Light-induced stomatal opening requires phosphorylation of the C-terminal autoinhibitory domain of plasma membrane H⁺-ATPase.

ABSTRACT: Plasma membrane H⁺-ATPase provides the driving force for light-induced stomatal opening. However, the mechanisms underlying the regulation of its activity remain unclear. Here, we show that the phosphorylation of two Thr residues in the C-terminal autoinhibitory domain is crucial for H⁺-ATPase activation and stomatal opening in Arabidopsis thaliana. Using phosphoproteome analysis, we show that blue light induces the phosphorylation of Thr-881 within the C-terminal region I, in addition to penultimate Thr-948 in AUTOINHIBITED H⁺-ATPASE 1 (AHA1). Based on site-directed mutagenesis experiments, phosphorylation of both Thr residues is essential for H⁺ pumping and stomatal opening in response to blue light. Thr-948 phosphorylation is a prerequisite fo

SUBMITTER: Fuji S 

PROVIDER: S-EPMC10879506 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature