Crassulacean acid metabolism guard cell anion channel activity follows transcript abundance and is suppressed by apoplastic malate

Crassulacean acid metabolism guard cell anion channel activity follows transcript abundance and is suppressed by apoplastic malate

© 2020 University of Glasgow New Phytologist © 2020 New Phytologist Trust.

Bibliographische Detailangaben
Veröffentlicht in:The New phytologist. - 1979. - 227(2020), 6 vom: 04. Sept., Seite 1847-1857
1. Verfasser: Lefoulon, Cécile (VerfasserIn)
Weitere Verfasser: Boxall, Susanna F, Hartwell, James, Blatt, Michael R
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2020
Zugriff auf das übergeordnete Werk:The New phytologist
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Kalanchoë fedtschenkoi apoplast circadian stomatal regulation crassulacean acid metabolism guard cell anion channel malic acid metabolism voltage clamp Anions Malates
Beschreibung
Zusammenfassung:© 2020 University of Glasgow New Phytologist © 2020 New Phytologist Trust.
Plants utilising crassulacean acid metabolism (CAM) concentrate CO2 around RuBisCO while reducing transpirational water loss associated with photosynthesis. Unlike stomata of C3 and C4 species, CAM stomata open at night for the mesophyll to fix CO2 into malate (Mal) and store it in the vacuole. CAM plants decarboxylate Mal in the light, generating high CO2 concentrations within the leaf behind closed stomata for refixation by RuBisCO. CO2 may contribute to stomatal closure but additional mechanisms, plausibly including Mal activation of anion channels, ensure closure in the light. In the CAM species Kalanchoë fedtschenkoi, we found that guard cell anion channel activity, recorded under voltage clamp, follows KfSLAC1 and KfALMT12 transcript abundance, declining to near zero by the end of the light period. Unexpectedly, however, we found that extracellular Mal inhibited the anion current of Kalanchoë guard cells, both in wild-type and RNAi mutants with impaired Mal metabolism. We conclude that the diurnal cycle of anion channel gene transcription, rather than the physiological signal of Mal release, is a key factor in the inverted CAM stomatal cycle
Beschreibung:Date Completed 14.05.2021
Date Revised 08.03.2023
published: Print-Electronic
Citation Status MEDLINE
ISSN:1469-8137
DOI:10.1111/nph.16640