Antiviral indolicidin variant peptides: Evaluation for broad-spectrum disease resistance in transgenic Nicotiana tabacum

Cationic peptides play an important role in the natural defenses against microbial infections of most of the living organisms. Indolicidin, a cationic peptide derived from bovine neutrophils, demonstrates in vitro antibacterial, antifungal and antiviral activity against animal pathogens. To evaluate efficacy of this peptide aganist plant pathogens, especially viruses, here we describe engineering transgenic plants, expressing indolicidin variants (10R and 11R). The variants were tested in vitro, for their effectiveness against plant pathogenic bacteria, fungi and TMV. Genes encoding these peptides were introduced into the tobacco cultivar (Nicotiana tabacum var. Xanthi). Leaf assays of transgenic plants showed enhanced resistance against several pathogens including significant resistance against TMV challenge. This is the first report of heterologous cationic peptide mediated antiviral resistance in engineered plants. # 2006 Elsevier Ireland Ltd. All rights reserved.