Comparative expression analysis of sucrose phosphate synthase gene family in a low and high sucrose Pakistani sugarcane cultivars

Abstract

Sugarcane is the world’s largest cultivated crop by biomass and is the main source of sugar and biofuel. Sucrose phosphate synthase (SPS) enzymes are directly involved in the synthesis of sucrose. Here, we analyzed and compared one of the important gene families involved in sucrose metabolism in a high and low sucrose sugarcane cultivar. A comprehensive in silico analysis of the SoSPS family displayed their phylogenetic relationship, gene and protein structure, miRNA targets, protein interaction network (PPI), gene ontology and collinearity. This was followed by a spatial expression analysis in two different sugarcane varieties. The phylogenetic reconstruction distributed AtSPS, ZmSPS, OsSPS, SoSPS and SbSPS into three main groups (A, B, C). The regulatory region of SoSPS genes carries ABRE, ARE, G-box, and MYC as the most dominant cis-regulatory elements. The PPI analysis predicted a total of 14 unique proteins interacting with SPS. The predominant expression of SPS in chloroplast clearly indicates that they are the most active in the organelle which is the hub of photosynthesis. Similarly, gene ontology attributed SPS to sucrose phosphate synthase and glucosyl transferase molecular functions, as well as sucrose biosynthetic and disaccharide biological processes. Overall, the expression of SPS in CPF252 (high sucrose variety) was higher in leaf and culm as compared to that of CPF 251 (low sucrose variety). In brief, this study adds to the present literature about sugarcane, sucrose metabolism and role of SPS in sucrose metabolism thereby opening up further avenues of research in crop improvement.