| Title: | Volatile ester formation in roses. Identification of an acetyl-coenzyme A. Geraniol/Citronellol acetyltransferase in developing rose petals |
| Author(s): | Shalit M; Guterman I; Volpin H; Bar E; Tamari T; Menda N; Adam Z; Zamir D; Vainstein A; Weiss D; Pichersky E; Lewinsohn E; |
| Address: | "Department of Vegetable Crops, Newe Ya'ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel" |
| ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
| Abstract: | "The aroma of roses (Rosa hybrida) is due to more than 400 volatile compounds including terpenes, esters, and phenolic derivatives. 2-Phenylethyl acetate, cis-3-hexenyl acetate, geranyl acetate, and citronellyl acetate were identified as the main volatile esters emitted by the flowers of the scented rose var. 'Fragrant Cloud.' Cell-free extracts of petals acetylated several alcohols, utilizing acetyl-coenzyme A, to produce the corresponding acetate esters. Screening for genes similar to known plant alcohol acetyltransferases in a rose expressed sequence tag database yielded a cDNA (RhAAT1) encoding a protein with high similarity to several members of the BAHD family of acyltransferases. This cDNA was functionally expressed in Escherichia coli, and its gene product displayed acetyl-coenzyme A:geraniol acetyltransferase enzymatic activity in vitro. The RhAAT1 protein accepted other alcohols such as citronellol and 1-octanol as substrates, but 2-phenylethyl alcohol and cis-3-hexen-1-ol were poor substrates, suggesting that additional acetyltransferases are present in rose petals. The RhAAT1 protein is a polypeptide of 458 amino acids, with a calculated molecular mass of 51.8 kD, pI of 5.45, and is active as a monomer. The RhAAT1 gene was expressed exclusively in floral tissue with maximum transcript levels occurring at stage 4 of flower development, where scent emission is at its peak" |
| Keywords: | "Acetyltransferases/genetics/isolation & purification/*metabolism Acyclic Monoterpenes Amino Acid Sequence Esters/*metabolism Flowers/enzymology/genetics/growth & development/metabolism Gene Expression Regulation, Enzymologic Gene Expression Regulation, Pl;" |
| Notes: | "MedlineShalit, Moshe Guterman, Inna Volpin, Hanne Bar, Einat Tamari, Tal Menda, Naama Adam, Zach Zamir, Dani Vainstein, Alexander Weiss, David Pichersky, Eran Lewinsohn, Efraim eng Research Support, Non-U.S. Gov't 2003/04/15 Plant Physiol. 2003 Apr; 131(4):1868-76. doi: 10.1104/pp.102.018572" |
