Authors who contributed equally to the work.
Genetic dissection of basal defence responsiveness in accessions of Arabidopsis thaliana
Article first published online: 21 APR 2011
© 2011 Blackwell Publishing Ltd
Plant, Cell & Environment
Volume 34, Issue 7, pages 1191–1206, July 2011
How to Cite
AHMAD, S., VAN HULTEN, M., MARTIN, J., PIETERSE, C. M. J., VAN WEES, S. C. M. and TON, J. (2011), Genetic dissection of basal defence responsiveness in accessions of Arabidopsis thaliana. Plant, Cell & Environment, 34: 1191–1206. doi: 10.1111/j.1365-3040.2011.02317.x
- Issue published online: 9 JUN 2011
- Article first published online: 21 APR 2011
- Accepted manuscript online: 17 MAR 2011 04:45AM EST
- Received 30 December 2010; received in revised form 7 March 2011; accepted for publication 7 March 2011
- basal resistance;
- genetic variation;
- priming of defence
Basal resistance involves a multitude of pathogen- and herbivore-inducible defence mechanisms, ranging from localized callose deposition to systemic defence gene induction by salicylic acid (SA) and jasmonic acid (JA). In this study, we have explored and dissected genetic variation in the responsiveness of basal defence mechanisms within a selection of Arabidopsis accessions. Responsiveness of JA-induced PDF1.2 gene expression was associated with enhanced basal resistance against the necrotrophic fungus Plectosphaerella cucumerina and the herbivore Spodoptera littoralis. Conversely, accessions showing augmented PR-1 induction upon SA treatment were more resistant to the hemi-biotrophic pathogen Pseudomonas syringae, and constitutively expressed defence-related transcription factor (TF) genes. Unexpectedly, accessions with primed responsiveness to SA deposited comparatively little callose after treatment with microbe-associated molecular patterns. A quantitative trait locus (QTL) analysis identified two loci regulating flagellin-induced callose and one locus regulating SA-induced PR-1 expression. The latter QTL was found to contribute to basal resistance against P. syringae. None of the defence regulatory QTLs influenced plant growth, suggesting that the constitutive defence priming conferred by these loci is not associated with major costs on plant growth. Our study demonstrates that natural variation in basal resistance can be exploited to identify genetic loci that prime the plant's basal defence arsenal.