NHX1 — Solanum lycopersicum

Summary

SlNHX1 (SOLYC06G008820.3) on tomato chromosome 6 encodes a sodium/hydrogen exchanger belonging to the NaH_exchanger and cation/H_exchanger_CPA1 families, with lithium:proton and potassium:proton antiporter activity. This vacuolar membrane protein is associated with ion homeostasis, cadmium tolerance, alkaline stress tolerance, and bacterial wilt resistance in tomato. It has been linked to numerous traits including yield, sodium uptake and content, seedling height, chlorophyll content, harvest index, lycopene content, photosynthetic rate, water use efficiency, and sugar content. The gene is associated with regulation of membrane potential, vacuolar membrane transport, sodium import, lithium export, cell pH regulation, and hormone metabolism. Studies of related genes in other species link this gene family to vacuolar pH homeostasis, salt tolerance, potassium accumulation, and heat and cold tolerance.