Journal
EMBO JOURNAL
Volume 30, Issue 8, Pages 1645-1658Publisher
WILEY
DOI: 10.1038/emboj.2011.68
Keywords
abscisic acid; bicarbonate; calcium; carbon dioxide; stomatal conductance
Categories
Funding
- National Science Foundation [MCB0918220]
- National Institutes of Health [GM060396]
- Bayer Crop Sciences
- Chemical Sciences, Geosciences, and Biosciences Division of the Office of Basic Energy Sciences at the US Department of Energy [DOE-DE-FG02-03ER15449]
- Human Frontiers in Science Program
- King Abdullah University of Science and Technology (KAUST) [KUS-F1-021-31]
- National Science Foundation of China [20701028]
- Estonian Science Foundation [7763, SF0180071S07]
- Direct For Biological Sciences
- Div Of Molecular and Cellular Bioscience [0918220] Funding Source: National Science Foundation
Ask authors/readers for more resources
Plants respond to elevated CO2 via carbonic anhydrases that mediate stomatal closing, but little is known about the early signalling mechanisms following the initial CO2 response. It remains unclear whether CO2, HCO3- or a combination activates downstream signalling. Here, we demonstrate that bicarbonate functions as a small-molecule activator of SLAC1 anion channels in guard cells. Elevated intracellular [HCO3-](i) with low [CO2] and [H+] activated S-type anion currents, whereas low [HCO3-](i) at high [CO2] and [H+] did not. Bicarbonate enhanced the intracellular Ca2+ sensitivity of S-type anion channel activation in wild-type and ht1-2 kinase mutant guard cells. ht1-2 mutant guard cells exhibited enhanced bicarbonate sensitivity of S-type anion channel activation. The OST1 protein kinase has been reported not to affect CO2 signalling. Unexpectedly, OST1 loss-of-function alleles showed strongly impaired CO2-induced stomatal closing and HCO3- activation of anion channels. Moreover, PYR/RCAR abscisic acid (ABA) receptor mutants slowed but did not abolish CO2/HCO3- signalling, redefining the convergence point of CO2 and ABA signalling. A new working model of the sequence of CO2 signalling events in gas exchange regulation is presented. The EMBO Journal (2011) 30, 1645-1658. doi:10.1038/emboj.2011.68; Published online 18 March 2011 Subject Categories: membranes & transport; plant biology
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available