Cloning And Functional Analysis Of Salt Tolerance Of S-adenosylmethionine Synthase HvSAMS2 Gene From Hordeum Vulgare L.

Barley(Hordeum vulgare L)is one of the most resistant gramineous crops to salt stress.Barley varieties show considerable genetic variation in salt tolerance.Identifying genes that respond to salt stress from barley and studying their functions is of great significance for breeding varieties with good quality and suitable for salt-damaged areas.In this study,a farmer's two-row barley was used as a material to clone an S-adenosylmethionine synthase gene.The physicochemical properties of the target gene were analyzed by bioinformatics.The expression pattern and utilization of the gene were analyzed using q RT-PCR analyzed subcellular localization,transformed Saccharomyces cerevisiae and Arabidopsis thaliana to explore the function of Hv SAMS2 gene.The main findings are as follows:1.The Hv SAMS2 gene was cloned from barley using homologous cloning.Bioinformatics analysis showed that the ORF of the Hv SAMS2 gene was 1185 bp,encoding 394 amino acids,and the encoded protein was a stable hydrophilic protein with a molecular weight of 42.83 k Da and a theoretical PI of 5.58.Phylogenetic analysis showed that the protein encoded by hv SAMS2 had the closest genetic relationship with Aegilops chinensis,with a sequence similarity of up to 93.06%.2.The expression pattern of Hv SAMS2 is tissue-specific,with the highest expression in roots,followed by leaves,and the lowest expression in stems.Hv SAMS2 protein is located on the nucleus and cell membrane.3.Construct the overexpression vector p YES2-Hv SAMS2 to transform S-cerevisiae auxotrophic INVSc1 for heterologous expression.Under normal conditions,there is no difference in the growth of the Hv SAMS2 gene strain and the empty vector yeast strain.Under different concentrations of salt stress,the growth difference between the two strains gradually increases with time,and the transgenic strain shows better salinity tolerance.4.Construct the overexpression vector Hv SAMS2-PGreen to transform Arabidopsis thaliana.The phenotypes of homozygous transgenic plants under salt stress were analyzed.The results showed that the loss of fresh weight and root length of transgenic Arabidopsis thaliana under salt stress was much lower than that of wild-type and insertion mutants.5.Hv SAMS2 gene participates in the response process of salt stress,mainly by increasing the content of Spd and Spm to improve the adaptability of plants to salt stress.