M. A. K. J. and E. P. are joint senior authors.
The phytohormone auxin is a component of the regulatory system that controls UV-mediated accumulation of flavonoids and UV-induced morphogenesis
Article first published online: 15 MAR 2012
Copyright © Physiologia Plantarum 2012
Special Issue: The Role of UV-B Radiation
Volume 145, Issue 4, pages 594–603, August 2012
How to Cite
Hectors, K., van Oevelen, S., Guisez, Y., Prinsen, E. and Jansen, M. A. K. (2012), The phytohormone auxin is a component of the regulatory system that controls UV-mediated accumulation of flavonoids and UV-induced morphogenesis. Physiologia Plantarum, 145: 594–603. doi: 10.1111/j.1399-3054.2012.01590.x
- Issue published online: 9 JUL 2012
- Article first published online: 15 MAR 2012
- Accepted manuscript online: 3 FEB 2012 01:13PM EST
- Received 28 June 2011; revised 2 November 2011
In plants, ultraviolet (UV)-B acclimation is a complex, dynamic process that plays an essential role in preventing UV-B damage to targets such as DNA and the photosynthetic machinery. In this study we tested the hypothesis that the phytohormone auxin is a component of the regulatory system that controls both UV-mediated accumulation of flavonoids and UV-induced morphogenesis. We found that the leaf area of Arabidopsis thaliana Col-0 plants raised under a low dose of UV radiation (0.56 kJ m−2 daily dose) was, on average, decreased by 23% relative to plants raised in the absence of UV-B, and this was accompanied by a decrease (P = 0.063) in free auxin in young leaf tissues. Compared to Col-0, both the auxin influx mutant axr4-1 and the auxin biosynthesis mutant nit1-3 displayed significantly stronger morphogenic responses, i.e. relative decreases in leaf area were greater for these two mutants. UV exposure also induced accumulation of flavonoids. In Col-0, increases in the concentrations of specific kaempferol derivatives ranged from 2.1- to 19-fold. Thus, UV induces complex changes in flavonoid–glycosylation patterns. Compared to Col-0, three auxin mutants displayed significantly different flavonoid profiles. Thus, based on mutant analysis, it is concluded that the phytohormone auxin plays a role in UV acclimation by regulating flavonoid concentration, flavonoid–glycosylation pattern and by controlling UV-induced morphogenic responses.