Sentinel Molecular Diagnostics for

Crop Agroterrorism


Dr. Joe Eugene Lepo

Center for Environmental Diagnostics and Bioremediation

University of West Florida, Pensacola


Tuesday, April 24th, at 4:30 5:30 p.m.

Ruhl Student Center, Community Room




            Crop disease is of major economic concern in the United States. Whether the disease is a natural occurrence or intentionally spread as an act of agroterrorism, methods that detect the introduction of the phytopathogens are essential to containment of the disease and ultimately saving the crop. We are developing a suite of molecular diagnostics, coupled with other approaches that will provide sentinel information for control and mitigation of crop agroterrorism. Iraq is suspected of delivering aflatoxin during the 1991 Gulf War; plants may serve as for delivery vectors for human and/or animal pathogens; and historical events emphasize the economic and sociological risk of agroterrorism events. For instance, Aspergillus-infested grain killed 100,000 turkeys in England; the Irish potato famine of 1845 killed 1 million Irish and prompted 1.5 million to emigrate; Dutch elm and American chestnut diseases have all but eliminated these trees.

            We have focused on fungal and bacterial epiphytic symbionts using molecular methods such as length heterogeneity polymerase chain reaction (LHPCR) and quantitative PCR (QPCR). One current focus of our research is to apply these methods to diagnostics for the recent invasion of the U.S. mainland by soybean rust fungi (Phakopsora pachyrhizi and P. meibomiae). We successfully detected rust fungi on soybeans in Northwest Florida prior to disease symptoms but post-Hurricane Ivan; the molecular tools did not detect the fungus on soybeans prior to Hurricane Ivan. We have developed PCR methods for detection of biosynthetic metabolic pathways in Aspergillus spp. that may produce aflatoxin; we are applying these to survey stored grains that are used for seed, as well as for animal and human food.

            Recent field studies by the CEDB agroterrorism research team allowed evaluation of diagnostics based on background patterns for epiphytic fungi and bacteria under controlled testing conditions. We are applying what we learned from two field seasons to focus on specific subsets of epiphytic organisms (e.g., fluorescent pseudomonads, members of Domain Archaea) as diagnostics for a variety of plant stressors. Collaborative work with Montana State University has explored plant response to physical and chemical stressors using DNA microarrays that can assess up-regulation or down-regulation of expression of a wide variety of genes.

            This presentation will survey the significant results and proposed directions of the agroterrorism diagnostic research conducted by the University of West Florida, CEDB research team.



This research was funded through contract DAAD13-01-C-0043, sub- agreement 6402-1000-00 from the University of South Florida, Center for Biodefense and the U.S. Department of Defense, Research Development and Engineering Command (RDECOM).






Dr. Joe Eugene Lepo is an Associate Professor of Microbiology at the University of West Florida (UWF) in the Department of Biology and the Center for Environmental Diagnostics and Bioremediation (CEDB).  He has been the Technical Director for the CEDB, Wetlands Research Laboratory since 1997.  Prior to arriving at UWF in 1991, Dr Lepo held faculty positions at University of Mississippi and as senior research scientists in industry.  His accolades include a Fulbright Fellowship at University of Helsinki, Finland, UWF Research and Creative Activities Award, and the UWF Million Dollar Research Club.  Dr. Lepo teaches undergraduates introductory microbiology, microbial physiology, microbial ecology, and a variety of special topics courses.  Dr. Lepo has mentored both undergraduate and graduates student research in topics including his recent work on crop bioterrorism and fungal pathogens, as well as, oil spill bioremediation, estuarine water quality and microbial ecology, and nitrogen fixation in legume root-nodulating Rhizobiales.  His interests and hobbies include writing, music, audio, home theater, guitar, literature, language, philosophy, running, snow skiing, swimming, bicycling, and microcomputer applications.