Iridoid Sex Pheromone Biosynthesis in Aphids Mimics Iridoid-Producing Plants |
| |
| Authors: | Dr Suzanne J Partridge Dr David M Withall Dr John C Caulfield Prof John A Pickett Prof Robert A Stockman Prof Neil J Oldham Dr Michael A Birkett |
| |
| Institution: | 1. Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK;2. School of Chemistry, Cardiff University, Cardiff, CF10 3AT UK;3. School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD UK |
| |
| Abstract: | Biosynthesis of (1R,4aS,7S,7aR)-nepetalactol ( 1 ) and (4aS,7S,7aR)-nepetalactone ( 2 ) in plants involves iridoid synthase (ISY), an atypical reductive cyclase that catalyses the reduction of 8-oxogeranial into the reactive enol of (S)-8-oxocitronellal, and cyclization of this enol intermediate, either non-enzymatically or by a nepetalactol-related short chain dehydrogenase enzyme (NEPS) that yields the nepetalactols. In this study, we investigated the biosynthesis in vivo of 1 and 2 in the pea aphid, Acyrthosiphon pisum, using a library of isotopically-labelled monoterpenoids as molecular probes. Topical application of deuterium-labelled probes synthesized from geraniol and nerol resulted in production of 2H4−lactol 1 and 2H4−lactone 2 . However, deuterium incorporation was not evident using labelled probes synthesized from (S)-citronellol. These results suggest that iridoid biosynthesis in animals, specifically aphids, may follow a broadly similar route to that characterised for plants. |
| |
| Keywords: | biosynthesis mass spectrometry molecular probe pea aphid sex pheromone |
|
|
