Abstract
Risk assessment of an antifungal peptide is a prerequisite before using the corresponding gene to produce broad-spectrum, fungal-resistant GM crops. In this study, a new, antifungal defensin peptide (Ca-AFP) isolated from chickpea (Cicer arietinum L.) was evaluated for biological activity, stability, and range of toxicity to determine risks in using the gene for transgenic crop production. The biological function of Ca-AFP was found to be highly stable in extreme pH (range from 2 to 10) and temperature (up to 100°C) conditions. The peptide also showed unaltered efficiency in a wide range of temperatures (from 15° to 42°C) indicating a wide functional temperature. Despite extreme stability, it was non-toxic to non-target organisms (e.g., bacteria and insect cell lines). When the viability of human cell lines together with erythrocytes were tested, the peptide was also found to be non-toxic. Only one B-cell epitope was determined with this amino acid sequence. Immunological tests with mice failed to develop any antibody, indicating the non-immunogenic nature of the peptide, and thus, the negligible possibility of it being an allergen. All these preliminary assessments suggest that Ca-AFP is a noble peptide worthy of exploring its efficiency in transgenic crops to combat fungal pathogens.
