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.
%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
}