Environmental regulation of leaf colour in red 35S:PAP1 Arabidopsis thaliana

• Published in: The New phytologist 2009-04, Vol.182 (1), p.102-115
• Main Authors: Rowan, Daryl D, Cao, Mingshu, Lin-Wang, Kui, Cooney, Janine M, Jensen, Dwayne J, Austin, Paul T, Hunt, Martin B, Norling, Cara, Hellens, Roger P, Schaffer, Robert J, Allan, Andrew C
• Format: Article
• Language: English
• Subjects: anthocyanin; Anthocyanins - chemistry; Anthocyanins - metabolism; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis - radiation effects; Arabidopsis Proteins; Arabidopsis thaliana; AtMYB75; Biomass; Biosynthesis; Cluster Analysis; Environment; Flavonoids; Flavonols; Flavonols - chemistry; Flavonols - metabolism; Gene expression; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genes, Regulator; Glycosides; Glycosides - chemistry; Glycosides - metabolism; Leaves; Light; liquid chromatography mass spectrometry; Pancreatitis-Associated Proteins; PAP1; Pigmentation - radiation effects; Plant Leaves - physiology; Plant Leaves - radiation effects; Plants; Solvents; stress response; Temperature; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2008.02737.x

High-temperature, low-light (HTLL) treatment of 35S:PAP1 Arabidopsis thaliana over-expressing the PAP1 (Production of Anthocyanin Pigment 1) gene results in reversible reduction of red colouration, suggesting the action of additional anthocyanin regulators. High-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LCMS) and Affimetrix®-based microarrays were used to measure changes in anthocyanin, flavonoids, and gene expression in response to HTLL. HTLL treatment of control and 35S:PAP1 A. thaliana resulted in a reversible reduction in the concentrations of major anthocyanins despite ongoing over-expression of the PAP1 MYB transcription factor. Twenty-one anthocyanins including eight cis-coumaryl esters were identified by LCMS. The concentrations of nine anthocyanins were reduced and those of three were increased, consistent with a sequential process of anthocyanin degradation. Analysis of gene expression showed down-regulation of flavonol and anthocyanin biosynthesis and of transport-related genes within 24 h of HTLL treatment. No catabolic genes up-regulated by HTLL were found. Reductions in the concentrations of anthocyanins and down-regulation of the genes of anthocyanin biosynthesis were achieved by environmental manipulation, despite ongoing over-expression of PAP1. Quantitative PCR showed reduced expression of three genes (TT8, TTG1 and EGL3) of the PAP1 transcriptional complex, and increased expression of the potential transcriptional repressors AtMYB3, AtMYB6 and AtMYBL2 coincided with HTLL-induced down-regulation of anthocyanin biosynthesis. HTLL treatment offers a model system with which to explore anthocyanin catabolism and to discover novel genes involved in the environmental control of anthocyanins.