ARA8 — Brassica juncea

Summary

BJUA09G52810S (BjARA8) on chromosome A09 of Indian mustard encodes a phytochelatin synthase, a papain-like cysteine peptidase superfamily member with phytochelatin synthase C-terminal and N-terminal domains. The enzyme exhibits glutathione gamma-glutamylcysteinyltransferase activity, ABC-type phytochelatin transporter activity, arsenite transporting ATPase activity, and binds cadmium, copper, and other metals. It is associated with phytochelatin biosynthesis, cellular detoxification of cadmium and copper ions, arsenite transport, indole glucosinolate breakdown, defense response by callose deposition in cell wall, and defence response to bacteria. The protein localizes to plastids and cytosol. Associations include auxin content, immune signaling, osmotic stress tolerance, and arsenic translocation. Studies of the Arabidopsis relative PCS1 link the family to heavy metal tolerance and accumulation, arsenic and cadmium detoxification, pathogen resistance, callose deposition, and stem lignification.