- Author: Kathy Keatley Garvey
It was the lab mates' first-ever conference, and they brought home first- and second-place awards, in addition to a second-place tie in the Cobb Bowl competition which memorializes Nathan Cobb (1859-1932), the father of nematology.
Alison Coomer Blundell, who will be a fourth-year doctoral candidate in Plant Pathology this fall, won first place in the three-minute student competition with her presentation on “Trade Offs Between Resistance Breaking and Fitness Cost in Root-Knot Nematodes.” She received a $250 award and a plaque.
Ching-Jung Lin, who will be a fourth-year doctoral student this fall, won second place in the 12-minute category with her presentation on "Elucidating the Role of MigPSY Peptides in Interactions Between Plants and Root-Knot Nematodes." She received a $250 prize.
The six-member Siddique lab team, "Meloidogyne Gang Gang," which included Blundell, Lin, third-year doctoral student Pallavi Shakya, and second-year doctoral student Veronica Casey, tied for second place in the Cobb Bowl, a jeopardy-like competition that can include both students and postdoctoral fellows on the teams.
"I am very humbled by the award and recognition but am very proud of seeing all my lab mates accomplish their presentations and get good feedback and recognition as well," said Blundell, who seeks a PhD in plant pathology. She holds two undergraduate degrees--a bachelor's degree in biology and a bachelor's degree in chemistry--from Concordia University, Seward, Neb.
“I was first introduced to nematodes in my undergraduate studies where I maintained C. elegans (Caenorhabditis elegans) cultures, but was introduced to plant parasitic nematodes when Dr. Siddique reached out to me about becoming a member in his lab," Blundell said. "This was my first time at SON, and for all my lab mates. SON has allowed me to meet people I have heard about or have talked to on Zoom, email, or twitter and also make new connections with many U.S. states and universities.”
Lin, a first-generation international student, credits co-principal investigator Professor Gitta Coaker of Plant Pathology and the Coaker Lab with mentoring her, offering presentation suggestions. "It was very much appreciated," she said.
- Question: "The Guava root-knot nematode."
Answer: "Meloidogyne enterolobii" - Question: "First report of root-knot nematodes."
Answer:"Who is Miles Joseph Berkeley?"
"The most difficult question, said team member Veronica Casey was: "The color of the first edition of the Journal of Nematology."
"The answer was simply, 'What is orange?' but many teams thought it was green," Casey related. "Another difficult question was 'The full species name of the Beech Leaf disease nematode.' The answer: "What is Litylenchus crenatae mccannii?"
The University of Idaho team won the Cobb Bowl. The UC Davis team, which also included a postdoctoral fellow from the University of Illinois and a graduate student from Montana State University, tied for second place with two other teams: AlohaNema, comprised primarily of students from the University of Hawaii, and Nemafolks, comprised of students from a number of universities, including Michigan State, Oregon State and Texas Tech. The other two teams represented the University of Florida and The Ohio State University.
Also at the SON meeting, Siddique participated in a session titled "Nematology Faces of the Future." In his five-minute self-introduction, he displayed a map showing how far he has traveled. A native of Multan, Pakistan, he received two degrees in Multan: his bachelor of science degree from the Government College Bosan Road in 2001 and his master's degree in botany from the Bahauddin Zakariya University in 2004. Then it was off to Vienna, Austria to receive his doctorate in 2009 in agriculture and biotechnology from the University of Natural Resources and Life Sciences. After serving as a research group leader for several years at the University of Bonn, Germany, he joined the UC Davis Department of Entomology and Nematology faculty in 2019 as an assistant professor and advanced to associate professor this year.
Alison Blundell Abstract
In her abstract, Blundell wrote: “Root-knot nematodes (RKNs), are among the most devastating pathogens of crops, causing substantial yield and economic losses worldwide. These parasitic organisms can infect over a hundred different plant species and can evade plant defense mechanisms by secreting a concoction of effectors. For decades, the Mi-1 resistance gene has been effective in detecting and inhibiting RKNs in tomatoes. However, the underlying mechanisms by which Mi-1 detects these pathogens remain largely unknown. In recent years, resistance-breaking populations have emerged in both greenhouse and field settings, posing a threat to the potency and effectiveness of the Mi-1 gene and, consequently, the tomato industry."
"We used two strains of M. javanica, one strain VW4, which is recognized by Mi-1, and another strain, VW5, which was selected from VW4 and can overcome resistance mediated by Mi-1," she explained. "Utilizing the newly constructed reference genome for M. javanica (VW4), we compared genomes of VW4 and VW5 and identified an approximately 650 kb region that is present in VW4 but missing in VW5. This missing region contains ten protein-coding genes, three of which encode putative effectors and are currently being tested as potential avirulence genes for Mi-1. In addition, we have conducted a series of infection assays on different host plants lacking Mi-1, and the results revealed a significantly lower egg count in VW5 when compared to VW4. We plan to expand these assays by testing additional M. javanica resistance-breaking strains collected from fields all over California to determine if this trade-off is consistent across other strains. Overall, our results suggest that although VW5 can overcome Mi-1, there is a trade-off in the form of compromised reproduction. This research helps to better understand the mechanism and components of Mi-1 and develop strategies for addressing resistance-breaking populations." (Co-researchers and authors include P. Shakya, M. Winter, D. Lunt, V. M.Williamson, and S. Siddique)
Ching-Jung Lin Abstract
In her abstract, Lin wrote: "Plant parasitic nematodes pose a severe threat to global food production. These parasites invade plant roots and establish permanent feeding sites, which serve as their sole source of nutrients. To manipulate host responses, they secrete effectors such as phytohormones or peptides that hijack the host's cellular machinery. Plants produce a family of peptides called Plant Peptide Containing Sulfated Tyrosine (PSY) that promote root growth via cell expansion and proliferation. Intriguingly, the bacterial pathogen Xanthomonas oryzae pv. oryzae also produce a PSY-like peptide called RaxX (required for activation of XA21 mediated immunity X), which contributes to bacterial virulence. Our previous research has identified a group of secreted peptides called MigPSYs in root-knot nematodes (Meloidogyne spp.) that resemble plant PSY peptides and stimulate root growth in Arabidopsis. We found that MigPSY transcript levels are highest during the early stages of infection in rice and tomato plants. Furthermore, down-regulating expression of MigPSY results in reduced root galling and egg production, suggesting that the MigPSYs serve as nematode virulence factors. To gain a better understanding of the roles of MigPSYs, I plan to characterize the mechanisms underlying their function and host perception in plants. This research is expected to provide valuable insights into the mechanism of nematode infection and may lead to the development of new methods for controlling plant-parasitic nematodes." (Co-researchers and authors include H. Z. Yimer, D. D. Luu, A. C. Blundell, M. F. Ercoli, P, Vieira, V. M. Wlliamson, P. C. Ronald and S. Siddique)
The next SON meeting is Aug. 4-9, 2024, in Park City, Utah.
- Author: Kathy Keatley Garvey
Powell was a Bohart Museum associate and a scientific collaborator, identifying scores of insects and attending many of the Lepidopterist Society meetings held there.
The open house, free and family friendly, is set from 7 to 11 p.m., Saturday, July 22 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus.
Plans call for scientists to set up their traditional blacklighting (ultraviolet or UV) display to attract moths and other night-flying insects. Bohart Research Affiliate John De Benedictus, a retired UC Davis Staff Research Associate, also known as "The Moth Man," usually heads the blacklighting project with several other scientists. De Benedictus received his master's degree in 1988 from UC Berkeley, studying with Powell. "I spent more time in the field with Jerry than any other grad student," he related. "I was privileged to be Jerry's student and lucky to have become his friend."
Jerry, born May 23, 1933 in Glendale, Calif., received his bachelor's degree in entomology at UC Berkeley in 1955 and his doctorate there in 1961. One of his most-read books, co-authored with Charles Hogue, is California Insects, Volume 44, published in 1980. The second edition, co-authored by Kip Will, Daniel Rubinoff and Powell and covering more than 600 species, was published in October, 2020.
In a tribute to Powell on its website, the Essig Museum posted in part:
"In his teen years he was heavily influenced by Charles 'Harbie' Harbison, who ran the Junior Naturalist Program at the San Diego Museum of Natural History, and sparked an interest in Jerry for butterflies and moths. Seeing his potential, Harbie recommended Jerry for the Entomology program at UC Berkeley, where he received his BS in 1955 and his PhD in 1961. While climbing through the ranks of Junior Entomologist (1961-62), Assistant Entomologist (1962-67), Associate Entomologist (1967-73), Entomologist (1973-94), Lecturer in Entomology (1964-69), Associate Professor (1969-73), and Professor (1973-94) at UC Berkeley, Jerry also became Curator (1972-2018) and Director (1993-1999) of the Essig Museum of Entomology (1972-1999) and Project Leader for the California Insect Survey (1963-1999). Although he retired as Director in 1999, Jerry remained a professor of the Graduate School until 2012 and maintained an active research program in Lepidoptera life histories and systematics until 2018, advising many students along the way. (See more on Essig website.)"
"Jerry's rearing program was the most extensive in the history of the study of New World Microlepidoptera," according to the Essig post. "For over 50 years he and his students processed more than 15,000 collections of larval or live adult Lepidoptera. Resulting data encompass more than 1,000 species of moths, through rearing either field-collected larvae or those emerging from eggs deposited by females in confinement. This total includes more than 60% of an estimated 1,500 species of Microlepidoptera occurring in California."
Powell gained international recognition when he detected the agricultural pest, the light brown apple moth, Epiphyas postvittana, in a ultralight (UV) trap on July 19, 2006 in his backyard in Berkeley.
"A consummate field biologist, Jerry's knowledge and interests were broad, allowing him to read landscapes and discover the most interesting and cryptic of species interactions," Oboyski noted. "This is well documented in over 220 publications, but also in the 60+ years of his field notes and rearing records that we are currently digitizing. He is the collector of over 400 holotypes of various insect orders, described over 170 species and 14 genera of moths, and honored by 41 patronyms. He also published papers on Hymenoptera, Coleoptera, Diptera, Dermaptera, and a Nematode. His legacy is impressive and will long be remembered."
Powell described himself as a "MothNut" on his vehicle license plate, and also displayed a sticker, "Larvae on Board."
The Bohart Museum, directed by UC Davis distinguished professor Lynn Kimsey, is the home of a global collection of eight million insect specimens; a live insect petting zoo; and a gift shop.
- Author: Kathy Keatley Garvey
A familiar figure at UC Davis, he served as an associate of the Bohart Museum of Entomology and a scientific collaborator, identifying scores of insects and attending many of the Lepidopterist Society meetings there.
Plans call for dedicating the Bohart Museum's "Night at the Museum" (formerly known as "Moth Night") to him. The open house, free and open to the public, is set from 7 to 11 p.m., Saturday, July 22. The museum is located in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis, campus.
Born May 23, 1933 in Glendale, Calif., Jerry received his bachelor's degree in entomology at UC Berkeley in 1955 and his doctorate there in 1961. One of his most-read books, co-authored with Charles Hogue, is California Insects, Volume 44, published in 1980. The second edition, co-authored by Kip Will, Daniel Rubinoff and Powell was published in October, 2020. Powell and Paul Opler 1938-2023) co-authored Moths of Western America, published in 2009.
In a tribute to Powell on its website, the Essig Museum posted in part:
"In his teen years he was heavily influenced by Charles 'Harbie' Harbison, who ran the Junior Naturalist Program at the San Diego Museum of Natural History, and sparked an interest in Jerry for butterflies and moths. Seeing his potential, Harbie recommended Jerry for the Entomology program at UC Berkeley, where he received his BS in 1955 and his PhD in 1961. While climbing through the ranks of Junior Entomologist (1961-62), Assistant Entomologist (1962-67), Associate Entomologist (1967-73), Entomologist (1973-94), Lecturer in Entomology (1964-69), Associate Professor (1969-73), and Professor (1973-94) at UC Berkeley, Jerry also became Curator (1972-2018) and Director (1993-1999) of the Essig Museum of Entomology (1972-1999) and Project Leader for the California Insect Survey (1963-1999). Although he retired as Director in 1999, Jerry remained a professor of the Graduate School until 2012 and maintained an active research program in Lepidoptera life histories and systematics until 2018, advising many students along the way. (See more on Essig website.)
"Jerry's rearing program was the most extensive in the history of the study of New World Microlepidoptera," according to the Essig post. "For over 50 years he and his students processed more than 15,000 collections of larval or live adult Lepidoptera. Resulting data encompass more than 1,000 species of moths, through rearing either field-collected larvae or those emerging from eggs deposited by females in confinement. This total includes more than 60% of an estimated 1,500 species of Microlepidoptera occurring in California."
Powell gained international recognition when he detected the agricultural pest, the light brown apple moth, Epiphyas postvittana, in a ultralight (UV) trap on July 19, 2006 in his backyard in Berkeley.
"Yet Powell's casual discovery that morning was just the beginning of something more serious: a moth infestation, a quarantine program and an all-out effort by state and federal authorities to stop a nasty creature that they concluded could threaten California's $38 billion agricultural market and--if unchecked--farms across the nation," wrote San Francisco Chronicle reporter Matthew B. Stannard in a June 3, 2007 piece, "Little Moth, Big Problem/Bay Area quarantine tries to halt the spread of ravenous pest."
In an email to colleagues on July 9, Peter Oboyski, executive director of the Essig Museum of Entomology, wrote in part: "With a heavy heart I am sad to report that professor Jerry Powell passed away this weekend. His contributions to our knowledge of California entomology, microlepidoptera, and insect life histories are inestimable, as is the value of the training he provided to his students. As one of those students, I am eternally grateful for the time, energy, and knowledge Jerry shared with me in the museum and the field."
"A consummate field biologist, Jerry's knowledge and interests were broad, allowing him to read landscapes and discover the most interesting and cryptic of species interactions," Oboyski wrote. "This is well documented in over 220 publications, but also in the 60+ years of his field notes and rearing records that we are currently digitizing. He is the collector of over 400 holotypes of various insect orders, described over 170 species and 14 genera of moths, and honored by 41 patronyms. He also published papers on Hymenoptera, Coleoptera, Diptera, Dermaptera, and a Nematode. His legacy is impressive and will long be remembered."
Powell described himself as a "MothNut" on his vehicle license plate, and also displayed a sticker, "Larvae on Board."
- Author: Kathy Keatley Garvey
“My interest in entomology started when I was a little girl, checking our prune and walnut orchards for pests with my dad,” said Wheeler-Dykes, whose office is based in Orland, Glenn County. “When I was a little bit older, I monitored pest populations for my uncle in his prune orchards during the summer.”
The former Becky Wheeler, she holds two degrees from UC Davis. She received her bachelor's degree in crop science and business management, with a minor in ag pest management, in 2010. She obtained her master's degree in entomology in 2013, studying with major professor and Extension entomologist Frank Zalom of the Department of Entomology and Nematology, now a UC Davis distinguished professor emeritus and recall professor. Extension entomologists Larry Godfrey (1956-2017) and Mary Louise Flint served on her thesis committee. Her thesis dealt with a species of mites in almond orchards: "Exploring Phoresy and Field Survival of Blattisocius keegani (Fox) (Acari: Ascidae) in Almond Orchards.”
“Taking Arthropod Pest Management with Frank Zalom and Larry Godfrey during my undergraduate studies at UC Davis was incredible; learning from two very experienced and knowledgeable researchers who had such a huge impact on agriculture was inspiring,” she said.
While at UC Davis, she served as a teaching assistant in Zalom's Arthropod Pest Management lab course in the winter of 2012, and as a staff research associate in the Andrew Walker lab, Department of Viticulture and Enology, from April 2015 to May 2018. Agricultural research positions followed.
“My career in ag research since graduate school has prepared me well,” she said. Prior to her selection as a UC Cooperative Extension advisor, she worked as an orchard researcher for Chico State Enterprises, beginning in May 2021. Her expertise also includes teaching ag ecology and soil science in the College of Agriculture, California State University, Chico. She served as a faculty mentor for Chico State STEM Connections in the 2022 Undergraduate Research Program, and as a faculty advisor for the Chico State Crops and Horticulture Club.
Wheeler-Dykes can be reached at bawheeler@ucanr.edu and (530) 884-9313.
- Author: Kathy Keatley Garvey
The research, “Root-Knot Nematodes Produce Functional Mimics of Tyrosine-Sulfated Plant Peptides,” is published in the current edition of the Proceedings of the National Academy of Sciences (PNAS).
It's like hijacking plant development to facilitate parasitism, according to nematologist Shahid Siddique, an associate professor in the Davis Department of Entomology and Nematology and one of the corresponding authors of this study. “This finding showcases an amazing case of convergent evolution across three different types of organisms, revealing how diverse life forms can develop similar strategies for survival.”
The root-knot nematode, which threatens global food security, is a small worm-like organism that is a highly evolved obligate parasite, or an organism that cannot survive without its host. It is known to infest some 2000 crops worldwide. “These parasites have a remarkable ability to establish elaborate feeding sites in roots, which are their only source of nutrients throughout their life cycle,” the authors wrote.
“Root-knot nematodes are a major threat to various crops, including fruit trees and vegetables,” Siddique said. “In California, tomatoes, almonds, and walnuts are among the major hosts susceptible to root-knot nematode infection.”
Siddique and UC Davis distinguished professor Pamela Ronald, a plant pathologist and geneticist in the Department of Plant Pathology and the Genome Center, are the joint corresponding authors. Joint first-authors are Henok Zemene Yemer, formerly of the Siddique lab and now with Gingko Bioworks, Emeryville, and Dee Dee Lu of the Ronald lab.
The team also included emerita professor Valerie Williamson of the former Department of Nematology; Maria Florencia Ercoli, postdoctoral fellow in the Ronald lab; Alison Coomer Blundell, a doctoral candidate in the Siddique lab; and Paulo Vieira of the USDA's Mycology and Nematology Genetic Diversity and Biology Laboratory, Beltsville, Md.
“Plant peptides containing sulfated tyrosine (PSY)-family peptides are peptide hormones that promote root growth via cell expansion and proliferation,” the authors explained. “A PSY-like peptide produced by a bacterial pathogen has been shown to contribute to bacterial virulence. Here, we discovered that PSY-like peptides are encoded by a group of plant-parasitic nematodes known as root-knot nematodes. These nematode-encoded PSY mimics facilitate the establishment of parasitism in the host plant. Our findings are an example of a functional plant peptide mimic encoded by a phytopathogenic bacterium (prokaryote) and a plant-parasitic nematode (an animal).”
The research involved gene expression analysis and parasitism of tomato and rice plants.
The project drew financial support from a collaborative grant awarded to Siddique and Ronald from the National Science Foundation's Division of Integrative Organismal Systems.
Siddique, a member of the UC Davis faculty since 2019, 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.”
Ronald, noted for her innovative work in crop genetics, especially rice, is recognized for her research in infectious disease biology and environmental stress tolerance. Thomson Reuters named her one of the world's most influential scientific minds and Scientfic American recognized her as among the world's 100 most influential people in biotechnology. In 2022 Ronald received the Wolf Prize in Agriculture.
The next steps? “Currently, we are working to understand the mechanism by which these peptides contribute to the nematode infection,” Siddique said. “This entails the characterization of receptors involved and gaining insights into transcriptional changes.”