Abstract Detail

Ecology

Fetters, Andrea [1], Cantalupo, Paul [2], Saenz Robles, Maria Teresa [1], Stephens, Jessica [3], Pipas, James [1], Ashman, Tia-Lynn [1].

Intimate interactions with diverse pollinator vectors shape the pollen virome of wild plants.

Microbes, including viruses, are often transmitted between plant hosts by insect vectors, and plant traits mediate plant-vector interactions. Thus, understanding the ways in which viruses can spread in natural communities and which plant traits influence plant-vector interactions is critical, especially since many plant viruses have host ranges encompassing multiple plant species. Pollen is a unique vehicle for plant virus spread. Pollen-associated viruses “hitchhike” on or are within pollen grains and are carried directly to new plant hosts by pollinating insects. In fact, in a previous study we found that wild plant species with floral traits that mediate increased and more intimate interactions with pollinator vectors—such as inflorescences, bilaterally symmetric flowers, and restricted access to floral rewards—had larger pollen viromes. In natural communities, it is common for co-flowering plant species to share pollinators, thus these species may also share pollen-associated viruses; however, this prediction has never been tested. To test the association between pollinator and pollen-associated virus sharing and to understand more thoroughly how interactions with pollinators may shape the pollen virome of wild plants, we performed a metagenomic survey of pollen from 18 wild co-flowering plant species spanning 12 plant families in the serpentine seeps of McLaughlin Natural Reserve, Lower Lake, California. These plant species are part of a larger community that is a biodiversity hotspot for small herbaceous annual and perennial flowering plant species and pollinating insects. The focal plant species exhibited variation in floral traits important for interactions with pollinator vectors and were observed to interact with different pollinator species. Using a virus discovery pipeline, we identified five known and many novel viruses, including 18 coding-complete novel viral genomes, as pollen-associated. We found that plant species that share pollinators do indeed share some of their pollen-associated viruses. Similar to our previous study, we also found that plant species with smaller corollas and bilaterally symmetric flowers had more pollen-associated viruses relative to those with larger corollas and radially symmetric flowers. Lastly, the data revealed that plant species with diverse pollinator partners (pollination generalists) had more pollen-associated viruses relative to plant species that were pollination specialists. Taken together, our results suggest that plant species that have more intimate interactions with multiple pollinator species have more pollen-associated viruses. Since floral traits mediate plant-pollinator vector interactions, both floral trait evolution and pollination generalization should be considered in future studies on the pollen virome.

1 - University of Pittsburgh, Biological Sciences, 4249 Fifth Avenue, Pittsburgh, PA, 15260, USA
2 - University of Pittsburgh, Biomedical Informatics, 5607 Baum Boulevard, Pittsburgh, PA, 15206, USA
3 - Westfield State University, Biology, 577 Western Avenue, Westfield, MA, 01086, USA

Keywords:
pollen
virome
floral traits
metagenomics
plant-pollinator interactions.

Presentation Type: Oral Paper
Session: ECO8, Ecology: Interactions
Location: /
Date: Friday, July 23rd, 2021
Time: 11:00 AM(EDT)
Number: ECO8005
Abstract ID:667
Candidate for Awards:Ecological Section Best Graduate Student Paper