The Department of Plant Pathology, Entomology and Microbiology at Iowa State University hosted a Ph.D. exit seminar on March 3 as part of the Spring Seminar Series. Marissa Roghair Stroud presented her research titled “Investigation of the genetic and molecular mechanisms of maize rhizosphere colonization by Pseudomonas putida using CRISPR interference and synthetic microbiomes.”
During the seminar, Roghair Stroud discussed the critical role that microbiomes play in plant health and growth. The rhizosphere, the narrow region of soil influenced by plant roots, contains diverse microbial communities that can support plant development, protect plants from pathogens, and influence nutrient availability. However, scientists are still working to understand how microbial genes and interactions shape the formation and stability of these communities.
Roghair Stroud and her collaborators developed the MAize Rhisozphere Synthetic Community (MARSc), a microbial community designed to model and study interactions among microbes. This system allows researchers to systematically analyze how microbial species interact with one another and with plant roots in controlled conditions.
A key component of Rohair Stroud’s research involved applying CRISPR interference (CRISPRi) to study gene function in the bacterium Pseudomonas putida. Using this approach, she identified genes essential for rhizosphere colonization, microbial interactions, and biofilm formation. These insights help reveal how bacteria establish themselves on plant roots and participate in complex microbial communities.
The seminar highlighted how combining synthetic microbiomes with advanced genetic tools provides powerful new ways to study plant-microbe interactions. By identifying the genetic mechanisms that allow beneficial microbes to colonize plant roots, this research may ultimately contribute to strategies that improve crop productivity and sustainability.