Investigation and Computational Analysis of Sulfotransferase (SOT) Gene Family in Potato (<em>Solanum tuberosum</em>): Insights Into Sulfur Adjustment for Proper Development and Stimuli Responses

Abstract

Various kinds of primary metabolisms in plants are modulated through sulfate assimilation that the uptake of this inorganic compound can be regulated via the sulfate transporters, such as sulfotransfer-ases (SOTs), engaged in the sulfur metabolism. In the current study a genome-wide approach has been utilized for recognition and characterization of SOT family genes in the significant nutritional crop po-tato (Solanum tuberosum L.). As a result, 29 StSOT genes were identified in the potato genome, which were mapped onto the nine S. tuberosum chromosomes. The protein motifs structure demonstrated two highly conserved 5' PSB region and 3' PB motif that are essential for sulfotransferase and catalytic ac-tivities. The protein-protein interaction networks also significantly demonstrated an interesting collabo-ration between SOTs and the other genes, such as PRTase, APS-kinase, protein phosphatase and APRs, in sulfur compounds biosynthesis and regulation of the flavonoid and brassinosteroid metabolic pro-cesses, which clearly detected the importance of sulfotransferases for potato proper growth/development and stress dealing. Notably, the homology modeling of StSOT proteins and dock-ing analysis of their ligand-binding sites revealed the presence of some stress-responsive residues, such as proline, glycine, serine and lysine, in their active sites. The expression assay of StSOT genes via the potato RNA-seq data clearly suggested the engagements of these gene family members in plants growth and extension as well as responses to various hormones and biotic/abiotic stimulus circum-stances. Our predictions can be informative for the functional characterization of the SOT genes in po-tato and may the other nutritional crops.