Doctoral students in the laboratory of nematologist Shahid Siddique, associate professor in the Department of Entomology and Nematology, excelled at the 62nd annual meeting of the Society of Nematologists (SON), held July 9-14 in Columbus, Ohio.

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 enrolled in the UC Davis Plant Pathology doctoral program, with a designated emphasis in biotechnology, in 2020. She obtained 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. She recently received a two-year, $32,000 Ministry of Education Taiwan Government Scholarship to Study Abroad (GSSA).

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.

Cobb Bowl. Six teams competed in 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."

"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.

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.”

Three graduate students in the laboratory of nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, have won travel awards to attend the 62nd annual conference of the Society of Nematologists (SON), set July 9-14 in Columbus, Ohio.

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.)