Chemical imitation of yeast fermentation by the drosophilid-pollinated deceptive trap-flower Aristolochia baetica (Aristolochiaceae)

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Thomas Rupp - , University of Salzburg (Author)
  • Birgit Oelschlägel - , Chair of Botany, TUD Dresden University of Technology (Author)
  • Regina Berjano - , University of Seville (Author)
  • Hafez Mahfoud - , Chair of Botany, TUD Dresden University of Technology (Author)
  • Daniele Buono - , Chair of Botany, TUD Dresden University of Technology (Author)
  • Torsten Wenke - , Chair of Botany, TUD Dresden University of Technology (Author)
  • Katharina Rabitsch - , University of Salzburg (Author)
  • Gerhard Bächli - , University of Zurich (Author)
  • Vesna Stanojlovic - , University of Salzburg (Author)
  • Chiara Cabrele - , University of Salzburg (Author)
  • Wujian Xiong - , University of Salzburg, Mianyang Normal University (Author)
  • Markus Knaden - , Max Planck Institute for Chemical Ecology (Author)
  • Andreas Dahl - , DRESDEN-concept Genome Center (CMCB Core Facility), TUD Dresden University of Technology (Author)
  • Christoph Neinhuis - , Chair of Botany, TUD Dresden University of Technology (Author)
  • Stefan Wanke - , Chair of Botany, TUD Dresden University of Technology, Universidad Nacional Autónoma de México, Goethe University Frankfurt a.M., Senckenberg Gesellschaft für Naturforschung (Author)
  • Stefan Dötterl - , University of Salzburg (Author)

Abstract

Deceptive flowers, unlike in mutualistic pollination systems, mislead their pollinators by advertising rewards which ultimately are not provided. Although our understanding of deceptive pollination systems increased in recent years, the attractive signals and deceptive strategies in the majority of species remain unknown. This is also true for the genus Aristolochia, famous for its deceptive and fly-pollinated trap flowers. Representatives of this genus were generally assumed to be oviposition-site mimics, imitating vertebrate carrion or mushrooms. However, recent studies found a broader spectrum of strategies, including kleptomyiophily and imitation of invertebrate carrion. A different deceptive strategy is presented here for the western Mediterranean Aristolochia baetica L. We found that this species is mostly pollinated by drosophilid flies (Drosophilidae, mostly Drosophila spp.), which typically feed on fermenting fruit infested by yeasts. The flowers of A. baetica emitted mostly typical yeast volatiles, predominantly the aliphatic compounds acetoin and 2,3-butandiol, and derived acetates, as well as the aromatic compound 2-phenylethanol. Analyses of the absolute configurations of the chiral volatiles revealed weakly (acetoin, 2,3-butanediol) to strongly (mono- and diacetates) biased stereoisomer-ratios. Electrophysiological (GC-EAD) experiments and lab bioassays demonstrated that most of the floral volatiles, although not all stereoisomers of chiral compounds, were physiologically active and attractive in drosophilid pollinators; a synthetic mixture thereof successfully attracted them in field and lab bioassays. We conclude that A. baetica chemically mimics yeast fermentation to deceive its pollinators. This deceptive strategy (scent chemistry, pollinators, trapping function) is also known from more distantly related plants, such as Arum palaestinum Boiss. (Araceae) and Ceropegia spp. (Apocynaceae), suggesting convergent evolution. In contrast to other studies working on floral scents in plants imitating breeding sites, the present study considered the absolute configuration of chiral compounds.

Details

Original languageEnglish
Article number114142
JournalPhytochemistry
Volume224
Publication statusPublished - Aug 2024
Peer-reviewedYes

External IDs

PubMed 38762152

Keywords

Keywords

  • Acetoin, Aristolochia baetica, Aristolochiaceae, Chemical mimicry, Deceptive pollination, Drosophilidae, Electroantennography, Floral scents, Phoridae, Stereochemistry