Through a mechanism called quorum sensing, bacteria are able to sense and respond to changes in their environments. They are also able to sense if they are alone or in groups. When bacterial numbers rise to high levels, they begin expressing genes for group activities. Group activities, like bioluminescence or toxin secretion, are energetically expensive, thus it is very important that they are highly regulated. I study how bioluminescence is regulated and what the evolutionary costs of expressing these genes are. Click the link below to learn more about the work my lab does! Picture is by the van Kessel lab!

When bacteria infect plants, they upregulate hundreds of genes and turn off expression of hundreds more. Without a “brain” it is quite impressive how bacteria can sense and respond to changes in their environments. How do bacteria know they are inside a plant? What are the minimal set of genes required to remain infectious? Through my research, I sought to answer questions like these utilizing reverse genetics approaches. Ultimately, I was very fascinated by how bacteria regulate expression of their genes under various conditions. Read more about the work my lab did by clicking the link below!

Fungi commonly infect crops, causing millions of dollars in agricultural damage each year. The development and usage of fungicides have been a major advancement in agriculture, as they prevent fungal pathogens from infecting plants. Overuse of fungicides has created a selective pressure for fungal pathogens, helping them evolve and develop resistance quicker. Fungicide resistance is becoming commonplace and poses a huge threat to the agricultural industry. Through my research I identified what fungicides were losing potency and how the fungal pathogen evolved to develop resistance. Read more about it by clicking the link below!

I presented my poster titled “Utilization of reverse genetics and fungicide sensitivity assays to study pathogens of two agronomic crops” through the VT-REEL fellowship at the summer 2018 Virginia Tech Office of Undergraduate Research Summer Symposium. Click the link below to read my abstract!

I presented my poster titled “Determining the role of iscR during Pantoea stewartii infection of corn through reverse genetics and plant assays” at the ASM Virginia Branch Meeting in Fall 2018 (pictured above) and also Virginia Tech Department of Biological Sciences Research Day Spring 2019. Click the link below to read my abstract!

I presented my posted titled “Determining the role of iscR during Pantoea stewartii infection of corn through reverse genetics and plant assays” at the APS Potomac Division Meeting in Spring 2019! Click the link below to read my abstract.

Bartholomew, H.P., Reynoso, G., Thomas, B.J., Mullins, C.M., Smith, C., Gentzel, I.N., Giese, L.A., Mackey, D.M., Stevens, A.M. (2021). The transcription factor Lrp of Pantoea stewartii subsp. stewartii controls capsule production, motility and virulence important for in planta growth. Frontiers in Microbiology. In press.

Kaur, N., Mullins, C., Kleczewski, N. M., & Mehl, H. L. (2021). Occurrence of Quinone Outside Inhibitor Resistance in Virginia Populations of Parastagonospora nodorum Infecting Wheat. Plant disease. PDIS-11.

Mullins, C., Packard, H., & Stevens, A.M. (2019). Determining the role of iscR during Pantoea stewartii infection of corn through reverse genetics and plant assays. Phytopathology (Vol. 109, No. 9).