Insight into starch biosynthesis in cereal endosperm

Abstract

Major storage reserve present in cereal endosperm is starch that forms the basis of yield in the most important crops of the world. Storage starch is composed of two D-glucose homopolymer, a near-linear polymer amylose and a highly branched glucan amylopectin. In endosperm, amylose is synthesized by ADP-glucose pyrophosphorylase and granule-bound starch synthase, whereas amylopectin synthesis requires coordinated series of enzymatic reactions catalyzed by ADP-glucose pyrophosphorylase, soluble starch synthase, branching and debranching enzyme. A recent advance in understanding the function of enzyme isoforms has provided new insight in addition to core reactions. This review describes our current view of understanding of storage starch biosynthesis inside the amyloplast of developing cereal endosperm.