Protocol Development for Enhanced DNA Visualization in the California Bay Laurel

Abstract

California native plants provide a promising alternative to traditional model systems to study chromosome organization. While observational field studies exist for detecting and quarantining the pathogen Phytophthora ramorum (P. ramorum), there is a lack of molecular tools to understand the pathogen and its foliar host, the California Bay Laurel (Umbellularia californica). P. ramorum is an invasive oomycete eukaryotic microorganism that is a pathogenic agent for the disease, Sudden Oak Death (SOD). This pathogenic agent is a cause for concern as it is responsible for the death and dramatic decline in coastal tanoak tree populations. In coastal rural regions, P. ramorum is a risk against the ongoing efforts of preservation of biodiversity, as 14% of Sonoma County has been affected by SOD. Observing chromosomes in vivo of U. californica is needed to develop molecular protocols for non-traditional host organisms. Our project aims to refine a histological DNA staining protocol for staining U. californica’s chromosomes. This will provide the basis for future work to investigate the effects of P. ramorum on chromosomal organization in normal and infected states of the Bay Laurel. By using the Bay Laurel as a new model system to study native host-pathogen interactions, it will allow us to unravel the molecular mechanisms of infection and develop strategies to protect California’s threatened coastal forest populations from SOD.

Results

Key Terms: pathogen, Phytophthora ramorum, California Bay Laurel (Umbellularia californica), Sudden Oak Death (SOD), coastal tanoak, biodiversity, Sonoma County, chromosomes, histological DNA staining protocol