Abstract: The GDP-mannose-3',5'-isomerase gene (GME) is a key rate-limiting enzyme in the ascorbate pathway that regulates AsA synthesis. In order to understand the function of GME gene family in pepper and its expression under abiotic stress,it provides a theoretical basis for the research of pepper resistance. This study identified the GME gene family of pepper by bioinformatics method,and analyzed the gene structure,domain,phylogenetic relationship,gene expression pattern and abiotic stress expression. The results showed that there were 2 GME family members in the pepper, CaGME1 and CaGME2,which were distributed on chromosomes 3 and 8,respectively,and both the two genes had 6 exons. CaGME1 and CaGME2 protein had highly conserved NADPH binding sites and substrate-specific binding sites in the NADB Rossmann family. The two GME proteins had zero signal peptide and transmembrane structure,belong to hydrophilic protein,it was most likely to be localized in a cell plasmid,and the secondary structure of the protein had Alpha helix,Beta turn and Random coil. Phylogenetic tree analysis showed that the amino acid sequence encoded by the two genes was closely related to tomato and potato. qRT-PCR analysis showed that, CaGME1 and CaGME2 were up-regulated under low temperature,methyl jasmonate and salt stress,induced by gibberellin. In summary,the different expressions of CaGME1 and CaGME2 genes under stress indicate that they play a role in abiotic stress,which can provide a reference for the research of pepper stress mechanism.

Key words: Pepper, L-ascorbic acid, GME gene family, Expression analysis

CLC Number: 

• Q78

• S641.03