A tonoplast‐localized magnesium transporter is crucial for stomatal opening in Arabidopsis under high Mg2+ conditions
Year: 2022
Type: article
Abstract: Plant stomata play an important role in CO2 uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing are still not completely understood. Here, through large-scale screening, we identified an Arabidopsis mutant (cst2 for closed stomata2) defective in stomatal opening under light condition. A map-based cloning combined with complementation test revealed that the mutant phenotype was caused by a nucleotide substitution of a gene, which domains show similarity to human Mg efflux transporter ACDP/CNNM. Functional analysis showed that CST2 encodes a tonoplast-localized transporter for Mg. This protein is constitutively and highly expressed in the guard cells. Furthermore, CST2 is phosphorylated by calcineurin B-like protein (CBL)-interacting protein kinases 26 (CIPK26) in vitro, which is probably required for its activation. Knockout of this gene resulted in stomatal closing and growth retardation under high Mg concentration conditions, while over-expression of this gene increased tolerance to high Mg. Our results indicate that CST2 plays an important role in maintaining Mg homeostasis in plant cells through sequestering Mg into vacuoles especially in guard cells and that this homeostasis is required for stomatal opening, which provide a novel insight into mechanism of stomatal opening in plants.
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