It's somewhat like that when plant-parasitic nematodes (microscopic round worms) play “chemical hide and seek” with their plant host, says plant pathologist Shahid Masood Siddique, an assistant professor in the UC Davis Department of Entomology and Nematology.
“The success of plant-parasitic nematodes depends on their ability to locate a suitable host in the soil,” says Siddique, corresponding author of the newly published Spotlight article, “Chemical Hide and Seek: Nematode's Journey to Its Plant Host,” in the journal Molecular Plant.
Nematodes can be deadly to plants, not only because of the direct damage they cause (they extract water and nutrients from their hosts such as wheat, soybeans, sugar beets, citrus, coconut, corn, peanuts, potato, rice, cotton and bananas) but the role of some species as virus vectors.
“Plant-parasitic nematodes are among the most destructive agricultural pests, causing more than $100 billion in losses per year in the United States,” Siddique said, noting that nematodes are especially damaging to potato, soybean and wheat crops.
Although the success of nematodes depends on their ability to locate a suitable host in the soil, what attracts them to their host “has largely remained unknown,” wrote the four-member UC Davis team of Siddique, Natalie Hamada, Henok Zemene Yimer and Valerie Williams. “Recent studies have revealed that host-seeking by nematodes is a complex process that involves multiple stages in the interaction.”
“Most damage is caused by a small group of root-infecting sedentary endoparasitic nematodes including cyst nematodes and root-knot nematodes (RKNs),” the team of UC Davis researchers wrote in their abstract. “Second stage juveniles (J2s) of plant-parasitic nematodes hatch from eggs into the soil and localize to the roots of host plants. The success of these non-feeding J2s depends on their ability to locate and infect a suitable host.”
For eight decades, scientists have researched the attraction of plant-parasitic nematodes to the host root, ever since the pioneering Maurice Blood Linford (1901-1960) of the University of Illinois, Urbana, Ill., observed in 1939 that the larvae of root-knot nematodes congregate in the cell elongation region behind the root cap.
“Both volatile and soluble components in the rhizosphere have been shown to influence nematode movement,” the UC Davis researchers wrote. “Methyl salicylate, a volatile chemical root signal, has been demonstrated to be a strong root attractant for RKN towards several Solanaceous plants (nightshade family). The non-volatile tomato root exudate quercetin was shown to elicit concentration dependent attraction or repulsion effect against Meloidogyne incognita to host root. Three recent studies have revealed that the recognition of and response to hosts by infective juveniles is a complex process that involves multiple stages in the interaction.”
Siddique focuses his research on basic as well as applied aspects of interaction between parasitic nematodes and their host plants. “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.”
Entomologist Marlin Rice, a past president of the Entomological Society of America (ESA), penned the piece, titled "Bruce D. Hammock: Science Should Be Fun!"
Wrote Rice: "Bruce D. Hammock is widely known for his groundbreaking research in insect physiology, toxicology, pharmacology, and experimental therapeutics. Early contributions were in fundamental regulatory biology, development of both small molecules and recombinant viruses as environmentally friendly pesticides, and the application of accelerator mass spectrometry to biological science. His laboratory pioneered the use of immunoassay for the analysis of human and environmental exposure to pesticides and other contaminants.His laboratory provides graduate training that is diverse in disciplines and research areas. He recently formed a company, EicOsis, to develop an orally active non-addictive drug for inflammatory and neuropathic pain for humans and companion animals."
Hammock, who joined the UC Davis faculty in 1980 from UC Riverside, has directed the UC Davis Superfund Research Program (funded by the National Institutes of Health's National Institute of Environmental Health Sciences) for nearly four decades. He is a member of the National Academy of Sciences, and a fellow of the National Academy of Inventors and ESA.
A native of Little Rock, Ark., Bruce received his bachelor's degree in entomology (with minors in zoology and chemistry) magna cum laude from Louisiana State University, Baton Rouge, in 1969. He received his doctorate in entomology-toxicology from UC Berkeley in 1973 with John Casida at UC Berkeley. Hammock served as a public health medical officer with the U.S. Army Academy of Health Science, San Antonio, and as a postdoctoral fellow at the Rockefeller Foundation, Department of Biology, Northwestern University, Evanston, Ill.
Read the feature story here.
Some Related Links:
- Bruce Hammock and EicOsis, Innovator of the Year
- Bruce Hammock Receives $6 Million Grant
- Bruce Hammock Water Balloon Battle: 15 Minutes of Aim
- Research Could Lead to Drug to Prevent or Reduce Autism, Schizophrenia
- Hammock Lab Union Draws 100 Scientists from 10 Countries
- Bruce Hammock: Scientist Extraordinaire
(Editor's Note: Thanks to Lisa Junker, ESA's director of publications, communications and marketing, who reached out to "our publishers at Oxford" to grant free community access to this feature story in American Entomologist)
Grettenberger, who fills the vacated position of Larry Godfrey (1956-2007), received his bachelor of science degree in biology, with an ecology, evolution and organismal emphasis (honors Program) in 2009 from Western Washington University, Bellingham, Wash., and his doctorate in entomology in 2015 from Pennsylvania State University, State College, Pa. He served as a postdoctoral researcher in the Godfrey lab and later, the Frank Zalom lab, before accepting his current appointment of assistant Cooperative Extension specialist.
Grettenberger's fields of expertise include field and vegetable crops; integrated pest management; applied insect ecology, and biological control of pests.
He targets a wide variety of pests, including western spotted and striped cucumber, beetles, armyworms, bagrada bugs, alfalfa weevils, aphids, and thrips.
Among his current grants:
- Protection of rice from invertebrate pests
- Management of key cotton arthropod pests with insecticides and acaricides, a proactive approach to prepare for the invasion of the tomato leafminer (Tuta absoluta) into California
- Detection, biology and control of the exotic Swede midge (Contarinia nasturtii) for California cole crops
- Management of the western spotted and striped cucumber beetle in melon production
- Biological control of the bagrada bug
- Insecticide resistant alfalfa weevils in the western United States:Quantifying the scope of resistance and implementing a plan to manage the threat
- Insecticide resistance monitoring and evaluation of efficacy of current chemical tactics for managing aphids and thrips in lettuce
How did you get interested in entomology? Can you recall an occasion that sparked your interest?
I had biologist parents, and was drawn into entomology at a pretty young age. I spent plenty of time looking in flowers and turning over logs looking for insects. Once I started thinking about going to graduate school for entomology, I decided to focus on the intersection of agricultural entomology and insect ecology. I wanted to work on applied issues in entomology.
How would you describe yourself?
I like tackling problems, which has worked out well with my work in applied entomology and extension. I can be intensely focused and immensely distracted, which I would say has its pluses and minuses.
What do you like best about your work?
I love working in applied entomology and that I get to use research to better understand pests and work to develop IPM tools. The breadth of crops I cover is both a bit overwhelming but immensely exciting because of the diversity in pest issues, types of tactics that are applicable, and interesting ecological/biological questions among the various crop pests. I also get to work with great people, both within my lab and with all of the various collaborators/cooperators. I have met and worked with a lot of fantastic people this first year, and I also think my lab is off to a great start.
Where were you born and where did you spend your childhood?
I was born in Portland, Ore., but I primarily grew up in Olympia, Wash. As you might imagine, I grew up with lots of rain, but in a beautiful area.
What are your research plans/goals here at UC Davis? What drew you to UC Davis?
Thus far, I have been focused on projects in crops where there has historically seen solid research by UC Davis (such as rice and cotton) and have been developing new projects and collaborations. For better or worse, IPM is never static, so my research will be continually evolving to address pest management needs and has already been shifting this first year. Because I have an extension appointment, stakeholder needs have driven much of my work and this will continue to be a theme.
I was drawn to Davis by the many opportunities it would afford working in agricultural entomology. The department has a great reputation academically and the people in it are great as well. I also would have (and have had) the opportunity to connect with many other great researchers in the UC system, both campus- and county-based. There are many crops and pests to work on. We are quite literally surrounded by crops I work in, including alfalfa, rice, and tomatoes. I even found some alfalfa weevil on my run last weekend.
What do you like to do in your leisure time?
My primary hobby is running, ideally on trails and long distances. I can deal with the nearly zero elevation gain in our area, but I like to get out to where there are some hills. I also like to be outdoors in general and spending time with my family (wife/dog/cat; dog will go on adventure runs with us, cat only gets the backyard).
What would people be surprised to know about you?
I don't like all foods, but I will try basically anything just to see what it tastes like. I think some people are also surprised by the amount of food I can eat at one time.
You can do that and more at the ninth annual UC Davis Biodiversity Museum Day on Saturday, Feb. 15 when 13 museums and collections showcase their projects. The event, to take place from 9 a.m. to 4 p.m., is free and family friendly. All 13 sites are within walking distance except for the Häagen-Dazs Honey Bee Haven on Bee Biology Road and the Raptor Center on Old Davis Road.
The science-based event, always held the Saturday of Presidents' Day weekend, features the diversity of life. It is billed as a “free, educational event for the community where visitors get to meet and talk with UC Davis scientists from undergraduate students to staff to emeritus professors and see amazing objects and organisms from the world around us,” according to Biodiversity Museum Day coordinator Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology. The schedule is online at http://biodiversitymuseumday.ucdavis.edu/schedule.html. Last year's event drew more than 4000 visitors. Schedules vary from collection to collection.
- The Botanical Conservatory, the Greenhouses along Kleiber Hall Drive, will be open from 9 a.m. to 4 p.m.
The following five will be open from 9 a.m. to 1 p.m.:
- Arboretum and Public Garden, Shields Oak Grove, alongside the Vet School, Garrod Drive on campus
- Bohart Museum of Entomology, Room 1124 and Main Hall 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 and Mail Hall, Academic Surge Building, Crocker Lane
- Paleontology Collection, Earth and Physical Sciences Building, 434 LaRue Road
Two collections will be open from 10 a.m. to 2 p.m.:
- 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
These five will be open from noon to 4 p.m.:
- Anthropology Museum, 328 Young Hall and grounds
- 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
- Marine Invertebrate Collection, Sciences Laboratory Building, off Kleiber Hall Drive
New this year will be public talks from noon to 1 p.m. in 194 Young Hall. The slate of speakers (each will give a 15-minute presentation and questions and answers will follow):
- Art Shapiro, distinguished professor of evolution and ecology, will discuss “Are Our Butterflies in Trouble?” (“Yes, they mostly are in trouble,” he says. He will discuss “How do we know and why?”)
- Gabrielle Nevitt, professor of animal behavior (on leave), will speak on “How Do Sub-Antarctic Seabirds Find their Food in the Vast Ocean?” (“They follow their nose," she says, "and sometimes it gets them into trouble.”)
- Melanie Truan, research ecologist, UC Davis Museum of Wildlife and Fish Biology, will cover “Biodiversity Studies at the UC Davis Wildlife Museum.” Biodiversity studies, she says, “can tell us a lot about the world and how it is functioning. This is especially important today where the influence of Homo sapiens is having profound impacts on the planet and its inhabitants.” She will touch on some of the ways that the UC Davis Museum of Wildlife and Fish Biology incorporates biodiversity into its research.
All participating museums and collections have active education and outreach programs, Yang said, but the collections are not always accessible to the public. Maps, signs and guides will be available at all the collections, and also online at http://biodiversitymuseumday.edu, and on social media, including Facebook and Twitter, @BioDivDay.
Capsule information on each:
Melissa Cruz Hernandez, outreach and leadership program manager, Arboretum and Public Garden, notes that the Arboretum activities will all be at the Shields Oak Grove, alongside the School of Veterinary Medicine, Garrod Drive. This is a change from last year. The Arboretum Ambassadors are planning fun-filled oak tree conservation activities the whole family will enjoy. “Learn about the many contributions oaks make to sustaining habitat biodiversity, what UC Davis and the Arboretum and Public Garden are doing to protect the trees, and win prizes for participating in the games at the Shields Oak Grove!”
Hernandez announced the following Arboretum activities:
- GATEways Outreach Ecological group: Learn what it is like to live as an oak tree through a life size board game and win prizes! Explore the ecological impacts oaks have in our community and discover about how the changing climate is impacting this important species.
- GATEways Outreach Humanities group: Did you know the US Constitution was signed in oak gall ink? Join us and try out oak gall ink for yourself, and engage in mindfulness activities.
- Museum Education: Take a self-guide tour through our iconic oak grove and learn about the unique characteristics of 12 of our favorite trees.
- Emily Griswold Tour: Join oak expert and Director of GATEways Horticulture, Emily Griswold, on an engaging tour of the oak grove. Uncover behind the scenes information about the grove and get your quercus questions answered.
Bohart Museum of Entomology, 9 a.m. to 1 p.m.
TheBohart Museum of Entomology, located in Room 1124 of the Academic Surge Building onCrocker Lane, is the home of a global collection of nearly 8 million insect specimens. Insect scientists will meet with the public to help them explore insects and spiders (arachnids). Highlights will include the 500,000-specimen butterfly/moth collection, curated by entomologist Jeff Smith. The Bohart maintains a live “petting zoo,” comprised of Madagascar hissing cockroaches, walking sticks and tarantulas. Also, the UC Davis Library set up a Mary Foley Benson exhibit in the Academic Surge hallway. It will be up ponly for the month of February. "The library, is, of course full of special collections including very important research materials on bees and on nematodes," noted Tabatha Yang, the Bohart education and outreach coordinator.
Visitors to the The California Raptor Center, located at 1340 Equine Lane, Davis, just off Old Davis Road, will see a living collection of non-releasable raptors. The center's educational ambassador birds will be out "on the glove," so visitors can get a close view of the birds of prey, and talk to the volunteers. Julie Cotton, volunteer and outreach coordinator, said visitors will see "on the glove" Swainson's hawks, a white-tailed kite, barn owl, great-horned owls and a eregrine falcon. Viewable in their exhibits will be golden eagles, American kestrels, turkey vultures, prairie falcon and Western screech owls.
Museum of Wildlife and Fish Biology, 9 a.m. to 1 p.m
The Museum of Wildlife and Fish Biology, located in Room 1394 of the Academic Surge Building, Crocker Lane (off LaRue Road) will feature an action packed morning with displays highlighting carnivores, bats, reptiles and fish, said director Andrew Engilis Jr. Visitors will see specimen preparation demonstrations. Also planned is a kids' craft table.
Paleontology Collection, 9 a.m. to 1 p.m.
Visitors at the Paleontology Collection, located in the Earth and Physical Sciences Building, 434 LaRue Road, 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.
The Phaff Yeast Culture Collection in the Department of Food Science, and the Wine Yeast and Bacteria collection in the Department of Viticulture and Enology, are jointly hosting exhibits and tours. They are located at the Robert Mondavi Institute Teaching Winery and Brewery Building, 392 Old Davis Road, on campus. Visitors to the yeast collection exhibits can taste kombucha and Vegemite, smell lots of different species of yeast, look at yeast and bacteria cells under the microscope, learn about the history of yeast research at UC Davis, and hear about the latest discoveries coming out of the UC Davis yeast collections, says Kyria Boundy-Mills, curator of the Phaff Yeast Culture Collection, Food Science and Technology.
Anthropology Museum, noon to 4 p.m.
Visitors to the Department of Anthropology Museum, located in 328 Young Hall, will see collections of archaeological, ethnographic, biological and archival materials. They will "experience our cultural diversity through art pieces from around the world, our complex evolutionary history through primate skeletons and fossil hominin casts, or how archaeologists at UC Davis work across the globe to understand past cultural diversity through the artifacts people leave behind," said Professor Christyann Darwent of the Department of Anthropology. "There will also be an opportunity for visitors to learn to make tools from obsidian stone and to throw a spear with an atlatl."
The Botanical Conservatory, 9 a.m. to 4 p.m.
"We again expect our cacao tree to be loaded with ripe fruit for display amongst the plethora of plant we'll be displaying!" says collections manager Ernesto Sandoval. "We'll also be showcasing our very well established pond that made a splash last year and newly added small epiphyte tree along with three towering Titan Arums in leaf! if the outdoor weather is good, Visitors will be encouraged to take a walk over to the nearby Joe and Emma Lin Biological Orchard and Gardens and bask in the biodiversity of these sizable plots of Biodiversity and the neatly pruned fruit tree orchard." The Botanical Conservatory is located on Kleiber Hall Drive.
Visitors to the Center for Plant Diversity Herbarium, located in Room 1026 of the Sciences Laboratory Building, central campus (off Kleiber Hall Drive), can tour the collection area, see plant pressing and mounting demonstrations, “pet our plant zoo” (a table showcasing the diversity of plants, including mosses, pine cones, ferns and flowering plants); look and plants under a microscope, and view oak exhibit. The children's activity? Making herbarium specimens, says curator Ellen Dean.
Häagen-Dazs Honey Bee Haven, noon to 4 p.m.
Visitors to the Häagen-Dazs Honey Bee Haven, a half-acre bee demonstration garden located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility, Bee Biology Road, can learn about bees and see the plants they frequent, said manager Christine Casey. Guests will learn how to identify bees. They can also use a bee vacuum to catch, observe and release bees. A six-foot long sculpture of a worker bee by artist Donna Billick of Davis anchors the haven.
Nematode Collection, noon to 4 p.m.
The nematode collection will open from noon to 4 p.m. in the Science Laboratory Building, off Kleiber Hall Drive. It will feature both live and slide-mounted nematodes, as well as jars of larger parasites. Nematodes, also called worms, are described as “elongated cylindrical worms parasitic in animals or plants or free-living in soil or water. They exist in almost every known environment.”
Marine Invertebrate Collection, noon to 4 p.m.
The Marine Invertebrate Collection in the Science Laboratory Building, off Kleiber Hall Drive, will have touch tanks, preserved specimens, and some displays showing aspects of marine ecology and evolution. There will also be a seashell activity for kids, said Ivana Li. "In our touch tanks, we'll likely have sea stars and sea urchins. We are showing all the different geographical locations from which they were collected. This means that people can match up where specimens like our slipper lobster or salp came from. Other displays that we will have are on how to distinguish true crabs from other animals, and a display on seaweed ecology."
The sponsors made it all possible to have this event free to the public, Yang said. Ink Monkey is providing 300 t-shirts for the volunteers, and Marrone Bio Innovations and Novozymes are also major supporters. Other supporters include the UC Davis Honey and Pollination Center, UC Davis Library, White Labs Inc., Margaret Berendsen, Fletchers Real Estate, Peter Lash and Dan Potter.
Further information is available on the UC Davis Biodiversity Museum Day website.
Jefferson Wright, the eighth grader at Emerson Middle School, Davis, who is pictured on the UC Davis Biodiversity Museum Day website, says: "I have always liked museum day and every year it gets better and better. I can't wait to go this year!"
Jefferson has been attending the Biodiversity Museum Day “since he was very little,” said committee chair Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology.
This year's UC Davis Biodiversity Museum Day, the ninth annual, is scheduled Saturday, Feb. 15 and will showcase 13 museums or collections. Free and family friendly, the event is a science-based day at which visitors of all ages can meet and talk with UC Davis scientists—from undergraduates to staff to emeriti professors—“and see amazing objects and organisms from the world around us,” said Yang.
The 2019 event drew more than 4,000 visitors. It's always held the Saturday of Presidents' Weekend. Displays range from ancient dinosaur bones to stick insects; from hawks to honey bees; and from California condor specimens to carnivorous plants.
Sponsors (two openings available) who pledge by Jan. 6 to donate $3000 will receive “Presenting Sponsor” recognition (donor name or company logo) on the T-shirts, as well as recognition on social media fliers, fliers, banners and other entities.
Other contributors are “Biodiversity Allies” or $1500 donors (four openings available); “Biodiversity Supporters” or $500 donors, and “Biodiversity Friends” or $100 donors. General supporters, who can give what they can throughout the year, are also needed. More information on how to give is on the UC Davis Biodiversity Museum website. All donations are tax-deductible and much appreciated, the organizers said.
Here are the participants:
- Arboretum and Public Garden
- Bohart Museum of Entomology
- Botanical Conservatory
- California Raptor Center
- Center for Plant Diversity
- Department of Anthropology Museum
- Häagen-Dazs Honey Bee Haven
- Marine Invertebrate Collection (not linked)
- Museum of Wildlife and Fish Biology
- Nematode Collection
- Paleontology Collection
- Phaff Yeast Culture Collection
- Viticulture Enology Culture Collection
The 13 museums or collections represent nine departments, all within walking distance on campus except the Raptor Center on Old Davis Road and the bee garden on Bee Biology Road. The UC Davis Department of Entomology and Nematology will showcase three museums or collections: Bohart Museum of Entomology, Haagen-Dazs Honey Bee Haven, and the Nematode Collection.
The UC Davis Biodiversity Museum Day, founded in 2011, is billed as an annual event for the public to learn about nature, science and the work of UC Davis around the globe. The science-based day focuses on natural history showcasing the university's critically important, research and teaching collections, the committee related. Many students attend Biodiversity Museum Day to gather information on career choices.
All participating museums and collections have active education and outreach programs, but the collections are not always accessible to the public. In the event of rain, alternative locations are planned for the outdoor sites.
For more information on sponsors, contact Charlie Lemcke, assistant director, Foundation and Corporate Engagement, at firstname.lastname@example.org or (530) 754-4102.