WX1 — Oryza sativa Japonica

Summary

OS06G0133000, designated WX1 (also known as GBSS1, Waxy, or OsGBSS1) in rice (Oryza sativa Japonica) on chromosome 6, encodes a granule-bound starch synthase with starch synthase activity (EC 2.4.1.242). This enzyme is localized to the amyloplast and is associated with starch and amylopectin anabolism. WX1 is associated with amylose content, a key determinant of grain quality, and has been linked to numerous grain traits including head rice yield, grain appearance, grain shape, grain size, seed weight, starch content, and glucose content. The gene is also connected to panicle and spikelet density, culm length, leaf width, root volume, days to heading and maturity, heat and cold tolerance, photosynthetic rate, and heterosis. Studies of related genes in other species link the GBSS family to amylose biosynthesis and chain length distribution, as well as flour and bread-making quality traits.