Plant defensin AhPDF1.1 is not secreted in leaves but it accumulates in intracellular compartments
Article first published online: 16 JUN 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 1, pages 140–150, October 2011
How to Cite
Oomen, R. J. F. J., Séveno-Carpentier, E., Ricodeau, N., Bournaud, C., Conéjéro, G., Paris, N., Berthomieu, P. and Marquès, L. (2011), Plant defensin AhPDF1.1 is not secreted in leaves but it accumulates in intracellular compartments. New Phytologist, 192: 140–150. doi: 10.1111/j.1469-8137.2011.03792.x
- Issue published online: 2 SEP 2011
- Article first published online: 16 JUN 2011
- Received: 30 March 2011, Accepted: 3 May 2011
- green fluorescent protein (GFP) fusion protein;
- intracellular retention;
- plant defensin;
- subcellular localization
- •Apart from their antifungal role, plant defensins have recently been shown to be involved in abiotic stress tolerance or in inhibition of root growth when added in plant culture medium. We studied the subcellular localization of these proteins, which may account for these different roles.
- •Stable and transient expression of AhPDF1.1::GFP (green fluorescent protein) fusion proteins were analysed in yeast and plants. Functional tests established that the GFP tag did not alter the action of the defensin. Subcellular localization of AhPDF1.1 was characterized: by imaging AhPDF1.1::GFP together with organelle markers; and by immunolabelling AhPDF1.1 in Arabidopsis halleri and Arabidopsis thaliana leaves using a polyclonal serum.
- •All our independent approaches demonstrated that AhPDF1.1 is retained in intracellular compartments on the way to the lytic vacuole, instead of being addressed to the apoplasm.
- •These findings challenge the commonly accepted idea of secretion of defensins. The subcellular localization highlighted in this study could partly explain the dual role of plant defensins on plant cells and is of major importance to unravel the mechanisms of action of these proteins at the cellular level.