Calcium-Dependent and -Independent Stomatal Signaling Network and Compensatory Feedback Control of Stomatal Opening via Ca2+ Sensitivity Priming[W]
by Laanemets K. , Brandt B., Li J., Merilo E., Wang Y.-F., Keshwani M. M., Taylor S. S., Kollist H., Schroeder J. I. (2013)
Kristiina Laanemets 2 ,
Benjamin Brandt2 ,
Junlin Li2 ,
Ebe Merilo2 ,
Malik M. Keshwani,
Susan S. Taylor,
Hannes Kollist3 ,
Julian I. Schroeder 3 *
Institute of Technology, University of Tartu, Tartu 50411, Estonia (K.L., E.M., H.K.);
Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093–0116 (B.B., J.L., J.I.S.);
College of Forest Resources and Environment, Nanjing Forestry University, Nanjing 210037, China (J.L.);
Institute of Plant Physiology and Ecology, Shanghai Institute for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200032, China (Y.-F.W.);
Department of Pharmacology, School of Medicine, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093–0654 (M.M.K., S.S.T.)
In conclusion, recent findings show that stomata compensate for excessively open apertures by mechanisms that include constitutive priming (enhancement) of Ca2+ sensitivity, as found in slac1 guard cells (Laanemets et al., 2013; Figs. 1 and 2; Supplemental Fig. S1).
The finding that stomatal regulation can adapt to and compensate for impaired stomatal responses (Laanemets et al., 2013) could be of broader relevance for plant-environment interactions.
A precise biochemical and cellular understanding of the mechanisms that ensure compensatory regulation of stomatal movements and detailed mechanisms mediating specificity in Ca2+ signaling remain to be elucidated in plants.
ABA- and CO2-induced Ca2+ sensitivity priming in guard cells (Young et al., 2006; Siegel et al., 2009; Chen et al., 2010; Xue et al., 2011) provides a system that can explain calcium signaling specificity in guard cells and adds to other (nonexclusive) models for Ca2+ signaling specificity in plants (Kudla et al., 2010).
An in depth biochemical and cellular understanding of mechanisms mediating specificity in Ca2+ signaling is also a present goal in animal cell signaling research (Berridge, 2012).
The hypotheses and models proposed here (Fig. 4) could enable the underlying specificity mechanisms to be characterized at an in depth mechanistic level in a plant cell system.