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United States Department of Agriculture

Agricultural Research Service

Title: Protein Profiles and Antifungal Activities of Kernel Extracts from Corn Genotypes Resistant and Susceptible to Aspergillus Flavus

Authors
item Guo, Baozhu
item Brown, Robert
item Lax, Alan
item Cleveland, Thomas
item Russin, J. - LOUISIANA STATE UNIV.
item Widstrom, Neil

Submitted to: Biochemistry and Biophysics Research Communication
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 24, 1997
Publication Date: N/A

Interpretive Summary: The fungus Aspergillus flavus produces a poison called aflatoxin when it infects corn. Aflatoxin contamination of food and feeds made from corn is a serious problem that threatens human and animal health. Developing strategies to reduce or eliminate aflatoxin contamination has become a priority in recent years. Many approaches have been explored, including cultural and biological control practices, control of kernel-feeding insects using insecticides, and chemical and physical detoxification of grain. Host-corn resistance is the best way to solve this problem. Our efforts have been focusing on enhancing host resistance. Mechanisms of resistance to infection by the fungus and accumulation of aflatoxin were studied using kernels of resistant and susceptible corn genotypes. Proteins from kernel extracts of corn genotypes were analyzed using several methods of polyacrylamide gel electrophoresis. Consistent differences in protein profiles were detected. Several proteins were unique to, or present in greater concentration in, resistant genotypes. Extracts of resistant kernels showed markedly greater antifungal activity against A. flavus and two other fungi, Fusarium oxysporum f.sp. lycopersici and F. moniliforme than did susceptible kernel extracts. Results from this study suggest a role for kernel proteins in resistance to A. flavus infection and aflatoxin contamination, and in the future it may be interesting to investigate the gene regulation for these proteins.

Technical Abstract: Mechanisms of resistance to infection by the fungus Aspergillus flavus and accumulation of aflatoxin were studied using kernels of resistant (GT-MAS:gk, Mp420) and susceptible (Pioneer 3154, Deltapine G-4666) corn genotypes. Proteins from kernel extracts of corn genotypes were analyzed using several methods of polyacrylamide gel electrophoresis. Consistent differences in protein profiles were detected among genotypes. Several proteins were unique to, or present in greater concentration in, resistant genotypes, whereas others were present only in susceptible genotypes. Extracts of resistant kernels showed markedly greater antifungal activity against A. flavus and two other fungi, Fusarium oxysporum f.sp. lycopersici and F. moniliforme than did susceptible kernel extracts. Results from the present study suggest a role for kernel proteins in resistance to A. flavus infection and aflatoxin contamination in corn genotypes GT-MAS:gk and Mp420.

Last Modified: 4/23/2014
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