Cytosolic calcium signals elicited by the pathogen‐associated molecular pattern flg22 in stomatal guard cells are of an oscillatory nature. Issue 4 (22nd September 2014)

• Record Type: Journal Article
• Authors: Thor, Kathrin; Peiter, Edgar
• Is Part Of: New phytologist. Volume 204:Issue 4(2014)
• Page Start: 873
• Page End: 881
• Publication Date: 2014-09-22
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13064
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13064-abs-0001"> <title>Summary</title> <p> <list id="nph13064-list-0001" list-type="bullet"> <list-item> <p>Changes in cytosolic free calcium ([Ca<sup>2+</sup>]<sub>cyt</sub>) are an early and essential element of signalling networks activated by the perception of pathogen‐associated molecular patterns (PAMPs), such as flg22. The flg22‐induced calcium signal has been described on whole‐plant, but not on single‐cell scale so far. Also, the Ca<sup>2+</sup> sources and channels contributing to its generation are still obscure.</p> </list-item> <list-item> <p>Ratiometric fluorescence imaging employing the calcium reporter Yellow Cameleon 3.6 was performed to analyse the flg22‐induced calcium signature in single guard cells of <italic>Arabidopsis thaliana</italic>. Calcium stores and channel types involved in its generation were determined by a pharmacological approach.</p> </list-item> <list-item> <p>In contrast to the calcium signal determined on whole‐plant level, the signature on single‐cell level is not characterized by one sustained response, but by oscillations in [Ca<sup>2+</sup>]<sub>cyt</sub>. These oscillations were abolished by EGTA and lanthanum, as well as by U73122, neomycin and TMB‐8, but only partially or not at all affected by inhibitors of glutamate receptor‐like channels and cyclic nucleotide‐gated channels.</p> </list-item> <list-item> <p>Our analyses suggest that the response observed on whole‐plant level is the summary of oscillations occurring in single cells. Parallel to external calcium, influx via channels located at internal stores contributes to the signal.</p> </list-item> </list> </p> </abstract>