Past PMB Seminars
For a schedule of all Plant & Microbial Biology events, seminars, and lectures visit our calendar.
How plant cells measure themselves and why it matters
Across biological kingdoms, cell size has important developmental and physiological roles, but its regulation remains unclear [1]. In the Arabidopsis shoot stem cell niche, cell size is one of the features that is maintained in a steady state over long periods of cell proliferation. We have found that meristem cell size is maintained by a feedback between cell growth and cell cycle progression...
Bacterial threat assessment of bacteriophage infection
Monitoring the extracellular environment for danger signals is a critical aspect of cellular survival. However, the danger signals released by dying bacteria and the mechanisms bacteria use for threat assessment remain largely unexplored. Here,we show that lysis of Pseudomonas aeruginosa cells releases polyamines that are subsequently taken up by surviving cells via a mechanism that relies on...
Tsujimoto Lecture: Deciphering the human gut microbiome with chemistry
The human body is colonized by trillions of microorganisms that exert a profound influence on human biology, in part by providing functional capabilities that extend beyond those of host cells. In particular, there is growing evidence linking chemical processes carried out by the human gut microbiome to diseases such as colorectal cancer. However, we still do not understand the vast majority of...
Engineering the mycobacterial cell envelope
The Siegrist lab studies the cell envelope, an essential interface between a bacterium and its surroundings. This dynamic structure accommodates growth and division while protecting against environmental insults. Because it is necessary for viability and composed of molecules that are not present in eukaryotic cells, the bacterial envelope has been a fruitful target for antibiotics. We focus on...
Flexible plant development for a changing world
Plants may respond to environmental stimuli by modifying their development. As the major organs of photosynthesis, leaves must regulate their size, position, and gas-exchange capacity to adapt and compete. Stomata, microscopic valves on the surface of plants, are essential for the regulated exchange of carbon dioxide from the atmosphere with water vapor from inside the plant. Asymmetric cell...
Adaptation strategies in a clonally evolving fungal pathogen
A hallmark of fungal pathogens is the ability to dynamically re-shape their growth and metabolism during the interaction with the host. The infection process is driven by rapid responses in cell signaling and gene expression as well as by long-term changes in genome structure. Understanding the molecular basis of this remarkable cellular and genetic plasticity is critical to control fungal...
Decolonizing Botany
What does it mean to practice biology as a feminist? Tracing the colonial roots of botany, I re-imagine a more inclusive and capacious field of botany untethered and decentered from its origins in histories of racism, slavery, and colonialism. Drawing on recent scholarship in the biological sciences, , indigenous, postcolonial and feminist Science and Technology Studies (STS), I show how gender, race, class, sexuality, and nation shape the foundational language, terminology, and theories of modern botany, and how botany remains grounded in the violence of its colonial pasts. "Decolonizing Botany" is a project that reckons with these difficult origins and lays a roadmap to imagine a new feminist botany that harnesses the power of feminist thought to reimagine the practices of experimental biology.
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Bacteria to Beetles: Microbial Specialized Metabolism across Biological Scales
Microbes are incredible biochemists, capable of producing a vast array of specialized molecules whose activities have been honed over evolutionary time. These microbial natural products, also called ‘secondary’ or ‘specialized’ metabolites, revolutionized the treatment of bacterial, fungal, and helminthic infections, and have seen wide use as anti-cancer drugs and immunosuppressants. Despite our medical dependence on these molecules, our knowledge of the ecology of these specialized metabolites, i.e. how they function in natural settings, is extremely limited. The goals of my research program are to understand the drivers and roles of specialized metabolism across biological scales, and to use this knowledge to inform discovery of novel natural products. In this talk, I will discuss our efforts ranging from understanding specialized metabolism by specific cells within colonies of single microbes to specialized metabolism occurring in diverse microbial environments on a continental scale.
Hormone-induced cell fate reprogramming during plant regeneration
Shoot regeneration has been widely used for generation of genetically modified major crops such as rice, maize and wheat. Despite recent achievements in the development of genome editing tools based on the CRISPR-Cas9 technology, the future crop design is limited by current methods of improving shoot regenerative capacity. We are now using molecular genetic tools to understand how auxin and...
[POSTPONED] Metatranscriptomic analysis uncovers prevalent viral ORFs compatible with mitoribosomal translation in environmental samples
The genetic diversity of eukaryotic RNA viruses is poorly described, due to sparse sampling and biases towards pathogens that impact human health or commercial agriculture. Positive single-stranded RNA viruses exhibit a distinct ability to restructure the endomembranes of host cells to facilitate their propagation. Mitochondria in particular are attractive targets for viral replication, given...