Open stomata 1 (OST1) kinase controls R-type anion channel QUAC1 in Arabidopsis guard cells.

Under drought stress, the stress hormone ABA addresses the SnR kinase OST1 via its cytosolic receptor and the protein phosphatase ABI1. Upon activation, OST1 phosphorylates the guard cell S-type anion channel SLAC1. Arabidopsis ABI1 and OST1 loss-of-function mutants are characterized by an extreme wilting 'open stomata' phenotype. Given the fact that guard… CONTINUE READING