Molecular Ecology

Use of molecular techniques to identify non-culturable microbes has revolutionized microbial ecology. While most of this work has focused on prokaryotes, studies of microscopic eukaryal (protist) molecular ecology are also helping understand how gene abundance, regulation, and flow contribute to structuring microbial assemblages, metabolism, and environmental impact. Much of my lab is set up for this work, which is of interest to students who want to learn molecular biology techniques and apply them to problems of ecology.

I am working in two areas: protist genetic diversity in extreme environments, and plant-microbe interactions.

Genetic Diversity of protists in acid hydrothermal systems:
Lassen Volcanic National Park

In spring 2005, my graduate student Patty Brown presented her work at the American Society for Microbiology meeting in Atlanta, and received her M.S. degree. Her work was supported by a grant from Sigma Xi and is now in press at J. Eukaryotic Microbiology.

Poster Presented at ASM, 2005

Survey of Protist Genetic Diversity in the Hydrothermal Environments of Lassen Volcanic National Park N-063

Click on the thumbnails for full-sized photos.

LVNP hydrothermal systems

Isolation of Cyanidium-like algae from Boiling Springs Lake

Mary Ellen Sanders, Isolation of Cyanidium-like algae from BSL
Link to M.E.S.'s poster

Currently, I am collaborating with Drs. Patty Siering and Mark Wilson (Humboldt State Univ.) and Ken Stedman (Portland State Univ.). We have chosen Boiling Springs Lake as the site for a possible NSF Microbial Observatory, to study integrated eukaryotic, prokaryotic and viral diversity and dynamics. Although we have not received funding so far, we are continuing pilot studies and hope to resubmit. Engineering students at PSU are currently building a remotely operated vehicle to sample BSL waters.

Photos of BSL

Response of root-associated (rhizosphere) bacteria to plant defense gene expression

csuperbDr. Kris Blee, CSUC, and I are interested in how plant defense gene expression might affect bacterial populations in the root environment, or rhizosphere. John Hein’s master’s thesis investigated the possibility that entire soil microbial communities can be selectively altered by manipulated expression of the plant defense pathway systemic acquired resistance (SAR). SAR is a broad scale systemic defense response against necrotizing bacterial, fungal, and viral pathogens. The ABI 310 genetic analyzer allows us to use terminal restriction fragment length polymorphism (T-RFLP) analysis as a tool to measure bacterial community structure. We are attempting to determine whether or not communities from the same initial soil can be altered by the presence of Arabidopsis thaliana plants that are either constitutive mutants for SAR, or that lack this defense altogether.

J. Hein received his M.S. degree in Spring 2006. His research is in press as of July 2007; please e-mail me for a copy of the manuscript.