Abstract: Glycerol-3-phosphateacyltransferase (GPAT) is a key enzyme in lipid biosynthesis that plays an important role in basic cellular metabolism related to plant growth and development and stress tolerance. In this study, theHvGPAT5gene in the barley (Hordeum vulgareL.) ‘Morex’ was cloned and subjected to bioinformatics analysis and relative expression analysis under abiotic stress. The results showed that the coding region ofHvGPAT5was 1203 bp in length, encoding a peptide of 400 residues. The protein was proposed to be a basic unstable hydrophobic protein and consisted of four transmembrane domains. Subcellular localization analysis indicated thatHvGPAT5was distributed in cell membrane. The conserved domain analysis showed HvGPAT5 contained a conserved acyltransferase structural domain, which was a typical member of the GPAT family. The phylogenetic analysis presented that HvGPAT5 had the closest relationship with homologues in the wheat, which belonged to the same subfamily asArabidopsis ATS1. Protein interaction analysis indicatedHvGPAT5acted as a core gene that interacted closely with other members of the barley GPAT protein family. Spatiotemporal expression analysis showed thatHvGPAT5had relatively high expression in leaves, but low expression in other tissues. Meanwhile, the relative expression ofHvGPAT5was significantly up-regulated in both roots and leaves under abiotic stress (drought, salt, and low temperature), indicating thatHvGPAT5possibly played a positive regulatory role in the abiotic stress response of barley. This study laid a foundation for the further exploration of the biological functions ofHvGPAT5and provided a candidate gene for the study of barley abiotic stress tolerance.

Key words: Hordeum vulgare;HvGPAT5, gene cloning, abiotic stress, expression analysis