PSU Plant Pathology Association

Featured Member: Li Guo

I come from Mainland China and have been studying in Penn State's Plant Pathology Department since 2006. I received my Bachelor's degree in Plant Protection from Northwest Agricultural and Forestry University in China; now, I'm doing my Ph.D. research with Dr. Gretchen Kuldau on genetics of a fungus, Fusarium verticillioides, and its interaction with maize plants. F. verticillioides causes ear rot, stalk rot and seedling blight of corn worldwide and produces fumonisin mycotoxins. Fumonisins cause several fatal animal diseases and are associated with human neural tube defects and esophageal cancer. The primary objective of my research is to understand the genetic basis of the fungal development and the pathogenicity of F. verticillioides on the host plant. Using a combination of molecular genetics and genomic approaches, I'm studying the functions of several fungal genes in F. verticillioides during the fungal in vitro and in planta growth and figuring out how the fungus forms pathogenic and endophytic relationships with host plants in molecular levels. For example, one of these genes contributes to fungal vegetative growth and pathogenicity by regulating reactive oxygen species production in F. verticillioides. I'm also using a technique called promoter trapping to identify F. verticillioides genes that are specifically expressed when the fungus causes diseases or endophytically colonize maize plants. By looking at these gene functions, I'm hoping to gain an understanding of some underlying mechanisms of the disease expression and fungal endophytic growth on maize plants, which will help us mitigate both the disease and fumonisin accumulation in corn production.