- Author: Kathy Keatley Garvey
The open-access journal Nature Communications, published the peer-reviewed research Oct. 19.
“Plant-parasitic nematodes are a threat to crop production,” said Siddique, an assistant professor in the UC Davis Department of Entomology and Nematology. “We used a combination of genomic, genetic, and biochemical approaches to show that the plant pathogen cyst nematode possesses an incomplete vitamin B5 synthesis pathway, of potential prokaryotic origin, which is complemented by its plant host. This approach has identified new targets for future development of nematode-resistant crops.”
The 33-member research team included scientists from universities in Germany, France, The Netherlands, Poland, and the United Kingdom, as well as scientists from three universities in the United States: Iowa State University, Ames; and the University of Tennessee, Knoxville; and UC Davis.
The article is titled “The Genome and Lifestage-Specific Transcriptomes of a Plant-Parasitic Nematode and its Host Reveal Susceptibility Genes Involved in Trans-Kingdom Synthesis of Vitamin B5.”
“The scarcity of classical resistance genes highlights a pressing need to find new ways to develop nematode-resistant germplasm,” the scientists wrote in their abstract. “Here, we sequence and assemble a high-quality phased genome of the model cyst nematode Heterodera schachtii to provide a platform for the first system-wide dual analysis of host and parasite gene expression over time, covering all major parasitism stages. Analysis of the hologenome of the plant nematode infection site identified metabolic pathways that were incomplete in the parasite but complemented by the host. Using a combination of bioinformatic, genetic, and biochemical approaches, we show that a highly atypical completion of vitamin B5 biosynthesis by the parasitic animal, putatively enabled by a horizontal gene transfer from a bacterium, is required for full pathogenicity. Knockout of either plant encoded or now nematode-encoded steps in the pathway significantly reduces parasitic success. Our experiments establish a reference for cyst nematodes, further our understanding of the evolution of plant parasitism by nematodes, and show that congruent differential expression of metabolic pathways in the infection hologenome represents a new way to find nematode susceptibility genes. The approach identifies genome-editing-amenable targets for future development of nematode-resistant crops.”
Corresponding authors are Florian Grundler of the Rheinische Friedrich-Wilhelms-University of Bonn, Germany, and Sebastian Eves-van den Akker of the Crop Science Centre, Department of Plant Sciences, University of Cambridge, UK.
Research in the Siddique lab focuses on basic as well as applied aspects of interaction between parasitic nematodes and their host plants. “Plant-parasitic nematodes are destructive pests causing losses of billions of dollars annually,” Siddique said. “The long-term object of our research is not only to enhance our understanding of molecular aspects of plant–nematode interaction but also to use this knowledge to provide new resources for reducing the impact of nematodes on crop plants in California.”
- Author: Kathy Keatley Garvey
He will present his in-person seminar at 4:10 p.m. in 122 Briggs Hall. It also will be virtual; the Zoom link is https://ucdavis.zoom.us/j/99515291076.
"Twenty years ago while attempting to develop a new concept for studying insect aging in the wild, I discovered a previously unknown mathematical identity now referred to in the formal demography literature as the eponym Carey's Equality—the age distribution of a stationary population equals the distribution of lifetimes yet to come," Professor Carey says in his abstract. "In this seminar I will present my attempts at both operationalizing the concept for study of populations of insects and other non-human species, and generalizing it for applications to groups with fixed numbers of members and where renewal involves birth and death processes."
"These general applications include data from a British cemetery, the National Basketball Association, the Baltimore Longitudinal Health Study, the U.S. Congress (both chambers) and the world population," said Carey, a member of the UC Davs Department of Entomology and Nematology faculty since 1980. "After discussing implications and extensions of the identity, I will wrap up with descriptions of five simple but important demographic relations that all entomologists should know."
Highly honored for his research, teaching and public service, Carey served as the principal investigator of a 10-year, $10 million federal grant on “Aging in the Wild,” encompassing 14 scientists at 11 universities.
Biodemography Textbook. In 2020, he and Deborah Roach, professor and chair of the University of Virginia's Department of Biology, co-authored a 480-page textbook, Biodemography: An Introduction to Concepts and Methods, published by Princeton University Press and hailed as the “definitive textbook for the emerging field of biodemography, integrating biology, mathematics and demography.” Carey recently created a free-access, video guidebook with a playlist of 175 separate presentations, subtitled in 300 different languages. He storyboarded the script, turned graphs, schematics, tables and equations into animated slides, and then with teleprompter assistance, narrated and video-recorded the 175 presentations, which span 12 hours of viewing. It appears on UC Berkeley Population Sciences website at https://bit.ly/3FTge7u.
An internationally recognized teacher, Carey won a 2018 global award in the Robert Foster Cherry Award for Great Teaching Program, an academic competition sponsored every two years by Baylor University, Waco, Texas. He received the 2015 Distinguished Achievement in Teaching Award from the Entomological Society of America (ESA) and the 2014 Distinguished Teaching Award from the Pacific Branch of ESA. The UC Davis Academic Senate honored him as the recipient of its 2014 Distinguished Teaching Award, given to internationally recognized professors who excel at teaching.
Carey is a fellow of four organizations: American Association for the Advancement of Science, Entomological Society of America, California Academy of Science and the Gerontological Society of America. He holds a doctorate in entomology (1980) from UC Berkeley, and two degrees from Iowa State University: a bachelor of science degree in animal biology (1973) and a master's degree in entomology (1975).
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, coordinates the spring seminars. He may be reached at ssiddique@ucdavis.edu for any technical issues regarding Zoom.
/span>- Author: Kathy Keatley Garvey
Her seminar begins at 4:10 p.m. The Zoom link: https://ucdavis.zoom.us/j/99515291076
"My lab studies the ecology and evolution of host-symbiont interactions," Wood says. "We're especially interested in the causes and consequences of conflicts that arise as hosts navigate interactions with multiple partners. I will talk about three recent projects in my lab that explore how antagonists affect host-symbiont interactions in the model mutualism between legumes and nitrogen-fixing bacteria."
As an evolutionary biologist, Wood is interested in the evolutionary ecology and evolutionary genetics of species interactions. Her research interests include ecology and biodiversity, plant biology, evolution and genetics, epigenetics and genomics.
Wood holds a bachelor of arts degree in English literature (2008) from Swarthmore (Penn.) College. She received her doctorate in biology from the University of Virginia in 2015. Her dissertation: "The Consequences of Environmental Heterogeneity for Fitness, Selection, and Inheritance."
Wood served as a postdoctoral fellow at the University of Toronto from 2015 to 2018 before accepting a faculty position at the University of Pittsburgh. She joined the University of Pennsylvania faculty in July 2020. (See profile)
Nematologist Shahid Siddique, who coordinates the UC Davis Department of Entomology and Nematology seminars, will introduce Wood. For any technical issues involving the Zoom presentation, he may be reached at ssidique@ucdavis.edu.
The remaining spring seminars:
Wednesday, May 25 (virtual and in-person at 122 Briggs Hall)
James R. Carey, UC Davis distinguished professor
UC Davis Department of Entomology and Nematology
Title: "The Conceptual Sweep of a Mathematical Discovery in Insect Demography: From Estimation of Medfly Population Age Structure to an Historical Analysis of U.S. Congress Incumbency Distributions, 1785-2000”
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
Wednesday, June 1 (virtual and in-person at 122 Briggs Hall)
Isgouhi Kaloshian, Divisional Dean, Agricultural and Natural Resources
UC Riverside
Title: "Root-Knot Nematode Perception and Immune Signaling in Arabidopsis"
Host: Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology
- Author: Kathy Keatley Garvey
Siddique served as an invited speaker and chaired a nine-presentation session on nematode-plant interactions. He also was elected to the governing board member of the European Society of Nematology (ESN), and will serve a four-year term.
Siddique, who joined the UC Davis faculty in March 2019 as an assistant professor after serving as a research group leader for several years at the University of Bonn, Germany, delivered his address on “How Plants Recognize Nematodes: Signals and Signalling.”
Siddique focuses his research on "elucidating interactions between parasitic nematodes and their hosts using molecular and basic applied methodologies." Plant-parasitic nematodes are destructive pests causing losses of billions of dollars, he says on his lab website. "While these pests have been investigated mainly because they pose a major threat to food security globally, they are also intellectually fascinating due to their highly evolved interkingdom interactions with host plants."
Coomer, who recently won a worldwide competition sponsored by the International Federation of Nematology Societies (IFNS) for her three-minute thesis on root-knot nematodes, presented her award-winning video, “Trade-Offs Between Virulence and Breaking Resistance in Root-Knot Nematode.” She received a busary as well as a certificate signed by ICN president Larry Duncan of the University of Florida and conference chair Pierre Abad of France, a senior scientist at INRA, a French public research institute dedicated to agricultural science. Coomer also showcased her work on a life-sized poster.
IFNS annually hosts the three-minute thesis competition “to cultivate student academic and research communication skills, and to enhance overall awareness of nematodes and the science of nematology.” Coomer, a doctoral student in plant pathology with an emphasis on nematology, is working on her dissertation, “Plant Parasitic Nematode Effectors and Their Role in the Plant Defense Immune System.”
The international meeting, themed “Crossing Borders: A World of Nematode Diversity and Impact to Discover" to reconcile the importance of agricultural production with that of environmental conservation, drew 682 nematologists from 57 countries. Among them were 100 student and early career scientist busary recipients. The scientific program of 32 concurrent sessions included 288 oral presentations, 12 workshops, 12 keynote speakers and more than 500 poster presentations.
It was the first in-person meeting in two years due to the COVID-19 pandemic.
- Author: Kathy Keatley Garvey
Mostafa Zamanian, an assistant professor in the Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, will speak on "Combing Target and Whole-Organism Paradigms for Anthelmintic Discovery" at the May 11th virtual seminar hosted by the UC Davis Department of Entomology and Nematology.
His seminar begins at 4:10 p.m., Pacific Daylight time. The Zoom link is https://ucdavis.zoom.us/j/99515291076.
"Soil and vector-transmitted parasitic nematodes (roundworms) infect over one billion people and are a major cause of global morbidity," Zamanian says in his abstract. "Parasite control in both human and animal medicine is suboptimal and threatened by the growing prospects of anthelmintic resistance. Motivated by the need for new treatments and curiosity about basic parasite biology, I will present recent work addressing questions about how mosquito-transmitted parasitic nematodes navigate through host tissues and manipulate their host environments to survive. We will discuss how advanced transcriptomic approaches can move us towards a better understanding of the molecular basis for these essential parasite behaviors, and how we can effectively combine 'target-based' and 'whole-organism' screening pipelines to help identify novel antiparasitics."
Zamanian holds a bachelor's degree in biochemistry and a doctorate in neuroscience from Iowa State University. He served as a postdoctoral fellow at McGill University and Northwestern University before joining the faculty of the University of Wisconsin.
On his website, Zamanian relates that "Neglected Diseases (NTDs) caused by parasitic worms (helminths) impose a debilitating health and economic burden throughout much of the world. These global diseases of poverty infect over 1.5 billion humans and exert their damage through a wide range of species-specific clinical manifestations. Parasitic diseases are also a major challenge to animal and plant health. The central ambition of our laboratory is to combine molecular, genetics, and computational approaches to make discoveries that improve our understanding of parasite biology and host-parasite interactions, as well as our ability to treat parasitic infections. This includes identifying new targets for drug discovery, elucidating mechanisms of drug resistance, and developing new tools for parasite manipulation and phenotypic screening. We directly study human and animal parasites, including mosquito-borne filarial nematodes, soil-transmitted nematodes, and snail-transmitted blood flukes."
Nematologist Shahid Sidduqe coordinates the Department of Entomology and Nematology seminars. For any technical issues regarding the Zoom link, contact him at ssiddique@ucdavis.edu.
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