Screening And Functional Identification Of Synthetic Hydrophilic Short Peptide Gene NLEAs And Candidate Genes

Soil salinization is usually caused by special natural or artificial reasons,which will interfere with the growth and development of crops.Identifying or synthesizing salt-tolerance-related genes and obtaining transgenic crops with significantly improved salt tolerance will increase the yield of crops on saline-alkali land or expand the suitable area of crops in saline-alkali land,which will help to ensure food security.In recent years,with the development of synthetic biology,its applied research in agriculture has gradually been carried out.In the early stage of this study,bioinformatics analysis was performed on the LEA protein database.Several NLEA genes were assembled and synthesized,and the NLEA1 gene that was significantly related to salt tolerance was selected.On this basis,a gene library of hydrophilic short peptide NLEAs was synthesized and through systematic screening,NLEA8 and NLEA13 genes were obtained.The main research is as follows:1.The previous study found that the synthetic hydrophilic short peptide gene NLEA1 can significantly improve the salt tolerance of yeast,and constructed a transgenic plant overexpressing NLEA1.The phenotypic identification results of this study showed that the leaves of transgenic plants could still remain green in 300 mM NaCl solid medium or 200 mM NaCl solution,while the leaves of wild-type plants turned white,indicating that NLEA1 significantly improved the salt tolerance of Arabidopsis.2.In order to obtain more salt-tolerant related short peptide NLEA genes,10 hydrophilic amino acid synthesis units were randomly combined and arranged,142 NLEA genes were synthesized,and a yeast expression vector pYES2-NLEA was constructed and transformed.After preliminary salt-tolerance screening of transgenic yeast,two hydrophilic short peptide genes were obtained.After further confirming the phenotype,an overexpression vector was constructed for phenotype identification in plants.3.Using the method of bioinformatics analysis,the amino acid sequences of NLEA8 and NLEA13 were analyzed for physical and chemical properties,transmembrane domains and protein secondary structure,and the possible mechanism of hydrophilic short peptides to improve salt tolerance was predicted.In summary,this study verified the salt tolerance function of NLEA1 on plants,and further screened NLEA8 and NLEA13,which provided the theoretical basis for the application of NLEA series genes,and also elite genes for crop genetic improvement.