Fungal and bacterial pathogens significantly impact global crop yields, causing substantial economic losses and food insecurity. While chemical pesticides are effective, their excessive and improper use poses risks to the environment and human health. Antimicrobial peptides (AMPs)—components of innate immunity in plants and animals—are promising candidates for the development of novel, eco-friendly antimicrobials for agriculture and medicine. This study explores the antimicrobial activity of several γ-core peptides derived from defensins of Thinopyrum elongatum, a wild plant species known for its stress resistance. All peptides carried a net positive charge. 3D structural modeling indicated that most peptides adopted an α-helical conformation, with one predicted to form an anti-parallel β-hairpin structure. The conservation of the γ-core peptide sequences across Poaceae defensins was demonstrated, underscoring the importance of these peptide regions in biological functions of defensins. Antimicrobial assays demonstrated that all peptides exhibited broad-spectrum activity, with efficacy depending on the peptide’s amino acid sequence, 3D structure, and the pathogen tested. Notably, the peptide with the highest positive charge and β-hairpin structure showed the strongest pathogen inhibition. Additionally, synergistic interactions between some peptides against Fusarium oxysporum, which enhanced their antimicrobial effects, were shown. Our findings highlight the potential of wheatgrass γ-core peptides as templates for developing new peptide-based antimicrobials for agricultural and medical applications.
Slezina et al. (Sat,) studied this question.