title: Environmental influences on maize-Aspergillus flavus interactions and aflatoxin production.
abstract: Since the early 1960s, the fungal pathogen Aspergillus flavus (Link ex Fr.) has been the focus of intensive research due to the production of carcinogenic and highly toxic secondary metabolites collectively known as aflatoxins following pre-harvest colonization of crops. Given this recurrent problem and the occurrence of a severe aflatoxin outbreak in maize (Zea mays L.), particularly in the Southeast U.S. in the 1977 growing season, a significant research effort has been put forth to determine the nature of the interaction occurring between aflatoxin production, A. flavus, environment and its various hosts before harvest. Many studies have investigated this interaction at the genetic, transcript, and protein levels, and in terms of fungal biology at either pre- or post-harvest time points. Later experiments have indicated that the interaction and overall resistance phenotype of the host is a quantitative trait with a relatively low heritability. In addition, a high degree of environmental interaction has been noted, particularly with sources of abiotic stress for either the host or the fungus such as drought or heat stresses. Here, we review the history of research into this complex interaction and propose future directions for elucidating the relationship between resistance and susceptibility to A. flavus colonization, abiotic stress, and its relationship to oxidative stress in which aflatoxin production may function as a form of antioxidant protection to the producing fungus.
authors.affiliation: Department of Plant Pathology, University of Georgia Tifton, GA, USA.
authors.forename: Jake C
authors.initials: JC
authors.lastname: Fountain
authors.affiliation: Crop Protection and Management Research Unit, Agricultural Research Service - United States Department of Agriculture Tifton, GA, USA.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Scully
authors.affiliation: Crop Genetics and Breeding Research Unit, Agricultural Research Service - United States Department of Agriculture Tifton, GA, USA.
authors.forename: Xinzhi
authors.initials: X
authors.lastname: Ni
authors.affiliation: Department of Plant Pathology, University of Georgia Tifton, GA, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Kemerait
authors.affiliation: Department of Crop and Soil Sciences, University of Georgia Tifton, GA, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Lee
authors.affiliation: Department of Plant Pathology and Crop Physiology, Louisiana State University Baton Rouge, LA, USA.
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology, University of Georgia Tifton, GA, USA ; Crop Protection and Management Research Unit, Agricultural Research Service - United States Department of Agriculture Tifton, GA, USA.
authors.forename: Baozhu
authors.initials: B
authors.lastname: Guo
keywords: aflatoxin contamination; environment effects; host resistance; maize; oxidative stress