Phosphorylation of the zinc finger transcriptional regulator ZAT6 by MPK6 regulates Arabidopsis seed germination under salt and osmotic stress

► The gene expression of ZAT6 is increased by salt or osmotic stress treatment. ► ZAT6 positively regulates seed germination under stress condition. ► ZAT6 interacts with MPK6 in vitro and in planta. ► MPK6 phosphorylates ZAT6 on two terminal serine residues. ► Phosphorylation of ZAT6 by MPK6 is required for its function.