Lewis Lab

Welcome to the Lewis Lab!

We are interested in understanding how plants defend themselves against pathogens. We study the HopZ family of type III effector proteins from Pseudomonas syringae and the immune responses they elicit in plant hosts. We use many different techniques to investigate plant immunity, including genetics, molecular biology, biochemistry, cell biology, genomics, high-throughput screens, and next-generation sequencing. Our long-term goals are to understand the molecular mechanisms of plant immunity, and to identify strategies for durable resistance in plants. We are a collaborative group of scientists who are committed to creativity, curiosity and excellence in science, training the next generation of scientists, and fostering a welcoming environment that values all people.

The Lewis Lab is located at the Plant Gene Expression Center (PGEC) in Albany, California and is part of a unique collaboration between the Agricultural Research Service of the US Department of Agriculture and the Plant and Microbial Biology Department at the University of California, Berkeley.

Jennifer D. Lewis

Plant Gene Expression Center

800 Buchanan St.

Albany, CA 94710

jdlewis@berkeley.edu, jennifer.lewis@usda.gov

Lab Phone: 510.559.5964

Office Phone: 510.559.5909

Fax: 510.559.5678

Research Highlight

Nate's review on natural diversity and rational engineering for immunity against pathogens is now published in Plant, Cell & Environment!

Marlo talks about bugs on plants at PubScience

Marlo gave a talk to the general public about different insects that can be found on your plants, through the student-led outreach program, PubScience. Students give monthly talks at Ocean View Brew Works on various scientific topics.

Lab interacts with local farmers

Fresh from the Farm: A conversation with growers, connecting farmers with scientists. The lab visited Cloverfield Farm to learn about their growing practices and learned about challenges facing organic farmers. See more Fresh from the Farm.

Congratulations Lewis Lab graduates 2026!

Congratulations to Sam Rosen, Ajeyo Baidyaroy, Greg Schumann and Sieun Park who graduated from UC Berkeley in June! Sam, Ajeyo and Greg majored in Microbial Biology. Sieun majored in Molecular Environmental Biology. Sam will be starting graduate school at Northeastern University in the fall. Ajeyo and Greg are continuing over the summer. Ajeyo, Greg and Sieun are pursuing health fields.

Sam shares her research at the RCNR research symposium!

Undergraduate student Sam Rosen presented her honors research project. Sam screened a diversity panel of cultivated and wild tomato accessions for immune responses to effectors from Pseudomonas syringae. New sources of disease resistance will help protect plants from infection.

Former undergraduate student receives Marie Curie!

Former undergraduate student, Arvind Nandakumar, has received a Marie Curie fellowship for graduate study at ETH Zurich. Arvind will focus on bioprinting of thick tissue constructs. Congratulations Arvind!

Research Highlight

Our collaborative paper, with Aymerick Eudes and Jana as co-first author, has been published at Plant, Cell & Environment! In collaboration with Aymerick's lab at LBNL, we showed that resistance to Pseudomonas syringae is enhanced in transgenic Arabidopsis overexpressing tyramine. The transgenic lines show differences in their circadian rhythms, stomatal regulation and flavonoid content. The impacts on abiotic stress may influence plant responses to biotic stress.

We welcome a new rotation student!

Mary Biggs is a new rotation student in the lab. Mary earned her B.Sc. from Fordham University.

Marlo talks about plant diseases at PubScience

Marlo gave a talk to the general public about plant diseases through the student-led outreach program, PubScience. Students give monthly talks at Ocean View Brew Works on various scientific topics.

Lab interacts with local farmers

Fresh from the Farm: A conversation with growers, connecting farmers with scientists. The lab visited Live Earth Farm to learn about their growing practices and learned how to make compost tea. See more Fresh from the Farm.

Congratulations to Lewis Lab graduates 2025!

Congratulations to Louis Sharratt, Alisia Silva, and Rachelle Punsalan who graduated from UC Berkeley in June! Lou majored in Conservation and Resource Studies. Alisia majored in Molecular Environmental Biology. Rachelle majored in Microbial Biology and will be pursuing health fields.

Rachelle presents at RCNR Symposium!

Undergraduate student Rachelle Punsalan presented her research at the RCNR honors symposium! Rachelle examined early defense responses in different mutant lines to determine their role in plant immunity.

We welcome a new postdoc!

Dr. Yuan Chen is a new postdoc in the Lewis Lab. She joins us with experience in plant development.

Research Highlight

Our collaborative paper with Bryan Swingle has been published at Frontiers in Microbiology! In collaboration with Bryan's lab at Cornell and Adam Deutschbauer's lab at LBNL, we identified new genes important for motility in Pseudomonas syringae using a random barcoded transposon library that our lab developed. Bacterial motility is important for virulence of plant pathogenic bacteria.

Research Highlight

Our collaborative paper with Yasu Kadota and Ken Shirasu is now published at The Plant Cell! Using our high-throughput next-generation based yeast two-hybrid screen (QIS-Seq), we found that the Pseudomonas syringae effector HopF2 interacts with a pattern-recognition receptor QSK1. QSK1 is a negative regulator of basal defenses. By targeting QSK1, HopF2 promotes bacterial virulence.

Research Highlight

Jana's first-author paper is published in Frontiers in Plant Science! Using a seedling-based screen that our lab developed, we identified complex resistance to Pseudomonas syringae in wild tomato. Previous graduate students Nate Diplock and Ilea Chau-ly, as well as previous undergrads Jamie, Liz, Steven and Taylor also contributed to the project. This project will help identify new sources of disease resistance in wild relatives of crop species.

Research Highlight

Nate's first-author paper is published in Plant Physiology! Nate identified mutants in ZED1 that were able to recognize Pseudomonas syringae effector HopZ1a without triggering autoimmune responses. He showed that one ZED1 mutant could be coupled with tomato ZAR1 to enable effector recognition. Since ZAR1 is highly conserved in plants, this suggests effector recognition could be broadened to non-model species. Former postdoc Dr. Mael Baudin and former undergrad Derek Xiang also contributed to this project, along with our collaborators Dr. James Murphy, Dr. Isabelle Lucet and their lab members at the Walter and Eliza Hall Institute of Medical Research, Australia.

Congratulations Dr. Nate Diplock!

Nate Diplock has successfully finished his dissertation and is now Dr. Diplock! Nate's dissertation work focused on natural and engineered sources of resistance to Pseudomonas syringae. He will join BluumBio as a staff scientist to pursue biotechnological approaches to bioremediation.

Past lab news can be viewed here.

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