Researching Innate Plant Immunity
Walter Gassmann Lab
Research Interests
The innate immune response triggered by plant immune receptors is very potent at preventing pathogen spread. Consequently, this response also has the potential to be detrimental to the host if not regulated properly. Apart from the regulation of immune receptor expression and accumulation it is still unclear how this fine-tuning of the immune system is achieved. Research in the Gassmann lab addresses this gap in knowledge using genetics, molecular and cell biology, and proteomics. The cultivation of genetically uniform plants over large areas frequently selects for pathogen strains that can overcome innate plant defenses, and large crop losses can ensue. While many examples of plants with constitutively active defenses with improved pathogen resistance are known, these usually are associated with biomass and yield reductions. It is therefore important to understand plant immune regulatory systems to ultimately generate plants with increased pathogen defenses in the absence of growth defects and yield penalties.
PRINCIPAL INVESTIGATOR
Walter Gassmann
Director, Bond LSC
Principal Investigator, Bond LSC
Professor of Plant Science & Technology
phone(573) 882-7957
email gassmannw@missouri.edu
As Bond LSC’s director, Gassmann works with the Vice Chancellor for Research to develop and implement plans for growth of the MU research enterprise. That includes partnering with academic units to attract research groups to MU and Bond LSC — one of the research centers administered by the Division of Research, Innovation, and Impact (RII). He supervises Bond LSC staff that assist in making all our center’s amazing science possible. He enjoys mentoring junior researchers in his lab, who study the plant innate immune system and the pathogens that attack plants.
Gassmann was born in Karachi, Pakistan. He received his Dipl. rer. nat. (MS) in 1990 from the Swiss Federal Institute of Technology Zurich (ETHZ) and his PhD in Plant Biology from UC San Diego in 1996 researching plant membrane transporters in the lab of Dr. Julian Schroeder. After post-doctoral studies at UC Berkeley in the lab of Dr. Brian Staskawicz he joined the Department of Plant Microbiology and Pathology (now Division of Plant Science & Technology) at the University of Missouri in 2000 as an assistant professor of plant microbiology and pathology.
He moved into Bond LSC in 2004 when it opened. In 2017, he stepped into the role of interim director of the Bond LSC upon retirement of its third director, Dr. Jack Schulz, and he was named director in 2021. He is currently a Professor in the Division of Plant Science and Technology, he is a member of the Interdisciplinary Plant Group (IPG), and he is a principal investigator at Bond LSC. In 2016, he was elected a fellow of the American Association for the Advancement of Science (AAAS).
ABOUT THE LAB
The Gassmann lab focuses on the plant innate immune system, in particular, how it is activated and how it is kept in check to prevent harmful side effects such as stunted growth and reduced seed yield when the immune system is overactive. Its current interests include the regulation of immune protein complexes by protein condensation and regulation of translation. This builds on the discovery of new components of a plant’s immune machinery that contribute to tight control of immune and other stress responses. These advances were originally made with the commonly used research plant Arabidopsis and have led to new initiatives to characterize immune system components in lettuce.
More specifically, the lab research works on a genetic screen for mutants with a narrowly defined upregulation of immune receptor signaling identified SRFR1, a negative regulator of plant immunity. Interestingly, SRFR1 is widely conserved between plants and other organisms, including humans. To date Arabidopsis SRFR1 is the only family member with an assigned function. How SRFR1 controls the immune system and other stress responses is an active research area in the lab. SRFR1 and its ability to form biomolecular condensates in specialized root cells during root development is also a current focus to understand SRFR1’s role in balancing signals and response outputs.
On the pathogen side, the lab studies bacteria that deploy effectors into host cells to manipulate plant physiology and limit immune responses, specifically focusing on a bacterial effector called AvrRps4 that has been studied for many years. AvrRps4 is processed inside the host cell into two parts after it is transferred from the bacterial cell. It had long been assumed that only one half of the effector plays a virulence role in the plant, with the other half serving as a transfer signal for the protein to be delivered into the plant cell. They recently showed that this part of the effector also has functions inside the plant cell and identified plant species that recognize this peptide to mount an immune response. A more complete understanding of virulence functions encoded in the composite effector AvrRps4 will shed light on strategies pathogens use to manipulate their hosts.
LAB MEMBERS
Leland Cseke
Research Lab Manager
Jianbin Su
Research Scientist/Academic
Research Topics
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Bacterial pathogenesis
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CRISPR-based gene editing in plants
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Deep learning and AI for biological data
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Gene editing
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Genomic tools and systems biology
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Host-pathogen interactions
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Multi-stress plant responses
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Plant immunity and stress responses
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Plant-microbe interactions
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Bacterial pathogenesis
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CRISPR-based gene editing in plants
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Deep learning and AI for biological data
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Gene editing
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Genomic tools and systems biology
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Host-pathogen interactions
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Multi-stress plant responses
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Plant immunity and stress responses
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Plant-microbe interactions
In The News
Jan. 9, 2024
Bond Life Sciences Center: A 20-year journey of scientific triumphs
From the fifth floor of the Bond LSC, one can look down and see the bridges that connect the facility and foster daily interactions and collaboration. |Photo by Beni Adelstein, Bond LSC By Beni Adelstein When Julia Rodriguez walked into Bond Life Sciences Center in 2004, she and dozens of others were part of a new campus experiment. As an administrative staff member for the newly minted center, she had a big task ahead of her, but, as Bond LSC approaches its 20th anniversary, she thinks the trajectory and results largely accomplished their aims.
April 7, 2021
Defense or growth: a complicated balance
The figure shows the wild type of the plant to the left. The mutant type to the far right shows when the negative regulator SRFR1 and the TOPLESS gene TPR2 are absent in a plant, the immune system intensifies and the plant stops growing. | Photo contributed by Walter Gassmann, Bond LSC. By Lauren Hines | Bond LSC The plant immune system isn’t active all the time. Plants must decide to either defend against disease or grow, but not simultaneously. The reason behind this process is not fully understood, and the Walter Gassmann lab at…
Feb. 9, 2021
Gassmann Named Permanent Director of Bond LSC
Yesterday, Tom Spencer, MU’s interim vice chancellor for research and economic development, officially named Bond LSC Interim Director Walter Gassman to the permanent director role. Below is Spencer’s announcement. Colleagues, Today, I am pleased to announce that Walter Gassmann, professor in the Division of Plant Sciences and a member of the Interdisciplinary Plant Group, has agreed to serve as director of the Bond Life Sciences Center (LSC) effective this month. Walter stepped into the role of interim director at Bond LSC July 1, 2017. Since then, his…