Research Area

Molecular genetics of plant-microbe interactions and pathogen detection

Description of Research

A major focus of the research in my laboratory is directed towards understanding the biology of the interaction between small grain cereal host species, primarily barley and wheat, and smut and bunt pathogens. Germane to these processes are genes that function in dimorphic switching from a yeast-like, budding form of the fungus, to the filamentous, pathogenic form. We have cloned one of the genes involved in switching from Ustilago hordei and demonstrated that it encodes an alpha subunit of a heterotrimeric G protein. Its role in a cyclic AMP-mediated signal transduction pathway which functions to control dimorphic switching and pathogenicity is under investigation. To assist the potato industry in the identification of Clavibacter michiganensis subsp. sepedonicus, the causal agent of bacterial ring rot disease of potato, we have developed a PCR ELISA-based detection assay that is based on the amplification of multiple sites in the genome of this pathogen. Research is underway to evaluate the system in field and clinic environments.

Research Group Members

Faculty Research Assistants/Associates

Asa Preston

Courses

BOT 664 Fungal Genetics

BOT 692 Selected Topics: Plant Pathology

Related Publications

Loubens, M., G. Richter, D. Mills and J.P. Bohin. 1992. A pathogenicity gene of Pseudomonas syringae pv. syringae complements a defect in periplasmic glucan biosynthesis in Escherichia coli K-₁₂. Pages 491-496 in Lemattre, M. et al. (eds), Plant Pathogenic Bacteria. INRA editions.

Mills, D. and J. Agnan. 1994. Cyclic AMP regulates the dimorphic switch in Ustilago hordei. Pages 247-250 in Daniels, M.J. et al. (eds), Advances in Molecular Genetics of Plant-Microbe Interactions. Kluwer Academic Publishers.

McCluskey, K., J. Agnan and D. Mills. 1994. Characterization of genome plasticity in Ustilago hordei. Current Genetics 26:486-493.

Mills, D. J, Agnan and K. McCluskey. 1996. Cyclic AMP controls dimorphic switching of Ustilago hordei. pp 83-92 in Molecular Aspects of Pathogenicity and Resistance : Requirement for Signal Transduction, D. Mills et al (eds). APS Press, St. Paul, MN.

Mills, D., B.W. Russell, and J. Williams Hanus, 1997. Specific detection of Clavibacter michiganensis subsp. sepedonicus by polymerase chain reaction primers that amplify three unique DNA sequences isolated by subtraction hybridization. Phytopathology 87:853-861.

Lichter, A. and D. Mills.1997. FIL1, a G-protein a subunit that mediates dimorphic switching of Ustilago hordei. Mol Gen Genet 256:426-435.

Lichter, A. and D. Mills. 1998. Control of pigmentation of Ustilago hordei: The effect of pH, Thiamin and involvement of the cAMP cascade. Fungal Genet and Biol 25:63-74.