Cultural and genetic approaches to manage aflatoxin contamination: recent insights provide opportunities for improved control

Authors: OJIAMBO, PETER - North Carolina State University; BATTILANI, PAOLA - Università Cattolica Del Sacro Cuore; Cary, Jeffrey; BLUM, BURT - University Of Arkansas; CARBONE, IGNAZIO - North Carolina State University

Submitted to: Phytopathology
Publication Type: Review Article
Publication Acceptance Date: 6/4/2018
Publication Date: 9/5/2018
Citation: Ojiambo, P.S., Battilani, P., Cary, J.W., Blum, B.H., Carbone, I. 2018. Cultural and genetic approaches to manage aflatoxin contamination: recent insights provide opportunities for improved control. Phytopathology. 108:1024-1037. https://doi.org/10.1094/PHYTO-04-18-0134-RVW.
DOI: https://doi.org/10.1094/PHYTO-04-18-0134-RVW

Interpretive Summary: Aspergillus (A.) flavus is a mold that can produce the group of carcinogenic and mutagenic compounds known as aflatoxins, as well as many other toxic chemicals. Aflatoxin causes aflatoxicosis when aflatoxins are ingested through contaminated food and feed. In addition, aflatoxin contamination is a major problem, from both an economic and health aspect, in developing countries, especially Asia and Africa, where cereals and peanuts are an important food crops. Early measures for control of A. flavus infection and consequent aflatoxin contamination centered on creating unfavorable environments for the mold pathogen and destroying contaminated products. While development of atoxigenic (non-aflatoxin producing) strains of A. flavus as viable commercial biocontrol agents has marked a unique advance for control of aflatoxin contamination, particularly in Africa, new insights into the biology and sexuality of A. flavus are now providing opportunities to design improved atoxigenic strains for sustainable biocontrol of aflatoxin. Further, progress in the use of molecular technologies such as incorporation of antifungal genes in the host and host-induced gene silencing, is providing knowledge that could be harnessed to develop corn lines that are resistant to infection by A. flavus and aflatoxin contamination. This review summarizes the substantial progress that has been made to understand the biology of A. flavus and mitigate aflatoxin contamination with emphasis on maize. Concepts developed to date can provide a basis for future research efforts on the sustainable management of aflatoxin contamination.

Technical Abstract: Aspergillus flavus is a morphologically complex species that can produce the group of polyketide derived carcinogenic and mutagenic secondary metabolites, aflatoxins, as well as other secondary metabolites such as cyclopiazonic acid and aflatrem. Aflatoxin causes aflatoxicosis when aflatoxins are ingested through contaminated food and feed. In addition, aflatoxin contamination is a major problem, from both an economic and health aspect, in developing countries, especially Asia and Africa, where cereals and peanuts are an important food crops. Early measures for control of A. flavus infection and consequent aflatoxin contamination centered on creating unfavorable environments for the pathogen and destroying contaminated products. While development of atoxigenic (non-aflatoxin producing) strains of A. flavus as viable commercial biocontrol agents has marked a unique advance for control of aflatoxin contamination, particularly in Africa, new insights into the biology and sexuality of A. flavus are now providing opportunities to design improved atoxigenic strains for sustainable biocontrol of aflatoxin. Further, progress in the use of molecular technologies such as incorporation of antifungal genes in the host and host-induced gene silencing, is providing knowledge that could be harnessed to develop germplasm that is resistant to infection by A. flavus and aflatoxin contamination. This review summarizes the substantial progress that has been made to understand the biology of A. flavus and mitigate aflatoxin contamination with emphasis on maize. Concepts developed to date can provide a basis for future research efforts on the sustainable management of aflatoxin contamination.