NHX1 — Brassica juncea

Summary

BJUB04G49780S (BjNHX1) on chromosome B04 of Indian mustard encodes a sodium/hydrogen exchanger belonging to the CPA1 family, with potassium:proton antiporter activity and sodium transporter activity. It is associated with vacuolar membrane transport, sodium import, cell pH regulation, and photoprotection, and is localized to the vacuolar membrane and plastid. The gene is associated with regulation of stomatal closure, leaf development, chlorophyll fluorescence, and detoxification. Traits associated with BjNHX1 include photosynthetic rate, chlorophyll content, and salt tolerance, while phenotypes include hypocotyl elongation, cell expansion, flower development, and vacuolar pH regulation. Studies of related genes in other species link the family to salt tolerance, ion homeostasis, heat tolerance, and biomass production.