Transgenic expression of cecropin B, an antibacterial peptide from Bombyx mori, confers enhanced resistance to bacterial leaf blight in rice.

The short persistence of cecropin B peptide in plants, due to post-translational degradation, is a serious impediment in its effective utilization for developing bacterial resistance transgenic plants. Two DNA constructs encoding the full-length precursor of cecropin B peptide and the mature sequence of cecropin B peptide preceded by a signal peptide derived from rice chitinase gene were transformed in rice. The differences in the transcriptional levels in independent transgenic lines showed moderate to high expression of cecropin B gene that correlated well with the differences in cecropin B accumulation observed by Western blot analysis. The development of lesions resulting from infection by Xanthomonas oryzae pv. oryzae was significantly confined in the infected leaflet of transgenic lines, when compared with the control plants.