The nine-member research team, led by Frank Schroeder, a BTI professor and also a professor in Cornell University's Department of Chemistry and Chemical Biology, detailed how plants speak “roundworm language” for self-defense. The work is published Jan. 10 in the journal Nature Communications.
The researchers studied chemicals called ascarosides, which the worms produce and secrete to communicate with each other. Williamson helped analyze the data and helped make some key insights toward the paper's conclusions, the BTI scientists related.
The team found that plants “talk” to nematodes by metabolizing ascarosides and secreting the metabolites back into the soil.
“It's not only that the plant can ‘sense' or ‘smell' a nematode,” Schroeder said in a BTI news release. “It's that the plant learns a foreign language, and then broadcasts something in that language to spread propaganda that ‘this is a bad place.' Plants mess with nematodes' communications system to drive them away.”
The study built on the team's previous work showing that plants react to ascr#18 – the predominant ascaroside secreted by plant-infecting nematodes – by bolstering their own immune defenses, thereby protecting them against many types of pests and pathogens.
In those earlier studies, “We also saw that when ascr#18 was given to plants, the chemical disappears over time,” according to lead author Murli Manohar, a senior research associate at BTI.
That observation, along with published literature suggesting plants could modify pest metabolites, led the team to hypothesize that “plants and nematodes interact via small molecule signaling and alter one another's messages,” Schroeder said.
To probe that idea, the team treated three plant species – Arabidopsis, wheat and tomato – with ascr#18 and compared compounds found in treated and untreated plants. They identified three ascr#18 metabolites, the most abundant of which was ascr#9.
The researchers also found Arabidopsis and tomato roots secreted the three metabolites into the soil, and that a mixture of 90% ascr#9 and 10% ascr#18 added to the soil steered nematodes away from the plant's roots, thereby reducing infection.
The team hypothesized that nematodes in the soil perceive the mixture as a signal, sent by plants already infected with nematodes, to “go away” and prevent overpopulation of a single plant. Worms may have evolved to hijack plant metabolism to send this signal. Plants, in turn, may have evolved to tamper with the signal to appear as heavily infected as possible, thereby fooling would-be invaders.
“This is a dimension of their relationship that no one has seen before,” said Manohar. “And plants may have similar types of chemical communication with other pests.”
Although the mixture of ascr#9 and ascr#18 could serve as a crop protectant, Schroeder said there should be no detriment to using straight ascr#18 on crops, as described in the team's earlier research.
“Ascr#18 mainly primes the plant to respond more quickly and strongly to a pathogen, rather than fully inducing the defensive response itself,” he said. “So there should be no cost to the plant in terms of reduced growth, yield or other problems.”
The team also showed that plants metabolize ascr#18 via the peroxisomal β-oxidation pathway, a system conserved across many plant species.
“This paper uncovers an ancient interaction,” Schroeder said. “All nematodes make ascarosides, and plants have had millions of years to learn how to manipulate these molecules.”
He added: “Plants aren't passive green things. They are active participants in an interactive dialog with the surrounding environment, and we will continue to decipher this dialog.”
These discoveries are being commercialized by a BTI and Cornell University-based startup company, Ascribe Bioscience, as a family of crop protection products named PhytalixTM.
Scientists affiliated with four institutions--BTI, Cornell, UC Davis and the USDA's Robert W. Holley Center for Agriculture and Health--co-authored the paper. Grants from USDA and the National Institutes of Health funded the research.
Ella Mae Noffsinger, 84, who retired in 1991 as the senior museum scientist in charge of the UC Davis Nematode Collection, passed away March 22, 2018 in Woodland. She was a longtime resident of Palm Gardens Assisted Living, Woodland.
Noffsinger was instrumental in the development of the nematode collection, and collaborated with many nematologists in the description of species, said Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology. Active in the Society of Nematologists (SOM) when few women were participating, she served on the SOM executive board and as the editor of the Nematology Newsletter, as well as numerous other committees.
During her career, her research and work took her from Colorado to Wisconsin to Chile: from the Beet Sugar Development Foundation in Fort Collins, to the University of Wisconsin, in Madison, and to Santiago, Chile, from 1967 to 1969. She worked with UC Davis nematologist M. W. Allen for many years.
A native of Center, Colo., she was born into the rural ranching family of Doc and Ruth Noffsinger on March 15, 1934. She received her bachelor's degree at what is now Colorado State University, and her master's degree in 1958 from California State University in zoology.
After retiring, she spent most of her time along the coast of Brookings, Ore., enjoying fishing, and other coastal pursuits. She is preceded in death by her parents and brothers. Survivors include her many nieces and nephews, as well as her close friends in the Woodland and Davis area.
Memorial donations may be made to the Salvation Army, "or the charity of your choice," her family indicated.
History of Nematology at UC Davis
DAVIS--Crowds will "explore the diversity of life" at 13 museums or collections during the seventh annual UC Davis Biodiversity Museum Day on Saturday, Feb. 17. The event, set from 9 a.m. to 4 p.m. is free and open to the public.
Displays will range from ancient dinosaur bones to live praying mantises, from hawks to honey bees and from California condor specimens to carnivorous plants. Last year's Biodiversity Museum Day drew more than 4000 visitors to campus.
This is a family friendly, science-based event, said Biodiversity Museum Day chair Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology. All 13 museums or collections are within walking distance on campus except for the Häagen-Dazs Honey Bee Haven on Bee Biology Road and the Raptor Center on Old Davis Road. Openings vary from 9 a.m. to 1 p.m. and from noon to 4 p.m.
The following will be open from 9 a.m. to 1 p.m.:
- Arboretum and Public Garden, Good Life Garden, next to the Robert Mondavi Wine and Food Science Institute, 392 Old Davis Road, on campus
- Bohart Museum of Entomology, Room 1124 of the Academic Surge Building, Crocker Lane
- California Raptor Center, 340 Equine Lane, off Old Davis Road
- Museum of Wildlife and Fish Biology, Room 1394, Academic Surge Building, Crocker Lane
- Paleontology Collection, Earth and Physical Sciences Building, 434 LaRue Road
- Phaff Yeast Culture Collection, Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
- Viticulture and Enology Culture Collection, Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
The following will be open from noon to 4 p.m.:
- Anthropology Museum, 328 Young Hall and grounds
- Design Museum, 124 Cruess Hall, off California Avenue
- Botanical Conservatory, Greenhouses along Kleiber Hall Drive
- Center for Plant Diversity, Sciences Laboratory Building, off Kleiber Hall Drive
- Häagen-Dazs Honey Bee Haven, Bee Biology Road, off Hopkins Road (take West Hutchison Drive to Hopkins)
- Nematode Collection, Sciences Laboratory Building, off Kleiber Hall Drive
All participating museums and collections have active education and outreach programs, Yang said, but the collections are not always accessible to the public. In the event of rain, alternative locations are planned for the outdoor sites. Maps, signs and guides will be available at all the collections, online, and on social media, including Facebook and Twitter, @BioDivDay.
Capsule information about each museum or collection:
The Arboretum and Public Garden display will be from 9 a.m. to 1 p.m. at the Good Life Garden, next to the Robert Mondavi Wine and Food Science Institute, 392 Old Davis Road, on campus. It will join two other collections: Phaff Yeast and Viticulture and Enology. The Arboretum activities will be interactive; Learning-by-Leading Students are creating the content that will be featured on the day of Biodiversity Day. Coordinator: Melissa Cruz, outreach and leadership program coordinator.
Bohart Museum of Entomology
The Bohart Museum of Entomology will be open from 9 a.m. to noon in Room 1124 of the Academic Surge Building on Crocker Lane, off LaRue Road. The Bohart is the home of a global collection of nearly 8 million insect specimens. Highlights will include the 500,000-specimen butterfly/moth collection, curated by entomologist Jeff Smith; display of praying mantises, including orchid mantises, by UC Davis entomology student Lohit Garikipati; and a Belize insect collection display by Smith and fellow Bohart Museum associates Fran Keller and Dave Wyatt from their latest expedition. "You'll be able to see the tremendous diversity of butterflies, moths and mantids, and talk to the scientists who have just returned from there," said Tabatha Yang, education and outreach coordinator. "There will be orchids and orchid bees connecting the Bohart Museum's work with plant biology and science."
California Raptor Center
The California Raptor Center on 1340 Equine Lane, Davis, just off Old Davis Road, will be open from 9 a.m. to 1 p.m. A living collection of non-releasable raptors will be on exhibit. The center's educational ambassador birds will be out "on the fist" in the fenced yard by the museum, so visitors can get a close look at wild raptors while talking to the volunteers and learning about the magnificent birds of prey that live in this area, said Julie Cotton, volunteer and outreach coordinator. The on-site museum, recently renovated, features redesigned exhibits and a new touch-screen display. Coordinator: Julie Cotton, volunteer and outreach coordinator.
Museum of Wildlife and Fish Biology
The Museum of Wildlife and Fish Biology, in Room 1394 of the Academic Surge Building, Crocker Lane (off LaRue Road) will be open from 9 a.m. to 1 p.m. Visitors can view the bird and mammal museum specimen taxidermy demonstrations; explore the research collections with museum docents; see the newly acquired California condors on display, and see other specimens on display, including Papua New Guinea birds and mammals, reptiles and amphibians, primates and marine fishes. Note that strollers are not allowed in classroom or museum, they can be parked them under adjacent stairwell. Visitors are also asked to wash their hands before entering museum. Coordinator: Andrew Engilis Jr., director.
The Paleobiology Collection will be open from 9 a.m. to 1 p.m. in the Earth and Physical Sciences Building, 434 LaRue Road. Visitors can view fossil specimens dating from as old as 550 million years ago to more recent animal skeletons. Paleontology graduate students in invertebrate and vertebrate paleontology will answer questions and provide interesting factoids. Coordinator: Mark Deblois, Department of Earth and Planetary Sciences.
Phaff Yeast Culture Collection and Viticulture and Enology Culture Collection
These collections will be open from 9 a.m. to 1 p.m. in the Robert Mondavi Institute for Wine and Food Science, 392 Old Davis Road, on campus. Visitors can learn about the importance of microbes in research, biotechnology, and food and beverages, and about the proud history of two of the world's prominent microbe collections. The Phaff Yeast Culture Collection is part of the Department of Food Science and Technology department, and the Viticulture and Enology Culture Collection is part of the Department of Viticulture and Enology. Visitors can see and smell dozens of yeast species, learn how yeasts and bacteria are important for making fermented foods and beverages (even clothes can be made from microbes), taste vegemite, marmite and kombucha tea; learn about cutting edge research using these microbe collections; and tour the UC Davis teaching winery and brewery.
The microbe collection activities will be in the Robert Mondavi Institute Brewery, Winery and Food Processing building, which is in the southwest area of the complex of orange buildings at Old Davis Road and Hilgard Lane. Coordinators: Kyria Boundy-Mills, Phaff collection curator and specialist, Food Science and Technology, and Lucy Joseph, Viticulture and Enology collection curator and senior museum scientist.
The Department of Anthropology Museum in 328 Young Hall will be open from noon to 4 p.m. The Anthropology Museum curates collections of archaeological, ethnographic, biological and archival materials. The theme is "Year of the Dog" and there will be a scavenger hunt for kids to find all the hidden dogs in the exhibits, and people can test their skills as an ancient hunter and toss an atlatl dart or learn to make a tool from volcanic stone, says zooarchaeologist Christyann Darwent. The Anthropology Museum curates collections of archaeological, ethnographic, biological and archival materials. The museum maintains a teaching collection that includes casts and reproductions of artifacts from a variety of prehistoric human groups. Coordinator: Christyann Darwent, associate professor.
The Design Museum will be open from noon to 4 p.m. in Room 124 of Cruess Hall. Professor Timothy McNeil and curator Adrienne McGraw will staff the exhibit, It's Bugged: Insects' Role in Design, which explores the connections between people and insects. This is a special opening just for Biodiversity Museum Day. (The exhibit opened Jan. 8 and continues through April 22; regular hours are weekdays from noon to 4 p.m. and Sundays from 2 to 4 p.m.) "It's Bugged" includes art from hornet nest paper; beetle-gallery sculptures, and insect-themed clothing from the Department of Design faculty and graduate students; and insect specimens from the Bohart Museum of Entomology and insect photos from UC Davis alumnus Alex Wild, curator of entomology at the University of Texas, Austin. Coordinators: Timothy McNeil, professor, and Adrienne McGraw, exhibition curator.
The Botanical Conservatory
The Botanical Conservatory, greenhouses on Kleiber Hall Drive, will be open from noon to 4 p.m. Visitors can expect a multi-sensory experience of a plethora of plants primarily from the tropical and subtropical biomes. Featured plants and displays include the always popular carnivorous plants, fruiting specimens of Chocolate (Theobroma) and Coffee (Coffea), various Amorphophallus species at various stages of leaf and possibly flowering individuals, an assortment of cacti, succulents and other desert dwellers, and finally an assortment of winter blooming South African Bulbs to further entice the senses. Coordinator: Ernesto Sandoval, collections manager.
Center for Plant Diversity Herbarium
The Center for Plant Diversity Herbarium, open from noon to 4 p.m. in Room 1026 of the Sciences Laboratory Building, central campus (off Kleiber Hall Drive), will exhibit Hmong medicinal and culinary herbs. Viewers can view and identify plants under the microscope and watch plant pressing and mounting demonstrations. A kids' area activity will include pressed plants/glue/paper. Coordinator: Ellen Dean, curator.
Häagen-Dazs Honey Bee Haven
Häagen-Dazs Honey Bee Haven, a half-acre bee demonstration garden next to the Harry H. Laidlaw Jr. Honey Bee Research Facility, Bee Biology Road, will be open from noon to 4 p.m. Activities include catch-and-release bee viewing and making "Feed the Bees" seed cookies. The haven was installed in the fall of 2009. A six-foot-long bee sculpture, Miss Beehaven, by artist Donna Billick, co-founder and co-director of the UC Davis Art/Science Fusion Program, anchors the haven. Other art, coordinated by entomology professor Diana Ullman, co-founder and director of the Art/Science Fusion Program, and Billick, also graces the haven. Guests will see bee condos occupied by leafcutter bees and mason bees. Robbin Thorp, distinguished emeritus professor of entomology, has recorded more than 80 different species of bees in the garden. Coordinator: Christine Casey, academic program management officer.
The nematode collection will open from noon to 4 p.m. in the Science Laboratory Building, central campus (off Kleiber Hall Drive). Visitors can expect to see live and preserved nematode specimens. Highlights include the huge jars of whale intestinal worms. Nematodes, also called worms, are elongated cylindrical worms parasitic in animals or plants or free-living in soil or water. They exist in almost every known environment. The many different species eat everything from bacteria and fungi to plant and animal tissue. Coordinator: Corwin Parker, nematology doctoral student.
For further information about the Biodiversity Day, access the UC Davis Biodiversity Museum Day website.
The Society of Nematologists (SON) will present him with its Teaching Excellence Award at its 55th annual meeting, set July 17 – 21 in the city of Montreal, Quebec, Canada.
Caswell-Chen, who joined the UC Davis Department of Nematology (now the Department of Entomology and Nematology) in 1989, was praised as being an “exemplary teacher who loves to teach and interact with his students.”
“Ed is known for his enthusiasm, dedication, high-quality instruction and keen interest in helping his students understand and appreciate nematology—from the undergraduate level to the graduate level and beyond,” his nominators said.
“If I had to distill my endorsement of Ed into a single sentence, it would be that he has unbridled passion and dedication when it comes to getting undergraduates excited about science,” said nematologist Steve Nadler, professor and chair of the Department of Entomology and Nematology. “His dedication to teaching is truly altruistic, and although he has maintained a solid program of research, his major effort in recent years has involved teaching undergraduate and graduate students.”
Over the last five years, Caswell-Chen has taught 24 undergraduate courses, enrolling some 2400 students. His commitment to teaching includes five years of service as associate dean of the Graduate Program, UC Office of Graduate Studies. He is a former chair of the UC Davis Department of Nematology, and the Graduate Group in Ecology.
Caswell-Chen, who considers teaching his No. 1 priority, says the classroom is “an important forum for communication with students, and an opportunity for outreach with respect to the Agricultural Experiment Station mission, especially when lecturing to undergraduates in nematology, animal biology, and science and society courses.” His students describe his courses as informative, interesting and engaging.
Caswell-Chen said his philosophy of teaching “is that to be effective, teaching must engage students by highlighting the relevance of course material, and instructors must capture student attention through enthusiasm and supportive stimulation of student creativity. Interaction helps students learn how to think, ask questions, and form connections among the diverse facts they learn in their courses.”
“If students are participating and engrossed with the topic in the classroom, they don't immediately realize that they are learning—they are carried along by their thinking and engagement with the material,” he said. “All of these features of effective classroom instruction are relatively easy to attain when the subject matter is nematology—and biology, for that matter—because of the field's many fascinating and relevant aspects. In a nematology course, one can incorporate a wide range of intriguing topics, from nematode biodiversity and the deep, hot biosphere to soil ecology, to the fascinating interactions between nematodes and other organisms, to the importance of animal parasites and means for their management, to plant parasites, nematicides, and genetic engineering of crop plants for nematode resistance, to topics in aging and neurobiology from research on the model nematode Caenorhabditis elegans.”
Caswell-Chen is known for his research on the life history and ecology of C. elegans, a free-living or non-parasitic nematode that lives in temperate soil environments.
His interest and dedication to undergraduate education is reflected in his current service as the chair of the UC Davis Academic Senate Undergraduate Council, membership on the UC system-wide Educational Policy Committee, and his recent appointment as vice chair of that same Educational Policy Committee for the coming academic year.
UC Davis researcher Kristi Sanchez, former undergraduate student who received her doctorate from him in 2014 and served as his teaching assistant, described him as “the best professor I've ever had.”
“I have not met another professor at UC Davis who not just focuses on his research but enjoys, loves and wants to make teaching classes a priority for undergraduate students,” Sanchez said. “He is always about the students and making sure they understand the material. He always goes out of his way to provide more office hours so they can learn the material better or ask questions. And he is a professor who has the students text him instead of emailing him. The students love it.”
She credited him with inspiring her to pursue her degree and career in nematology. “Ed has given me many opportunities to pursue research questions that I would like to investigate, provides great advice and not just as a major professor but a father figure. He has pushed me to follow my goals and with my hard work, anything is possible.”
Said graduate student Chris Pagan, who has known Caswell-Chen for 12 years, beginning as an undergraduate student and then as a lab technician: “Ed makes the classroom a comfortable place. He is always approachable, and always genuinely interested in hearing what students have to say. Ed is always revising his lecture material and methods. He is constantly seeking new ways to keep students engaged.”
Nematologist Becky Westerdahl, UC Davis professor of entomology and nematology, praised Caswell-Chen for his excellence in teaching and as “one of the first professors at UC Davis to embrace the use of World Wide Web technology for teaching…He was instrumental in obtaining, establishing and maintaining the first web server for teaching in the Department of Nematology.” She said Caswell-Chen provides his students with “an excellent foundation, not just as future researchers, but as future educators as well.”
Caswell-Chen also teaches animal biology courses and Science and Society courses. He sometimes teaches freshman seminars by using the Campus Book Project selections, such as “Why Are All the Black Kids Sitting Together in the Cafeteria” and “Half the Sky.” He has also taught his own selection of topics, including “The Ancient Middle East: Cradle of Civilization, Religion and Science” and “Protest Songs.”
Caswell-Chen received his bachelor's and master's degrees in botany and plant pathology from Michigan State University in 1979 and 1982, respectively, and his doctorate in 1985 in plant pathology from UC Riverside. He began his academic career in 1985 as an assistant professor in the University of Hawaii's Department of Plant Pathology before joining the UC Davis faculty in 1989.
"The average grocery store must dispose of more than 600 pounds of meats and produce every day when the products pass their sell-by date," Lewis says. "Where does it go? Currently, most waste food from groceries ends up in landfills. This costs grocery stores significantly, and wastes food and energy."
"A start-up company in this area, California Safe Soils LLC, is developing a novel solution to this problem by turning this wasted food into an agricultural product for soil nutrition. Nutrient management is a serious challenge to agriculture in California. Coupled with the need for providing the necessary nutrients to grow crops is the increasing concern of nitrate contamination of ground and surface water that comes from agricultural uses. A new product, called Harvest to Harvest, is in the testing phase as a soil amendment that aids in nutrient management."
"In this seminar, I'll describe the manufacturing of the material, the business plan of the company and the role of agricultural and ecological research in the research and development of this new product."
Of his research, Lewis says on his website: "My research program is wide-ranging in the scope of the questions asked and in the taxa that are studied. There is, however, a common thread to the work that takes place in my laboratory; we seek to understand why and how organisms find, recognize, assess and exploit resources. We ask questions about how insects and nematodes make decisions about resource utilization and what the fitness outcomes of the decisions are. To answer these kinds of questions, we engage in studies of behavior, population ecology, community ecology and evolutionary biology with several groups of insects, nematodes and bacteria. There are also intentional links to more practical pursuits including biological control of crop pests, predicting the impact of crop management on pest and beneficial organisms and restoration ecology. I see no difference between what is traditionally called 'basic' and 'applied' research, thus the links of nearly all of the work in the laboratory to agricultural or environmental concerns is explicit."
Lewis, who joined the UC Davis faculty in 2004, received his doctorate in entomology from Auburn University, Auburn, Ala.; his master's degree in entomology from the University of Missouri, Columbia; and his bachelor's degree in natural resources from Cornell University, Ithaca, NY.
He served as a post-doctoral research associate for the UC Davis Department of Entomology, Rutgers University, from 1991 to 1994; assistant research professor at Rutgers from 1994 to 1995. He joined the Department of Entomology, University of Maryland, in 1995 as a research associate and then served as an assistant professor in the Department of Entomology, Virginia Tech, from 1998 to 2004 before joining the UC Davis faculty.
A past president of the former UC Davis Department of Nematology, Lewis is active in the Entomological Society of America, Ecological Society of America, Society of Invertebrate Pathology and the Society of Nematologists. His professional service includes editor-in-chief of Biological Control; North American editor of Biopesticides International; and trustee of the Society of Invertebrate Pathology.
Lewis' seminar is the second in a series of spring-quarter seminars hosted by the UC Davis Department of Entomology and Nematology. All seminars are held on Wednesdays from 12:10 to 1 p.m. in 122 Briggs and are coordinated by assistant professor Brian Johnson. The seminars are video-recorded for later viewing on UCTV.