HMA2 — Oryza sativa Japonica

Summary

Rice HMA2 (Os06g0700700) encodes a P-type ATPase of the IB subfamily, with heavy-metal-associated domains, and has been annotated with cadmium-exporting, copper, and zinc transporter activities. In rice, HMA2 is associated with drought stress, and with zinc partitioning and cadmium translocation from roots to shoots, as well as with grain cadmium concentration, root elongation, and phloem loading. The gene is linked to detoxification of cadmium and copper ions, cellular zinc ion homeostasis, and response to cobalt ion. Localisation evidence connects the product to the vacuolar membrane, Golgi membrane, and plasmodesmata. Associations with grain yield, plant height, chlorophyll content, and bacterial disease response have also been recorded. Studies of related genes in other species link the HMA family to cadmium and zinc translocation, metal tolerance, and seed zinc content.