Abstract
In Arabidopsis thaliana cell suspension, abscisic acid (ABA) induces changes in cytosolic calcium concentration ([Ca2+]cyt) which are the trigger for ABA-induced plasma membrane anion current activation, H+-ATPase inhibition, and subsequent plasma membrane depolarization. In the present study, we took advantage of this model to analyze the implication of intracellular Ca2+ stores in ABA signal transduction through electrophysiological current measurements, cytosolic Ca2+ activity measurements with the apoaequorin Ca2+ reporter protein and external pH measurement. Intracellular Ca2+ stores involvement was determined by using specific inhibitors of CICR channels: the cADP-ribose/ryanodine receptor (Br-cADPR and dantrolene) and of the inositol trisphosphate receptor (U73122). In addition experiments were performed on epidermal strips of A. thaliana leaves to monitor stomatal closure in response to ABA in presence of the same pharmacology. Our data provide evidence that ryanodine receptor and inositol trisphosphate receptor could be involved in ABA-induced (i) Ca2+ release in the cytosol, (ii) anion channel activation and H+-ATPase inhibition leading to plasma membrane depolarization and (iii) stomatal closure. Intracellular Ca2+ release could thus contribute to the control of early events in the ABA signal transduction pathway in A. thaliana.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.