Gain-of-function mutations of AtNHX1 suppress sos1 salt sensitivity and improve salt tolerance in Arabidopsis

Abstract Soil salinity severely hampers agricultural productivity. Under salt stress, excess Na + accumulation causes cellular damage and plant growth retardation, membrane transporters play central roles in uptake exclusion to mitigate these adverse effects. In this study, we performed sos1 suppressor mutant (named sup ) screening uncover potential genetic interactors of SOS1 additional tolerance mechanisms. Map-based cloning sequencing identified a group mutants harboring dominant gain-of-function mutations the vacuolar /H antiporter gene AtNHX1 . The variants showed enhanced transporter activities yeast cells increased Arabidopsis wild type plants. Ion content measurements indicated that at level, resulted likely due sequestration. However, reduced shoot but root under indicating role limiting translocation from shoot. We also another suppressors with loss-of-function AtHKT1 Loss-of-function additively suppressed sensitivity, which indicates three transporters, SOS1, function independently coordinately controlling homeostasis Arabidopsis. Our findings provide valuable information about target amino acids NHX1 for editing improve crops.