Phytosphingosine-phosphate is a signal for AtMPK6 activation and Arabidopsis response to chilling
Article first published online: 11 JAN 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Special Issue: Featured papers on ‘Bioenergy trees’
Volume 194, Issue 1, pages 181–191, April 2012
How to Cite
Dutilleul, C., Benhassaine-Kesri, G., Demandre, C., Rézé, N., Launay, A., Pelletier, S., Renou, J.-P., Zachowski, A., Baudouin, E. and Guillas, I. (2012), Phytosphingosine-phosphate is a signal for AtMPK6 activation and Arabidopsis response to chilling. New Phytologist, 194: 181–191. doi: 10.1111/j.1469-8137.2011.04017.x
- Issue published online: 24 FEB 2012
- Article first published online: 11 JAN 2012
- Received: 13 October 2011, Accepted: 18 November 2011
- Arabidopsis thaliana;
- long-chain bases;
- MAP kinase;
- •Long-chain bases (LCBs) are pleiotropic sphingolipidic signals in eukaryotes. We investigated the source and function of phytosphingosine-1-phosphate (PHS-P), a phospho-LCB rapidly and transiently formed in Arabidopsis thaliana on chilling.
- •PHS-P was analysed by thin-layer chromatography following in vivo metabolic radiolabelling. Pharmacological and genetic approaches were used to identify the sphingosine kinase isoforms involved in cold-responsive PHS-P synthesis. Gene expression, mitogen-activated protein kinase activation and growth phenotypes of three LCB kinase mutants (lcbk1, sphk1 and lcbk2) were studied following cold exposure.
- •Chilling provoked the rapid and transient formation of PHS-P in Arabidopsis cultured cells and plantlets. Cold-evoked PHS-P synthesis was reduced by LCB kinase inhibitors and abolished in the LCB kinase lcbk2 mutant, but not in lcbk1 and sphk1 mutants. lcbk2 presented a constitutive AtMPK6 activation at 22°C. AtMPK6 activation was also triggered by PHS-P treatment independently of PHS/PHS-P balance. lcbk2 mutants grew comparably with wild-type plants at 22 and 4°C, but exhibited a higher root growth at 12°C, correlated with an altered expression of the cold-responsive DELLA gene RGL3.
- •Together, our data indicate a function for LCBK2 in planta. Furthermore, they connect PHS-P formation with plant response to cold, expanding the field of LCB signalling in plants.