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Evidence for multiple receptors mediating RALF-triggered Ca2+ signaling and proton pump inhibition


Gjetting, SK and Mahmood, K and Shabala, L and Kristensen, A and Shabala, S and Palmgren, M and Fuglsang, AT, Evidence for multiple receptors mediating RALF-triggered Ca2+ signaling and proton pump inhibition, The Plant Journal, 104, (2) pp. 433-446. ISSN 1365-313X (2020) [Refereed Article]

Copyright Statement

2020 Society for Experimental Biology and John Wiley & Sons Ltd

DOI: doi:10.1111/tpj.14935


Acidification of the apoplastic space facilitates cell wall loosening and is therefore a key step in cell expansion. PSY1 is a growth-promoting secreted tyrosine-sulfated glycopeptide whose receptor directly phosphorylates and activates the plasma membrane H+-ATPase, which results in acidification and initiates cellular expansion. Although the mechanism is not clear, the Rapid Alkalinization Factor (RALF) family of small, secreted peptides inhibits the plasma membrane H+-ATPase, leading to alkalinization of the apoplastic space and reduced growth. Here we show that treating Arabidopsis thaliana roots with PSY1 induced the transcription of genes encoding the RALF peptides RALF33 and RALFL36. A rapid burst of intracellular Ca2+ preceded apoplastic alkalinization in roots triggered by RALFs, with peptide-specific signatures. Ca2+ channel blockers abolished RALF-induced alkalinization, indicating that the Ca2+ signal is an obligatory part of the response and that it precedes alkalinization. As expected, fer mutants deficient in the RALF receptor FERONIA did not respond to RALF33. However, we detected both Ca2+ and H+ signatures in fer mutants upon treatment with RALFL36. Our results suggest that different RALF peptides induce extracellular alkalinization by distinct mechanisms that may involve different receptors.

Item Details

Item Type:Refereed Article
Keywords:receptors, Ca2+ signaling, proton pump, RALF, apoplastic pH, cell elongation, FERONIA, PSY1 peptide, receptor kinase, signaling pathway, Arabidopsis thaliana
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Other plant production and plant primary products
Objective Field:Other plant production and plant primary products not elsewhere classified
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Shabala, S (Professor Sergey Shabala)
ID Code:147645
Year Published:2020
Web of Science® Times Cited:22
Deposited By:TIA - Research Institute
Deposited On:2021-11-10
Last Modified:2022-04-21

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