Genome-wide analysis of the structural genes regulating defense phenylpropanoid metabolism in Populus
Article first published online: 1 AUG 2006
Volume 172, Issue 1, pages 47–62, October 2006
How to Cite
Tsai, C.-J., Harding, S. A., Tschaplinski, T. J., Lindroth, R. L. and Yuan, Y. (2006), Genome-wide analysis of the structural genes regulating defense phenylpropanoid metabolism in Populus. New Phytologist, 172: 47–62. doi: 10.1111/j.1469-8137.2006.01798.x
- Issue published online: 1 AUG 2006
- Article first published online: 1 AUG 2006
- Received: 4 April 2006 Accepted: 28 April 2006
- phenylpropanoid metabolism;
- condensed tannins;
- phenolic glycosides;
- flavonoid biosynthesis;
- hydroxycinnamate derivatives;
- Populus genome
- • Salicin-based phenolic glycosides, hydroxycinnamate derivatives and flavonoid-derived condensed tannins comprise up to one-third of Populus leaf dry mass. Genes regulating the abundance and chemical diversity of these substances have not been comprehensively analysed in tree species exhibiting this metabolically demanding level of phenolic metabolism.
- • Here, shikimate-phenylpropanoid pathway genes thought to give rise to these phenolic products were annotated from the Populus genome, their expression assessed by semiquantitative or quantitative reverse transcription polymerase chain reaction (PCR), and metabolic evidence for function presented.
- • Unlike Arabidopsis, Populus leaves accumulate an array of hydroxycinnamoyl-quinate esters, which is consistent with broadened function of the expanded hydroxycinnamoyl-CoA transferase gene family. Greater flavonoid pathway diversity is also represented, and flavonoid gene families are larger. Consistent with expanded pathway function, most of these genes were upregulated during wound-stimulated condensed tannin synthesis in leaves.
- • The suite of Populus genes regulating phenylpropanoid product accumulation should have important application in managing phenolic carbon pools in relation to climate change and global carbon cycling.