Chemical ecologist Yuko Ishida of Toyama, Japan, a former UC Davis post-doctoral researcher who shared the same lab--and the same bench--in Briggs Hall that Duffey did, is the lead co-author of a cover story recently published in the Proceedings of the National Academy of Sciences (PNAS) about an invasive species of millipede that secrets hydrogen cyanide as a defensive mechanism. (See research paper)
Ishida and Duffey never met but they shared a love of science and chemical ecology, in addition to the same lab.
At the time of his death, Duffey was a professor and vice chair of the UC Davis Department of Entomology. When chemical ecologist/professor Walter Leal joined the UC Davis Department of Entomology faculty in 2000, he occupied the former labs of professors Duffey and Susumu Maeda (1950-1998) and memoralized their lives and work by naming his lab the “Honorary Maeda-Duffey lab.”
Ishida worked in the Honorary Maeda-Duffey lab from May 2001 to November 2007 at UC Davis.
“Yuko loves to tackle challenging problems and he is well prepared to solve them,” said Leal, former chair of the UC Davis Department of Entomology and now with the UC Davis Department of Molecular and Cellular Biology.
Ishida also photographed the millipede, found in southern Japan, for the PNAS cover.
The four scientists all work at the Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, and are affiliated with the Asano Active Enzyme Molecule Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Toyama.
“To discover more efficient and stable HNLs, we focused on the invasive cyanogenic millipede as a bioresource,” the scientists wrote. “The HNL identified from the millipede showed not only the highest specific activity toward benzaldehyde among known HNLs, including the almond HNL in industrial use, along with wide temperature and pH stabilities, but also high enantioselectivity in the synthesis of various cyanohydrins. These properties make it suitable as an industrial biocatalyst. Arthropods are likely to be valuable sources of potential biocatalysts for the next generation of industrial biotechnology.”
“There followed several papers on the biochemistry of HCN production and the production of other defensive compounds in these interesting animals,” they wrote. “After arriving at UC Davis, Sean began a long series of brilliant studies on the chemical mechanisms used by plants to fend off attack by insects and various pathogens. This work centered on resistance in tomatoes, and over the years he collaborated with numerous students and colleagues. Studies analyzed the role of numerous chemicals produced by plants including tomatine, proteinase inhibitors, and various plant oxidative enzymes. Recent studies had included analyses of induced defenses and the interactions of chemicals with the biological agents such as parasitoids and baculoviruses used in various IPM and biological control programs.”
“A constant theme and frequently emphasized message in Sean's work was the fact that chemical-biological interactions were rarely simple and straightforward,” they wrote. “He stressed that in order to understand plant-insect interactions, for example, it was necessary to understand the interactions among plant chemicals, the overall characteristics of the insect's diet, the physiological state of the insect, and the modifiable characteristics of plant and insect. Chemical and biological context and chemical mixture were seen as critical determinants of biological activity; a simple view that natural products functioned merely as "toxins" or isolated defensive factors was often misleading.”
Carey, Dingle and Ullman praised Duffey's "truly interdisciplinary research that included several joint projects with members of the Entomology Department and also with colleagues in the departments of Nematology Ecology and Plant Pathology. We all experienced Sean insisting over and over that interactions are not simple and that one must understand the chemistry, the physiology, and the ecology to really understand interactions between plants, insects, and their pathogens. Sean's legacy is an outstanding record of how to go about studying plant-insect interactions, not just the gathering of data on interactions that occur.”
The legacy continues...
Hoover, who received her doctorate in entomology from UC Davis in 1997, will discuss “Co-Evolution in a Host Baculovirus System” from noon to 1 p.m. in 366 Briggs Hall.
She will be in California in conjunction with her trip to Ventura to participate in the Gordon Research Conference, an international forum for the presentation and discussion of frontier research in the biological, chemical, and physical sciences, and their related technologies.
“The gypsy moth has a long co-evolutionary history with its host specific baculovirus, Lymantria dispar NPV,” Hoover said. “As a result, the gypsy moth has evolved counter-defenses against the virus, while in return the virus has strategies for increasing its own fitness at the expense of the host. For example, anti-viral defenses include apoptosis of infected cells (despite viral inhibitor of apoptosis genes), while the virus manipulates host behavior to enhance transmission to new hosts, which is an example of the extended phenotype.”
While a grad student at UC Davis, Hoover studied with major professors Bruce Hammock and Sean Duffey (1943-1997). After a one-year postdoctoral position at UC Berkeley, she joined the faculty of the Penn State University Department of Entomology in 1998.
Her research program at Penn State focuses on invasive species, including development of trapping techniques for the Asian longhorned beetle; gut microbial symbionts of the Asian longhorned beetle and hemlock woolly adelgid; functions of key viral genes in transmission of the gypsy moth baculovirus and anti-viral defenses; and biological control of hemlock woolly adelgid.
Hoover is the lead author of the highly acclaimed research, “A Gene for an Extended Phenotype,” published Sept. 9, 2011 in Science. It was selected for the Faculty of 1000 (F1000), which places her work in its library of the top 2 percent of published articles in biology and medicine.
It happened 14 years ago tomorrow. Chemical ecologist Sean Duffey (right), then professor and vice chair of the UC Davis Department of Entomology--and known for taking teaching, research, public service and administrative duties to exciting new levels--died May 21, 1997 of lung cancer. He was 53.
He left a legacy treasured by the faculty, students and staff, not to mention his family, friends and colleagues. Every day many pass by the “Au Revoir Sean Duffey” wall memorial on the third floor of Briggs Hall. The work of Davis sculptor Donna Billick (a self-described "20th century cave artist") and Davis calligraphy artist Marilyn Judson, it contains recollections of his life. It includes images of everything from the insects he studied, to the hat he wore, to a soccer ball he kicked.
And every May, the faithful place flowers there in his memory.
Felton will deliver the Thomas and Nina Leigh Distinguished Alumni Seminar on “Dialogues at the Plant-Herbivore Interface” at 6 p.m. in Ballroom B of the new UC Davis Conference Center, located across from the Mondavi Center.
The lecture is open to the public and will be preceded by a reception at 5 p.m. A buffet dinner for invited guests will follow Felton’s talk.
Felton, professor and head of the Penn State Department of Entomology since 2000, received his doctorate in entomology from UC Davis in 1988. He did postdoctoral work at UC Davis from 1988 to 2000, and then joined the University of Arkansas, Fayetteville, advancing to professor in 1998.
About his talk, Felton says: “Our understanding of induced resistance against herbivores has grown immeasurably during the last several decades. Based upon the emerging literature, I argue that induced resistance represents a continuum of phenotypes that is determined by the plant’s ability to integrate multiple suites of signals of plant and herbivore origin.”
“Herbivore-derived cues may be perceived by plants to elicit defensive responses, but herbivores may also partially evade plant defenses through a variety of secreted effectors. A more comprehensive model describing induced resistance is needed that illustrates the range of signals arising from early detection through herbivore feeding, and finally, through subsequent plant generations.”
Leigh joined the UC Davis Department of Entomology in 1958, retiring in 1991 as an emeritus professor. However, like many entomologists, he continued to remain active in his research and collaboration until his death on Oct. 26, 1993.
Thomas Leigh, Sean Duffey and Gary Felton…three familiar faces in the world of entomology and all dedicated to learning, teaching and giving back. As poet laureate Maya Angelou so eloquently wrote: ”When you learn, teach. When you get, give.”
They’ve done just that.