Cloning and functional analysis of 5 glyphosate-response-genes in mutant Enterobacter NRS-1 strain

Abstract:

[Objective] The mechanism of microbe’s tolerance to glyphosate stress is controlled by complex genetic systems including the target gene and many related regulation genes. In the present study, five different expression genes (DEGs) of a mutant Enterobacter strain NRS-1 were identified, the function and interaction were investigated to reveal the role of non-target genes on glyphosate resistance. The work intends to provide potential gene resources for transgenic breeding of glyphosate resistance. [Methods] DEGs of NRS-1 may play a role on the processes of protein biosynthesis, metabolism, cell membrane etc. Accordingly, five DEGs, encoding elongation factor G (fusA), periplasmic protein (osmY), ornithine carbamoyltransferase 2, chain F (argF), thymidine phosphorylase (deoA), succinate dehydrogenase flavoprotein subunit (sdhA), were selected. The sequences of the genes were obtained through T-A cloning, the functions were detected though analyses of prokaryotic expression and transgenic programs. Moreover, the interaction between five genes and the glyphosate-target gene aroA (5-enolpyruvylshikimate-3-phosphate synthase) was also detected using bacteria two-hybrid system and KEGG pathway bioinformatic analysis. [Results] The characteristic of five genes was revealed. According to the performance of prokaryotic expression and transgenic Arabidopsis thaliana, genes were confirmed to help cell to improve the tolerance to glyphosate. The genes argF, deoA have better resistance trait than other genes, similar as the target gene aroA. It seems that the pathways including the synthesis and metabolism of aromatic amino acids, amine acids containing thymine and arginine might be important for NRS-1 to tolerant to glyphosate. Regulation network showed a complicated relationship between the five selected gene and aroA, and no direct interaction was found between them. [Conclusion] The selected five genes had positive effects on the resistance to glyphosate stress, among them, argF, deoA were better than others. Complex gene interaction could be found between genes and aroA.

Key words:Enterobacter, Glyphosate tolerance, Different expressed genes, Gene interaction, Gene regulatory network