IDENTIFICATION AND ENHANCEMENT OF SEED-BASED BIOCHEMICAL RESISTANCE IN CROPS TO AFLATOXIN PRODUCING PATHOGENS
Location: Food and Feed Safety Research
Title: Application of biotechnology towards the enhancement of maize resistance to aflatoxin contamination by Aspergillus flavus
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: November 5, 2007
Publication Date: May 15, 2008
Citation: Brown, R.L., Chen, Z., Menkir, A., Cleveland, T.E., Bhatnagar, D. 2008. Application of biotechnology towards the enhancement of maize resistance to aflatoxin contamination by Aspergillus flavus. In: Thangadurai, D. (ed) Crop Improvement and Biotechnology, Bioscience Publications, India. p. 57-67.
Contamination of maize with aflatoxins by the fungi Aspergillus flavus and A. parasiticus poses serious health hazards to humans and animals worldwide. This important fact and the regulations instituted in many countries to control the occurrence of aflatoxins in foods and feed have stimulated research aimed at eliminating their presence in maize and other susceptible crops. While aflatoxin’s potential for being a health hazard has been checked by these regulations in countries where imposed, the developing world, especially Africa, has already felt the impact of these mycotoxins on human health. Cultural management practices that limit conditions favoring aflatoxin production should be practiced, however, these do not eliminate aflatoxins, nor are they always cost effective to growers. Due to more recent innovations in germplasm screening techniques and the identification of resistant maize lines, host resistance, always a potentially valuable approach for combating crop disease, may now be closer to realization. Breeding strategies including the use of a laboratory-based kernel screening assay are developing germplasm, not only with resistance to aflatoxin formation, but also with good agronomic characteristics. Germplasm should soon be available for use, not only in the U.S., but in Africa as well. The identification of resistance-associated proteins and corresponding genes in resistant germplasm may provide clarity as to the mechanisms of aflatoxin-resistance, as well as lead to markers for use in maize breeding programs. Proteomics has enhanced the identification of the proteins/genes that may be involved in resistance. A. flavus genomics should speed up our understanding of host-pathogen interactions and possibly contribute to the development of resistance against fungal biosynthesis of aflatoxin.