Sucrose Synthase Expressions in Sugarcane and Their Relations with Sucrose Accumulation

Expression sequence tags and tentative consensus sequences of sucrose synthase (SUS) genes in sugarcane database were blasted based on well-characterized SUS genes from other fully genome sequenced plant species. SUS expression profiles from RT-qPCR on an elite cultivar Q117 grown in glasshouse showed distinctive but overlapped patterns of SUS members over different tissues and developmental stages. Further characterization on field grown high- vs. lowsugar lines demonstrated relatively tight correlations between sucrose contents in whole cane juice and transcript levels of two SUS members at different developmental stages, as well as their enzyme activities in sucrose cleavage direction. Prospects of the experiment results on enhancement of sucrose accumulation in sugarcane molecular breeding by manipulating SUS genes were discussed