A glutathione S-transferase IbGSTL2 interacts with IbcPGM to increase starch content and improve starch quality in sweetpotato

A glutathione S-transferase (GST) gene IbGSTL2 was cloned and characterized from sweetpotato. It harbored a variation associated with starch content in storage roots. Overexpression of IbGSTL2 increased starch content and amylopectin proportion, decreased gelatinization temperature, and improved degree of crystallinity in sweetpotato storage roots, while its RNA interference resulted in the opposite trends. IbGSTL2 physically interacted with IbcPGM, an enzyme of sucrose metabolism, and improve starch content and quality by regulating genes involved in starch biosynthesis.