Status of DIMBOA and phenolic acids in transgenic Bt corn

Experiments were conducted to investigate the status of DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and phenolic acids in leaves of some transgenic Bt corn hybrids. Comparison between Bt corn hybrids and their corresponding non-transgenic near-isogenic lines suggested that the introduction of the Bt gene has adverse effects on the biosynthesis and accumulation of DIMBOA and some phenolic acids, such as ferulic acid, in the corn plants. Under conditions of either water or nitrogen stress, the accumulation of DIMBOA in the leaves of the Bt corns could be enhanced. The results of this study suggest that caution must be taken when considering the introduction of Bt corns into China because Bt corns may have a weaker capacity, relative to traditional Chinese corn hybrids, to synthesise DIMBOA and some forms of phenolic acids in the leaves and, therefore, reduce the plant’s resistance to pathogens, diseases, and pests other than the targetted corn borer.