Stomatal closure is known to be associated with early defence responses of plant cells triggered by microbe-associated molecular patterns (MAMPs). However, the molecular mechanisms underlying these guard-cell responses have not yet been elucidated. We therefore studied pathogen-induced changes in ion channel activity in Hordeum vulgare guard cells. Barley mildew (Blumeria graminis) hyphae growing on leaves inhibited light-induced stomatal opening, starting at 9 h after inoculation, when appressoria had developed. Alternatively, stomatal closure was induced by nano-infusion of chitosan via open stomata into the sub-stomatal cavity. Experiments using intracellular double-barreled micro-electrodes revealed that mildew stimulated S-type (slow) anion channels in guard cells. These channels enable the efflux of anions from guard cells and also promote K+ extrusion by altering the plasma membrane potential. Stimulation of S-type anion channels was also provoked by nano-infusion of chitosan. These data suggest that MAMPs of mildew hyphae penetrating the cuticle provoke activation of S-type anion channels in guard cells. In response, guard cells extrude K+ salts, resulting in stomatal closure. Plasma membrane anion channels probably represent general targets of MAMP signaling in plants, as these elicitors depolarize the plasma membrane of various cell types.
%0 Journal Article
%1 koers2011barley
%A Koers, S.
%A Guzel-Deger, A.
%A Marten, I.
%A Roelfsema, M. R. G.
%D 2011
%J Plant Journal
%K S-type anion-channel barley chitosan guard-cell mildew
%N 4
%P 670-680
%R 10.1111/j.1365-313X.2011.04719.x
%T Barley mildew and its elicitor chitosan promote closed stomata by stimulating guard-cell S-type anion channels
%U http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2011.04719.x/full
%V 68
%X Stomatal closure is known to be associated with early defence responses of plant cells triggered by microbe-associated molecular patterns (MAMPs). However, the molecular mechanisms underlying these guard-cell responses have not yet been elucidated. We therefore studied pathogen-induced changes in ion channel activity in Hordeum vulgare guard cells. Barley mildew (Blumeria graminis) hyphae growing on leaves inhibited light-induced stomatal opening, starting at 9 h after inoculation, when appressoria had developed. Alternatively, stomatal closure was induced by nano-infusion of chitosan via open stomata into the sub-stomatal cavity. Experiments using intracellular double-barreled micro-electrodes revealed that mildew stimulated S-type (slow) anion channels in guard cells. These channels enable the efflux of anions from guard cells and also promote K+ extrusion by altering the plasma membrane potential. Stimulation of S-type anion channels was also provoked by nano-infusion of chitosan. These data suggest that MAMPs of mildew hyphae penetrating the cuticle provoke activation of S-type anion channels in guard cells. In response, guard cells extrude K+ salts, resulting in stomatal closure. Plasma membrane anion channels probably represent general targets of MAMP signaling in plants, as these elicitors depolarize the plasma membrane of various cell types.
@article{koers2011barley,
abstract = {Stomatal closure is known to be associated with early defence responses of plant cells triggered by microbe-associated molecular patterns (MAMPs). However, the molecular mechanisms underlying these guard-cell responses have not yet been elucidated. We therefore studied pathogen-induced changes in ion channel activity in Hordeum vulgare guard cells. Barley mildew (Blumeria graminis) hyphae growing on leaves inhibited light-induced stomatal opening, starting at 9 h after inoculation, when appressoria had developed. Alternatively, stomatal closure was induced by nano-infusion of chitosan via open stomata into the sub-stomatal cavity. Experiments using intracellular double-barreled micro-electrodes revealed that mildew stimulated S-type (slow) anion channels in guard cells. These channels enable the efflux of anions from guard cells and also promote K+ extrusion by altering the plasma membrane potential. Stimulation of S-type anion channels was also provoked by nano-infusion of chitosan. These data suggest that MAMPs of mildew hyphae penetrating the cuticle provoke activation of S-type anion channels in guard cells. In response, guard cells extrude K+ salts, resulting in stomatal closure. Plasma membrane anion channels probably represent general targets of MAMP signaling in plants, as these elicitors depolarize the plasma membrane of various cell types.},
added-at = {2017-04-04T14:43:53.000+0200},
author = {Koers, S. and Guzel-Deger, A. and Marten, I. and Roelfsema, M. R. G.},
biburl = {https://www.bibsonomy.org/bibtex/22ba862431bb2a1580cc5772a91700fb3/robroelfsema},
doi = {10.1111/j.1365-313X.2011.04719.x},
interhash = {0b0975d63391bbad230a13e759997567},
intrahash = {2ba862431bb2a1580cc5772a91700fb3},
issn = {09607412},
journal = {Plant Journal},
keywords = {S-type anion-channel barley chitosan guard-cell mildew},
number = 4,
pages = {670-680},
refid = {16},
timestamp = {2017-04-04T14:48:22.000+0200},
title = {Barley mildew and its elicitor chitosan promote closed stomata by stimulating guard-cell S-type anion channels},
url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2011.04719.x/full},
volume = 68,
year = 2011
}