Genome-Wide Analysis of the Trehalose-6-Phosphate Synthase (TPS) Gene Family and Expression Profiling of ScTPS Genes in Sugarcane

The trehalose-6-phosphate synthase (TPS) gene family plays important roles in conferring plant stress resistance, but a comprehensive analysis of the gene family is lacking for sugarcane (Saccharumspp. hybrids). The objective of this study is to document functional classification, evolutionary characterization, and expression profiling of sugarcaneTPSgene (ScTPS) family. Nine putativeScTPSgenes were identified and assigned to two distinct classes based on gene structure and phylogeny. Phylogenetic analysis showed that 31TPSgenes fromArabidopsis, rice and sugarcane could be divided into five distinct clades, suggesting that there were at least five orthologous groups in monocot and dicot plants. Evolution analysis ofTPSgenes revealed thatTPSfamily members appeared to have undergone strong negative selection. The strength of the selective pressure differed in most clades, especially Class ITPSgenes, experienced significantly stronger negative selection pressure than Class IITPSgenes. There were alsocis-regulatory elements related to phytohormones and abiotic stresses. Additionally,ScTPSgenes were found to exhibit divergent expression in response to simulated drought, salinity, and ABA stresses. SinceScTPSgenes function in sugarcane adaptation to environmental stimuli, it might be used as a molecular marker in screening sugarcane germplasm for increased stress resistance.