Molecular cloning and expression analysis of sucrose phosphate synthase genes in cassava (Manihot esculenta Crantz)

Abstract

AbstractSucrose phosphate synthase (SPS), a key rate-limiting enzyme in the sucrose biosynthesis pathway in plants, is encoded by a multi-gene family. Until recently, the identification and characterization of theSPSgene family have been performed for dozens of plant species; however, few studies have involved a comprehensive analysis of theSPSfamily members in tropical crops, such as cassava (Manihot esculentaCrantz). In the current study, fiveSPSgenes (MeSPS1,MeSPS2, MeSPS3,MeSPS4,andMeSPS5) were isolated from cassava, and their sequence characteristics were comprehensively characterized. TheseMeSPSgenes were found distributed on five chromosomes (Chr2, Chr14, Chr15, Chr16, and Chr18). Phylogenetic analysis showed that theMeSPSprotein sequences were clustered into three families, together with otherSPSsequences from both dicot and monocot species (families A, B, and C). The spatio-temporal expression pattern analysis ofMeSPSgenes showed a tissue-specific and partially overlapping expression pattern, with the genes mainly expressed in source tissues during cassava growth and development. Correlation analysis revealed that the expression ofMeSPSgenes correlated positively with root starch content, indicating that the expression ofMeSPSgenes might accelerate the rate of starch accumulation in the roots of cassava plants.