Characterization of genes in guar gum biosynthesis based on quantitative RNA-sequencing in guar bean (Cyamopsis tetragonoloba).

Guar gum is an important raw material in the food, textile and oil industries, but the biosynthesis of guar gum remains unclear. To illuminate the genes involved in guar gum biosynthesis, guar beans from 30 and 40 days after flowering (DAF) were used for RNA sequencing in this study. A total of 2,535 and 2,724 preferentially expressed genes were found in 30 and 40 DAF endosperm, and 3,720 and 2,530 preferentially expressed genes were found in 30 and 40 DAF embryos, respectively. Of these, mannan synthase genes, α-galactosyltransferase genes and cellulose synthase genes were preferentially expressed in the endosperm from 30 and 40 DAF. The high expression level of these glycometabolism genes in endosperm is consistent with the expectation that the main component of guar gum is galactomannan. We believe that genes related to guar gum biosynthesis found in this study will be useful for both new variety development via genetic engineering and synthetic biology research on guar gum biosynthesis in the future.