Genome-wide identification and characterization of Glutathione S-transferase gene family in Cajanus cajan and their expression profiling under different developmental stages in anatomical tissues

Abstract

Plant glutathione S-transferases (GSTs) are multifunctional conserved protein superfamily that is involved in various biological processes such as growth and development, cellular detoxification, stress biology, and various signaling processes. In the current study, a comprehensive genome-wide identification and characterization of the GST gene family were performed in the agriculturally important legume crop Cajanus cajan. A total of 68 GST genes were identified that belong to eight GST classes based on their conserved domains and motifs. Among 68 CcGST genes, 37 CcGST genes were found on seven Cajanus chromosomes and the remaining CcGST genes were found on the scaffold. Segmental and tandem duplication, both were the driving forces of CcGST gene family expansion. The conserved pattern of exon and intron structure among the different GST classes was observed. The secondary prediction showed the dominance of α- helices. Ser is the highly phosphorylated site in CcGSTs. The subcellular localization prediction of CcGSTs revealed their dominance in the cytoplasm. The physicochemical properties of major CcGST proteins reveal that they are acidic in nature. The expression profiling study revealed the high expression of CcGSTU38, CcGSTU40, CcGSTU44, CcGSTL3, CcGSTL4, CcEF1G1, CcEF1G2, CcDHAR2 and CcGSTF6 in most of the developmental stages in different anatomical tissues. The molecular docking study of highly expressed CcGSTU38 with eight herbicide safeners revealed its highest binding affinity with Fenclorim (-5.44 kcal/mol). This gene could be a potential candidate for future molecular characterization under herbicide stress. The results of the current study endow us with the further functional analysis of Cajanus GSTs in the future.