Sulphotransferase (SOT) genes in wheat providing tolerance against drought and heat

Abstract

Abstract Sulphotransferase (SOT) genes that are involved in sulphonation during sulphate metabolism, represent a conserved family of genes, which provide tolerance against abiotic stresses like heat and drought in plants. In plants, sulphate metabolism is a component of primary metabolism, where SOTs catalyze sulphonation. In the present study in wheat, 107 TaSOT genes were identified; 78 of these genes were identified through genome-wide search and the remaining 29 identified through SOT domain (PF00685) (sulfotransferase family protein). All 107 genes were mapped onto individual chromosomes. The length of these ranged from 969bp to 7636bp; 73 (68%) of these 107 genes are intronless. The gene sequences were associated with 48 different cis regulatory elements. The genes also carry some tandem/segmental duplications, SSRs (simple sequence repeats), target sites for miRNAs and sequences for some lncRNAs. The promoters of some genes also carried transcription factor binding sites (TFBS). The SOT proteins carried two highly conserved 5’-phosphosulphate-binding (5’ PSB) regions and a 3’-phosphate-binding (3’ PB) motif that are essential for SOT activities. Homology modeling of TaSOT proteins and docking analysis of their ligand-binding sites revealed the presence of important amino acids in their active sites. An expression assay of TaSOT genes via wheat RNA-seq data suggested engagement of these genes in growth, development and responses to various hormones and biotic/abiotic stresses. The results of the present study should help in further functional characterization of SOT genes in wheat and other related crops.