- Author: Kathy Keatley Garvey
- 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.
The University of Idaho team, one of six teams competing, won the Cobb Bowl. The study material is based on six decks of nematode trading cards created by Jon Eisenback, professor in Virginia Tech's School of Plant and Environmental Sciences. He also hosted the game as "SmartAlex EisenTrebeck." He asked questions in the form of an answer, such as:
- 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."
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.
"Plant-parasitic nematodes are destructive pests causing losses of billions of dollars annually," Siddique says on his website. "Economic, health, and environmental considerations make natural host plant resistance a preferred strategy for nematode control, but there are limitations to this approach. In many cases, the resistance conferred by resistance genes is partial, and some of the nematodes are able to survive. Similarly, nematode resistance genes are often effective against only one or a few species, whereas plants are exposed to several pathogens in the field. Another concern is the emergence of pathotypes that can overcome resistance. In view of all these limitations, it is important to identify additional mechanisms and tools that can be used to develop novel and sustainable approaches to the management of nematodes."
The Siddique lab focuses its 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."
- Author: Kathy Keatley Garvey
Today, during the 62nd annual international conference of the Society of Nematologists, being held July 9-14 in Columbus, Ohio, The Proceedings of the National Academy of Sciences (PNAS) published a UC Davis research team's important--and exciting--research paper on root-knot nematodes.
It's online at “Root-Knot Nematodes Produce Functional Mimics of Tyrosine-Sulfated Plant Peptides."
Basically, the researchers discovered that “both a harmful plant bacterium and a parasitic worm can mimic a plant peptide hormone to enhance their ability to infect plants.”
It's a joint project of nematologist Shahid Siddique, an associate professor in the Davis Department of Entomology and Nematology, and Siddique and UC Davis distinguished professor Pamela Ronald, a plant pathologist and geneticist in the Department of Plant Pathology and the Genome Center. They are the 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.
It's like hijacking plant development to facilitate parasitism, according to Siddique. “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.”
“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.
Plant-parasitic nematodes (PPNs) are among the most destructive plant pathogens, causing an annual economic loss of $8 billion to U.S. growers and more than $100 billion worldwide, the authors said.
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 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.”
- 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.”
- Author: Kathy Keatley Garvey
Doctoral student Ching-Jung Lin of the laboratory of nematologist Shahid Siddique, associate professor, UC Davis Department of Entomology and Nematology, is the recipient of a two-year, $32,000 Ministry of Education Taiwan Government Scholarship to Study Abroad (GSSA).
The scholarships are awarded to young Taiwanese doctoral students in various fields to support their research.
Lin enrolled in the UC Davis plant pathology doctoral program, with a designated emphasis in biotechnology, in 2020. In the Siddique lab, she is working on nematode transformation and nematode-induced plant immunity.
Lin received her bachelor's degree in agronomy in 2015 from the National Chung Hsing University, Taichung, Taiwan, and her master's degree in plant biology in 2018 from National Taiwan University, Taipei, Taiwan. Her master's research, in the lab of Chiu-Ping Cheng, involved the study of tomato innate immunity mediated by bacterial-wilt-associated QTL (quantitative trait locus) genes. Before joining the Siddique lab, she was a research assistant in the lab of Erh-Min Lai of Academic Sinica, where she studied Agrobacterium-triggered immunity in Arabidopsis.
“I am fascinated by plant-microbe interaction,” Lin says. ‘Currently I am interested in the development of functional genetic tools in plant-parasitic nematodes and the characterization of nematode-induced plant immunity.
A frequent presenter at conferences, Lin presented her research at the 2023 Bay Area Worm meeting at UC Davis; the 2019 International Society for Molecular Plant-Microbe Interactions (IS-MPMI) Congress in Glasgow, and at several Taiwanese conferences. She will compete in a 12-minute presentation competition at the 62nd annual Society of Nematologists' meeting, to be held July 9-14 at The Ohio State University, Columbus. She received a $600 Bayer Crop Science Student Travel Award to attend the conference.
Lin also presented at the 2019 at International Society for Molecular Plant-Microbe Interactions (IS-MPMI) Congress in Glasgow, and at several Taiwanese conferences.
Plant-parasitic nematodes are destructive pests causing losses of billions of dollars annually. Siddique says the research in his lab “focuses on elucidating interactions between plant parasitic nematodes and their hosts using molecular and applied methodologies.”
- Author: Kathy Keatley Garvey
Alison Coomer, Pallavi Shakya and Ching-Jung Lin are among the record 18 students given travel awards by SON, thanks to industry sponsors. All travel award recipients will deliver a presentation or provide a poster at the international meeting.
Bayer Crop Science will sponsor 10 travel awards, and Microbes, Inc., Certis Biologicals and Corteva, will each sponsor two awards. In addition, the United Soybean Board will provide two travel awards to students presenting nematode research in soybean production.
Alison Coomer
Alison, a third-year graduate student in the Department of Plant Pathology, is focusing her research on plant parasitic nematodes, specifically root-knot nematodes, and their molecular mechanisms to defend against plant immune systems. "I am also working to gain more understanding in the defense mechanism in plants towards plant parasitic nematodes."
Alison, originally from the St. Louis, Mo., region, received two undergraduate degrees from Concordia University, Neb.: a bachelor's degree in biology and a bachelor's degree in chemistry.
"I am very thankful to Cobb Foundation and Mai-Ferries-Bird for receiving one of the most prestigious student awards: Cobb Foundation/Mai-Ferris-Bird Student Travel Award," she said.
In her leisure time, Alison enjoys "the outdoors, animals of all varieties, and serving my community."
Pallavi Shakya
Pallavi is a second-year doctoral student in Siddique lab. "I come from Nepal, the land of Himalayas and I am interested in exploring plant parasitic nematodes from a combination of plant pathology and bioinformatics viewpointism," she related. Pallavi received her master's degree in plant biotechnology from Wageningen University in the Netherlands where she was introduced to transcriptomics of potato cyst nematodes.
"Working with these nematodes showed me the importance of understanding plants along with the parasites they have co-evolved with," she said. "In the Siddique lab, I plan to learn about the genomics and transcriptomics aspects of plant-nematode interaction."
"I am very thankful to Bayer Crop Science for my student travel award, and I am looking forward to meeting all the amazing nematologists in the meeting."
Ching-Jung Lin
Ching-Jung is a doctoral student in the Department of Plant Pathology with a designated emphasis in biotechnology. "I am fascinated by plant-microbe interaction," she said. "Currently I am interested in the development of functional genetic tools in plant-parasitic nematodes and the characterization of nematode-induced plant immunity. Originally from Taiwan, she holds a bachelor of science degree in agronomy from National Chung-Hsing University, and a master's degree in plant biology from National Taiwan University.
"I am very thankful to Bayer Crop Science for funding my student award and I look forward to delivering my presentation at the SON conference," she said. Outside of the lab, Ching-Jung enjoys "reading, jogging, playing badminton, and going to the gym." And, she added, "I am a coffee and dog person."
Research in Shahid Siddique Lab
Research in the Siddique lab focuses on basic as well as applied aspects of interaction between parasitic nematodes and their host plants. "The long-term object of our research," he says, "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."
SON is an international organization formed to advance the science of nematology in both its fundamental and economic aspects.
"Nematodes are the most abundant multicellular animals on the face of the earth," SON relates on its website. "They occur literally everywhere--in soil and decaying matter from the poles to the tropics, in all forms of plant life, in the bodies of almost all animals, including humans, and in insects. Living in such diverse environments as the sand and mud of the ocean bottom, stony mountain soils, and arid polar deserts are thousands to millions of nematodes per square meter."
SON defintes nematodes as "nonsegmented roundworms with complete sensory, digestive, excretory, and reproductive systems. Most, but not all, are microscopic. The variety of nematode forms and habitats is almost unbelievable: they range from the minute inhabitant of your favorite mushroom to the 27-foot-long parasite in the placenta of a sperm whale."
"Nematodes are essential elements of ecosystems, but most have no direct effect on humans," the SON website points out. "Those that do, however, can be devastating. In many places, people still suffer from diseases such as elephantiasis, river blindness, and hookworm, caused by nematodes. In most places, the effect on humans is indirect. For example, in the United States, plant-parasitic nematodes cause more than $3 billion worth of crop losses each year, and cause similar losses in cattle, sheep, and swine." (See more information about nematodes on its website.)
