Mary Beth Mudgett
Academic Appointments
- Associate Professor, Biology (School of Humanities and Sciences)
Key Documents
Contact Information
- Academic Offices
Personal Information EmailAlternate Contact Franco Errico Administrative Assistant Email Tel Work 650-723-6311
Professional Overview
Honors and Awards
- Chambers Fellow, Stanford University (2011-2014)
- Terman Fellow, Stanford University (2004-2010)
- Teacher of the Year, Associated Students of Stanford University (2008)
- Hellman Faculty Scholar, Stanford University (2005-2006)
- National Research Service Award, National Institute of Health (1997-1999)
- Graduate Research Achievement Award, University of California, Los Angeles (1992)
Professional Education
| PhD: | University of California, Los Angeles, Biochemistry (1994) |
| BA: | Ithaca College, Biochemistry (1989) |
Graduate & Fellowship Program Affiliations
Internet Links
Scientific Focus
Current Research Interests
My laboratory studies the biochemical mechanisms used by bacterial pathogens to alter plant physiology during infection. Extensive genetic and phenotypic data indicate that the bacterial type three secretion (T3S) system and its protein substrates (referred to as T3S effectors) are the major virulence determinants that promote pathogen colonization in plants. The paradigm for T3S effector function has been that these proteins collectively suppress host defense responses to promote colonization and disease progression. The biological function(s) of most T3S effectors, however, is extremely limited and biochemical support for this paradigm is lacking. Thus, the goal of my research has been to elucidate T3S effector function, identify host targets, and provide fundamental knowledge of how perturbation of host signaling pathways leads to bacterial pathogenesis. To do so, we study the T3S effectors in Xanthomonas campestris pathovar vesicatoria (Xcv), the causal agent of leaf spot disease.
Our research currently focuses on the characterization of three Xcv T3S effectors: XopN, XopD, and AvrBsT. We discovered that these effectors modulate three distinct nodes of defense signal transduction, supporting the paradigm that T3S effectors encode defense suppressors. In addition, our work challenges this paradigm by demonstrating that one effector suppresses disease symptom development, thus illuminating the importance of tolerance promoting factors in bacterial-plant interactions. A few of our important findings include:
1) a novel screen to identify new Xanthomonas T3S effector proteins translocated into plant cells during infection
2) demonstrating that the XopN effector suppresses basal defense and physically interacts with a new tomato receptor kinase associated with basal immunity
3) demonstrating that the XopD effector is a plant-specific SUMO protease that represses host transcription, promotes pathogen growth, and suppresses host defense responses at the late stages of tissue colonization
4) identifying new proteins that control phospholipid signaling and disease resistance responses following AvrBsT perturbation
Publications
- Xanthomonas type III effector XopD desumoylates tomato transcription factor SlERF4 to suppress ethylene responses and promote pathogen growth. Cell Host Microbe. 2013; (2): 143-54
- Regulation of cell wall-bound invertase in pepper leaves by Xanthomonas campestris pv. vesicatoria type three effectors. PLoS One. 2012; (12): e51763
- Tomato TFT1 is required for PAMP-triggered immunity and mutations that prevent T3S effector XopN from binding to TFT1 attenuate Xanthomonas virulence. PLoS Pathog. 2012; (6): e1002768
- Comparative analysis of the XopD type III secretion (T3S) effector family in plant pathogenic bacteria. Mol Plant Pathol. 2011; (8): 715-30
- Sugar transporters for intercellular exchange and nutrition of pathogens. Nature. 2010; (7323): 527-32
- SOBER1 phospholipase activity suppresses phosphatidic acid accumulation and plant immunity in response to bacterial effector AvrBsT. Proc Natl Acad Sci U S A. 2009; (48): 20532-7
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