NHX1 — Solanum lycopersicum

Summary

Tomato gene NHX1 (also known as SOS1) on chromosome 1 encodes a cation/proton exchanger of the CPA1 family with sodium:hydrogen exchanger, lithium:proton antiporter and potassium:proton antiporter activities. In tomato, NHX1 is associated with ion homeostasis, ionic balance, cadmium tolerance, alkaline stress tolerance and bacterial wilt resistance. The gene is linked to vacuolar membrane transport, sodium import and cell pH regulation, and localises to the tonoplast, vacuole and endosome. Associations include traits such as fruit weight, lycopene content, relative yield, sodium uptake, nitrogen content, drought sensitivity, leaf chlorosis, and shoot and root fresh weight. Related genes in other species link the family to high-salinity stress tolerance and sodium homeostasis, as well as vacuolar pH regulation, potassium accumulation, and heat and cold tolerance.