Pollination by sexual deception—it takes chemistry to work

• Published in: Current opinion in plant biology 2016-08, Vol.32, p.37-46
• Main Authors: Bohman, Björn, Flematti, Gavin R, Barrow, Russell A, Pichersky, Eran, Peakall, Rod
• Format: Article
• Language: English
• Subjects: Alkanes - metabolism; Alkenes - metabolism; Animals; Biological Assay - methods; Female; Male; Pollination - physiology
• ISSN: 1369-5266; 1879-0356
• DOI: 10.1016/j.pbi.2016.06.004

[Display omitted] •Semiochemicals are of vital importance for pollination of sexually deceptive plants.•Plants sexually exploit diverse insects with diverse semiochemicals.•The first genes involved in the biosynthesis of these chemicals have been identified.•General recommendations for further advancing chemical discovery are provided. Semiochemicals are of paramount importance in sexually deceptive plants. These plants sexually lure specific male insects as pollinators by chemical and physical mimicry of the female of the pollinator. The strategy has evolved repeatedly in orchids, with a wide diversity of insect groups exploited. Chemical communication systems confirmed by field bioassays include: alkenes and alkanes in bee pollinated Ophrys species, keto-acid and hydroxy-acids in scoliid wasp pollinated O. speculum, and cyclohexanediones and pyrazines in thynnine wasp pollinated Chiloglottis and Drakaea orchids, respectively. In Ophrys, stearoyl-acyl carrier protein desaturase (SAD) enzymes have been confirmed to control species level variation in alkene double bond position. The production of cyclohexanediones in Chiloglottis unexpectedly depends on UVB light, a phenomenon unknown for other plant specialised metabolites. Potential biosynthetic pathways for other systems are explored, and alternative approaches to further accelerate chemical discovery in sexually deceptive plants are proposed.