Docimo, T , Leone, Antonella , Mattana, M , Fumagalli, E , Dalpiaz, F , Consonni, R , De Tommasi, N , Coraggio, I , Monti, L .
Tickling the plant phenylpropanoid pathway by overexpression of a novel rice Myb.
Several compounds, belonging to the plant phenylpropanoids, have been demonstrated to play a crucial role in the plant defence response or to be pharmacologically bioactive. We have previously reported by microarray analysis that the rice Osmyb4 gene, when ectopically expressed in A. thaliana plants, enhances the expression of many genes of shikimate and phenylpropanoid pathway. To further investigate the role of this transcription factor in driving the biosynthesis of plant phenylpropanoids, the Osmyb4 gene was ectopically expressed in different plant systems. Compared to their relative untransformed (empty vector) plants, Osmyb4 induced the accumulation of specific phenylpropanoids depending on the plant species: sinapoylmalate (SM) in Arabidopsis plants, chlorogenic acid (CGA) in tobacco plants and rosmarinic acid in Salvia sclarea hairy roots. Several genes encoding enzymes yielding common precursors of this pathway (PAL, C4H, C3H) were up-regulated in both Arabidopsis and tobacco Osmyb4 overexpressing plants. Higher level of CGA in tobacco transgenic plants was associated with activation of genes encoding enzymes for the CGA synthesis (4CL1, C3H, 4CL2 and HQT). These last genes were unexpectedly up-regulated in transgenic Arabidopsis plants, which, however, accumulated preferentially SM, due to up-regulation of the SMT gene. Altogether these data indicate that Osmyb4 is a conserved regulator of the biosynthetic pathway of the phenylpropanoids and may be used as an excellent tool to genetically manipulate this pathway in crop and medicinal plants.
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1 - University of Salerno, Dept. Pharmaceutical sciences
2 - University of Salerno, Dept. Pharmaceutical Sciences, Via ponte Don Melillo s/n, Fisciano, 84024, Italy
3 - National research Council, Institute of Plant Biology and Biotechnology
4 - National Reserach Council, Institute of Plant Biology and Biotechnology
5 - National Research Council, Istituto per lo Studio delle Macromolecole
6 - National Research Council, Institute of Plant Genetics- IGV Portici
myb transcription factor
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM