Abstract
Guard cells represent a unique single cell-type system for the study of cellular responses to abiotic and biotic perturbations that affect stomatal movement. Decades of effort through both classical physiological and functional genomics approaches have generated an enormous amount of information on the roles of individual metabolites in stomatal guard cell function and physiology. Recent application of metabolomics methods has produced a substantial amount of new information on metabolome control of stomatal movement. In conjunction with other “omics” approaches, the knowledge-base is growing to reach a systems-level description of this single cell-type. Here we summarize current knowledge of the guard cell metabolome and highlight critical metabolites that bear significant impact on future engineering and breeding efforts to generate plants/crops that are resistant to environmental challenges and produce high yield and quality products for food and energy security.
Highlights
Guard cells as a unique plant single cell-type perform many functions essential to plant growth and survival
An osmolyte that contributes to stomatal opening, can be generated from hexoses and phosphorylated hexoses obtained from guard cell starch degradation or from triose-phosphates produced in guard cell chloroplasts and exported to the cytoplasm where triose-P metabolism yields malate among other metabolites
Considering the roles of established metabolites in guard cell functions, we have begun the heydays of functional genomics, fluxomics, and systems biology toward understanding of this highly sophisticated single cell type model system
Summary
Guard cells as a unique plant single cell-type perform many functions essential to plant growth and survival. It has been proposed that as sucrose accumulates in the apoplast, its osmotic effect drives water efflux from guard cells, resulting in a decrease in stomatal apertures in a mechanism that inversely coordinates photosynthesis and transpiration rates (Lu et al, 1997; Outlaw and De Vlieghere-He, 2001). An osmolyte that contributes to stomatal opening, can be generated from hexoses and phosphorylated hexoses obtained from guard cell starch degradation or from triose-phosphates produced in guard cell chloroplasts and exported to the cytoplasm where triose-P metabolism yields malate among other metabolites. Methylglyoxal, an oxygenated short aldehydic glycolytic intermediate, can induce stomatal closure in A. thaliana accompanied by extracellular reactive oxygen species (ROS) production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and suppression of free cytosolic (Ca2+) oscillations (Hoque et al, 2012) These results indicate a strong interconnectivity between central carbon metabolism and ABA signaling in guard cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
