Abstract:

The glutasidyl thiotransferase gene(GST)can be involved in the process of plants responding to abiotic stresses.In order to understand the ability of ZmGST in response to salt and drought stress in maize,the ZmGST gene was obtained by RT-PCR cloning using the inbred line CA66 of maize as the material,and the gene was bioinformatically analyzed,and the relative expression of the gene in different tissues of maize and simulated drought and salt stress was analyzed by Real-time fluorescence,and the prokaryotic expression vector was constructed and treated with drought and salt.The results showed that the CDS sequence of ZmGST gene was 384 bp in length and encoded 127 amino acids,and the bioinformatics analysis showed that the gene belonged to the Tau family,was a hydrophilic unstable protein,did not have a transmembrane structure,had 12 phosphorylation modification sites,found no signal peptide,was a non-secreted protein,and subcellular localization predicted that ZmGST was located in the nucleus and cytoplasm.The homologous sequence results showed that ZmGST was the closest related to Sorghum bicolor,and had the highest similarity with ZmGSTU14 gene.The promoter analysis results were found to contain TC-rich repeats and other elements,which are involved in defense and stress response.Real-time fluorescence quantitative results showed that the expression of ZmGST gene was the highest in maize roots and was upregulated by salt stress,which reached the highest level after 24 h of treatment.The results of salt and drought stress at the prokaryotic level showed that the recombinant plasmid pET28a-ZmGST could grow normally in medium with different salt concentrations,and the simulated drought was inhibited.It is speculated that ZmGST gene plays an important role in maize response to salt stress.

Key words: Maize, ZmGST, Salt stress, Prokaryotic expression, qRT-PCR