Chapter 8: Detoxification Strategies for Mycotoxins in Plant Breeding

Many plant pathogenic fungi produce secondary metabolites that are toxic to animals (mycotoxins). Some of these toxins act as virulence factors, facilitating host plant colonization. Detoxification of mycotoxins in plants reduces mycotoxin exposure; for mycotoxins involved in pathogenesis, it also improves plant resistance to fungal infection. Enzymatic activities of plants towards fungal toxins are limited. The detoxification of HC toxin, destruxin B, fusaric acid, oxalate and deoxynivalenol by plants was studied most extensively. While the detoxification of HC toxin and destruxin B efficiently protects certain crops from the fungal diseases in which these toxins are involved, detoxification of fusaric acid and oxalate in plants is limited. Detoxification of deoxynivalenol by glycosylation is an important resistance mechanism of cereal plants against Fusarium head blight. Enhancement of plant detoxification activities towards fungal toxins by genetic engineering was suggested at Kinki University in Osaka in the 1980s. Since then, genetically modified model plants and crops detoxifying numerous fungal toxins have been generated and studied. Maize plants detoxifying fumonisins and wheat plants detoxifying deoxynivalenol were tested most extensively. The implementation of these developments in plant production and the resulting health benefits for consumers and farm animals have been obstructed by opposition to genetically modified crops.