CS1 — Oryza sativa Japonica

Summary

OS07G0694700 (CS1/APX2) on rice chromosome 7 encodes a haem peroxidase superfamily protein with L-ascorbate peroxidase activity (EC 1.11.1.11) and additional annotated molecular functions including p-coumarate 3-hydroxylase activity, glycolipid binding, and siRNA binding. The gene is associated with the ascorbate-glutathione cycle, cellular oxidant detoxification, and chloroplast-nucleus signaling. In rice, APX2 is linked to plant growth, shoot architecture, leaf height, seed traits including thousand kernel weight, cold stress, salt response, gall midge resistance, and sterility. APX1 family members are associated with blast resistance, Magnaporthe oryzae immunity, salicylic acid response, and cold tolerance at reproductive stage. The protein localizes to chloroplast thylakoid membranes, peroxisome membranes, and stress granules. Additional associations include starch grain shape, amylose content, aluminum tolerance, bacterial blight resistance, and spikelet fertility.