Volatile microbial semiochemicals and insect perception at flowers

Authors: CROWLEY-GALL, AMBER - University Of California, Davis; Rering, Caitlin; Rudolph, Arthur; VANNETTE, RACHEL - University Of California, Davis; Beck, John

Submitted to: Current Opinion in Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2020
Publication Date: 10/20/2020
Citation: Crowley-Gall, A.C., Rering, C.C., Rudolph, A.B., Vannette, R.L., Beck, J.J. 2020. Volatile microbial semiochemicals and insect perception at flowers. Current Opinion in Insect Science. 44:23-34. https://doi.org/10.1016/j.cois.2020.10.004.
DOI: https://doi.org/10.1016/j.cois.2020.10.004

Interpretive Summary: Flowers use colors, shapes, and odors to entice pollinators (animals or insects that move pollen between flowers, assisting plant reproduction). Floral aroma can be changed by microorganisms like yeast and bacteria, which often colonize flowers. Microorganisms have been shown to add their own odor compounds to the floral blend, as well as increase and/or decrease certain scent components produced by the flower. These changes to aroma can influence how pollinators perceive a flower, in turn changing the flower’s attractiveness to the bee. However, despite the important role of floral microorganisms and their changes to floral scent, relatively little is known about the type and scope of changes to floral aroma which occur due to microorganisms, or how pollinators like bees might detect and respond to those changes. ARS Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL as well as researchers at the University of California, Davis reviewed published literature describing this topic, providing a perspective on areas needing further research. Reflections and conclusions based on available studies of floral microorganisms and associated bee responses will help ARS scientists inform the wider scientific community on this topic, thereby improving future studies and strategies aimed at improving the health of bees, thus supporting the production of valuable agricultural commodities.

Technical Abstract: Many plant-associated microbial communities produce volatile signals that influence insect responses, yet the impact of floral microorganisms has received less attention than other plant microbiomes. Floral microorganisms alter plant and floral odors by adding their own emissions or modifying plant volatiles. These contextual and microbe species-specific changes in floral signaling are detectable by insects and can modify their behavior. Opportunities for future work in flora l systems include identifying specific microbial semiochemicals that underlie insect behavioral responses and examining if insect species vary in their responses to microbial volatiles. Examining if documented patterns are consistent across diverse plant–microbe–insect interactions and in realistic plant-based studies will improve our understanding of how microbes mediate pollination interactions in complex system.