Molecular aspects of the antagonistic interaction of smoke-derived butenolides on the germination process of Grand Rapids lettuce (Lactuca sativa) achenes
Article first published online: 9 OCT 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 4, pages 1060–1073, December 2012
How to Cite
Soós, V., Sebestyén, E., Posta, M., Kohout, L., Light, M. E., Van Staden, J. and Balázs, E. (2012), Molecular aspects of the antagonistic interaction of smoke-derived butenolides on the germination process of Grand Rapids lettuce (Lactuca sativa) achenes. New Phytologist, 196: 1060–1073. doi: 10.1111/j.1469-8137.2012.04358.x
- Issue published online: 5 NOV 2012
- Article first published online: 9 OCT 2012
- Manuscript Accepted: 23 AUG 2012
- Manuscript Received: 6 JUN 2012
- Generation Challenge Programme
- Hungarian-South African S&T Cooperation Programme
- Hungarian Scientific Research Fund. Grant Number: OTKA 100763
- National Research Foundation
- South Africa, the University of KwaZulu-Natal
- IOCB. Grant Number: Z40550506
- abscisic acid;
- Lactuca sativa ;
- Smoke-derived compounds provide a strong chemical signal to seeds in the soil seed bank, allowing them to take advantage of the germination niche created by the occurrence of fire. The germination stimulatory activity of smoke can largely be attributed to karrikinolide (KAR1), while a related compound, trimethylbutenolide (TMB), has been shown to have an inhibitory effect on germination. The aim of this study was to characterize the interaction of these potent fire-generated compounds.
- Dose–response analysis, leaching tests and a detailed transcriptome study were performed using highly KAR1-sensitive lettuce (Lactuca sativa cv ‘Grand Rapids’) achenes.
- Dose–response analysis demonstrated that the compounds are not competitors and TMB modulates germination in a concentration-dependent manner. The transcriptome analysis revealed a contrasting expression pattern induced by the compounds. KAR1 suppressed, while TMB up-regulated ABA, seed maturation and dormancy-related transcripts. The effect of TMB was reversed by leaching the compound, while the KAR1 effect was only reversible by leaching within the first 2 h of KAR1 treatment.
- Our findings suggest that the compounds may act in concert for germination-related signaling. After the occurrence of fire, sufficient rainfall would contribute to post-germination seedling recruitment by reducing the concentration of the inhibitory compound.