SS4 — Oryza sativa Indica Group

Summary

BGIOSGA000900 (SS4, OiSS4) on indica rice chromosome 1 encodes a starch synthase family protein with starch synthase, glycogen (starch) synthase, and transglycosidase activities, and contains a starch-binding domain. The gene is associated with starch and amylopectin biosynthesis, mannan metabolism, cell wall pectin biosynthesis, and endosperm and seed development. It has been linked to traits including starch content, amylose content, glucose content, grain size, anthocyanin content, jasmonic acid content, pericarp color, shoot growth angle, and root morphology. Localization evidence connects the protein to the amyloplast, chloroplast thylakoid, thylakoid lumen, and stromule. The gene is also associated with responses to cold and abscisic acid, photoprotection, and DNA repair. Studies of related genes in other species link the SS4 family to starch granule initiation, granule number, and mannan biosynthesis.