A tonoplast-localized magnesium transporter is crucial for stomatal opening in Arabidopsis under high Mg²⁺ conditions.

ABSTRACT: Plant stomata play an important role in CO₂ uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing under changing environmental conditions are still not completely understood. Through large-scale genetic screening, we isolated an Arabidopsis mutant (closed stomata2 (cst2)) that is defective in stomatal opening. We cloned the causal gene (MGR1/CST2) and functionally characterized this gene. The mutant phenotype was caused by a mutation in a gene encoding an unknown protein with similarities to the human magnesium (Mg²⁺ ) efflux transporter ACDP/CNNM. MGR1/CST2 was localized to the tonoplast and showed transport activity for Mg²⁺ . This protein was constitutively and highly expressed in guard cells. Knockout of

SUBMITTER: Inoue SI 

PROVIDER: S-EPMC9804957 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature