Plant selenium accumulation and salt stress tolerance regulation gene GmLsi2L and application thereof

Abstract

The invention discloses a plant selenium accumulation and salt stress tolerance regulation gene GmLsi2L and application thereof, and belongs to the field of gene engineering. The nucleotide sequence of the gene is shown as SEQ ID NO: 5, and the amino acid sequence of the gene is shown as SEQ ID NO: 6. The system is mainly located in endoplasmic reticulum. Experiments prove that the selenium accumulation capacity of arabidopsis thaliana can be remarkably improved through overexpression of the GmLsi2L gene, and the total selenium content of the arabidopsis thaliana treated by 40 mu M Na2SeO3 is remarkably increased compared with that of wild arabidopsis thaliana; meanwhile, the tolerance of the plant to salt stress, selenium stress and composite stress is enhanced, and the fresh weight and chlorophyll content of an overexpressed strain are superior to those of a wild type. The gene can be applied to genetic improvement of crops, the nutritional value and stress resistance of agricultural products can be improved, and a new path is provided for variety optimization of crops such as soybeans and utilization of saline-alkali soil.

Description

Technical Field

[0001] This invention relates to the field of genetic engineering technology, and in particular to a gene regulating selenium accumulation and salt stress tolerance in plants. GmLsi2L And its applications. Background Technology

[0002] Selenium (Se) is an essential trace element for maintaining health in humans and animals, and it is also a beneficial element for plants. Improving dietary selenium intake through crop selenium fortification has become a hot research topic in recent years. It can not only improve selenium deficiency in humans but also help plants cope with various adverse environmental stresses.

[0003] Therefore, discovering novel genes that combine selenium accumulation regulation and salt tolerance, and applying them to soybean genetic improvement, has become the key to breaking through existing technological bottlenecks and achieving increased soybean yield and improved quality. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a gene regulating selenium accumulation and salt stress tolerance in plants. GmLsi2L And its applications. Based on transcriptome data from NGS (next-generation sequencing) and SMRT (single-molecule real-time) sequencing, this invention cloned a novel Lsi2-like gene (named...) from the soybean variety "Dongnong 690". GmLsi2L It, along with two other Lsi2 homologs, is located on chromosome 16. Phylogenetic analysis results indicate that soybean... GmLsi2L It is more closely related to the Lsi2 protein in Arabidopsis thaliana and tomato, and to the protein in horsetail. Lsi2 The Lsi2 protein in both Arabidopsis thaliana and tomato lacks silicon transport activity, and its function is currently unknown. Analysis of cis-regulatory elements in the gene promoter region indicates that... GmLsi2L The promoter region contains a large number of promoter elements involved in stress response and hormone response, including response elements of ABA, biotin, jasmonic acid, ethylene, salicylic acid, gibberellin, drought stress and high salt stress.

[0005] In a first aspect, this invention provides a gene regulating selenium accumulation and salt stress tolerance in plants. GmLsi2L The gene GmLsi2L The nucleotide sequence is as shown in SEQ ID NO:5, or a nucleotide sequence that has more than 90% homology with the sequence shown in SEQ ID NO:5 and encodes the same functional protein.

[0006] In a second aspect, the present invention provides a gene derived from the above-described gene. GmLsi2LThe encoded protein, the amino acid sequence of which is shown in SEQ ID NO: 6.

[0007] In a third aspect, the present invention provides a recombinant expression vector comprising the gene described above. GmLsi2L .

[0008] In a fourth aspect, the present invention provides a host cell comprising the recombinant expression vector described above, wherein the host cell is Escherichia coli DH5α, Agrobacterium tumefaciens EHA105, or a plant cell.

[0009] In a fifth aspect, the present invention provides the gene. GmLsi2L The application of the protein, expression vector, or host cell described herein in regulating selenium accumulation and / or salt tolerance in plants.

[0010] Furthermore, genes GmLsi2L By introducing and overexpressing the substance in plants, the plant's ability to absorb and accumulate selenium and / or its salt tolerance can be improved.

[0011] Furthermore, the plants include soybeans, Arabidopsis thaliana, tomatoes, or corn.

[0012] In a sixth aspect, the present invention provides a method for cultivating transgenic plants with high selenium accumulation, comprising using genetic engineering techniques to overexpress the aforementioned gene or increase the content or activity of the aforementioned protein in the plant.

[0013] In a seventh aspect, the present invention provides a method for improving the salt tolerance of plants, comprising using genetic engineering techniques to overexpress the genes described above or to increase the content or activity of the proteins described above in plants.

[0014] The beneficial effects of this invention include at least the following: (1) Cloned by this invention GmLsi2L Genes can significantly enhance the ability of plants to absorb and accumulate selenium. After treatment with 40 μM Na2SeO3, the total selenium content of Arabidopsis thaliana overexpression lines was significantly increased compared with wild type. This provides a key functional gene for selenium biofortification of crops, which can effectively improve the selenium nutrition level of agricultural products and meet the dietary selenium intake requirements of humans.

[0015] (2) The present invention provides GmLsi2L The gene can simultaneously enhance the plant's tolerance to salt and selenium stress. Under single salt stress of 150 mM NaCl, single selenium stress of 20 μM Na2SeO3, and combined salt and selenium stress, the overexpressing lines showed significantly higher fresh weight and chlorophyll content than the wild type, and exhibited better growth. This can effectively reduce the inhibitory effect of environmental stresses such as salinity, alkalinity, and high selenium on crop growth and reduce yield loss.

[0016] (3) The present inventionGmLsi2L For the first time, the gene has been confirmed to have both selenium accumulation regulation and salt tolerance functions, providing new gene resources and technical pathways for the synergistic improvement of multiple traits in crops.

[0017] (4) The present invention GmLsi2L The gene sequence is well-defined (nucleotide SEQ ID NO: 5, amino acid SEQ ID NO: 6), and its subcellular localization is clear (mainly located in the endoplasmic reticulum). The overexpression vector construction method is mature and highly reproducible. This gene can not only be applied to the genetic improvement of soybeans, but also provides a reference gene target for selenium accumulation and stress resistance enhancement in other crops such as Arabidopsis thaliana and tomato, adapting to the breeding needs of various crops.

[0018] (5) Through regulation GmLsi2L Gene expression can improve the selenium nutritional quality and salt tolerance of crops such as soybeans, which can not only increase the yield and self-sufficiency of local crops, but also expand the utilization value of marginal lands such as saline-alkali land, which is of great practical significance for ensuring national food security and optimizing the agricultural industrial structure. Attached Figure Description

[0019] Figure 1 Subcellular localization of GmLsi2L.

[0020] Figure 2 For 11 Arabidopsis thaliana species GmLsi2L Expression level of GmLsi2L in overexpression lines.

[0021] Figure 3 Arabidopsis thaliana GmLsi2L Changes in total selenium content in overexpression lines after exogenous selenium treatment.

[0022] Figure 4 Arabidopsis thaliana GmLsi2L Fresh weight, chlorophyll content, and visual representation of overexpression lines after treatment with selenium, salt, and selenium + salt.

[0023] Figure 5 For soybeans GmLsi2L Visual representation of the growth status of overexpression lines after treatment with selenium, salt, and a combination of selenium and salt. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0026] The following specific embodiments illustrate the solution proposed in this invention: Example 1 1. GmLsi2L Gene cloning and construction of overexpression vectors Using soybean variety 'Dongnong 690' as the experimental material, after germination and rooting, the seedlings were transplanted into hydroponic containers (370×250×100 mm). 3 After growing in 1 / 2 Hoagland nutrient solution for one week, seedlings were treated with 0, 20, and 100 μM Na₂SeO₃ and nano-selenium, respectively. Seven days later, seedling leaves were collected and rapidly ground under liquid nitrogen. Total RNA was extracted using Trizol reagent, digested with DNase I, and the integrity of the total RNA was detected by 1% agarose gel electrophoresis. The concentration and purity of the total RNA were determined using a NanoDrop-2000 spectrophotometer. The total RNA was then reverse transcribed into cDNA using a reverse transcription kit and sent to the company for transcriptome sequencing. Based on the NGS (next-generation sequencing) and SMRT (single-molecule real-time) transcriptome sequencing results of selenium-enhanced soybeans, the Lsi2L gene, which is highly responsive to exogenous selenium, was screened. Specific primers F1: 5'-TCTCTCTCGAGCTTTCGCGAGCTCATGGCATTAGCACCGGTTC-3' (SEQ ID NO: 1) and R1: 5'-TCGCCCTTGCTCACCATGGATCCTCTTATGAGTGTCAAACCAATAGCA-3' (SEQ ID NO: 2) were designed based on its complete ORF sequence. Soybean cDNA was used as a template for amplification, and the PCR product was excised and recovered to obtain the target gene fragment. The PC1300s vector was digested with restriction endonucleases SacI and BamHI. The digested PC1300s vector was then seamlessly ligated to the target gene fragment using the Uniclone One Step Seamless Cloning Kit. The recombinant product was transformed into *E. coli* DH5α competent cells and plated on LB medium containing Kan resistance. After single colonies grew, positive clones were picked and amplified by PCR using primers F2: 5'-AACTGTTCTATTGCTTGGAGGACC-3' (SEQ ID NO: 3) and R2: 5'-AGAAGATGGTGCGCTCCTG-3' (SEQ ID NO: 4). After agarose gel electrophoresis, the target band was recovered and sequenced. The sequencing results were compared with the full-length cDNA sequences in the reference genome and third-generation transcriptome data. Simultaneously, the sequenced sequence was entered into the bioinformatics software BIOXM to locate its largest open reading frame. The GmLsi2L gene fragment obtained by the PCR reaction had the nucleotide sequence shown in SEQ ID NO: 5. Every three bases were translated into one amino acid, encoding a total of 314 amino acid residues. The resulting amino acid sequence is shown in SEQ ID NO: 6. This indicates that the PC1300S-GmLsi2L overexpression vector (PC1300S-GFP-GmLsi2L) has been successfully constructed.

[0027] Nucleotide sequence SEQ ID NO: 5: ATGTCTCATTTCAACTCCCTTAATTCTCAAGAATGGAATGCCCGCATAGACAGTTTTAATATTCCAAATTCCCCTCAAGTTCAGACTCTAAGAAACCGGTCAGCGGCAATTGATGGTGAAATTGACAGGGTTCTTAGTAACACATTAGATTCCACAAGAAACTCAAATGCATCAAAGGAGGAGACAAATGGTATGCCTCCTTTAACAAAGGAGGAAATAAATGGCAGTCCTTCAAAAGATGATGGAATAGTAGATAAACCAGTAGAAGCACATGTCTTGCTTACTTTAGAAGAAAAGGACTATACAAGTGTTAGATGGAAATATATACTGTGGAAATCCTGCGTATACATAATCACATTAGGAATGTTGATTGCAATGCTTCTAGGTTTGAATATGTCATGGACTGCTATTTCAGCTGCACTAGCTTTGGTAGTTCTTGATTTCAAAGATGCTAGGCCAAGCTTAGAGAAGGTTTCCTATTCACTCTTGATATTCTTTTGTGGAATGTTCATCACAGTAGATGGCTTCAACAGAACTGGGATTCCAGGTGCTCTTTGGGATGTCATGGAGCCTTATTCTCGAGTAAATCAAGCTAGTGGAGTAGCAATACTTGCTCTAGTTATATTAATCCTATCAAATGTGGCTTCAAACGTACCAACTGTTCTATTGCTTGGAGGACCAGTTGCAGCCTCAGCTGCTGCAATTTCCCAAGCGGATGAGAAGAAAGCATGGCTCATCTTGGCTTGGGCCAGCACAGTTGCAGGGAACCTTTCACTATTGGGATCAGCTGCTAACTTGATAGTGTGTGAACAAGCTCGCCGAGCCCCCAACATTGCATACACATTAACCTTCTGGAGCCATCTGAAATTTGGTCTTCCTTCCACCCTTATAATCACTGCTATTGGTTTGACACTCATAAGATGA Protein sequence SEQ ID NO: 6: MSHFNSLNSQEWNARIDSFNIPNSPQVQTLRNRSAAIDGEIDRVLSNTLDSTRNSNASKEETNGMPPLTKEEINGSPSKDDGIVDKPVEAHVLLTLEEKDYTSVRWKYILWKSCVYIITLGMLIAMLLGLNMSWTAISAALALVVLDFKDARP SLEKVSYSLLIFFCGMFITVDGFNRTGIGPGALWDVMEPYSRVNQASGVAILALVILILSNVASNVPTVLLLGGPVAASAAAISQADEKKAWLILAWASTVAGNLSLLGSAANLIVCEQARRAPNIAYTLTFWSHLKFGLPSTLIITAIGLTLIR 2. GmLsi2L Subcellular localization according to GmLsi2L Primers with specific restriction enzyme sites were designed and synthesized based on the gene coding sequence (CDS) and the multiple cloning site of the PC1300S-GFP vector. Total RNA was extracted from fresh soybean leaf tissue and reverse transcribed into cDNA. The cDNA was then amplified by PCR and purified by gel extraction. GmLsi2L The CDS fragment of the gene (with the stop codon removed) was purified by double digestion with the PC1300S-GFP vector. The fragment was then ligated overnight at 16°C using T4 DNA ligase to construct a recombinant vector. The recombinant product was transformed into *E. coli* DH5α competent cells. After colony PCR, double enzyme digestion verification, and sequencing identification, the positive recombinant plasmid PC1300S-GFP-GmLsi2L was obtained. Simultaneously, this plasmid and the empty PC1300S-GFP vector plasmid were transformed into *Agrobacterium tumefaciens* competent cells (EHA105) to obtain positive *Agrobacterium tumefaciens* engineered bacteria.

[0028] The PC1300S-GFP-GmLsi2L and PC1300S-GFP empty vector plasmids were co-transformed into Arabidopsis protoplasts with the endoplasmic reticulum-specific marker vector pCAMBIA1300-35S-ER-mCherry-HDEL. The steps are as follows: Select rosette leaves of 4-week-old Arabidopsis thaliana (Col-0) and cut them into 2 mm wide filaments. Enzymatically hydrolyze the filaments in a shaker in the dark for 2-3 h using a solution (1-1.5% cellulase R10, 0.2-0.4% sorbase R10, 0.4 M mannitol, 20 mM KCl, 20 mM MES (pH 5.7)). After filtration, add half the volume of filtrate to a solution of 200 mM CaCl2 and centrifuge at 800 rpm for 3 min, discarding the supernatant. Wash and resuspend the filtrate in W5 solution (2 mM MES (pH 5.7), 154 mM NaCl, 125 mM CaCl2, 5 mM KCl), and let stand on ice for 30 min. Then, use MMg solution (4 mM MES (pH 5.7), 0.4 M mannitol, 15 mM KCl, 20 ... Resuspend protoplasts in MgCl2 and keep on ice for later use. Add 10 μg of the target plasmid to 200 μL of protoplast suspension, mix with 200 μL of 40% PEG transformation solution, and incubate at room temperature for transformation. Add 800 μL of W5 solution to terminate the reaction. Centrifuge and discard the supernatant, then resuspend in 1 mL of WI solution (0.5 M mannitol, 4 mM MES, 20 mM KCl) and incubate at 22 ℃ in the dark for 16-22 h. After incubation, retain about 100 μL of the resuspended solution, take 20 μL and drop it onto a slide. First, observe the GFP channel under an upright fluorescence microscope, then culture in low light for 8-10 h. Observe the subcellular localization under a laser confocal microscope (Figure 1). The results show that GmLsi2L is mainly located in the endoplasmic reticulum.

[0029] 3. Arabidopsis thaliana GmLsi2L Obtaining and identifying transgenic plants with overexpression Plasmids were extracted from the correctly sequenced monoclonal bacteria and transformed into Agrobacterium EHA105 strain using the heat shock method. Positive clones were obtained by selective LB medium (50 mg / L Rif, 100 mg / L Kan). After bacterial culture, Arabidopsis thaliana Columbia wild-type WT plants (purchased from Arashare) were infected using the flower immersion method. The harvested T0 generation seeds were positively identified using hygromycin and gene primers. The obtained positive lines were continued to be planted and harvested individually until the T2 generation seeds were harvested.

[0030] The expression levels of GmLsi2L in mutant strains were detected using qPCR, and the results are as follows: Figure 2 As shown, 35S::GmLsi2L#6 and 35S::GmLsi2L#13 had the highest expression levels. Hygromycin was used to screen the seeds of the T3 generation, and 35S::GmLsi2L#6 and 35S::GmLsi2L#13 were harvested and the seeds were preserved for subsequent experiments.

[0031] 4. Arabidopsis thaliana GmLsi2L Determination of selenium accumulation in overexpressing transgenic plants after sodium selenite treatment For testing GmLsi2L The changes in total selenium content in overexpressing plants after exogenous selenium treatment were compared with those of WT and GmLsi2L Seeds of homozygous overexpression lines (#6, #13) were sterilized and sown in 1 / 2 MS medium. After vernalization at 4 ℃ for 3 days, they were placed in a tissue culture room for further culture for 7 days. Seedlings of uniform growth were then transplanted into seedling trays for soil cultivation. After 3 weeks of cultivation, the seedlings were watered with 40 μM Na₂SeO₃ every three days. Samples were collected one week after treatment, and the total selenium content in the samples was determined using hydride atomic fluorescence spectrometry. A control group was watered with distilled water during the same period. Results are as follows. Figure 3 As shown, compared to the control, after one week of treatment with 40 μmol / L sodium selenite... GmLsi2L The total selenium content was significantly increased in the gene-overexpressing plants, indicating that... GmLsi2L Overexpression lines can significantly increase selenium accumulation in Arabidopsis plants, which is beneficial for improving selenium biofortification effects and nutritional value.

[0032] 5. Identification of selenium and salt tolerance in Arabidopsis thaliana GmLsi2L overexpression transgenic plants To further explore GmLsi2L Whether gene treatment with selenium and salt affects the salt tolerance of transgenic plants was investigated by selecting WT and... GmLsi2L Phenotypic analysis was performed on gene-overexpressing plants under single-selenium, selenium + salt, and single-salt treatments. Seeds from homozygous overexpressing WT and GmLsi2L lines (#6, #13) were sterilized and randomly agitated into 1 / 2 MS medium using a pipette tip. After vernalization at 4 ℃ for 3 days, the seeds were transferred to a tissue culture room for 7 days. Seedlings with uniform growth were then transplanted into 1 / 2 MS medium containing 0, 20 μM Na2SeO3, 150 mM NaCl, and 150 mM NaCl + 20 μM Na2SeO3 for 7 days. Fresh weight and chlorophyll content were measured for each line, and observations and photographs were taken. Figure 4 As shown, in each process GmLsi2L The overexpression lines (#6, #13) showed significantly greater growth than the wild-type (WT). Meanwhile, GmLsi2LThe biomass and chlorophyll content of the overexpressing homozygous plants were significantly higher than those of the wild-type plants under single selenium, single salt, and selenium + salt treatments, indicating that the gene has good tolerance to selenium and salt stress and can play a good role in enhancing the high salt toxicity of the environment through selenium.

[0033] 6. Soybean Gm Lsi2L Obtaining and identifying overexpressing transgenic plants according to GmLsi2L Based on the CDS sequence of the gene (SEQ ID NO.5) and the multiple cloning site of the pCAMBIA3301 vector, specific primers with corresponding restriction endonuclease sites were designed (the upstream primer contains a BamHI restriction site, and the downstream primer contains a SacI restriction site). PCR amplification was performed using soybean cDNA as a template. The amplification products were detected by 1% agarose gel electrophoresis, and the target fragment was recovered by gel excision. GmLsi2L (Gene CDS sequence). The plant expression vector pCAMBIA3301 and the recovered... GmLsi2L The target gene band was double-digested with BamHI and SacHI, respectively. The digestion products were recovered via agarose gel electrophoresis and ligated overnight at 16°C using T4 DNA ligase. The ligation products were transformed into *E. coli* DH5α competent cells, plated on LB agar containing 50 mg / L kanamycin, and incubated at 37°C for 12–16 h. Single colonies were picked for PCR identification. Positive colonies were inoculated into LB liquid medium for amplification, and plasmids were extracted for double enzyme digestion and sequencing verification. Recombinant vectors with correct sequencing were considered successfully constructed. GmLsi2L Overexpression vector (pCAMBIA3301-GmLsi2L).

[0034] This embodiment uses the Agrobacterium EHA105-mediated genetic transformation method to construct... GmLsi2LThe overexpression vector was transformed into Agrobacterium EHA105 strain via electroporation. Then, the soybean variety "Dongnong 50" was transformed by Agrobacterium infection of soybean cotyledonary nodes. Infected soybean seedlings were inoculated onto MS solid medium containing 0.02% acetylsylgenone and co-cultured at 25°C in the dark for 3-5 days. After co-culture, the seedlings were transferred to MS liquid medium containing glufosinate (5 mg / L) for sublethal concentration selection culture for 21 days. Simultaneously, the presence of bar / pat protein in the selected transgenic plants was directly identified using the Bar test paper method. Successfully transformed positive seedlings (T0) were transplanted into sterile soil. After seed maturity, they were harvested, and the harvested seeds (T1 generation) were sown again in sterile soil and cultured in a greenhouse. Positive seedlings with glufosinate resistance (i.e., GmLsi2L overexpressing soybean plants) were screened and identified by spraying with glufosinate (5 mg / L). In addition, genomic DNA was extracted from resistant seedlings and identified by PCR using specific primers (F3: 5'-TGGGCAGCCCGATGACAGCGACCAC-3'; R3: 5'-ACCGAGCCGCAGGAACCGCAGGAGT-3'). Plants that could amplify the target fragment were identified as positive transgenic plants.

[0035] To further investigate whether the GmLsi2L gene is affected by selenium and salt treatments in transgenic plants, soybean WT “Dongnong 50” and GmLsi2L gene overexpression lines (GmLsi2L-OE2 and GmLsi2L-OE8) seedlings of uniform growth were treated with selenium (50 μM Na2SeO3), salt (150 mM NaCl), and selenium + salt (20 μM Na2SeO3 + 150 mM NaCl) for 7 days, and their phenotypes were observed. The results showed that ( Figure 5 In the high-selenium (50 μM Na2SeO3) treatment group, the overexpressing plants ( GmLsi2L- OE8 Compared to wild-type plants (WT), the expression group showed better growth, taller plants, larger leaves, and better root development. In the selenium + salt (20 μM Na2SeO3 + 150 mM NaCl) combined treatment group, wild-type plants showed significantly improved growth compared to the single salt (150 mM NaCl) treatment, but the plants were still smaller and growth was inhibited. The overexpressing plants (…) GmLsi2L-OE2, GmLsi2L-OE8 The salt damage symptoms were significantly reduced, the plants were growing well, and the survival rate was over 85%.

[0036] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0037] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A gene regulating selenium accumulation and salt stress tolerance in plants. GmLsi2L Its characteristics are, The gene GmLsi2L The nucleotide sequence is as shown in SEQ ID NO:5, or a nucleotide sequence that has more than 90% homology with the sequence shown in SEQ ID NO:5 and encodes the same functional protein.

2. A gene according to claim 1 GmLsi2L The encoded protein is characterized by, The amino acid sequence of the protein is shown in SEQ ID NO:

6.

3. A recombinant expression vector, characterized in that, Contains the gene as described in claim 1 GmLsi2L .

4. A host cell, characterized in that, The recombinant expression vector of claim 3 is included, wherein the host cell is Escherichia coli DH5α, Agrobacterium tumefaciens EHA105, or plant cells.

5. The gene according to claim 1 GmLsi2L The application of the protein of claim 2, the expression vector of claim 3, or the host cell of claim 4 in regulating plant selenium accumulation and / or salt tolerance.

6. The application according to claim 5, characterized in that, Genes GmLsi2L By introducing and overexpressing the substance in plants, the plant's ability to absorb and accumulate selenium and / or its salt tolerance can be improved.

7. The application according to any one of claims 5-6, characterized in that, The plants mentioned include soybeans, Arabidopsis thaliana, tomatoes, or corn.

8. A method for cultivating transgenic plants with high selenium accumulation, characterized in that, This includes using genetic engineering techniques to overexpress the gene of claim 1 in plants or to increase the content or activity of the protein of claim 2 in plants.

9. A method for improving the salt tolerance of plants, characterized in that, This includes using genetic engineering techniques to overexpress the gene of claim 1 in plants or to increase the content or activity of the protein of claim 2 in plants.

Images