JXB Advance Access originally published online on April 20, 2009
Journal of Experimental Botany 2009 60(7):2191-2202; doi:10.1093/jxb/erp097
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© 2009 The Author(s).
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details)
RESEARCH PAPER |
Light-induced vegetative anthocyanin pigmentation in Petunia


1New Zealand Institute for Plant and Food Research Limited, Private Bag 11-600, Palmerston North, New Zealand
2Institute of Molecular Biosciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
3Institute of Natural Resources, Massey University, Private Bag 11-222, Palmerston North, New Zealand
* To whom correspondence should be addressed. E-mail: lewisd{at}crop.cri.nz
The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillarisx(Petunia axillarisxPetunia hybrida cv. Rose of Heaven)]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (Amax). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors.
Key words: Anthocyanin, bHLH, flavonol, Lc, Leaf colour, light, MYB, photosynthesis, vegetative pigmentation
Present address: Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan.
Present address: School of Biological Sciences, University of Canterbury, Private Bag 4-800, Christchurch, New Zealand.
Received 15 January 2009; Revised 3 March 2009 Accepted 4 March 2009