Joanne Emerson

Joanne Emerson

Position Title
Assistant Professor

Plant Pathology


Emerson, an assistant professor in the Department of Plant Pathology, specializes in viral communities in soil. Emerson completed her Ph.D. in Earth and Planetary Science at UC Berkeley and conducted postdoctoral research at the University of Colorado at Boulder, the University of Arizona and The Ohio State University before joining the faculty at UC Davis in 2017.

Research interests:

Viral communities, microbial ecology, soil and plant viral ecology, carbon and nutrient cycling, biogeochemistry, greenhouse gas emissions, agricultural productivity, plant health and disease

Brief overview:

I study soil and plant-associated viruses. Soil harbors an incredible abundance and diversity of viruses that infect bacteria, fungi, plants and other organisms. I am working to discover new viruses and understand their impacts on soil and plant health. 

Viruses can cause disease and mortality, and they also significantly influence ecosystem ecology and environmental chemistry. For example, viruses kill about 30 percent of the bacteria in the oceans every day, which affects the flow of carbon and nutrients to marine organisms both large and small. Viruses are likely to have similar ecological impacts in soil, but we know very little about soil viruses. My lab is working to bridge that knowledge gap to promote healthy soil ecosystems. We use genomic and computational approaches to discover what viruses are present in different soils, what organisms they infect, how they impact their hosts, and how they affect carbon cycling and plant health and productivity. 

Current projects:

  • Comparing virus-microbe-plant ecology in a variety of soils associated with healthy and diseased crops to uncover viral impacts on ecological responses to biocontrol agents, organic farming practices, biochar and changing environmental conditions
  • Recovering RNA viral communities from soil and plant tissues to discover new viruses and potential emerging plant pathogens
  • Assessing the relative proportions and ecological implications of two primary viral lifestyles—one results in host mortality and the other can be a persistent infection—to promote a better understanding of healthy soils