Genome-wide identification of TPS genes in sesame and analysis of their expression in response to abiotic stresses

Trehalose and its precursor, trehalose-6-phosphate, play critical roles in plant metabolism and response to abiotic stresses. Trehalose-6-phosphate synthase (TPS) is a key enzyme in the trehalose synthesis pathway. Hence this study identified TPS genes in sesame (SiTPSs) and examined their expression patterns under various abiotic stresses. Totally, ten SiTPSs were identified and comprehensively characterized. SiTPSs were found to be unevenly distributed on five out of 13 sesame chromosomes and were predicted to be localized in chloroplasts and vacuoles of cells. Phylogenetic analysis classified SiTPS proteins into two groups (I and II), which was supported by gene structure and conserved motif analyses. Analysis of cis-acting elements in promoter regions of SiTPSs revealed that they might primarily involve developmental and environmental responses. SiTPSs exhibited different expression patterns in different tissues and under different abiotic stresses. Most group II SiTPS genes (SiTPS4 - SiTPS10) were strongly induced by drought, salt, waterlogging, and osmotic stress. Particularly, SiTPS10 was the most significantly up-regulated under various abiotic stresses, indicating it is a candidate gene for improving sesame tolerance to multiple abiotic stresses. Our results provide insight into the TPS gene family in sesame and fundamental resources for genomics studies towards dissecting SiTPS genes’ functions.