Skip to main content
padlock icon - secure page this page is secure

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

Download Article:
 Download
(PDF 665.1 kb)
 
Summary

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 mmnitrate and compared with a nitrate reductase-deficient mutant [Nia30(145)] growing on 12 mmnitrate. 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.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: carbon-nutrient hypothesis; nicotine; nitrate; nitrate reductase; phenylpropanopids; secondary metabolism

Document Type: Research Article

Affiliations: Department 2, Max Planck Institute for Molecular Plant Physiology, Am Muehlenberg 1, D-14476 Golm, Germany

Publication date: May 1, 2006

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more