Identification, evolutionary and expression analysis of the galactinol synthase (GolS) genes in Panicum virgatum L. and Panicum hallii : An in silico approach

Abstract

Galactinol synthase (GS; EC 2.4.1.123) is an important enzyme which catalyzes the first step in the raffinose family oligosaccharides (RFOs) biosynthetic pathway. Galactinol synthase genes (GolS) are encoded by multiple genes in the genomes of monocots and dicots and these allelic variants participate in many biological processes. This study presents the first genome-wide analysis of GolS genes in two switchgrass species. We identified a total of six GolS genes/proteins in Panicum virgatum L. and P. hallii genome. Furthermore, we analyzed in silico all PhGolS and PvGolS genes in terms of protein length, molecular weight, theoretical isoelectric point, and 3D protein structure. The subcellular location was mainly predicted as cytoplasmic. Genomic organization revealed that most PhGolS and PvGolS genes have two or three exons. Subsequently, the conserved motifs were identified; they demonstrated high group-specificity in all PhGolS and PvGolS proteins. Comparative phylogenetic analysis of the PhGolS and PvGolS proteins revealed two distinct groups. Synteny events comparisons of the GolS genes in genus Panicum with those of Arabidopsis thaliana, Oryza sativa, Zea mays, and Brachypodium distachyon led to the identification of several orthologous genes, which provided that the GolS genes in plants happened to feature distinct origins, and the synteny of them are conserved among monocots. Transcriptional profiles revealed that GolS genes were expressed in different tissues, indicating that these genes may be involved in various physiological functions. Collectively, the results obtained from this study provide valuable information for further functional characterization of the GolS genes in these important switchgrass species.