| Title: | Understanding in vivo benzenoid metabolism in petunia petal tissue |
| Author(s): | Boatright J; Negre F; Chen X; Kish CM; Wood B; Peel G; Orlova I; Gang D; Rhodes D; Dudareva N; |
| Address: | "Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA" |
| ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
| Abstract: | "In vivo stable isotope labeling and computer-assisted metabolic flux analysis were used to investigate the metabolic pathways in petunia (Petunia hybrida) cv Mitchell leading from Phe to benzenoid compounds, a process that requires the shortening of the side chain by a C(2) unit. Deuterium-labeled Phe ((2)H(5)-Phe) was supplied to excised petunia petals. The intracellular pools of benzenoid/phenylpropanoid-related compounds (intermediates and end products) as well as volatile end products within the floral bouquet were analyzed for pool sizes and labeling kinetics by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Modeling of the benzenoid network revealed that both the CoA-dependent, beta-oxidative and CoA-independent, non-beta-oxidative pathways contribute to the formation of benzenoid compounds in petunia flowers. The flux through the CoA-independent, non-beta-oxidative pathway with benzaldehyde as a key intermediate was estimated to be about 2 times higher than the flux through the CoA-dependent, beta-oxidative pathway. Modeling of (2)H(5)-Phe labeling data predicted that in addition to benzaldehyde, benzylbenzoate is an intermediate between l-Phe and benzoic acid. Benzylbenzoate is the result of benzoylation of benzyl alcohol, for which activity was detected in petunia petals. A cDNA encoding a benzoyl-CoA:benzyl alcohol/phenylethanol benzoyltransferase was isolated from petunia cv Mitchell using a functional genomic approach. Biochemical characterization of a purified recombinant benzoyl-CoA:benzyl alcohol/phenylethanol benzoyltransferase protein showed that it can produce benzylbenzoate and phenylethyl benzoate, both present in petunia corollas, with similar catalytic efficiencies" |
| Keywords: | Acyltransferases/chemistry/genetics/metabolism Amino Acid Sequence Benzaldehydes/metabolism Benzene Derivatives/*metabolism Benzoates/metabolism Conserved Sequence Flowers/enzymology/genetics/*metabolism Kinetics Molecular Sequence Data Petunia/enzymology; |
| Notes: | "MedlineBoatright, Jennifer Negre, Florence Chen, Xinlu Kish, Christine M Wood, Barbara Peel, Greg Orlova, Irina Gang, David Rhodes, David Dudareva, Natalia eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2004/08/03 Plant Physiol. 2004 Aug; 135(4):1993-2011. doi: 10.1104/pp.104.045468. Epub 2004 Jul 30" |
