Spatial and temporal distribution of Bt proteins in Bt maize leaves

To learn the spatial and temporal distribution of Bt proteins in Bt maize leaves, Bt protein levels of Bt maize leaves and their corresponding non-transgenic lines were detected and analysed by the ELISA method. The results showed that Bt proteins were expressed in the leaves of Bt maize varieties during all periods of their growth, while no such Bt proteins were detected in the leaves of non-transgenic maize varieties. The range of leaf Bt proteins was 1.08∼5.81 µg.g−1 FW, which could effectively protect Bt maizes from the corn borer pest during their growth periods. Furthermore, the younger leaves of Bt maizes had significantly lower levels of Bt proteins than their older leaves. In most periods, Bt protein content of Bt maize leaves under drought stress was lower than that under normal growth conditions, but Bt protein content under nutrition stress was higher than that under normal growth conditions. The results provided a full pattern of the spatial and temporal distribution of Bt proteins in Bt maize leaves.