HMA4 — Brassica napus

Summary

BnHMA4 (HMA4) on chromosome C07 of oilseed rape encodes a P-type ATPase of the IB subfamily, a cation-transporting ATPase with annotated activities including cadmium, zinc, copper, and potassium transmembrane transporter functions. The gene is associated with metal ion transport, detoxification of copper and cadmium, cellular zinc and copper homeostasis, and response to cobalt, zinc, and toxic substances. It has been linked to photosynthetic rate, germination rate, nitrate uptake, stomatal resistance, and seedling growth and development traits. Phenotypic associations include cadmium tolerance and translocation, zinc resistance and concentration gradients, leaf zinc concentration, and fungal resistance. The product localises to the vacuolar membrane, Golgi, plasmodesma, plasma membrane, and mitochondria. Studies of related genes in other species connect the family to zinc translocation, cadmium accumulation and xylem loading, seed zinc content, and metal homeostasis.