Judith P. Sinn

  • Senior Research Assistant
Judith P. Sinn
320 Buckhout Lab (office)
307 Buckhout Lab (lab)

University Park, PA 16802
Work Phone: 814-863-7399
Fax: 814-863-7217

Areas of Expertise

  • Molecular biology
  • Plant bacteriology
  • Development of novel controls for citrus greening and fire blight
  • Genetics of virulence and auxotrophy in Erwinia amylovora


  1. B.S., Environmental Resource Management, Penn State
  2. M.S., Plant Pathology, Penn State

Program Interests

As Senior Research Assistant in Dr. Tim McNellis' lab, my research focuses on host and pathogen genes and proteins involved in bacterial disease processes. We employ molecular and genetic tools to elucidate mechanisms contributing to host susceptibility and pathogen virulence.  Current work includes mutational studies with Erwinia amylovoraPantoea ananatis, and Xanthomonas campestris pv pelargoniia, causal agents of fire blight of pome fruits, center rot of onion, and bacterial blight of geranium, respectively, and a project involving citrus greening disease (huánglóngbìng), caused by Candidatus Liberibacter.


Ramos, L.S., Sinn, J.P., Lehman, B.L., Pfeufer, E.E., Peter, K.A., and McNellis, T.W. (2015) Erwinia amylovora pyrC mutant causes fire blight despite pyrimidine auxotrophy. Letters in Applied Microbiology 60: 572–579. 

Ramos, L. S., Lehman, B. L., Sinn, J. P., Pfeufer, E. E., Halbrendt, N. O., and McNellis, T. W. (2013) The fire blight pathogen Erwinia amylovorarequires the rpoN gene for pathogenicity in apple.  Molecular Plant Pathology 14:838-843

Lee, S. A., Ngugi, H. K., Halbrendt, N. O., O'Keefe, G., Lehman, B., Travis, J. W., Sinn, J. P., and McNellis, T. W. 2010. Virulence Characteristics Accounting for Fire Blight Disease Severity in Apple Trees and Seedlings. Phytopathology 100:539-550.

Sinn, J. P., Oh, C. S., Jensen, P. J., Carpenter, S. C. D., Beer, S. V., and McNellis, T. W. 2008. The C-terminal half of the HrpN virulence protein of the fire blight pathogen Erwinia amylovora is essential for its secretion and for its virulence and avirulence activities. Molecular Plant-Microbe Interactions 21:1387-1397.

Sinn, J. P., Schlagnhaufer, C. D., Arteca, R. N., and Pell, E. J. 2006. Ozone-induced ethylene and foliar injury responses are altered in 1-aminocyclopropane-1-carboxylate synthase antisense potato plants. New Phytologist 164:267-277.

Taylor, M. D., Sinn, J. P., Davis, D. D., and Pell, E. J. 2002. "The impact of ozone on a salt marsh cordgrass (Spartina alterniflora)." Environmental Pollution 120: 701-705.

Pell, W. J., Sinn, J. P., Brendley, B. E., Samuelson, L., Vinten-Johansen, C., Tien, M. and Skillman, J. 1999. "Differential response of four tree species to ozone-induced acceleration of foliar senescence." Plant, Cell and Environment 22:779-790.

Pell, E. J., J. P. Sinn, and C. Vinten Johansen. 1995. "Nitrogen supply as a limiting factor determining the sensitivity of Populus tremuloides Michx. to ozone stress." New Phytologist 130:437-446.

Pell, E. J., Sinn, J. P., Eckardt, N., Vinten Johansen, C., Winner, W. E., and Mooney, H. A. 1993." Response of radish to multiple stresses: Influence of season and genotype on plant response to ozone and soil moisture deficit." New Phytologist 123:153-163.

Campbell, C. L., Bruck, R. I., Sinn, J. P., and Martin, S. B. 1988. Influence of acidity level in simulated rain on disease progression in four plant pathosystems. Environmental Pollution 53:219-234.

Sinn, J. P., and Pell, E. J. 1984. Impact of repeated nitrogen dioxide exposures on composition and yield of potato foliage and tubers. J. Amer. Soc. Hort. Sci. 109:481-484.

Sinn, J. P., Pell, E. J., and DeCaria, A. 1984. A nitrogen dioxide generating system for use in air pollution research. Agricultural Experiment Station Progress Report 382, The Pennsylvania State University, University Park, PA

Sinn, J. P., Pell, E. J., and Kabel, R. L. 1984. Uptake of nitrogen dioxide by potato plants. APCA Journal 34:668-669.