%0 Journal Article %1 RN1010 %A Huang, S. G. %A Waadt, R. %A Nuhkat, M. %A Kollist, H. %A Hedrich, R. %A Roelfsema, M. R. G. %D 2019 %J New Phytologist %K (aba) abscisic acid myOwn %N 1 %P 177-187 %R 10.1111/nph.15985 %T Calcium signals in guard cells enhance the efficiency by which abscisic acid triggers stomatal closure %U /brokenurl#<Go to ISI>://WOS:000477211200001 %V 224 %X During drought, abscisic acid (ABA) induces closure of stomata via a signaling pathway that involves the calcium (Ca2+)-independent protein kinase OST1, as well as Ca2+-dependent protein kinases. However, the interconnection between OST1 and Ca2+ signaling in ABA-induced stomatal closure has not been fully resolved. ABA-induced Ca2+ signals were monitored in intact Arabidopsis leaves, which express the ratiometric Ca2+ reporter R-GECO1-mTurquoise and the Ca2+-dependent activation of S-type anion channels was recorded with intracellular double-barreled microelectrodes. ABA triggered Ca2+ signals that occurred during the initiation period, as well as in the acceleration phase of stomatal closure. However, a subset of stomata closed in the absence of Ca2+ signals. On average, stomata closed faster if Ca2+ signals were elicited during the ABA response. Loss of OST1 prevented ABA-induced stomatal closure and repressed Ca2+ signals, whereas elevation of the cytosolic Ca2+ concentration caused a rapid activation of SLAC1 and SLAH3 anion channels. Our data show that the majority of Ca2+ signals are evoked during the acceleration phase of stomatal closure, which is initiated by OST1. These Ca2+ signals are likely to activate Ca2+-dependent protein kinases, which enhance the activity of S-type anion channels and boost stomatal closure.

@article{RN1010, abstract = {During drought, abscisic acid (ABA) induces closure of stomata via a signaling pathway that involves the calcium (Ca2+)-independent protein kinase OST1, as well as Ca2+-dependent protein kinases. However, the interconnection between OST1 and Ca2+ signaling in ABA-induced stomatal closure has not been fully resolved. ABA-induced Ca2+ signals were monitored in intact Arabidopsis leaves, which express the ratiometric Ca2+ reporter R-GECO1-mTurquoise and the Ca2+-dependent activation of S-type anion channels was recorded with intracellular double-barreled microelectrodes. ABA triggered Ca2+ signals that occurred during the initiation period, as well as in the acceleration phase of stomatal closure. However, a subset of stomata closed in the absence of Ca2+ signals. On average, stomata closed faster if Ca2+ signals were elicited during the ABA response. Loss of OST1 prevented ABA-induced stomatal closure and repressed Ca2+ signals, whereas elevation of the cytosolic Ca2+ concentration caused a rapid activation of SLAC1 and SLAH3 anion channels. Our data show that the majority of Ca2+ signals are evoked during the acceleration phase of stomatal closure, which is initiated by OST1. These Ca2+ signals are likely to activate Ca2+-dependent protein kinases, which enhance the activity of S-type anion channels and boost stomatal closure.}, added-at = {2024-02-14T14:38:32.000+0100}, author = {Huang, S. G. and Waadt, R. and Nuhkat, M. and Kollist, H. and Hedrich, R. and Roelfsema, M. R. G.}, biburl = {https://www.bibsonomy.org/bibtex/2d443c64d1bc9c9e6ea526f7a98206f12/rainerhedrich_2}, doi = {10.1111/nph.15985}, interhash = {56b2096c7c01f9c0ec5376f884d2ca02}, intrahash = {d443c64d1bc9c9e6ea526f7a98206f12}, issn = {0028-646x}, journal = {New Phytologist}, keywords = {(aba) abscisic acid myOwn}, note = {It5ti Times Cited:50 Cited References Count:73}, number = 1, pages = {177-187}, timestamp = {2024-02-14T14:38:32.000+0100}, title = {Calcium signals in guard cells enhance the efficiency by which abscisic acid triggers stomatal closure}, type = {Journal Article}, url = {/brokenurl#<Go to ISI>://WOS:000477211200001}, volume = 224, year = 2019 }