Overall Research Project Description The microbiome, a collection of symbiotic microbes within and on a host, has broad implications, ranging from human health to ecosystem balance and sustainable agriculture. Both plants and animals rely on a healthy microbiome for growth and fitness. Maintaining a healthy microbiome is vital for survival, as an unhealthy microbiome reduces fitness and can even lead to death. Creating a healthy microbiome involves controlling pathogens while nurturing beneficial microbes. Yet, pathogens and beneficial microbes are often very similar and distinguishing between them is challenging, even with advanced techniques. The immune system likely plays a role, but the details are complex and unclear.

While mammals employ two immune strategies, plants offer a simpler model to study immune-microbe interactions due to their possession of only one, akin to ours. Contrary to the animal gut, plant roots are externally colonized by microbes, allowing easier live studies on an intact organism. Therefore, the Thoms lab uses plant roots to investigate how immunity discerns pathogenic and beneficial bacteria and shapes bacterial growth based on their lifestyles. To identify how immunity distinguishes between bacterial lifestyles, you will use a model system composing of the plant root, a pathogen, and a beneficial strain. We have found that this pathogen induces a novel potent immune response, while the beneficial does not. Working in teams of two, you will use immune assays to perform a classic forward genetic screen. You will screen through plant mutants to identify candidates that are unable to induce an immune response to the pathogen. The candidate mutants will be full genome sequenced to identify the mutated genes and to discover the novel immune pathways required for distinguishing friend from foe.