Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Regulation of secondary metabolism by the carbon–nitrogen status in tobacco: nitrate inhibits large sectors of phenylpropanoid metabolism

Regulation of secondary metabolism by the carbon–nitrogen status in tobacco: nitrate inhibits... Interactions between nitrogen and carbon metabolism modulate many aspects of the metabolism, physiology and development of plants. This paper investigates the contribution of nitrate and nitrogen metabolism to the regulation of phenylpropanoid and nicotine synthesis. Wild‐type tobacco was grown on 12 or 0.2 mm nitrate and compared with a nitrate reductase‐deficient mutant [Nia30(145)] growing on 12 mm nitrate. Nitrate‐deficient wild‐type plants accumulate high levels of a range of phenylpropanoids including chlorogenic acid, contain high levels of rutin, are highly lignified, but contain less nicotine than nitrogen‐replete wild‐type tobacco. Nia30(145) resembles nitrate‐deficient wild‐type plants with respect to the levels of amino acids, but accumulates large amounts of nitrate. The levels of phenylpropanoids, rutin and lignin resemble those in nitrogen‐replete wild‐type plants, whereas the level of nicotine resembles that in nitrate‐deficient wild‐type plants. Expression arrays and real time RT‐PCR revealed that a set of genes required for phenylpropanoid metabolism including PAL, 4CL and HQT are induced in nitrogen‐deficient wild‐type plants but not in Nia30(145). It is concluded that nitrogen deficiency leads to a marked shift from the nitrogen‐containing alkaloid nicotine to carbon‐rich phenylpropanoids. The stimulation of phenylpropanoid metabolism is triggered by changes of nitrate, rather than downstream nitrogen metabolites, and is mediated by induction of a set of enzymes in the early steps of the phenylpropanoid biosynthetic pathway. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Plant Journal Wiley

Regulation of secondary metabolism by the carbon–nitrogen status in tobacco: nitrate inhibits large sectors of phenylpropanoid metabolism

Download PDF
16 pages

Loading next page...
 
/lp/wiley/regulation-of-secondary-metabolism-by-the-carbon-nitrogen-status-in-jVxo4oZbem

References (86)

Publisher
Wiley
Copyright
Copyright © 2006 Wiley Subscription Services, Inc., A Wiley Company
ISSN
0960-7412
eISSN
1365-313X
DOI
10.1111/j.1365-313X.2006.02715.x
pmid
16640592
Publisher site
See Article on Publisher Site

Abstract

Interactions between nitrogen and carbon metabolism modulate many aspects of the metabolism, physiology and development of plants. This paper investigates the contribution of nitrate and nitrogen metabolism to the regulation of phenylpropanoid and nicotine synthesis. Wild‐type tobacco was grown on 12 or 0.2 mm nitrate and compared with a nitrate reductase‐deficient mutant [Nia30(145)] growing on 12 mm nitrate. Nitrate‐deficient wild‐type plants accumulate high levels of a range of phenylpropanoids including chlorogenic acid, contain high levels of rutin, are highly lignified, but contain less nicotine than nitrogen‐replete wild‐type tobacco. Nia30(145) resembles nitrate‐deficient wild‐type plants with respect to the levels of amino acids, but accumulates large amounts of nitrate. The levels of phenylpropanoids, rutin and lignin resemble those in nitrogen‐replete wild‐type plants, whereas the level of nicotine resembles that in nitrate‐deficient wild‐type plants. Expression arrays and real time RT‐PCR revealed that a set of genes required for phenylpropanoid metabolism including PAL, 4CL and HQT are induced in nitrogen‐deficient wild‐type plants but not in Nia30(145). It is concluded that nitrogen deficiency leads to a marked shift from the nitrogen‐containing alkaloid nicotine to carbon‐rich phenylpropanoids. The stimulation of phenylpropanoid metabolism is triggered by changes of nitrate, rather than downstream nitrogen metabolites, and is mediated by induction of a set of enzymes in the early steps of the phenylpropanoid biosynthetic pathway.

Journal

The Plant Journal – Wiley

Published: May 1, 2006

Keywords: ; ; ; ; ;

There are no references for this article.