Study
Nectar bacteria, but not yeast, weaken a plant–pollinator mutualism
Vannette, Rachel L.; Gauthier, Marie-Pierre L.; Fukami, Tadashi
Proceedings of the Royal Society B, 2013
Flowers were sterilised and then inoculated with a nectar yeast, a nectar bacterium, both, or neither, and left available to wild pollinators. Nectar chemistry was measured and visitation recorded, so that the microbial treatment was the only variable distinguishing otherwise identical flowers.
- Studied in
- Mimulus aurantiacus, Metschnikowia reukaufii
- Sample size
- flowers inoculated with defined microbial treatments
Microbial colonisation altered nectar sugar composition and pH within days. Bacterial colonisation reduced pollinator visitation and plant reproductive success relative to sterile flowers; yeast colonisation did not, and yeast-colonised flowers were visited more than bacterium-colonised ones.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Nectar microbes are a third party in the pollination interaction, modifying the reward and thereby the behaviour of the animals it was meant to attract.
How NatureHQ reads it
A useful complication of the tidy two-party story. The plant makes the nectar and does not control what is in it by the time an animal arrives: microorganisms delivered on the mouthparts of previous visitors have been fermenting it. Whether that is a cost to the plant depends on which microbe arrived, which nothing in the arrangement decides.
- One plant species and a small set of cultured microbes.
- Sterilising a flower is itself a manipulation with effects beyond removing microbes.
- Visitation was measured rather than seed set, so the reproductive consequence is inferred.
Sterilising flowers and then deciding what lives in them
Nectar is full of yeasts and bacteria carried in by pollinators. Does that change anything for the plant?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: The Royal SocietyPublished by the Royal Society.
doi.org/10.1098/rspb.2012.2601
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-10.