Arabidopsis transcriptional response to extracellular Ca2+ depletion involves a transient rise in cytosolic Ca2+. Issue 2 (8th July 2014)

• Record Type: Journal Article
• Authors: Wang, Jing; Tergel, Tergel; Chen, Jianhua; Yang, Ju; Kang, Yan; Qi, Zhi
• Is Part Of: Journal of integrative plant biology. Volume 57:Issue 2(2015)
• Page Start: 138
• Page End: 150
• Publication Date: 2014-07-08
• Subjects: Plants -- Periodicals; Plants -- China -- Periodicals; Electronic journals; 580.5
• DOI: 10.1111/jipb.12218
• Languages: English
• ISSNs: 1672-9072

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="jipb12218-sec-0001" sec-type="section"> <p>Ecological evidence indicates a worldwide trend of dramatically decreased soil Ca<sup>2+</sup> levels caused by increased acid deposition and massive timber harvesting. Little is known about the genetic and cellular mechanism of plants' responses to Ca<sup>2+</sup> depletion. In this study, transcriptional profiling analysis helped identify multiple extracellular Ca<sup>2+</sup> ([Ca<sup>2+</sup>]<sub>ext</sub>) depletion‐responsive genes in <italic>Arabidopsis thaliana</italic> L., many of which are involved in response to other environmental stresses. Interestingly, a group of genes encoding putative cytosolic Ca<sup>2+</sup> ([Ca<sup>2+</sup>]<sub>cyt</sub>) sensors were significantly upregulated, implying that [Ca<sup>2+</sup>]<sub>cyt</sub> has a role in sensing [Ca<sup>2+</sup>]<sub>ext</sub> depletion. Consistent with this observation, [Ca<sup>2+</sup>]<sub>ext</sub> depletion stimulated a transient rise in [Ca<sup>2+</sup>]<sub>cyt</sub> that was negatively influenced by [K<sup>+</sup>]<sub>ext</sub>, suggesting the involvement of a membrane potential‐sensitive component. The [Ca<sup>2+</sup>]<sub>cyt</sub> response to [Ca<sup>2+</sup>]<sub>ext</sub> depletion was significantly desensitized after the initial treatment, which is typical of a receptor‐mediated signaling event. The response was insensitive to an animal Ca<sup>2+</sup> sensor antagonist, but was suppressed by neomycin, an inhibitor of phospholipase C. Gd<sup>3+</sup>, an inhibitor of Ca<sup>2+</sup> channels, suppressed the [Ca<sup>2+</sup>]<sub>ext</sub>‐triggered rise in [Ca<sup>2+</sup>]<sub>cyt</sub> and downstream changes in gene expression. Taken together, this study demonstrates that [Ca<sup>2+</sup>]<sub>cyt</sub> plays an important role in the putative receptor‐mediated cellular and transcriptional response to [Ca<sup>2+</sup>]<sub>ext</sub> depletion of plant cells.</p> </sec> </abstract>