSEVQSEPRLKEEYCGLGFQYNYTDSSLESAFCAQFPSLHQMSPLQDMFMYKPF.

[0048] In the present invention, the primer pair for amplifying the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.3~4; SEQ ID NO.3 is the upstream primer CsNAC41-F, and the sequence is: CTCAAGCTTGGATCCATGGCCTCCGATTTGCAGTTACCG; SEQ ID NO.4 is the downstream primer CsNAC41-R, and the sequence is: AACGAAAGCTCTAGATCAAAATGGCTTGTACATGAACAT.

[0049] In the present invention, the primer pair for detecting the expression amount of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.5-6; SEQ ID NO.5 is an upstream primer, and the sequence is: CAATTTCTGGGCGAATCCCG; SEQ ID NO.6 is a downstream primer, and the sequence is: TACTTCGCTCGTGAACTCCG.

[0050] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0051] Example 1

[0052] The nucleotide sequence of the cucumber salt-tolerance gene CsNAC41 is shown in SEQ ID NO.1, and has a length of 888 bp; the amino acid sequence of the protein encoded by the nucleotide sequence is shown in SEQ ID NO.2, and encodes 295 amino acids.

[0053] Example 2

[0054] RNA was extracted from the roots, stems, leaves, flowers and fruits of cucumber variety 9930, reverse transcribed into cDNA, and real-time fluorescence quantitative PCR was performed using the fluorescent quantitative primer pair of CsNAC41 (shown in SEQ ID NO.5~6) to detect the expression level of cucumber salt tolerance gene CsNAC41 in cucumber roots, stems, leaves, flowers and fruits. The results are shown in Figure 1 shown.

[0055] Figure 1 The results showed that the cucumber salt tolerance gene CsNAC41 was most highly expressed in roots, followed by leaves.

[0056] Example 3

[0057] Cucumber variety 9930 was subjected to salt stress (200 mM NaCl). Specifically, 2-week-old cucumber seedlings were placed in a 200 mM NaCl solution for treatment. Cucumber leaves were taken at different time points to detect the expression changes of the cucumber salt-tolerance gene CsNAC41. The results are as follows: Figure 2 shown.

[0058] Different lowercase letters in the figure indicate significant differences (P<0.05).

[0059] Figure 2 The results showed that the expression level of cucumber salt-tolerance gene CsNAC41 was the highest after 24 h of salt stress.

[0060] Example 4

[0061] The cucumber variety 9930 was treated with abscisic acid (ABA). Specifically, 2-week-old cucumber seedlings were placed in a 100 μM ABA solution for treatment. Cucumber leaves were taken at different time points to detect the expression level of the cucumber salt tolerance gene CsNAC41 under abscisic acid (ABA) treatment. Figure 3 shown.

[0062] Different lowercase letters in the figure indicate significant differences (P<0.05).

[0063] Figure 3 The results showed that the expression level of cucumber salt-tolerance gene CsNAC41 first increased and then decreased with the treatment time, reaching the highest value at 3 h, indicating that cucumber salt-tolerance gene CsNAC41 participates in stress response through ABA signaling in plants.

[0064] Example 5

[0065] The full-length CDS sequence of cucumber salt-tolerance gene CsNAC41 was amplified by PCR to obtain the nucleotide sequence shown in SEQ ID NO.1, which was connected with the overexpression vector pHB to obtain the recombinant expression vector pHB-CsNAC41 (35S: CsNAC41). The recombinant expression vector was transformed into Agrobacterium competent GV3101, and the Agrobacterium liquid containing the recombinant plasmid was obtained using LB liquid medium and Kan and Rif antibiotics. The Agrobacterium liquid containing the recombinant plasmid pHB-CsNAC41 (35S: CsNAC41) was used to infect wild-type Arabidopsis and collect T 0 The T was screened using 1 / 2 MS medium supplemented with hygromycin. 1 The resistant seedlings were further screened to obtain T 3 Homozygous plants of the T 3 After the homozygous plants of the first generation were planted in nutrient soil for 3 weeks, RNA was extracted from the leaves and reverse transcribed into cDNA. The expression level of the CsNAC41 gene in the positive plants was analyzed using a specific fluorescent quantitative primer pair for the cucumber salt tolerance gene CsNAC41. Figure 4 shown.

[0066] The primers used for PCR amplification of the full-length CDS sequence of cucumber salt tolerance gene CsNAC41 were: CsNAC41-F (SEQ ID NO.3): CTCAAGCTTGGATCCATGGCCTCCGATTTGCAGTTACCG; CsNAC41-R (SEQ ID NO.4): AACGAAAGCTCTAGATCAAAATGGCTTGTACATGAACAT.

[0067] The PCR reaction program for PCR amplification of cucumber salt-tolerance gene CsNAC41 was as follows: 95℃ for 3 min; 95℃ for 15 s, 60℃ for 15 s, and 72℃ for 60 s, 35 cycles; 72℃ for 5 min.

[0068] The primer pair for specific fluorescent quantitative PCR is shown in SEQ ID NO.5~6; SEQ ID NO.5 is an upstream primer, and the sequence is: CAATTTCTGGGCGAATCCCG; SEQ ID NO.6 is a downstream primer, and the sequence is: TACTTCGCTCGTGAACTCCG.

[0069] The reaction program of specific fluorescence quantitative PCR was as follows: 95°C for 30 s, 1 cycle; 95°C for 5 s, 60°C for 30 s, 40 cycles.

[0070] Figure 4The results showed that among the 8 positive plants screened, the expression level of cucumber salt tolerance gene CsNAC41 was higher in plants 3 and 9, which were named OE3 and OE9, respectively. OE3 and OE9 were used as transgenic plants for subsequent experiments.

[0071] Example 6

[0072] Cucumber salt tolerance gene CsNAC41 overexpression lines OE3 and OE9 and wild-type Arabidopsis seeds were sown in 1 / 2MS medium. Five days later, the seedlings were moved to 1 / 2 MS medium with 125 mM NaCl and cultured vertically. Seven days later, the growth phenotypes of overexpression plants and wild-type plants were observed and their root length changes were measured.

[0073] The results are as follows Figure 5 shown.

[0074] Different lowercase letters in the figure indicate significant differences (P<0.05).

[0075] Figure 5 The results showed that there was no significant difference in the growth and root length of the wild type WT and the overexpression lines OE3 and OE9 under normal growth conditions. After 125 mM NaCl salt stress, the root length of the plants was inhibited after stress, but the root length of the two transgenic lines OE3 and OE9 was significantly longer than that of the wild type. The above results show that overexpression of the cucumber salt tolerance gene CsNAC41 can improve the tolerance of transgenic seedlings to salt stress.

[0076] Example 7

[0077] Cucumber salt tolerance gene CsNAC41 overexpressing plants OE3 and OE9 and wild-type Arabidopsis seeds were sown in 1 / 2MS medium. Five days later, the seedlings were moved to 1 / 2 MS medium with 10 μM ABA and cultured vertically. Seven days later, the growth phenotypes of the overexpressing plants and wild-type plants were observed and their root length changes were measured. The results are shown in Figure 6 shown.

[0078] Different lowercase letters in the figure indicate significant differences (P<0.05).

[0079] Figure 6 The results showed that after 10 μM ABA induction, the root length of the overexpression lines OE3 and OE9 and the wild-type Arabidopsis plants was inhibited, but the root length of the two transgenic lines OE3 and OE9 was significantly longer than that of the wild type. In summary, overexpression of the cucumber salt tolerance gene CsNAC41 can improve the resistance of transgenic seedlings to ABA treatment.

[0080] Example 8

[0081] Seeds of wild-type Arabidopsis WT and overexpressing Arabidopsis OE3 and OE9 were sown in 1 / 2 MS medium, cultured for 7 days, and then planted in nutrient soil. After 4 weeks, they were irrigated with 200 mM NaCl salt solution. After 9 days, the growth of the plants was observed, and the phenotypic growth was photographed. Leaves at the same position of different groups were cut for chlorophyll content determination and relative conductivity analysis. 0.2 g of leaves were decolorized with 5 mL of anhydrous ethanol, and the OD values ​​were measured at wavelengths of 665 nm and 649 nm to calculate the chlorophyll content. The results are as follows: Figure 7 As shown in the figure, 10 mL of deionized water was added to 0.1 g of leaves, and the mixture was placed at 25°C for 1 h after vacuuming for 30 minutes, with multiple oscillations during the period. The conductivity R1 was measured at 25°C, and the conductivity R2 was measured after 20 minutes of water bath at 95°C. The relative conductivity = R1 / R2. Figure 7 shown.

[0082] Different lowercase letters in the figure indicate significant differences (P<0.05).

[0083] Figure 7 The phenotypic pictures of the control group showed that there was no difference in the growth of the transgenic plants and the wild type. Under the treatment of 200 mM NaCl, the rosette leaves at the bottom of the wild type plants had obviously wilted and yellowed, while the overexpression plants (OE3 and OE9) did not wilt or yellow, and their growth was significantly better than that of the wild type. And from the total content of chlorophyll a and chlorophyll b and the relative conductivity measurement, it can be seen that the resistance of transgenic plants to salt stress after stress is significantly higher than that of the wild type.

[0084] Example 9

[0085] The leaves of wild-type Arabidopsis thaliana and overexpression lines OE3 and OE9 that had been treated differently were taken to detect the activities of superoxide dismutase (SOD) and peroxidase (POD). The results are as follows: Figure 8 Different lowercase letters in the figure indicate significant differences (P<0.05).

[0086] Genes from leaves of wild-type Arabidopsis thaliana and overexpression lines OE3 and OE9 were extracted under salt stress conditions to study the expression of salt stress response-related genes AtP5CS under salt stress conditions. 、 The gene expression of AtRD22 and AtRbohF is shown in Fig. 9 Different lowercase letters in the figure indicate significant differences (P<0.05).

[0087] Figure 8The results showed that there was no significant difference in the POD and SOD activities of the plants before salt stress. After salt stress, the POD and SOD contents of the overexpression strains (OE3 and OE9) were significantly higher than those of the wild type. The results showed that the transgenic strains overexpressing the cucumber salt-tolerant gene CsNAC41 could more effectively remove reactive oxygen species (ROS) in cells, thereby reducing the damage of salt stress to plants.

[0088] Fig. 9 The results showed that the expression levels of AtP5CS, AtRD22 and AtRbohF were significantly higher than those of the wild type after salt stress, indicating that overexpression of the cucumber salt-tolerance gene CsNAC41 can improve plant tolerance to salt stress by enhancing proline synthesis and protecting cells from damage caused by dehydration.

[0089] As can be seen from the above embodiments, the present invention provides a cucumber salt-tolerant gene CsNAC41, and the nucleotide sequence of the cucumber salt-tolerant gene CsNAC41 is shown in SEQ ID NO.1. The gene length of the present invention is 888 bp, encoding 295 amino acids. The cucumber salt-tolerant gene CsNAC41 of the present invention has the highest expression level in cucumber fruit, and the expression level of the gene is the highest at 24 h of salt stress. By transforming Arabidopsis thaliana with the cucumber salt-tolerant gene CsNAC41 of the present invention, a transgenic Arabidopsis thaliana with tolerance to salt stress and strong stress resistance can be obtained.

[0090] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, characterized in that: The method comprises the following steps: constructing a recombinant expression vector containing the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing to obtain a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector; The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB; The Agrobacterium is GV3101; The plant is Arabidopsis thaliana.

2. Use of a protein encoded by the cucumber salt-tolerant gene CsNAC41 shown in SEQ ID NO.1 in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, characterized in that: The protein encoded by the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.

2.

3. Use of a recombinant expression vector in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, characterized in that: The recombinant expression vector comprises the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 and an empty vector; The empty vector is the overexpression vector pHB.

4. The use according to claim 3, characterized in that: The method for using a recombinant expression vector in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants comprises the following steps: transforming the recombinant expression vector into Agrobacterium, culturing to obtain recombinant bacteria carrying the recombinant expression vector, and infecting plant plants with the recombinant bacteria carrying the recombinant expression vector; The Agrobacterium is GV3101; The plant is Arabidopsis thaliana.

5. Use of a recombinant bacterium in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants, characterized in that: The recombinant bacteria include the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 or a recombinant expression vector and a host bacteria; The recombinant expression vector is the recombinant expression vector described in claim 3 or 4; The host bacteria is Agrobacterium GV3101.

6. The use according to claim 5, characterized in that: The method for using the recombinant bacteria in improving plant salt tolerance and / or cultivating salt-tolerant transgenic plants comprises the following steps: infecting plant plants with the recombinant bacteria; The plant is Arabidopsis thaliana.

7. A method for improving plant salt tolerance, characterized in that: The steps include: Overexpressing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 in a plant; or constructing a recombinant expression vector containing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing, obtaining a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector; The primer pair for amplifying the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.3-4; The primer pair for detecting the expression of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.5-6; The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB; The Agrobacterium is GV3101; The plant is Arabidopsis thaliana.

8. A method for cultivating salt-tolerant transgenic plants, characterized in that: The steps include: Constructing a recombinant expression vector containing the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1, transforming the recombinant expression vector into Agrobacterium, culturing to obtain a recombinant bacterium carrying the recombinant expression vector, and infecting a plant with the recombinant bacterium carrying the recombinant expression vector; The primer pair for amplifying the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.3-4; The primer pair for detecting the expression of the cucumber salt-tolerance gene CsNAC41 shown in SEQ ID NO.1 is shown in SEQ ID NO.5-6; The empty vector used in constructing the recombinant expression vector is the overexpression vector pHB; The Agrobacterium is GV3101; The plant is Arabidopsis thaliana.

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