%0 Journal Article %1 RN945 %A Xu, B. %A Feng, X. Y. %A Piechatzek, A. %A Zhang, S. Q. %A Konrad, K. R. %A Kromdijk, J. %A Hedrich, R. %A Gilliham, M. %D 2024 %J New Phytologist %K calcium myOwn %N 1 %P 73-81 %R 10.1111/nph.19390 %T The GABA shunt contributes to ROS homeostasis in guard cells of Arabidopsis %U /brokenurl#<Go to ISI>://WOS:001100328500001 %V 241 %X center dot gamma-Aminobutyric acid (GABA) accumulates rapidly under stress via the GABA shunt pathway, which has been implicated in reducing the accumulation of stress-induced reactive oxygen species (ROS) in plants.center dot gamma-Aminobutyric acid has been demonstrated to act as a guard-cell signal in Arabidopsis thaliana, modulating stomatal opening. Knockout of the major GABA synthesis enzyme Glutamate Decarboxylase 2 (GAD2) increases the aperture of gad2 mutants, which results in greater stomatal conductance and reduces water-use efficiency compared with wild-type plants.center dot Here, we found that the additional loss of GAD1, GAD4, and GAD5 in gad2 leaves increased GABA deficiency but abolished the more open stomatal pore phenotype of gad2, which we link to increased cytosolic calcium (Ca2+) and ROS accumulation in gad1/2/4/5 guard cells. Compared with wild-type and gad2 plants, glutamate was ineffective in closing gad1/2/4/5 stomatal pores, whereas lowering apoplastic calcium, applying ROS inhibitors or complementation with GAD2 reduced gad1/2/4/5 guard-cell ROS, restored the gad2-like greater stomatal apertures of gad1/2/4/5 beyond that of wild-type.center dot We conclude that GADs are important contributors to ROS homeostasis in guard cells likely via a Ca2+-mediated pathway. As such, this study reveals greater complexity in GABA's role as a guard-cell signal and the interactions it has with other established signals.

@article{RN945, abstract = {center dot gamma-Aminobutyric acid (GABA) accumulates rapidly under stress via the GABA shunt pathway, which has been implicated in reducing the accumulation of stress-induced reactive oxygen species (ROS) in plants.center dot gamma-Aminobutyric acid has been demonstrated to act as a guard-cell signal in Arabidopsis thaliana, modulating stomatal opening. Knockout of the major GABA synthesis enzyme Glutamate Decarboxylase 2 (GAD2) increases the aperture of gad2 mutants, which results in greater stomatal conductance and reduces water-use efficiency compared with wild-type plants.center dot Here, we found that the additional loss of GAD1, GAD4, and GAD5 in gad2 leaves increased GABA deficiency but abolished the more open stomatal pore phenotype of gad2, which we link to increased cytosolic calcium (Ca2+) and ROS accumulation in gad1/2/4/5 guard cells. Compared with wild-type and gad2 plants, glutamate was ineffective in closing gad1/2/4/5 stomatal pores, whereas lowering apoplastic calcium, applying ROS inhibitors or complementation with GAD2 reduced gad1/2/4/5 guard-cell ROS, restored the gad2-like greater stomatal apertures of gad1/2/4/5 beyond that of wild-type.center dot We conclude that GADs are important contributors to ROS homeostasis in guard cells likely via a Ca2+-mediated pathway. As such, this study reveals greater complexity in GABA's role as a guard-cell signal and the interactions it has with other established signals.}, added-at = {2024-02-14T14:38:32.000+0100}, author = {Xu, B. and Feng, X. Y. and Piechatzek, A. and Zhang, S. Q. and Konrad, K. R. and Kromdijk, J. and Hedrich, R. and Gilliham, M.}, biburl = {https://www.bibsonomy.org/bibtex/21a99d47a5fc7d69759a43a57415d303f/rainerhedrich_2}, doi = {10.1111/nph.19390}, interhash = {0b360552224556ee410f43d76061a65f}, intrahash = {1a99d47a5fc7d69759a43a57415d303f}, issn = {0028-646x}, journal = {New Phytologist}, keywords = {calcium myOwn}, note = {Ej3r3 Times Cited:0 Cited References Count:36}, number = 1, pages = {73-81}, timestamp = {2024-02-14T14:38:32.000+0100}, title = {The GABA shunt contributes to ROS homeostasis in guard cells of Arabidopsis}, type = {Journal Article}, url = {/brokenurl#<Go to ISI>://WOS:001100328500001}, volume = 241, year = 2024 }