Biofungicidal Potential of () Antifungal Protein NFAP and Novel Synthetic γ-Core Peptides.

Because of enormous crop losses worldwide due to pesticide-resistant plant pathogenic fungi, there is an increasing demand for the development of novel antifungal strategies in agriculture. Antifungal proteins (APs) and peptides are considered potential biofungicides; however, several factors limit their direct agricultural application, such as the high cost of production, narrow antifungal spectrum, and detrimental effects to plant development and human/animal health. This study evaluated the safety of the application of APs and peptides from the ascomycete as crop preservatives. The full-length AP (NFAP) and novel rationally designed γ-core peptide derivatives (PDs) γ-opt and γ-optGZ exhibited efficacy by inhibiting the growth of the agriculturally relevant filamentous ascomycetes . A high positive net charge, however, neither the hydrophilicity nor the primary structure supported the antifungal efficacy of these PDs. Further testing demonstrated that the antifungal activity did not require a conformational change of the β-pleated NFAP or the canonically ordered conformation of the synthetic PDs. Neither hemolysis nor cytotoxicity was observed when the NFAP and γ-opt were applied at antifungally effective concentrations in human cell lines. Similarly, the plants that served as toxicity model and were grown from seedlings that were treated with NFAP, γ-opt, or γ-optGZ failed to exhibit morphological aberrations, reduction in primary root length, or the number of lateral roots. Crop protection experiments demonstrated that NFAP and associated antifungal active γ-core PDs were able to protect tomato fruits against the postharvest fungal pathogen .