A tonoplast‐localized magnesium transporter is crucial for stomatal opening in Arabidopsis under high Mg2+ conditions
Year: 2022
Type: article
Abstract: Summary 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 this gene resulted in stomatal closing, decreased photosynthesis and growth retardation, especially under high Mg2+ conditions, while overexpression of this gene increased stomatal opening and tolerance to high Mg2+ concentrations. Furthermore, guard cell‐specific expression of MGR1/CST2 in the mutant partially restored its stomatal opening. Our results indicate that MGR1/CST2 expression in the leaf guard cells plays an important role in maintaining cytosolic Mg2+ concentrations through sequestering Mg2+ into vacuoles, which is required for stomatal opening, especially under high Mg2+ conditions.
Source: New Phytologist
DOI: 10.1111/nph.18410
Authors: Shin‐ichiro Inoue, Maki Hayashi, Sheng Huang, Kengo Yokosho, Eiji Gotoh, Shuka Ikematsu, Masaki Okumura, Takamasa Suzuki, Takumi Kamura, Toshinori Kinoshita, Jian Feng Ma
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $5,250
Awards: G124440452, Analysis of plasma membrane H+-ATPase during pollination in Brassicaceae self-incompatibility, G2047997065, G4607782047, Analysis of signal transduction of stomatal movements and regulation of plant growth, G4994050750, G506229809, Plasticity of mineral element transport system in response to soil environmental fluctuations in plants, G537732781, G5843147941, Elucidation of the activation mechanism of plasma membrane proton pump in stomatal opening, Development of plant light adaptation to weak light, Identification and functional characterization of protein kinases mediating blue light-dependent stomatal opening, Integrated analysis of mineral transport system in crops
OpenAlex ID: W4288691024