Cambridge Scientist to Speak on Plant-Nematode Parasitism

When you think about global food security, you may not immediately think of plant-parasitic nematodes. But you should.

They are a major threat to global food security, says Sebastian Eves-van den Akker of the Department of Plant Sciences, University of Cambridge, UK.

Eves-van den Akker will speak on "Effector Gene Birth in Plant-Parasitic Nematodes: Furnishing the Immunity and Development-Altering 'Tool Box' " at the Wednesday, Jan. 22th seminar of the UC Davis Department of Entomology and Nematology.  His seminar is from 4:10 to 5 p.m. in 122 Briggs Hall, off Kleiber Hall Drive, UC Davis campus.  Host: nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology.

In a recent publication in PLOS Genetics titled "Effector Gene Birth in Plant Parasitic Nematodes: Neofunctionalization of a Housekeeping Glutathione Synthetase Gene," Eves-van den Akker noted that "Plant parasitism has arisen four times independently within the phylum Nematoda, resulting in at least one parasite of every major food crop in the world. Some species within the most economically important order (Tylenchida) secrete proteins termed effectors into their host during infection to re-programme host development and immunity. The precise detail of how nematodes evolve new effectors is not clear."

He and his colleagues reconstructed the  evolutionary history of a novel effector gene family. They showed that "during the evolution of plant parasitism in the Tylenchida, the housekeeping glutathione synthetase (GS) gene was extensively replicated. New GS paralogues acquired multiple dorsal gland promoter elements, altered spatial expression to the secretory dorsal gland, altered temporal expression to primarily parasitic stages, and gained a signal peptide for secretion. The gene products are delivered into the host plant cell during infection, giving rise to 'GS-like effectors.'"

"Our results demonstrate the re-purposing of an endogenous housekeeping gene to form a family of effectors with modified functions," Eves-van den Akker wrote. "We anticipate that our discovery will be a blueprint to understand the evolution of other plant-parasitic nematode effectors, and the foundation to uncover a novel enzymatic function."

Eves-van den Akker  studied biology at the University of Leeds from 2007 to 2019. During his final year, in the lab of Professor P. E. Urwin, he became interested in plant-pathology, and "the fascinating and potentially useful abilities of plant-parasitic nematodes." From 2010 to 2014, he studied for a doctorate in plant-nematode “effectors,” jointly appointed between the University of Leeds and The James Hutton Institute.

In 2015, he was awarded a three-year Anniversary Future Leaders Fellowship from the Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid from the UK government. His fellowship was designed to understand the structural and molecular detail of nematode effector function.

That led to a discovery that provided what he calls "the first tangible insight into the regulatory processes underlying plant-nematode parasitism," and that in turn, resulted in his five-year BBSRC David Phillips Fellowship in 2018. With this second fellowship, he established a research group at the University of Cambridge and was elected Fellow of King's College.

Community ecologist Rachel Vannette, assistant professor, is coordinating the winter quarter seminars, all held on Wednesdays at 4:10 p.m. in 122 Briggs Hall. The remaining schedule:

Wednesday, Jan. 29
Elizabeth Crone, Tufts University, Medford, Mass.
Topic: "Why Are Monarch Butterflies Declining in the West?"
Hosts: Neal Williams, professor; Rachel Vannette, assistant professor

Wednesday, Feb. 5
Andrew Young, postdoctoral scholar at California Department of Food and Agriculture, Pest Diagnostic
Topic: Syrphids (title to be announced)
Host: Lynn Kimsey, professor and director of the Bohart Museum of Entomology

Wednesday, Feb. 12
Kevin Rice, University of Missouri, Columbia
Topic: "Lasers, Drones, and Growth Promoting Fungus: New Technologies for IPM"
Host: Ian Grettenberger, assistant professor

Wednesday, Feb. 19
Mercedes Burns, University of Maryland,Baltimore County
Topic: (pending) She studies evolutionary ecology of reproductive traits and behaviors, sexual conflict, reproductive polymorphism, arthropod biology
Host: Jason Bond, professor and Schlinger Chair in Insect Systematics

Wednesday, Feb. 26:
Faculty Flash Talks (featuring series of faculty members, including Rachel Vannette, Ian Grettenberger, Shahid Siddique, Geoffrey Attardo, Jason Bond)

Wednesday, March 4
Brendon Boudinot, doctoral candidate, Phil Ward lab, exit seminar
Topic: "Morphology and Evolution of the Insects, and the Ancestors of the Ants"
Host: Phil Ward, professor