Influence of cell-cell signaling on microbial colonization of alternate hosts
Vector-transmitted microbes cause many diseases that threaten human health and agricultural production. Vector transmitted microbes have complex but poorly understood density dependent cell-cell communication signals that alter trait expression to increase survival in different environments and to switch between hosts. To address this shortcoming, this project investigates the production of cell-cell communication signals by Xylella fastidiosa, an obligately insect transmitted plant pathogen, in response to host-specific chemical cues from plants and insects, and characterizes induced changes in microbial phenotype and consequences for insect vector and host plant colonization. X. fastidiosa has a reduced genome (~2.5Mb) and is only known to persist in plant xylem and leafhopper vector foregut, two environments composed of polysaccharides that are replicable in the lab. These factors make this natural system an ideal model for understanding regulation of complex microbial traits in alternate hosts and how these relate to transmission dynamics and broader disease epidemiology.
Training objectives are to learn experimental methods for characterizing induced microbial phenotypes and computational methods to describe the underlying transcriptional changes. The project aims to increase participation in biology in the affected agricultural community, on the UC Berkeley campus, and with K-12 students at local schools. Locally, on-farm presentations will focus on biological factors mediating pathogen transmission and how to minimize the amount of conventional pesticides used. Undergraduate researchers will be recruited through the Cal Women in Science and Engineering (WISE) program and trained in methods in microbiology, insect biology, and genomics. Curricula will be developed and presented at local schools focused on evaluating microbial biology issues in health and agriculture. The results generated from this project will be summarized in accessible language on the Xylella fastidiosa website (www.cnr.berkeley.edu/xylella/) which is freely accessible to the public.
