Sesbania cannabina Nramp5 gene and its application in cadmium hyperaccumulation
By cloning and verifying the ScNramp5 gene of Tianjing, the unclear problem of molecular regulation network during the cadmium absorption of Tianjing was solved, efficient repair of cadmium-contaminated soil and improvement of plant cadmium tolerance were achieved, and the application of biosensors was provided.
Patent Information
- Application Number
- CN202510428526.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-08-05
- Estimated Expiration
- 2045-04-08
AI Technical Summary
The existing technology lacks detailed analysis of the sequence, structure and expression pattern of Tianjing Nramp5 gene, and it is difficult to deeply understand its molecular regulatory network in the process of cadmium absorption. There are significant differences in the research on plant directly reference models, resulting in poor comparability of research results and lack of an effective technology system for cadmium-contaminated soil restoration.
The ScNramp5 gene of Tianjing was cloned, and its cadmium absorption and transport function was verified through yeast and transgenic rice, and a biosensor that responded to cadmium was constructed. The ScNramp5 gene was used to regulate the plant's ability to enrich cadmium, and new varieties of plant species were cultivated for cadmium contaminated soil repair.
The efficient expression of Tianjing ScNramp5 gene in the root system was achieved, which significantly improved the plant's ability to enrich cadmium, provided a theoretical basis and gene resource for the restoration of cadmium-contaminated soil, and constructed a biosensor with cadmium concentration response.
Smart Images
Figure CN119932051B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of genetic engineering, specifically the cloning of Sesbania cannabina Nramp5 genes and their functional applications in hyperaccumulating cadmium. Background Art
[0002] Cadmium has high toxicity, easy mobility and difficulty in degradation. After entering the human body through the food chain, it will accumulate in organs such as the kidneys and liver, causing various serious diseases such as renal failure and osteoporosis, posing a great threat to human health. After agricultural soil is polluted by cadmium, the growth of crops is hindered and the quality of agricultural products declines, which not only affects the economic benefits of agricultural production but also endangers food safety. The resistance and accumulation of cadmium in plants require precise regulation by genes. Deeply exploring the mechanism of cadmium absorption and accumulation in hyperaccumulating plants through molecular biology means has important value and significance for the future remediation of cadmium-polluted soil, blocking cadmium from entering the food chain and crop breeding improvement.
[0003] Sesbania cannabina, as green manure, has characteristics such as salt tolerance, waterlogging tolerance and strong adaptability, and plays a significant role in enhancing soil fertility, improving soil structure, inhibiting weed growth, reducing soil erosion and promoting soil microbial activities, which is of great significance for the sustainable development of agriculture. Arabidopsis thaliana and rice are commonly used model organisms in biological research. Although there are research results on in model plants, there are significant differences in genetic background, ecological adaptability, etc. between Sesbania cannabina and model plants, and the research conclusions of model plants cannot be simply applied to Sesbania cannabina. Nramp5
[0004] Currently, there is no report on the functional research of Sesbania cannabina Nramp5 There is a lack of detailed analysis of the gene sequence, structure and expression pattern of Sesbania cannabina Nramp5 genes, making it difficult to deeply understand its molecular regulation network during the cadmium absorption process. For Sesbania cannabina, deeply exploring its Nramp5 mechanism of cadmium absorption in vivo is helpful to further explore the potential of Sesbania cannabina in the remediation of cadmium-polluted soil, and at the same time can also provide a new perspective for understanding the mechanism of plant heavy metal tolerance. Summary of the Invention
[0005] In view of the above-mentioned prior art, the present invention provides Sesbania cannabina Nramp5 genes and their applications in hyperaccumulating cadmium, fully considering the significant differences in genetic background, ecological adaptability, etc. between Sesbania cannabina and model plants, and accurately interpreting the Nramp5 functions and mechanisms of Sesbania cannabina.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] In the first aspect of the present invention, there is provided a ScNramp5gene, the ScNramp5 gene is derived from Sesbania cannabina, and its nucleotide sequence is shown in SEQ ID NO.1, specifically as follows:
[0008] SEQ ID NO.1:
[0009]
[0010] The ScNramp5 protein amino acid sequence encoded by the gene is shown in SEQ ID NO.2, specifically as follows:
[0011] SEQ ID NO.2:
[0012] MASLQQQAESDAASRPIGGSNRIVALNVTPSNNNYDYDHDASSKHNQEKPGWRKFLSYVGPGFLVSLAYLDPGNMETDLQAGADHRYELLWVILIGLVFALIIQSLAANLGVCTGKHLSEICKAEYPLFVKYCLWLLAELAVIAADIPEVIGTAFALNILFHIPVWAGVLLTGFSTLLFLGLQRFGVRKLELLISILVFVMAGCFFGEMSYVKPPASDVLKGMFVPKLSGHGAVGDAIALLGALVMPHNLFLHSALVLSRKVPGSVRGINDACRFFLIESGFALFVAFLINVAMVSVSGTVCSANNLSTENNDRCSDLTLNSASFLLQNVLGRSSSTIYAIALLASGQSSAITGTYAGQYIMQGFLDLKMKKWIRNLVTRCIAITPSLIVSIIGGPSGAGRLIIIASMILSFELPFALIPLLKFSSSSTKMGPHKNSMIIIVFSWILGLGIIGINVYYLITAFVGWLIHSSLPKVANVFIGIIVFPLMAIYIISVIYLTFRKDTVKTFIETKNDPAIQTHVEKGFLNDGQLQLNQAPYREDLADIPLPQ。
[0013] In the second aspect of the present invention, there is provided ScNramp5 the application of the gene in any one of the following (1)-(4):
[0014] (1) Regulating the cadmium enrichment ability of plants;
[0015] (2) Regulating the cadmium tolerance of plants;
[0016] (3) Cultivating new plant varieties for cadmium-polluted soil remediation;
[0017] (4) Constructing a cadmium concentration-responsive biosensor.
[0018] The manifestation of regulating the cadmium enrichment ability of plants is as follows: ScNramp5Genes can be highly expressed in roots, thus regulating the efficient enrichment of cadmium by plants.
[0019] The present invention verifies through experiments that overexpression ScNramp5 the cadmium content in the root part of the overexpressed plants is significantly higher than that of the wild type, and the change in the cadmium content in the above-ground part is not obvious, indicating that ScNramp5 it can be highly expressed in roots.
[0020] The constructed cadmium concentration-responsive biosensor is constructed by coupling ScNramp5 genes with reporter genes to construct a cadmium concentration-responsive biosensor for real-time monitoring of cadmium pollution in the environment or food.
[0021] The reporter genes are: chloramphenicol acetyltransferase gene (cat), luciferase gene (luc), β-glucuronidase gene (gus), secreted alkaline phosphatase gene (seap), or green fluorescent protein gene (gfp).
[0022] In the third aspect of the present invention, there is provided ScNramp5 the application of the protein encoded by the gene in any one of the following (1)-(3):
[0023] (1) Regulating the cadmium enrichment ability of plants
[0024] (2) Regulating plant cadmium tolerance;
[0025] (3) Cultivating new plant varieties for cadmium-polluted soil remediation.
[0026] In the fourth aspect of the present invention, there is provided the application of the recombinant expression vector or genetically engineered bacterium containing ScNramp5 genes in any one of the following (1)-(4):
[0027] (1) Regulating the cadmium enrichment ability of plants
[0028] (2) Regulating plant cadmium tolerance;
[0029] (3) Cultivating new plant varieties for cadmium-polluted soil remediation;
[0030] (4) Constructing a cadmium concentration-responsive biosensor.
[0031] In the fifth aspect of the present invention, there is provided a method for improving the cadmium enrichment ability of plants, including the following steps: by overexpressing ScNramp5 genes or enhancing ScNramp5 the activity of the protein encoded by the gene to improve the cadmium enrichment ability of plants.
[0032] In the sixth aspect of the present invention, there is provided a method for cultivating cadmium-highly enriched plant varieties, the method comprising using the one containing ScNramp5The recombinant expression vector of the gene or the genetically engineered bacterium is transformed into a plant, and positive clones are screened to obtain a transgenic variety of a plant with high cadmium enrichment.
[0033] In the seventh aspect of the present invention, a method for repairing cadmium-polluted soil is provided. By planting the cultivated plant variety with high cadmium enrichment on the cadmium-polluted soil, the plants are harvested and centrally treated after cadmium enrichment, so as to achieve the repair of the cadmium-polluted soil.
[0034] The beneficial effects of the present invention:
[0035] The present invention first cloned the Sesbania cannabina ScNramp5 gene. By expressing the ScNramp5 gene in yeast, it was preliminarily determined that Sesbania cannabina ScNramp5 has the ability to transport, absorb and enrich cadmium. Further, after overexpressing the ScNramp5 gene in rice, it was found that the cadmium content in the root part of the overexpressed ScNramp5 rice was significantly higher than that of the wild type, while the cadmium content in the above-ground part changed insignificantly. This result indicates that ScNramp5 can be highly expressed in the roots, thereby efficiently enriching cadmium. The present invention mined the cadmium-overaccumulating ScNramp5 gene in Sesbania cannabina by molecular biological means, and verified the ScNramp5 function of cadmium enrichment and transport, providing an important theoretical basis and gene resources for using plants to repair cadmium-polluted soil and improving the cadmium tolerance of crops. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 For ScNramp5 -GFP fusion protein and co-localization of the plasma membrane marker FM4-64; from left to right are: ScNramp5 green fluorescence of
[0037] Figure 2 For the detection of Cd content in yeast Δycf1 cells transformed with the pDR196 empty vector (Ctrl) and ScNramp5 ; the data are mean ± standard deviation, n = 5.
[0038] Figure 3 For ScNramp5 analysis of the expression level of the overexpressed rice line; the expression level of the gene was detected by RT-qPCR analysis, and OsActin was used as an internal reference gene. According to the CT values of the internal reference gene and the related gene, 2 -ΔΔCT was used to represent the relative expression level. The statistical results are the mean ± standard error of 3 biological replicates, and the RT-qPCR detection result of the wild type is 1.
[0039] Figure 4 ForScNramp5 Characterization of cadmium absorption and accumulation capacity of transgenic rice materials; Figure 4 In A is ScNramp5 Phenotype of overexpressed transgenic rice plants under 0.5 μM CdCl2 treatment, bar = 10 cm; Figure 4 In B is under 0.5 μM CdCl2 treatment ScNramp5 Cd contents in roots and shoots of overexpressed transgenic rice plants, data are mean ± SD, n = 5. Specific implementation manners
[0040] It should be noted that the following detailed descriptions are all illustrative and aim to provide further explanations for this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.
[0041] As mentioned above, currently the soil heavy metal pollution is severe. Although there have been Nramp5 studies in Arabidopsis thaliana and rice model plants, there are significant differences between Sesbania cannabina and model plants in terms of genetic background, ecological adaptability, etc. Simply applying the research conclusions of model plants to Sesbania cannabina may lead to Nramp5 misinterpretation of the functions and mechanisms of Sesbania cannabina.
[0042] The existing studies on heavy metal absorption in Sesbania cannabina mostly stay at the macroscopic physiological level, and there are few studies on the molecular mechanisms such as gene cloning, expression regulation, and protein functions of Sesbania cannabina. Lack of detailed analysis of the gene sequences, structures, and expression patterns of Sesbania cannabina makes it difficult to deeply understand its molecular regulation network during cadmium absorption. At the same time, in the existing studies, the experimental designs lack systematicness and comprehensiveness, and the experimental conditions vary greatly among different studies, resulting in poor comparability of research results and inability to form a complete and unified theoretical system for the cadmium absorption and tolerance mechanisms of Sesbania cannabina. In addition, in the application research of Sesbania cannabina, Nramp5 no effective cadmium-contaminated soil remediation technology system based on this gene has been established, and there is still a large gap from actual application. Nramp5 Nramp5
[0043] Nramp5 Nramp5 The present invention aims to overcome the limitations of directly borrowing the research of model plants, fully consider the significant differences between Sesbania cannabina and model plants in terms of genetic background, ecological adaptability, etc., and particularly focus on the influence of Sesbania cannabina on the absorption and transport processes of heavy metal ions, so as to accurately interpret the Nramp5 functions and mechanisms of Sesbania cannabina. At the same time, it is committed to compensating for the deficiencies in the research of Sesbania cannabina itself, deeply carrying out research on the molecular mechanisms such as gene cloning, expression regulation, and protein functions of Sesbania cannabina, and detailedly analyzing the sequence and expression pattern of this gene. Through yeast and transgenic overexpressed rice, the Sesbania cannabinaNramp5 Function of cadmium absorption and transport
[0044] The following further describes in detail the specific implementation manners of the present invention in combination with embodiments. The following detailed descriptions are all illustrative and are intended to provide further descriptions of the present application, rather than limiting the scope of the present invention.
[0045] Example 1: ScNramp5 Cloning of gene and construction of vector
[0046] (1) Log in to the NCBI website to search for the Nramp5 amino acid sequences encoded by the proteins or cDNAs of the genes of different species, perform multiple sequence alignments, determine appropriate conserved regions, and use the primer design software Primer5.0 to design the primer sequences shown in SEQ ID NO.3 - SEQ ID NO.4.
[0047] F: ATGGCAAGCCTGCAACAA (SEQ ID NO.3);
[0048] R: TTATTGTGGTAGTGGGAT (SEQ ID NO.4).
[0049] (2) Extract the RNA of Tianjing (Lujing No. 5) and reverse-transcribe it into cDNA. Using the cDNA as a template and the primer sequences shown in SEQ ID NO.3 - SEQ ID NO.4, according to the reaction system shown in Table 1, pre-denature at 94°C for 3 min, denature at 94°C for 30 s, anneal and extend at 58°C for 2 min. After 35 cycles, fully extend at 72°C for 5 min and maintain at 10°C to perform ScNramp5 gene PCR amplification.
[0050] Table 1: Reaction system
[0051]
[0052] The product after PCR amplification is detected by 0.8% agarose gel electrophoresis. After sequencing, it shows that ScNramp5 the gene is 1650 bp, and the nucleotide sequence is as shown in SEQ ID NO.1.
[0053] (3) ScNramp5 Construction of gene vector: ScNramp5 After separating the gene PCR product by agarose electrophoresis, cut the gel and recover it. Connect the purified fragment to the pMD19-T intermediate vector according to the ligation reaction system shown in Table 2, and then transfer it into the competent cells of Escherichia coli DH5α. Coat it on the LB solid medium containing 50 μg / mL Amp and grow for 12 h - 16 h. Then pick the positive colonies for sequencing. Those with correct sequencing are the ones containingScNramp5 The recombinant plasmid of the full-length gene sequence, named ScNramp5 -P. Add glycerol with a volume ratio of 30% of the bacterial liquid to the correctly sequenced bacterial liquid and store it at -70 °C for later use.
[0054] Table 2: Ligation reaction system
[0055]
[0056] Example 2: ScNramp5 Subcellular localization of
[0057] Using the ScNramp5 -P constructed in Example 1 as a template, amplify the gene with the primer sequences shown in SEQ ID NO.5 - SEQ ID NO.6 ScNramp5 , restriction enzyme sites, and ligate it with the 1305-GFP vector to obtain the recombinant plasmid ScNramp5 -GFP;
[0058] F: CACCATTTACGAACGATAGGAGCTCggtaccatggcaagcctgcaacaacaagc (SEQ IDNO.5);
[0059] R: GCCCTTGCTCACCATCTGCAGGTCGACTTGTGGTAGTGGGATATCAGCTAAATC (SEQ IDNO.6).
[0060] Prepare aseptically grown rice seedlings (Nipponbare), isolate their protoplasts, perform PEG-mediated DNA transformation, and observe the fluorescence signal of the protoplasts using a ZEISS LSM710nlo confocal laser scanning microscope (63× oil immersion lens). The excitation light / emission light wavelengths used to observe the GFP and YFP fluorescence signals are 488 nm / 506 - 538 nm respectively, and the wavelength parameters for observing the RFP signal are 561nm / 575 - 630 nm. The results show that ScNramp5 The subcellular localization result of the GFP fusion protein of Figure 1 shows a plasma membrane type (
[0061] Example 3: ScNramp5 Application in the cadmium-sensitive yeast strain Δycf1
[0062] (1) Using ScNramp5 -P as a template, amplify the gene with the primer sequences shown in SEQ ID NO.7 - SEQ ID NO.8 ScNramp5 , EcoR1 and Xho1 restriction enzyme sites, and ligate it with the pEASY-Blunt intermediate vector to obtain the recombinant plasmid ScNramp5-PEA1;
[0063] F: GAATTC ATGGCAAGCCTGCAACAA EcoR1 (SEQ ID NO.7);
[0064] R:CTCGAG TTATTGTGGTAGTGGGAT Xho1 (SEQ ID NO.8).
[0065] (2) Insert the recombinant plasmid ScNramp5 -PEA1 obtained in step (1) into the pDR196 yeast expression vector to construct the expression vector pDR196- ScNramp5 ;
[0066] (3) Pick a single colony of Δycf1 from the YPDA plate and inoculate it into 4 ml of YPDA liquid medium, incubate at 30 °C, 225 rpm, with shaking for 18 - 20 h (overnight) until OD 600 = 0.8 - 1.0. Take 1 ml of the bacterial solution into a 1.5 ml centrifuge tube, at room temperature, centrifuge at 4000 rpm for 5 min, discard the supernatant, resuspend the cells with 1 ml of sterile water, pipette gently to mix evenly, centrifuge to collect the cells, and discard the supernatant. Resuspend the cells with 1 ml of 0.1 M LiAc, mix well, pipette gently to mix evenly, centrifuge to collect the cells again, and discard the supernatant. Finally, add 100 μl of 0.1 M LiAc to each 1.5 ml centrifuge tube to resuspend the cells for standby. Add the following reagents to each 1.5 ml centrifuge tube in sequence: 1 μg of the target plasmid (pDR196- ScNramp5 ), 500 μl of 50% PEG3350 Mix, 5 μl of DTT, then shake vigorously for about 1 min until completely mixed. Then place the 1.5 ml centrifuge tube in a 30 °C metal bath for incubation for 30 min, vortex vigorously every 10 min during this period. Subsequently, perform heat shock at 42 °C for 20 min, immediately place it on ice for 5 min, and then recover at 30 °C for 30 min. Centrifuge to collect the cells, at room temperature, centrifuge at 4000 rpm for 5 min, discard the supernatant. Suspend the cells with 200 μl of sterile water for each transformation, mix gently as much as possible, spread on SD-U solid plates (purchased from Beijing Coolaber Technology Co., Ltd.), and incubate at 30 °C for 4 days, then randomly pick monoclonal colonies for colony PCR verification.
[0067] (4) Yeast cadmium content determination: The Δycf1 strain (ctrl) transformed with the pDR196 empty vector in the logarithmic growth phase and the yeast Δycf1 strain transformed with pDR196- ScNramp5 in the logarithmic growth phase ( ScNramp5), to the liquid SD-U medium (purchased from Beijing Coolaber Technology Co., Ltd.), with an initial OD 600nm = 0.2, cultured at 30 °C with 200 rmp for 12 h, added 10 μM CdCl2, continued to culture for 2 h, harvested yeast cells by centrifugation at 4000 rpm at 4 °C, washed 3 times with 10 μΜ EDTA (pH = 8.0) at 4 °C, and then washed 3 times with ddH2O, freeze-dried, digested with 5 ml of high-purity concentrated HNO3 in a microwave digestion instrument, and determined the cadmium content by ICP-MS. The test results showed that the cadmium content in the yeast Δycf1 strain transformed with pDR196- ScNramp5 was significantly higher than that in the strain transformed with the pDR196 empty vector, and it was preliminarily determined that Sesbania cannabina ScNramp5 had the ability to absorb and enrich cadmium ( Figure 2 ).
[0068] Example 4: Overexpression ScNramp5 Application in rice
[0069] (1) Using ScNramp5 -P as a template, amplify the gene with the primer sequences shown in SEQ ID NO.9 - SEQ ID NO.10 ScNramp5 , BamH I and Kpn I restriction enzyme sites, and ligate with the pEASY-Blunt intermediate vector to obtain the recombinant plasmid ScNramp5 -PEA2;
[0070] ScNramp5 -PEA2-F: GAATTCATGGCAAGCCTGCAACAA (SEQ ID NO.9);
[0071] ScNramp5 -PEA2-R: CTCGAGTTATTGTGGTAGTGGGAT (SEQ ID NO.10).
[0072] (2) Insert the recombinant plasmid ScNramp5 -PEA2 obtained in step (1) into the pTCK303 vector to construct the expression vector pTCK303- ScNramp5 ;
[0073] (3) Transform the expression vector pTCK303- ScNramp5 obtained in step (2) into Agrobacterium, and infect the callus of Nipponbare rice with the obtained Agrobacterium transformed with the pTCK303- ScNramp5 plasmid. When screening for positive clones, due to ScNramp5The vector used for the overexpression rice transgenic material carries the GUS reporter gene expressed under the control of the 35s strong promoter. Transgenic positive seedlings were first obtained by GUS staining. Then, RNA was extracted from the positive seedlings and reverse transcribed into cDNA. Then, using the obtained cDNA as a template and the rice OsActin gene as an internal reference, RT-qPCR was used to ScNramp5 identify the overexpression effect of Figure 3 ( ScNramp5 ). Overexpression lines (OX1, OX2, OX3) were selected for subsequent experiments.
[0074] OsActin F: CAACACCCCTGCTATGTACG (SEQ ID NO.11);
[0075] OsActin R: CATCACCAGAGTCCAACACAA (SEQ ID NO.12).
[0076] ScNramp5 F: ATTGGCACAGCCTTTGCC (SEQ ID NO.13);
[0077] ScNramp5 R: TTTTAATACATCAGAAGC (SEQ ID NO.14).
[0078] (4) After surface sterilization of the rice seeds of WT (Nipponbare) and ScNramp5 the overexpression lines (OX1, OX2, OX3), they were germinated in 1 / 2 MS medium. After 7 days of germination, seedlings with uniform size and vigorous growth were selected and transferred to 10 liters of International Rice Research Institute (IRRI) nutrient solution (0.3 mM KH2PO4, 0.35 mM K2SO4, 1.0 mM CaCl2, 1.0 mM MgSO4·7H2O, 0.5 mM Na2SiO3, 20.0 μM Fe-EDTA, 9.0 μM MnCl2, 0.39 μM (NH4)6Mo7O4·2H2O, 20.0 μM H3BO3, 0.77 μM ZnSO4 and 0.32 μM CuSO4; pH value 5.5). The nutrient solution was changed every other day. After 15 days of culture, they were then treated with 0.5 μM CdCl2 for 5 days. Phenotypic observations were made, and the phenotypic photography results are shown as Figure 4 shown in A below.
[0079] Subsequently, the samples were dried at a constant temperature of 60 ± 2 °C until a constant weight was obtained, and weighed to determine the dry weight. The cadmium content was determined by digesting with 5 ml of analytical reagent grade concentrated HNO3 in a microwave digestion instrument, and the cadmium content in the above-ground parts and roots of rice seedlings was measured by ICP-MS. The wild type and ScNramp5 The detection results of the Cd content in the roots and shoots of overexpressing transgenic rice plants are shown as Figure 4 shown in B below. The detection results showed that, compared with the wild type, the cadmium content in the roots of the overexpressing ScNramp5 plants was significantly higher than that of the wild type, and the change in the cadmium content in the above-ground parts was not obvious. This result indicates that overexpression ScNramp5 can efficiently enrich cadmium. The overexpressing ScNramp5 transgenic plants obtained by transforming the recombinant expression vector containing the ScNramp5 gene into plants can be used as new plant varieties for the remediation of cadmium-polluted soil.
[0080] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification
[0081] equivalent replacement, improvement, etc. should be included within the protection scope of the present application.
Claims
1. Overexpression ScNramp5 Gene or enhancement ScNramp5 The expression level of gene-encoded protein is used in the following (1) or (2): (1) Improve the cadmium accumulation capacity of plant roots; (2) Cultivating plants for remediation of cadmium-contaminated soil; described ScNramp5 The nucleotide sequence of the gene is shown in SEQ ID No. 1, and the plant is Sesbania sesbania.
2. The use according to claim 1, characterized in that The plant cultivation for cadmium-contaminated soil remediation: ScNramp5 Recombinant expression vector of gene or containing ScNramp5 The gene is transformed into a plant by genetically engineered bacteria, and positive clones are obtained by screening.