Bt maize and mycotoxins: the current state of research

Abstract

The commercialisation of Bt (Bacillus thuringensis) maize expressing the Cry endotoxin specific for some types of Lepidopteran and Coleopteran pests has lead researchers to study the reduction in mycotoxin concentrations in Bt hybrids compared to the correspondent isogenic plants. Indeed, insect damage is one of the main inoculation pathways of mycotoxinogenic moulds. The present study aims to evaluate, according to the scientific literature published to date, the real efficiency of Bt maize hybrids in reducing the mycotoxin problem. The results obtained from the analysis of the literature do not show significant variations in the content of aflatoxins, zearalenone and trichothecenes, between Bt hybrids and corresponding isogenic control plants. The only mycotoxins where Bt hybrids have any effect are the fumonisin group, but even in this case studies in commercially planted fields have shown that their effect is mitigated by many biotic and abiotic factors.