| Title: | Does egg deposition by herbivorous pine sawflies affect transcription of sesquiterpene synthases in pine? |
| Author(s): | Kopke D; Schroder R; Fischer HM; Gershenzon J; Hilker M; Schmidt A; |
| Address: | "Max Planck Institute for Chemical Ecology, Beutenberg Campus, Hans-Knoll-Str. 8, 07745, Jena, Germany" |
| DOI: | 10.1007/s00425-008-0747-8 |
| ISSN/ISBN: | 0032-0935 (Print) 1432-2048 (Electronic) 0032-0935 (Linking) |
| Abstract: | "Scots pine (Pinus sylvestris; Pinaceae, Pinales) is known to defend against egg deposition by herbivorous sawflies by changing its terpenoid volatile blend. The oviposition-induced pine odor attracts egg parasitoids that kill the sawfly eggs. Here, we investigated whether sawfly egg deposition activates genes encoding pine terpene synthases by extracting mRNA from oviposition-induced P. sylvestris. Three new sesquiterpene synthases, PsTPS 1, PsTPS 2, and PsTPS 3, were isolated that were shown on heterologous expression in Escherichia coli to produce (E)-beta-caryophyllene and alpha-humulene (PsTPS 1), 1(10),5-germacradiene-4-ol (PsTPS 2), and longifolene and alpha-longipinene (PsTPS 3) as their principal products. Quantitative RT-PCR analyses revealed that transcript levels of PsTPS 1 and PsTPS 2 were significantly higher in oviposition-induced twigs that were attractive to the parasitoids than in non-attractive, artificially damaged twigs. Thus, our results demonstrate a specific transcription response to egg deposition, distinct from that caused by artificial wounding. Transcripts of PsTPS 3 did not change in response to egg deposition. The transcript levels of PsTPS 1, PsTPS 2, and PsTPS 3 were also determined in relation to time after egg deposition, since pine odor is attractive to the parasitoid only 72 h after egg deposition. Transcription rates of PsTPS 1 and PsTPS 2 were significantly enhanced only 72 h after egg deposition, thus matching the timing of odor attractiveness, while for PsTPS 3, enhanced transcription was not detected at any time period studied after egg deposition. The ecological significance of the oviposition-induced increase of sesquiterpene synthase transcripts is discussed" |
| Keywords: | "Alkyl and Aryl Transferases/chemistry/*genetics/metabolism Amino Acid Sequence Animals Cloning, Molecular Ecosystem *Feeding Behavior Gas Chromatography-Mass Spectrometry Gene Expression Regulation, Plant Hymenoptera/*physiology Molecular Sequence Data Ov;" |
| Notes: | "MedlineKopke, Diana Schroder, Roland Fischer, Hanna M Gershenzon, Jonathan Hilker, Monika Schmidt, Axel eng Research Support, Non-U.S. Gov't Germany 2008/05/22 Planta. 2008 Aug; 228(3):427-38. doi: 10.1007/s00425-008-0747-8. Epub 2008 May 21" |
