Zearalenone (ZEN) is an estrogenic mycotoxin produced by the necrotrophic cereal pathogen Fusarium graminearum. This mycotoxin is detoxified by ZHD101, a lactonohydrolase from Clonostachys rosea, or EGFP:ZHD101, its fusion to the C-terminus of an enhanced green fluorescence protein. We previously showed that egfp:zhd101 is efficiently expressed in T(0) leaves of rice. In this study, we assessed the feasibility of in planta detoxification of the mycotoxin using progeny. When protein extract from T(1) leaves was incubated with ZEN, the amount of the toxin decreased significantly as measured by HPLC. ZEN degradation activity was also detected in vivo in transgenic T(2) seeds. These results suggest that zhd101 can be exploited as an efficient and cost-effective system for protection of important cereals that are more susceptible to the pathogen (e.g., wheat and maize) from contamination with the estrogenic mycotoxin.