Biosynthesis of mono- and sesquiterpenes in strawberry fruits and foliage: 2H labeling studies

J Agric Food Chem. 2006 Feb 22;54(4):1473-8. doi: 10.1021/jf0523972.

Abstract

The biosynthesis of the monoterpene (S)-linalool and the sesquiterpene trans-(S)-nerolidol in fruits of Fragaria x ananassa Duch. cv. Eros and Florence and of the monoterpene (-)-alpha-pinene in Fragaria vesca was investigated by in vivo feeding experiments with [5,5-2H2]mevalonic acid lactone (d2-MVL) and [5,5-2H2]-1-deoxy-d-xylulose (d2-DOX). The feeding experiments indicate that (S)-linalool and trans-(S)-nerolidol in Fragaria x ananassa Duch. and (-)-alpha-pinene in F. vesca are exclusively synthesized via the cytosolic mevalonic acid pathway without any contribution from the plastidial 1-deoxy-D-xylulose/2-C-methyl-D-erythritol 4-phosphate (DOXP/MEP) route. Inhibition experiments revealed that even the presence of mevastatin, an export of plastid-derived isopentyl diphosphate/dimethylallyl diphosphate, cannot be induced. However, the enantioselective analysis shows that in Fragaria x ananassa Duch. cv. Eros and Florence both linalool enantiomers are present and that only (S)-linalool is labeled after administration of d2-MVL. Therefore, the origin of (R)-linalool in these fruits remains unknown. Contrarily, in Fragaria x ananassa Duch. foliage (R)-linalool is the dominant enantiomer. Feeding experiments revealed an incorporation of d2-MVL and d2-DOX at equal rates exclusively into (S)-linalool. Only in F. vesca foliage, where (R)-linalool is present at high enantiomeric purity (ee > 90%), is a de novo biosynthesis of the (R)-enantiomer via the DOXP/MEP pathway detectable. These results demonstrate a complex intraplant variation of (R)- and (S)-linalool biosynthesis via the cytosolic and plastidial route.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyclic Monoterpenes
  • Deuterium
  • Fragaria / metabolism*
  • Fruit / metabolism*
  • Gas Chromatography-Mass Spectrometry
  • Mevalonic Acid / analogs & derivatives
  • Mevalonic Acid / metabolism
  • Monoterpenes / metabolism*
  • Plant Leaves / metabolism*
  • Sesquiterpenes / metabolism*
  • Stereoisomerism
  • Xylulose / analogs & derivatives
  • Xylulose / metabolism

Substances

  • Acyclic Monoterpenes
  • Monoterpenes
  • Sesquiterpenes
  • Xylulose
  • 1-deoxy-2-pentulose
  • mevalonolactone
  • Deuterium
  • linalool
  • nerolidol
  • Mevalonic Acid