UC Davis Community Ecologist Involved in Tribute to Two Female Botanists

Botanists Beverly Rathcke (1945-2011) and Jeanne Baret 

would have been proud.

In their lifetimes, they didn't receive nearly enough credit for their work, but now they are memorialized in the names of newly described species of bacteria from the genus Acinetobacter that are specialized to flowers.

Meet Acinetobacter rathckeae and Acinetobacter baretiae.  

Here's what occurred: community ecologist Rachel Vannette, assistant professor in the UC Davis Department of Entomology and Nematology and eight colleagues recently described three new species of bacteria from the genus. The newly published research paper appears in the Microbiology Society's journal, International Journal of Systematic and Evolutionary Microbiology. See https://doi.org/10.1099/ijsem.0.004783.

Vannette isolated two of the new species from UC Davis sites. She isolated one on California fuchsia, Epilobium canum, located in the 100-acre UC Davis Arboretum and Public Garden. Its name: Acinetobacter rathckeae. It memorializes University of Michigan emerita and lauded female pollination biologist Beverly Rathcke (1945-2011). 

Vannette isolated another new species on California figwort or California bee plant, Scrophularia californica, in the 258-acre UC Davis Stebbens Cold Canyon Reserve, located near Winters and encompassing parts of Solano and Napa counties. Its name: Acinetobacter pollinis.  "It was named for its affinity for pollen, as it does not grow well in the absence of pollen," Vannette said. Both plants are natives and perennials.

“There's more to come on these bacteria and what they do in flowers but from what we know now they seem to germinate and 'eat' pollen,” Vannette said. “In any case, we love and appreciate our reserves and natural areas on campus: they are an awesome source of unexplored biodiversity and really interesting biology.” 

The third species the nine scientists described is A. baretiae, named for female botanist Jeanne Baret (1740-1807).

"So two of the three newly described species are named for noted female botanists, one a great pollination biologist and ecologist--Beverly Rathcke--and the other, historical botanist Jeanne Baret," Vannette pointed out.

Rathcke, who received her doctorate from the University of Illinois Urbana-Champaign in 1973,  served on the faculty of the University of Michigan's Department of Ecology and Evolutionary Biology from 1978 to 2010. She focused her research on community ecology, specifically, plant–animal interactions such as herbivory, competition, and pollination ecology. "She published some of the first papers using null models in community ecology," according to an obituary published by the Ecological Society of America. "She researched how environmental changes, such as introduced species, habitat fragmentation, and hurricane disturbances, affect species' reproductive success."

Baret, the first woman to circumnavigate the globe, disguised herself as a man and as an aide to botanist Philibert Commerson, to board the French ship, Etoile, on a 1766-69 expedition. "Baret captured the attention of Commerson because she possessed botanic knowledge that lay well beyond the competence of his professors and mentors," according to Glynis Ridley, author of The Discovery of Jeanne Baret: A Story of Science, the High Seas, and the First Woman to Circumnavigate the Globe. "She was an herb woman: one schooled in the largely oral tradition of the curative properties of plants."

Other co-authors are Tory Hendry, Lydia Baker, and Vivianna Sanchez of Cornell University; Sergio Alvarez-Perez, affiliated with KU Leuven University, Belgium and Complutense University, Spain; Megan Morris of Lawrence Livermore National Laboratory, Livermore; Kaoru Tsui of Kyoto University, Japan; Bart Lievens of KU Leuven and Tadashi Fukami of Stanford University. 

The abstract: “A detailed evaluation of eight bacterial isolates from floral nectar and animal visitors to flowers shows evidence that they represent three novel species in the genus Acinetobacter . Phylogenomic analysis shows the closest relatives of these new isolates are Acinetobacter apis , Acinetobacter boissieri and Acinetobacter nectaris, previously described species associated with floral nectar and bees, but high genome-wide sequence divergence defines these isolates as novel species. Pairwise comparisons of the average nucleotide identity of the new isolates compared to known species is extremely low (Acinetobacter species, for which the names Acinetobacter pollinis sp. nov., Acinetobacter baretiae sp. nov. and Acinetobacter rathckeae sp. nov. are proposed. The respective type strains are SCC477^T (=TSD-214^T=LMG 31655^T), B10A^T (=TSD-213^T=LMG 31702^T) and EC24^T (=TSD-215^T=LMG 31703^T=DSM 111781^T).” 

Rachel Vannette Lab
The Vannette lab is a team of entomologists, microbiologists, chemical ecologists, and community ecologists trying to understand how microbial communities affect plants and insects.

All plants are colonized by microorganisms that influence plant traits and interactions with other species, including insects that consume or pollinate plants, Vannette explains. She and her lab investigate the basic and applied aspects of microbial contributions to the interaction between plants and insects.

“Much of the work in my lab focuses on how microorganisms affect plant defense against herbivores and plant attraction to pollinators,” Vannette related. “For example, we are interested in understanding the microbial drivers of soil health, which can influence plant attractiveness to herbivores and the plant's ability to tolerate or defend against damage by herbivores. In addition, we are working to examine how microorganisms modify flower attractiveness to pollinators. This may have relevance in agricultural systems to improve plant and pollinator health.”

Vannette, who was selected a UC Davis Hellman Fellow in 2018, holds a doctorate in ecology and evolutionary biology (2011) from the University of Michigan.