Wound-Inducible Biosynthesis of Phytoalexin Hydroxycinnamic Acid Amides of Tyramine in Tryptophan and Tyrosine Decarboxylase Transgenic Tobacco Lines1
AUTOR(ES)
Guillet, Gabriel
FONTE
American Society of Plant Biologists
RESUMO
The wound-activated biosynthesis of phytoalexin hydroxycinnamic acid amides of tyramine was compared in untransformed and transgenic tobacco (Nicotiana tabacum) lines that express tryptophan decarboxylase (TDC), tyrosine decarboxylase (TYDC), or both activities. Transgenic in vitro-grown tobacco lines expressing TDC activity accumulated high levels of tryptamine but not hydroxycinnamic amides of tryptamine. In contrast, transgenic tobacco lines expressing TYDC accumulated tyramine as well as p-coumaroyltyramine and feruloyltyramine. The MeOH-soluble and cell wall fractions showed higher concentrations of wound-inducible p-coumaroyltyramine and feruloyltyramine, especially at and around wound sites, in TYDC and TDC ×TYDC tobacco lines compared to wild-type or TDC lines. All the enzymes involved in the biosynthesis of hydroxycinnamic acid amides of tyramine were found to be similarly wound inducible in all tobacco genotypes investigated. These results provide experimental evidence that, under some circumstances, TYDC activity can exert a rate-limiting control over the carbon flux allocated to the biosynthesis of hydroxycinnamic acid amides of tyramine.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1065369Documentos Relacionados
- cis-analysis of the wound-inducible promoter wun1 in transgenic tobacco plants and histochemical localization of its expression.
- Role of Jasmonates in the Elicitor- and Wound-Inducible Expression of Defense Genes in Parsley and Transgenic Tobacco.
- Wound-inducible expression of a potato inhibitor II-chloramphenicol acetyltransferase gene fusion in transgenic tobacco plants
- A novel pathogen- and wound-inducible tobacco (Nicotiana tabacum) protein with antifungal activity.
- Octadecanoid Precursors of Jasmonic Acid Activate the Synthesis of Wound-Inducible Proteinase Inhibitors.