NHX1 — Medicago truncatula

Summary

MTR_1G081900 (MtNHX1) on barrel medic chromosome 1 encodes a sodium/hydrogen exchanger belonging to the NaH_exchanger and cation/H_exchanger_CPA1 families, with potassium:proton antiporter, sodium:hydrogen exchanger and sodium transporter activities. The protein localises to the vacuolar membrane, vacuole, plastid, mitochondria, cytosol and plasmalemma. MtNHX1 is associated with sodium and potassium ion membrane transport, vacuolar membrane transport, cell pH regulation, regulation of stomatal closure, and response to salt. It has been linked to photosynthetic rate, chlorophyll content, and salt tolerance. Associations include cell expansion, root growth, flower development, stem internode length, leaf development, stomatal opening and closure, transpiration, auxin and potassium homeostasis, vacuolar pH, gravitropism, apical dominance, and nitrogen assimilation. Studies of related genes in other species link the family to salt tolerance, ion homeostasis, and heat and cold tolerance.