2.A.16.5.2
Slow anion channel homologue-3, SLAH3; nitrate is both a substrate and a gate opener (Geiger et al. 2011). Slow, weak voltage-dependent S-type anion efflux channel involved in maintenance of anion homeostasis (Negi et al. 2008). Binds to the highly selective inward-rectifying potassium channel KAT1 and inhibits its activity. Functions as an essential negative regulator of inward potassium channels in guard cells. Essential for the efficient stomatal closure and opening in guard cells (Zhang et al. 2016). The plasma membrane Glycine soja (soy bean) GsSLAH3 protein contains ten TMSs. GsSLAH3 expression is induced by NaHCO₃ treatment, suggesting an involvement to alkaline stress, and ectopic expression of GsSLAH3 in yeast increased sensitivity to alkali treatment (Duan et al. 2017). Overexpression of GsSLAH3 in Arabidopsis thaliana enhanced alkaline tolerance during germination, seedling and adult stages. Transgenic lines improved plant tolerance to KHCO₃ rather than high pH treatment. Overexpressing lines accumulated more NO3^- than wild type (Duan et al. 2017).