Related Experiment Video
Updated: Jul 4, 2026

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
A plastid protein crucial for Ca2+-regulated stomatal responses
Stefan Weinl1, Katrin Held1, Kathrin Schlücking1
1Molekulare Entwicklungsbiologie der Pflanzen, Institut für Botanik und Botanischer Garten, Universität Münster, Schlossplatz 4, 48149 Münster, Germany.
Abstract:
* Guard cell movements are regulated by environmental cues including, for example, elevations in extracellular Ca(2+) concentration. Here, the subcellular localization and physiological function of the Ca(2+)-sensing receptor (CAS) protein was investigated. * CAS protein localization was ascertained by microscopic analyses of green fluorescent protein (GFP) fusion proteins and biochemical fractionation assays. Comparative guard cell movement investigations were performed in wild-type and cas loss-of-function mutant lines of Arabidopsis thaliana. Cytoplasmic Ca(2+) dynamics were addressed in plants expressing the yellow cameleon reporter protein YC3.6. * This study identified CAS as a chloroplast-localized protein that is crucial for proper stomatal regulation in response to elevations of external Ca(2+). CAS fulfils this role through modulation of the cytoplasmic Ca(2+) concentration. * This work reveals a novel role of the chloroplast in cellular Ca(2+) signal transduction.
Related Concept Videos
Regulation of Transpiration by Stomata
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Protein Transport to the Stroma
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Protein Transport to the Inner Chloroplast Membrane
Cell Signaling in Plants

