Raymond
J. St. Leger
| Ph.D.
- Bath University, 1985 |
| Professor |
| Department
of Entomology |
| 4112 Plant
Sciences Building |
| University
of Maryland |
| College
Park, MD 20742-4454 |
| Telephone:
(301)-405-5402 |
| E-mail:
rl106@umail.umd.edu |
| Research
Interests: The evolution of host pathogen interactions. |
Research activities in Dr. St. Leger's laboratory have utilized the
insect pathogen Metarhizium anisopliae as a model fungus and the process
of differentiation of infection structures as a clearly defined developmental
system in order to examine the regulation and biochemical function of specific
changes in gene expression. This model provided tools to study signal
transduction pathways, pathogenicity, and to recognize the genes responsible
in many fungal/animal interactions-including those between fungi and human
or plant hosts. Identification of infection-specific genes has provided
a unique and innovative opportunity to determine whether the use of fungal
pathogenic proteins in various systems could provide a route for formulating
new products for crop protection. We have used fungal genes encoding
insecticidal toxins to produce recombinant fungi and viruses that have
improved pathogenic properties against insect pests. Among current
efforts, we are collaborating with scientists at the Colombian Coffee Federation
and the Noble Foundation (OK) in testing a multitude of fungal proteins
as candidates for producing pest-resistant transgenic crop plants.
Selected
Publications:
St. Leger, R.J., Joshi, L., Bidochka, M.J. and Roberts, D.W.,
1996. Construction of an improved mycoinsecticide overexpressing a toxic
proteace. Proc. Natl. Acad. Sci. USA 93:6349-6354.
St. Leger, R.J., Joshi, L. and Roberts, D.W., 1997. Adaptation
of proteases and carbohydrases of saprophytic, phytopathogenic and entomapathogenic
fungi to the requirements of their ecological niches. Microbiology
143:1983-1992.
St. Leger, R.J., Screen, S.T., and Shams-Pirzordeh, B. 2000. The
opportunism of Aspergillus flavus. Applied and Environmental Microbiology.
66:320-324.
Screen, S.E. and St. Leger, R.J. 2000. Cloning, expression
and substrate specificity of a fungal chymotrypsin. J. Biol. Chem.
275:6689-6694.
St. Leger, R.J. and Screen, S.T. 2000. In vitro utilization
of mucin, lung polymers, plant cell walls and insect cuticle by Aspergillus
fumigatus, Metarhizium anisopliae and Nectria haematococca.
Mycol. Research 104:463-471.
St. Leger, R.J. and Screen, S. 2001. Prospects for strain improvement
of fungal pathogens of insects and weeds. In: Fungal biocontrol
agents: Progress, problems and potential. Butt, T.M., Jackson,
C., and Morgan, N., editors. CAB International, pp. 219-238.
St. Leger, R.J. 2001. Development and testing of genetically improved
mycoinsecticides. In: Enhancing biocontrol agents and handling
risks. J. Gressel, T. Butts, G. Harman, A. Pilgeram, R. St. Leger
and D. Nuss, editors. Proceedings of a NATO Advanced Research Workshop,
June 9-15, 2001. Published (for NATO) by IOS Press. Amsterdam, The
Netherlands. pp. 229-239.
Return
to Research Index
St. Leger, R.J., Frank, D.C., Roberts, D.W. and Staples, R.C. 1992. Molecular
cloning and regulatory analysis of the cuticle-degrading protease structural
gene from the entomopathogenic fungus Metarhizium anisopliae. Eur. J. Biochem.
204: 991-1001.
St. Leger, R.J., May, B., Allee, L.L., Frank, D.C. and Roberts, D.W. 1992.
Genetic differences in allozymes and in formation of infection structures
among isolates of the entomopathogenic fungus Metarhizium anisopliae. J.
Invertebr. Pathol. 60: 89-101.
St. Leger, R.J., Staples, R.C. and Roberts, D.W. 1992. Cloning and regulatory
analysis of ssgA: A gene encoding a hydrophobin-like protein from the entomopathogenic
fungus, Metarhizium anisopliae. Gene 120: 119-124.
Bidochka, M.J. S.R.A. Walsh, M.E. Ramos, R.J. St. Leger, J.C. Silver and
D.W. Roberts. 1995. Fate of biological control introductions: Monitoring
an Australian fungal pathogen of grasshoppers in North America. Proc. Natl.
Acad. Sci. USA 93: 918-921.
St. Leger, R.J.,and Bidochka, M.J. 1996. Insect-fungal interactions. In:
Invertebrate Immunology (Soderhall, K., Vasta, G., and lwanaga, S., eds.)
SOS Publications. 443--479.
St. Leger, R.J., Joshi, L., Bidochka, M.J., and Roberts, D.W. 1996. Characterization
of chitinases from Metarhizium anisopliae, M. falvoviride and Beauveria
bassiana, and ultrastructural localization of chitinase production during
invasion of insect cuticle. Appl. Environ. Microbiol. 62: 907-912.
St. Leger, R.J., Joshi, L., Bidochka, M.J., and Roberts, D.W. 1996. Construction
of an improved mycoinsecticide over-expressing a toxic protease. Proc.
Natl. Acad. Sci. USA 93: 6349-6354.
St. Leger, R.J., Joshi, L. and Roberts, D.W. 1997. Adaptation of proteases
and carbohydrases of saprophytic, phytopathogenic and entomopathogenic
fungi to the requirements of their ecological niches. Microbiology 143:
1983-1992.
St. Leger, R.J., Joshi, L., and Roberts, D. 1998. Ambient pH is a major
determinant in the expression of cuticle-degrading enzymes and hydrophobin
by Metarhizium anisopliae. Applied and Environmental Microbiology 64: 709-713.
Joshi, L. and St. Leger, R.J. 1999. Cloning, expression and substrate specificity
of MeCPA; a Zn-carboxypeptidase that is secreted by an insect pathogenic
fungi into infected tissues. J. Biol. Chem. 274: 9803-9811
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Instruction
ENTM 788, Insect Pathology & Biotechnology
CPSP 218L, Biotechnology
BIOL 105
