AtPEPTIDE RECEPTOR2 mediates the AtPEPTIDE1‐induced cytosolic Ca2+ rise, which is required for the suppression of Glutamine Dumper gene expression in Arabidopsis roots. Issue 7 (13th March 2014)

• Record Type: Journal Article
• Authors: Ma, Chunli; Guo, Jie; Kang, Yan; Doman, Kohei; Bryan, Anthony C.; Tax, Frans E.; Yamaguchi, Yube; Qi, Zhi
• Is Part Of: Journal of integrative plant biology. Volume 56:Issue 7(2014)
• Page Start: 684
• Page End: 694
• Publication Date: 2014-03-13
• Subjects: Plants -- Periodicals; Plants -- China -- Periodicals; Electronic journals; 580.5
• DOI: 10.1111/jipb.12171
• Languages: English
• ISSNs: 1672-9072

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="jipb12171-sec-0001" sec-type="section"> <p>AtPEPTIDE RECEPTOR2 (AtPEPR2) is a member of leucine‐rich repeat receptor‐like kinase family and binds to a group of <italic>AtPROPEP</italic> gene‐encoded endogenous peptides, AtPeps. Previously, we found that AtPEPR2 plays a moderate role in the AtPep1‐mediated innate immunity responses in <italic>Arabidopsis</italic> leaf. In this study, we found that <italic>AtPEPR2</italic> promoter has strong activity in the vascular tissues of the roots and the <italic>atpepr2</italic> mutants showed a moderate but significantly shorter root phenotype. AtPEPR2 partially mediated AtPep1‐induced root elongation inhibition. AtPep1‐triggered cytosolic Ca<sup>2+</sup> transient rise in roots showed partial dependence on AtPEPR2 and fully on extracellular Ca<sup>2+</sup> ([Ca<sup>2+</sup>]<sub>ext</sub>). Transcriptional profiling analysis found that expression of 75% of AtPep1‐modulated genes in roots was fully dependent on <italic>AtPEPR2</italic>, of which two dramatically induced genes showed partial dependence on the [Ca<sup>2+</sup>]<sub>ext</sub>. <italic>Arabidopsis</italic> genome contains seven <italic>Glutamine Dumpers</italic> genes (<italic>AtGDUs</italic>), encoding amino acid exporters. Three of them (<italic>AtGDU2, 3, 5</italic>) were among the top 10 genes that were downregulated by AtPep1 through AtPEPR2 fully dependent pathway. Treatment with AtPep1 strongly suppressed promoter activity of <italic>AtGDU3</italic> in roots, which was relieved by chelating [Ca<sup>2+</sup>]<sub>ext</sub>. <italic>Arabidopsis</italic> overexpressing <italic>AtGDU3</italic> showed a shorter root phenotype and decreased sensitivity to the AtPep1‐mediated inhibition of root elongation. Taken together, this study demonstrated a significant role of AtPEPR2 in the AtPep1‐mediated signaling in the roots.</p> </sec> </abstract>