Figure 8
An overview of the starch biosynthesis processes in wheat endosperm. The starch biosynthesis includes sucrose degradation pathway, photosynthesis pathway as the raw materials source and starch biosynthesis pathway, and consists of two distinct phases: the glucan initiation process and the starch amplification process. ADPG is mainly synthesized by the cytosolic AGPase SSU and LSU, or supplied by sucrose degradation. The subsequent mechanisms underlying the glucan initiation process remain to be established. Branched dextrins are putatively processed by the coordinated activities of SS, BE, and/or DBE to produce the prototype of an amylopectin cluster structure, which further develops into amylopectin to establish the basic structure. Amylose is mainly synthesized by GBSS. Two AGPase SSU, two AGPase LSU and one Susy were phosphorylated. The protein levels are shown in coloured squares, indicating the change of expression for each developmental stage.