Current Personnel

Faculty

Pamela Ronald

Pamela Ronald

I am a professor in the Dept of Plant Pathology and the Genome Center at UC Davis. I have a PhD in Molecular and Physiological Plant Biology from UC Berkeley and was a postdoc at Cornell. I got interested in plant microbe interactions while studying biology at Reed College and later moved to Sweden to study mycorrhizal fungi. I enjoyed living in Sweden/France for three years but am glad to be back in California, where I grew up. When not doing science, I love to spend time hiking in the Sierra Nevada mountains with my friends, family and our dog.
Valley Stewart

Valley Stewart

I am Professor Emeritus in the Department of Microbiology & Molecular Genetics. I earned a B.A. in biology from the University of Colorado and a Ph.D. in microbiology from the University of Virginia, and completed postdoctoral training at Stanford University. I moved to UC Davis after twelve years on the faculty at Cornell University. My research focused on studying the physiology and genetics of enterobacteria. I have been collaborating with Prof. Ronald since 2016, focusing on Xanthomonas oryzae pv. oryzae. I love to play trumpet with the UC Davis symphony orchestra and concert band, and I also enjoy golfing, reading about politics and history, and spending time with my wife, our daughter and the family dog. https://biology.ucdavis.edu/people/valley-stewart

Staff

Randy Ruan

Randy Ruan

I am Professor Ronald’s Lab Manager. I graduated in Yangzhou University in China with a Master and Bachelor in Agronomy and Plant Genetics. I moved to United States in 1994 and joined Ronald lab in Dec 1994. I enjoy working with Pam and the hardworking lab group. Besides working on research and manage Ronald lab I spend most my spare time on gardening. Karen and I have a son Colin and two cats, Big Guy and Calypso.

Assistant Project Scientist

Maria Florencia Ercoli

Maria Florencia Ercoli

I am originally from Argentina; I have a Ph.D. in Biological Sciences and a BSc in Biotechnology from the National University of Rosario. During my Ph.D. I studied regulatory networks controlling Arabidopsis root development and discovered my passion for plant genetics and molecular biology. I decided to apply this expertise to a different plant model, a crop, so in 2018 I joined the Laboratory of Prof. Pamela Ronald as a Postdoctoral Scholar. I am currently working as part of a team that, using different approaches, aims to elucidate the molecular mechanisms underlying the ability of small peptides to control plant development and plant-microbe interactions. My passion is to see life through a microscope; therefore, I approached this key research question from a cellular biology perspective, studying the anatomical modifications these hormones are causing in detail. If you want to see fun pictures from our research, you can find me on Twitter (@NeCesiTo1TiemP0).
In my free time, I love spending time with my husband Jean and our dog Gino; we go for hikes, camping, and bike rides. I also love cooking, watercolor painting, and gardening.

Postdoctoral Scholars

Artur Teixeira de Araujo Junior

Artur Teixeira de Araujo Junior

I am a postdoc in Ronald Laboratory (Department of Plant Pathology – UC Davis). I have a PhD in Cellular and Molecular Biology from the Federal University of Rio Grande do Sul (Brazil) and a masters in Biotechnology from the Federal University of Pelotas (Brazil). I also had the experience of being a Rural Producer and Property manager in a farm for 6 years. This helped me to understand the vision of two very different points of work: developer of new technology and producer/user of these final products. I am responsible for the collection of rice mutants (KitBase) and sorghum mutants. My projects involve bioinformatics, laboratory and greenhouse work. I'm glad to study and learn about the modifications in the DNA and how these mutations can help the society with plants more tolerant to stress, more productive and with greater nutritional value in grains. In my free time, I like to improve my creative side and to do physical activities (hiking, climbing, among others).
Alyx Shigenaga

Alyx Shigenaga

I am a USDA-NIFA-AFRI Postdoctoral Fellow (Grant No. 2023-67012-39889) studying the role small, sulfated peptides play in facilitating bacterial infection of rice. I have a PhD in Plant Pathology from Colorado State University and a BSc in Microbiology and Botany from Humboldt State University (now Cal Poly Humboldt). During my PhD, I studied the role the plant hormone cytokinin plays in heat-induced disease susceptibility of plants to bacterial pathogens. The overall goal of my postdoctoral research in the Ronald Lab is to better understand how plants perceive plant- and microbe-derived peptides, to improve crop disease resistance. Besides doing science, I enjoy spending time with my husband and dog outdoors hiking, kayaking, or swimming.
Ellen Rim

Ellen Rim

I am a Life Sciences Research Foundation postdoctoral scholar studying rice immune receptor signaling with the goal of developing crops with greater pathogen resistance. I studied animal systems throughout my undergraduate years at Harvard College and PhD studies at Stanford University focusing on cell signaling in mammalian stem cells. Towards the end of graduate school, I became interested in plants and the role of plant sciences in addressing climate change and food security. In the Ronald Lab, I'm learning a lot about crops and engineering plant immune receptors to expand their pathogen recognition ability. Outside of lab, I enjoy cycling and playing ultimate frisbee.
Jin CY Liao

Jin CY Liao

I received my PhD in Plant Biology from Iowa State University. My PhD works were trying to understand the complicated molecular mechanisms by which plants regulate in response to dynamic environmental conditions. I particularly focused on the interplay between autophagy and phytohormone brassinosteroid signaling in Arabidopsis. I am currently working on the regulation of plant peptide hormones and their receptors in the Ronald Lab. Besides research, I am also passionate about travel and science communication. I have my own website Jin's LifeRχiv (https://jinsliferxiv.com/), and most of my posts are about plant biology. I create funny and cute illustrations/comics that explain the latest plant science research in a way everyone can understand.
Yejin Shim

Yejin Shim

I am a postdoctoral researcher in the Ronald Lab. Originally from Seoul, South Korea, I earned my Ph.D. in Crop Science and Biotechnology from Seoul National University, where I also completed my Bachelor’s and Master’s degrees. My doctoral research focused on the role of transcription factors in regulating key agronomic traits in rice, such as flowering time, leaf senescence, and drought stress tolerance. After studying diverse phenotypic traits in rice, my research interests became more focused on developing abiotic stress tolerant crops using genome editing to tackle climate change. In the Ronald Lab, I am currently investigating the role of the rice peptide hormone OsPSY in bridging environmental stress responses with plant growth and development. Outside of my research, I enjoy playing tennis and watching soccer matches. As a classical music enthusiast, I also love playing the violin and going to orchestra concerts.
Sangeetha Ramesh

Sangeetha Ramesh

I am a postdoctoral researcher in the Ronald lab. I grew up in Tamil Nadu, India, where I earned a Bachelor’s degree in Biotechnology (PSG College of Technology). Inspired by the impact of microbes in our life, I moved to the US to pursue a Ph.D. in Microbiology at the University of Illinois at Urbana-Champaign. For my Ph.D., I undertook interdisciplinary research focusing on the bioinformatics-guided discovery and biochemical characterization of microbially-derived peptidic natural products and proteins. During my graduate studies, I was intrigued by how microbes use natural products to communicate and establish relationships with different hosts, specifically plants. In the Ronald lab, I hope to learn about plant biology and study biochemical messengers that facilitate beneficial plant-microbe interactions. Outside of the lab, I enjoy hiking, cooking, playing shuttle badminton, and spending time with my friends and family.
Erin Huiting

Erin Huiting

I am a Schmidt Science Fellow and Postdoctoral Scholar in the Ronald Lab who is exploring plant genetic diversity to detect new innate immune genes across the plant kingdom. My long-term goal is to apply this knowledge to bioengineer multi-pathogen resistant crops. I initially studied HIV and human immunology at the NIH, and then pursued my Biomedical Sciences PhD at UCSF to examine the ancestral origin of cGAS innate immunity in bacteria. Here, I discovered a novel class of viral 'sponge' inhibitors that can block a diversity of nucleotide signaling pathways used in innate immunity across the tree of life. This work inspired me to explore innate immunity and host-pathogen interactions in an entirely new system: plants. During my postdoc training in the Ronald Lab, I'm excited to expand my understanding of plant biology and pathology, build a diverse, open-source dataset of plant genomes, and apply advanced bioinformatic tools to discover entirely new innate immune pathways in plants. Beyond the lab, I am an ardent advocate for equity and inclusion in science (ImmunoX iGEquity; Solving For) and women’s empowerment (WGE Fund). As a Colorado native, I also enjoy hiking, camping, and broadly exploring the outdoors with friends and family.

Junior Specialist

Tracy Weitz

Tracy Weitz

I am a recent graduate from UC Davis with a Bachelor's Degree in plant biology. I have a passion for molecular biology and plant-microbe interactions. My previous worked focused on the effects of elevated temperature on human pathogen contamination of lettuce. In my free time, I love to cook, bake, and spend time in nature.
Jack Carter

Jack Carter

I joined the Ronald lab in the beginning of 2024. I earned my Bachelor's Degree in Molecular, Cellular, Developmental Biology from the University of Colorado Boulder. Since graduating I have worked for a number of companies with work including, diagnostic PCR, next generation sequencing, and helping to organize and run plant pathology studies. At the Ronald Lab I work with Ellen and Oscar, developing pathogen resistance via directed evolution. I enjoy running, camping, and working on my classic Volkswagen bus.

Graduate Student Researchers

Oscar Garrett

Oscar Garrett

I joined the Ronald Lab as a junior specialist in late summer 2023. I earned my B.S. in Biology at Haverford College in Haverford, PA, but stem initially from rural Northeast Ohio. During my undergraduate studies, I investigated how microbes use small molecule messengers to communicate on a biomolecular level, focusing on interactions between marine phytoplankton, bacteria, and viruses. At the Ronald Lab, I've now shifted my focus to terrestrial plants, studying how rice recognizes and coordinates an immune response to pathogens. I hope to use this knowledge to engineer plants with enhanced pathogen recognition abilities. Outside of the lab, I enjoy cooking, gardening, hiking, and foraging for plants and fungi.
Alexander Howard

Alexander Howard

I am a graduate student who joined the Ronald Lab in the spring of 2023. I earned a B.S. in Biotechnology at the University of Nevada, Reno and am originally from Boise, Idaho. During my undergraduate I researched how drought stress influences 3'UTR isoform expression in grapevines. I found that 3'UTRs are highly dynamic and may play an important role in regulating transcript stability and translation during droughts. This work sparked an interest in bioinformatics which has remained a constant passion of mine ever since. My main goal at the Ronald Lab is to use bioinformatics and machine learning techniques to optimize the design of more effective immune receptors in plants. Beyond lab work I enjoy cooking and baking for friends, gardening, and outdoor activities like hiking and skiing.
Subah Soni

Subah Soni

I am a PhD student in the Microbiology Graduate Group at UC Davis. I grew up in New Jersey where I also got my B.S. in Biology with a concentration in molecular cell physiology from Monmouth University. I explored how Kumquat and Manuka Essential Oils impacted the growth, viability, and stress signaling in different cancer cell lines. I then obtained my ScM in Molecular Microbiology and Immunology from Johns Hopkins Bloomberg School of Public Health. I did research on how certain artificial sweeteners modulate the gut microbiome and their subsequent effects on host metabolic health. I am currently interested in how different environmental microbiomes can be modified to mitigate the effects of climate change. In my free time I like to read, write, cook, hike, and look after my plants.
Sarah Ng

Sarah Ng

I am a student in the Integrative Genetics and Genomics graduate group. I earned my B.S. in Plant Biology at UC Davis, along with a minor in Music. During this time, I researched quantitative trait loci (QTL) related to tomato fitness under heat stress and interspecific reproductive barriers between tomato and its wild relatives. I also discovered a passion for teaching and led a research training program that helped over 200 undergraduates develop basic laboratory skills. At the Ronald lab, I hope to continue researching ways to help plants adapt to a stressful, changing environment. When I'm not in the lab, I enjoy listening to podcasts, urban homesteading, and spending time with my partner and family.

Undergraduate Assistants

James Hochbrueckner

James Hochbrueckner

I am an undergraduate here at UC Davis double majoring in Plant Biology and Philosophy. I joined the lab in January of 2025 and currently work under Sarah to help her harvest, genotype, and study the PSY receptors in tomatoes. Outside of the lab you will most likely find me fishing, reading, or going on some fun outdoor adventure!
Daniel Winton

Daniel Winton

I am an undergraduate at UC Davis, and I joined the Ronald Lab at the beginning of 2025. I am a third-year student majoring in Biological Sciences with a minor in Japanese. I am originally from San Diego, California. I assist Sarah with her tomato genetics research on PSY receptors in both the greenhouse and the lab. Outside of the lab, I enjoy good food, playing spikeball, and skiing with my roommates.
Jiayi An

Jiayi An

I am a third-year Clinical Nutrition major with a keen interest in plant biology and molecular mechanisms. I joined the laboratory in January 2025, and under Yejin's guidance, I am assisting with her project, exploring the multiple functions of the rice peptide hormone OsPSY, primarily through genotyping and phenotyping. Outside the lab, I reduce stress by Muay Thai, paragliding, playing badminton and swimming.
Sanyukta Rohom

Sanyukta Rohom

I am an undergraduate student here at UC Davis, double majoring in Neurobiology, Physiology & Behavior, and Psychology. I have been part of the lab since January 2025. I work with Yejin to assist with her project, specifically in genotyping and phenotyping OsPSY overexpressing and knockout rice plants. In my free time, I like to dance, work out, be outdoors, and spend time with my friends and family.
Ingrid Jimenez Ledesma

Ingrid Jimenez Ledesma

I am an undergraduate student at UC Davis, double majoring in Medical and Molecular Microbiology and Chicano/x/a Studies. I joined the Ronald Lab in September 2024 and currently work with Florencia Ercoli, assisting with research on plant-microbe interactions. Outside the lab, I enjoy spending time with my pomeranian, Nami, reading, and watching TV shows.
Quinlin Schug

Quinlin Schug

I am an undergraduate student here at Davis, I am originally from Grass Valley California. I am majoring in biological sciences and joined the Ronald lab in January 2025. I work with Sangeetha assisting on her research focused on determining the substrate scope of a sulfotransferase protein in E. coli. Outside the lab I play ultimate frisbee and enjoy hiking and skiing with friends. 
Kathleen Do

Kathleen Do

I am a UC Davis undergraduate majoring in Molecular & Medical Microbiology with a minor in Global Disease Biology. I joined the Ronald Lab in January 2025 and currently work with Alyx Shigenaga. Under her guidance, I assist with her research on the effects of PSY receptor knockouts in rice plants, primarily by genotyping. When I'm not in the lab, I enjoy cooking, watching TV shows, embroidering, and spending time with my partner, friends, and family.