Abstract: Human defensin-1 (human neutrophil peptide-1, HNP-1) is one of the small peptides found recently in human neutrophils with high antimicrobial activity of broad spectra. In this work, HNP-1 plant expression vectors with different promoter, with prepropiece and without the pre- and most part of propiece of HNP-1 cDNA have been constructed, and a serial of agrobacteria have been reconstructed using these vectors by tri-gameting. Tobacco ( Nicotiana tabacum L. ) leaf discs were infected with these reconstructed agrobacteria and plants regenerated after about 1 month. Southern blotting analysis showed that HNP-1 cDNA had been integrated in tobacco genome, but ELISA analysis indicated that only transgenic plants infected with agrobacteria contained HNP-1 expression vectors with an improved CaMV 35S promoter and without pre- and most part of the propiece of HNP-1 cDNA can express HNP-1 at Iow level. Information from electron microscopic observation and external feature of the plants showed that these plants had the ability to defend plants from TMV infection at a certain concentration (0.2 to 0.8 mg/L). It was concluded that it was a prerequisite to introduce an efficient promoter to an expression vector for an effective expression of a foreign cDNA, and it was necessary to delete the pre- and most part of the propiece of an animal cDNA for its expression in plants. Furthermore, HNP-1 cDNA transferring into plants could create a novel method to produce antipathogenic crops.

Key words: Defensin-1, cDNA, Tobacco