%0 Journal Article %1 RN1026 %A Gutermuth, T. %A Herbell, S. %A Lassig, R. %A Brosché, M. %A Romeis, T. %A Feijó, J. A. %A Hedrich, R. %A Konrad, K. R. %D 2018 %J New Phytologist %K almt12 myOwn %N 3 %P 1089-1105 %R 10.1111/nph.15067 %T Tip-localized Ca -permeable channels control pollen tube growth via kinase-dependent R- and S-type anion channel regulation %U /brokenurl#<Go to ISI>://WOS:000430127000023 %V 218 %X Pollen tubes (PTs) are characterized by having tip-focused cytosolic calcium ion (Ca2+) concentration (Ca2+(cyt)) gradients, which are believed to control PT growth. However, the mechanisms by which the apical Ca2+(cyt) orchestrates PT growth are not well understood. Here, we aimed to identify these mechanisms by combining reverse genetics, cell biology, electrophysiology, and live-cell Ca2+ and anion imaging. We triggered Ca2+-channel activation by applying hyperpolarizing voltage pulses and observed that the evoked Ca2+(cyt) increases were paralleled by high anion channel activity and a decrease in the cytosolic anion concentration at the PT tip. We confirmed a functional correlation between these patterns by showing that inhibition of Ca2+-permeable channels eliminated the Ca2+(cyt) increase, resulting in the abrogation of anion channel activity via Ca2+-dependent protein kinases (CPKs). Functional characterization of CPK and anion-channel mutants revealed a CPK2/20/6-dependent activation of SLAH3 and ALMT12/13/14 anion channels. The impaired growth phenotypes of anion channel and CPK mutants support the physiological significance of a kinase- and Ca2+-dependent pathway to control PT growth via anion channel activation. Other than unveiling this functional link, our membrane hyperpolarization method allows for unprecedented manipulation of the Ca2+(cyt) gradient or oscillations in the PT tips and opens an array of opportunities for channel screenings.

@article{RN1026, abstract = {Pollen tubes (PTs) are characterized by having tip-focused cytosolic calcium ion (Ca2+) concentration ([Ca2+](cyt)) gradients, which are believed to control PT growth. However, the mechanisms by which the apical [Ca2+](cyt) orchestrates PT growth are not well understood. Here, we aimed to identify these mechanisms by combining reverse genetics, cell biology, electrophysiology, and live-cell Ca2+ and anion imaging. We triggered Ca2+-channel activation by applying hyperpolarizing voltage pulses and observed that the evoked [Ca2+](cyt) increases were paralleled by high anion channel activity and a decrease in the cytosolic anion concentration at the PT tip. We confirmed a functional correlation between these patterns by showing that inhibition of Ca2+-permeable channels eliminated the [Ca2+](cyt) increase, resulting in the abrogation of anion channel activity via Ca2+-dependent protein kinases (CPKs). Functional characterization of CPK and anion-channel mutants revealed a CPK2/20/6-dependent activation of SLAH3 and ALMT12/13/14 anion channels. The impaired growth phenotypes of anion channel and CPK mutants support the physiological significance of a kinase- and Ca2+-dependent pathway to control PT growth via anion channel activation. Other than unveiling this functional link, our membrane hyperpolarization method allows for unprecedented manipulation of the [Ca2+](cyt) gradient or oscillations in the PT tips and opens an array of opportunities for channel screenings.}, added-at = {2024-02-14T14:38:32.000+0100}, author = {Gutermuth, T. and Herbell, S. and Lassig, R. and Brosché, M. and Romeis, T. and Feijó, J. A. and Hedrich, R. and Konrad, K. R.}, biburl = {https://www.bibsonomy.org/bibtex/2e1e6bcb7d55b46663a01683b531fdd7b/rainerhedrich_2}, doi = {10.1111/nph.15067}, interhash = {fd4236da56762b7fcf98e848cb6c812c}, intrahash = {e1e6bcb7d55b46663a01683b531fdd7b}, issn = {0028-646x}, journal = {New Phytologist}, keywords = {almt12 myOwn}, note = {Sp. Iss. SI Gc9of Times Cited:41 Cited References Count:76}, number = 3, pages = {1089-1105}, timestamp = {2024-02-14T14:38:32.000+0100}, title = {Tip-localized Ca -permeable channels control pollen tube growth via kinase-dependent R- and S-type anion channel regulation}, type = {Journal Article}, url = {/brokenurl#<Go to ISI>://WOS:000430127000023}, volume = 218, year = 2018 }