- Author: Kathy Keatley Garvey
Well, how about nematodes? They can do "tricks," too.
Professor and plant pathology researcher Melissa Mitchum of the Department of Pathology, University of Georgia, willpresent the next UC Davis Department of Entomology and Nematology seminar.on "The Tricks Phytonematodes Use to Modulate Plant Development."
Her virtual seminar begins at 4:10 p.m., Pacific Time, on Wednesday, March 9, announced seminar coordinator and nematologist Shahid Siddique, assstant professor, UC Davis Department of Entomology and Nematology.
"Phytonematodes secrete a suite of effectors to modulate developmental programs of their hosts to cause disease," Mitchum says in her abstract. 'In this talk, I will highlight what we are learning about these effectors and the tricks they use to accomplish their goals."
Along with colleague Lisa Beamer of the University of Missouri, Mitchum is co-directing a four-year $1.2 million grant from the joint National Science Foundation and the U.S. Department of Agriculture National Institute of Food and Agriculture Plant-Biotic Interactions Program "to help combat a devastating soybean pathogen," according to a January 2022 news article in the Johnson City Press, Tenn. "The soybean cyst nematode, a microscopic roundworm, is responsible for annual crop losses of $1 billion in the U.S. alone," the news story relates.
Mitchum's research focuses "on molecular plant-nematode interactions with an emphasis on the sedentary endoparasitic cyst and root-knot nematodes," Mitchum says on her website. "Pathosystems include cyst (Heterodera glycines) nematode on soybean, cyst (Vittitadera zeaphila) nematode on corn, and root-knot (Meloidogyne spp.) nematodes on soybean, cotton, and peanut. We utilize the model plant Arabidopsis to accelerate our studies to dissect the molecular basis of parasitism by cyst (Heterodera schachtii) and root-knot nematodes. Our work addresses plant responses during compatible and incompatible plant-nematode interactions, the identification and functional analysis of nematode stylet-secreted effector proteins, and developmental reprogramming of host root cells via peptide mimicry and phytohormone manipulation. I work closely with plant breeders to develop high yielding, nematode resistant varieties. Current efforts are also focused on translating basic discoveries to develop novel approaches for nematode resistance in crop plant."
Mitchum received her bachelor's degree in biology in 1993 from the University of Puget Sound, Tacoma, Wash., and her master's degree in plant pathology from the University of Nebraska, Lincoln, in 1995. She obtained her doctorate in plant pathology, with a minor in biotechnology, from North Carolina State University, Raleigh, in 2001. Mitchum served as a postdoctoral fellow with the Developmental, Cell and Molecular Biology Group at Duke University in 2003.
For any seminar technical issues, Siddique may be reached at ssiddique@ucdavis.edu.
Want to learn the basics of nematodes, aka roundworms? Be sure to watch nematologist Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology in this YouTube video. He delivered this presentation virtually at the 2021 UC Davis Biodiversity Museum Day. He discusses what they are and why they're important to the ecosystem.
- Author: Kathy Keatley Garvey
How do they know?
Molecular biologist Adam Steinbrenner, an assistant professor of biology at the University of Washington, will explain his research at a UC Davis Department of Entomology and Nematology seminar on Wednesday, Feb. 23.
His public seminar, titled "Plant Immune Recognition of Insect Herbivores," will be both in-person and virtual. It begins at 4:10 p.m. (Pacific Time) in 122 Briggs Hall. The Zoom link is https://ucdavis.zoom.us/j/99515291076.
Steinbrenner and his team were the first to identify an immune recognition mechanism that sounds the alarm against chewing insects.
"From the moment of initial encounter with an insect herbivore, a suite of inducible plant defenses are triggered; however, the molecular mechanisms for recognition and response are not highly studied," Steinbrenner writes in his abstract. "Specific molecular patterns from insects can serve as elicitors of defense responses on host plants, but precise receptors mediating such responses have remained elusive. We recently identified a cell surface receptor, Inceptin Receptor (INR), which detects a set of ubiquitous peptide fragments found in the oral secretions of Lepidopteran larval herbivores. INR is specific to select legume species and may structure insect host range across this plant family. We hypothesize that INR serves as a recently evolved and highly potent mechanism to perceive a specific danger signal, above and beyond cues associated with generic tissue damage. I will discuss our recent transcriptiomic characterization of inceptin responses in bean and cowpea, highlighting strong anti-herbivore defense outputs which occur after inceptin treatment but not wounding alone. I will also compare plant responses to herbivory with well-characterized pathways mediating recognition of microbial pathogens.".
The Steinbrenner lab studies the molecular bases of plant immunity to pathogens and pests. "We are specifically interested in recognition and signaling functions of cell surface receptors and evolutionary processes driving novel immune specificity," he says on his website. He holds a bachelor of science degree in biology from Tufts University (2010) and a doctorate from UC Berkeley in plant biology (2015). He was awarded a Howard Hughes Medical Institute Postdoctoral Fellowship of $180,000 in 2016 and studied with Eric Schmelz at UC San Diego.
Steinbrenner served as the lead author of a paper published Nov. 23, 2021 in the Proceedings of the National Academy of Sciences on how cowpea plants detect that they're being eaten by caterpillars. In the article, A Receptor-Like Protein Mediates Plant Immune Responses to Herbivore-Associated Molecular Patterns, scientists from the University of Washington and UC San Diego reported that the cowpea plants harbor receptors on the surface of their cells that can detect a compound in caterpillar saliva and initiate anti-herbivore defenses.
"Despite chemical controls, crop yield losses to pests and disease generally range from 20-30 percent worldwide," Steinbrenner related in a University of Washington news release. "Yet many varieties are naturally resistant or immune to specific pests. Our findings are the first to identify an immune recognition mechanism that sounds the alarm against chewing insects.”
Wrote UW science writer James Urton: "The team showed that, in response to both leaf wounds and the presence of a protein fragment specific to caterpillar saliva, the cowpea's INR protein boosts the production of ethylene, a hormone that plants often produce in response to munching by herbivores and other types of environmental stress. The protein fragment in caterpillar spit that elicited this response, Vu-IN, is actually a fragment of a cowpea protein, which gets broken down by the caterpillar as it dines on cowpea leaves." (See full article.)
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, coordinates the Wednesday seminars. For any Zoom technical issues, contact him at ssiddique@ucdavis.edu.
- Author: Kathy Keatley Garvey
It's a name coined by futurist Herman Kahn in a 1967 essay describing a theoretical United States megalopolis extending from the metropolitan area of Boston to that of Washington, D.C.," according to Wikipedia.
Fast forward to the next seminar hosted by the UC Davis Department of Entomology and Nematology.
Research entomologist Vince D'Amico of the USDA's Forest Service Philadelphia Field Station will speak on "Monitoring and Ecological Research in the Forests of the BosWash Megalopolis" at 4:10 p.m., Wednesday, Feb. 9 in an in-person and virtual seminar hosted by the UC Davis Department of Entomology and Nematology.
The seminar will take place in 122 Briggs Hall. The Zoom link is https://ucdavis.zoom.us/j/99515291076
BosWash Megalopolis is the heavily populated area extending from Boston to Washington and including New York City, Philadelphia, and Baltimore.
"The temperate deciduous forest biome covers about 5 percent of the Earth's surface, but is home to 25 percent of the human population," D'Amico says in his abstract. "Once a huge tract of forested land, this area now consists of many thousands of small, heterogenous forests. Research in the FRAME (FoRests Among Managed Ecosystems) program is conducted over a network of permanent forest sites in the BosWash Megalopolis of the U.S. East Coast, to answer ecological questions at many trophic levels. I will discuss the results of some of this research."
FRAME researchers target temperate deciduous forests in the Anthropocene age, a current geological age viewed as the period during which human activity has been the dominant influence on climate and the environment.
From the website: "Our current work includes experimental and observational studies of soil and key species to understand interactions between plants, invertebrates, and vertebrates. Other research is focused on monitoring, manipulations aimed directly at site improvement, and technology transfer for better management of urban forest fragments. As of 2022, there are 60 FRAME sites in MA, PA, DE, MD and NC."
D'Amico, a 25-year research entomologist with USDA, has served on the adjunct faculty of the University of Delaware since 2001. His expertise includes ecosystems ecology, urban ecology an invasion ecology. D'Amico received his bachelor's degree in biology in 1989, and his doctorate from the University of Massachusetts, Amherst.
The Wednesday seminars are coordinated by nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology. For technical issues, contact ssiddique@ucdavis.edu.
- Author: Kathy Keatley Garvey
"Scientists now understand how certain animals can feed on picturesque, orange monarch butterflies, which are filled from head to abdomen with milkweed plant toxins.
"In high enough concentrations, milkweed can kill a horse, or a human. To be able to eat this plant, monarchs evolved a set of unusual cellular mutations. New UC Riverside research shows the animals that prey on monarchs also evolved these same mutations.
"A Current Biology journal article, published Nov. 22, 2021, describes the research that revealed these mutations in four types of monarch predators — a bird, a mouse, a parasitic wasp, and a worm." --EurekAlert.
The leading author of that research article, evolutionary biologist Simon "Niels" Groen, an assistant professor at UC Riverside, will discuss "Plant Toxins and the Evolution of Host-Parasite Interactions" when he presents a seminar to the UC Davis Department of Entomology and Nematology at 4:10 p.m., Wednesday, Feb. 2 in 122 Briggs Hall.
He will speak in person. The lecture also will be broadcast simultaneously on Zoom. The Zoom link: https://ucdavis.zoom.us/j/99515291076.
"Plants interact with incredibly diverse groups of animals including plant-feeding insects and nematodes as well as their natural enemies," Groen says in this abstract. "These interactions are influenced by toxic defensive chemicals that plants make. In my talk, I will focus on how plants evolved variation in production of these defensive chemicals and how animal parasites in turn evolved mechanisms enabling them to handle such toxins."
Groen, who joined the UC Riverside faculty in July 2021 following his postdoctoral research position (2014 to 2021) in the Noah Whiteman laboratory, Department of Ecology and Evolutionary Biology, University of Arizona, focuses his research on "understanding molecular mechanisms of adaptation in the context of species interactions and fluctuating environmental conditions."
A native of the Netherlands, he received his bachelor's degree and masters degree in biology from Wageningen University, Netherlands, and his doctorate in plant sciences from the University of Cambridge, UK.
Groen served as a visiting researcher from 2007 to 2008 in the Department of Multi-Trophic Interactions, Netherlands Institute of Ecology, and as a visiting researcher from 2008 to 2012 in the Department of Organismic and Evolutionary Biology, Harvard University.
"Growing up in The Netherlands, I became fascinated with plants and their responses to ever-changing environmental conditions while working as a 'ziekzoeker' in tulip fields outside of school hours," he writes in an author profile on the American Society of Plant Biologists website. The site featured him as the first author of “Evolutionary Systems Biology Reveals Patterns of Rice Adaptation to Drought-Prone Agro-Ecosystems," published Nov. 15, 2021 in the journal Plant Cell.
"A 'ziekzoeker' looks for diseased plants and I searched in particular for variegated white and red tulips--the ones you'd recognize from a golden-age Dutch still life painting," Groen related. "I learned how these tulips are infected with an aphid-transmitted virus and during my PhD in the group of John Carr at the University of Cambridge, I would further investigate the molecular mechanisms of how virus infections would change plant interactions with aphids and pollinators. I was gripped by the role that plant defensive chemicals play in shaping species interactions and I continued to study these as a postdoc with Noah Whiteman at the University of Arizona and the University of California, Berkeley.'
On the author page, he chronicled his previous work on the interactions between milkweeds and the monarch butterfly "and found out how the monarch evolved resistance to the cardenolide toxins that milkweeds make. While this work mostly revolved around a single gene of large effect, typically several or many genes are involved in organisms' evolutionary responses. As a Gordon and Betty Moore Foundation fellow in the group of Michael Purugganan at New York University, I learned about the latest developments in evolutionary genomics and systems biology while investigating patterns of natural selection on gene expression in rice populations that we grew under wet and dry field conditions with our collaborators at the International Rice Research Institute in The Philippines."
"The current paper (Plant Cell) is a culmination of this research," Groen related. "We found that under field drought rice plants do not just respond to changes in water availability, but also to concomitant changes in abundance of soil microbes that they interact with. As assistant professor in the Department of Nematology at the University of California, Riverside, I will continue to study rice and milkweed as well as plants from the nightshade family and look at the complex evolutionary tug-of-war between these plants and parasitic nematodes. Combining laboratory and field experiments, we will zoom in on the central role that plant chemicals play by using approaches from evolutionary and systems biology like the ones we describe in our paper."
Nematologist Shahid Siddique, assistant professor in the Department of Entomology and Nematology, coordinates the winter quarter seminars. He may be reached at ssiddique@ucdavis.edu for any technical issues involving the Zoom connection.
- Author: Kathy Keatley Garvey
The UC Davis Department of Nematology's winter quarter seminars will take place on Wednesdays at 4:10 p.m., beginning Jan. 5 and continuing through March 9, announced seminar coordinator and nematologist Shahid Siddique, assistant professor.
Both in-person and virtual seminars will be broadcast via Zoom at https://ucdavis.zoom.us/j/99515291076. The in-person seminars will be in 122 Briggs Hall.
First on tap is agroecologist Randa Jabbour of the University of Wyoming, who will present a virtual presentation at 4:10 p.m., Wednesday, Jan. 5 on "Interdisciplinary Collaborations in Pest Management Research--My Alfalfa Weevil Stories." UC Extension agricultural entomologist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology will host the seminar.
"Alfalfa weevil was first found in the Western United States in the early 1900s and continues to be a particularly problematic pest in the Western United States," Jabbour says in her abstract. "I will share current research to improve sustainability of alfalfa weevil management, much of which centers on timing –both harvest timing and pesticide spray timing. I will talk about my favorite things: biological control, interdisciplinarity, farmer perspectives, and new ideas from grad students."
Jabbour holds a bachelor of science degree (2003) from the Rochester Institute of Technology and a doctorate from Pennsylvania State University, where she focused on the biological pest control of insects. She served as a postdoctoral scholar from 2009 to 2010 at Washington State University, where "I studied the effects of pathogen diversity on host mortality of the Colorado potato beetle, gaining perspective in both biodiversity-ecosystem functioning research and the practical realities of 'big ag' potato fields." She completed a second post-doctoral position at the University of Maine, where she engaged in "balanced teaching and research responsibilities."
Jabbour's research at the University of Maine, in collaboration with social scientists and her supervisor Eric Gallandt, characterized New England organic farmer weed management philosophies, she wrote on her website. "This project was a great opportunity for me to incorporate the human dimension of pest management into my ecological research. I also collaborated with MS student Sonja Birthisel to quantify sources of variation of weed seed predation rates in a diverse Maine agricultural landscape. I particularly appreciate learning from the extensive experience of farmers, and I am passionate about supporting local food systems. I enjoy exploring the dramatic landscapes of the West, and feel as if I have just barely begun traveling around the big wondrous expanse that is my new home in Wyoming-- lots of ground to cover! In my spare time, I enjoy hiking, road trips, cooking, yoga, trying to be a runner again, and reading all sorts of things."
For the full schedule, see this page. For seminar technical issues, Siddique may be reached at ssiddique@ucdavis.edu.
