Ultrastructural and Molecular Implications of Ecofriendly Made Silver Nanoparticles Treatments in Pepper (Capsicum annuum L.)

Background: The increasing demand for sustainable agricultural practices has stimulated the exploration of nanotechnology-based solutions for plant protection. Silver nanoparticles (AgNPs) are considered promising eco-friendly nanomaterials with strong antifungal properties. Objective: This study aimed at the investigation involved a comprehensive approach to evaluate the potential of AgNPs as an antifungal agent against Fusarium oxysporum, a destructive pathogen responsible for severe yield losses in pepper (Capsicum annuum L.). Methodology: Ultrastrucural examination and molecular analyses were conducted to evaluate pepper plant responses to eco-friendly silver nanoparticles. Results: The results highlighted that AgNPs induced significant changes in the expression of defense-related genes, Def1.2, PAL3 and WRKY33, which collectively enhance the plant’s defense responses. Ultrastrucural analysis of leaf tissues revealed that treatment preserved cell wall integrity and chloroplast structure, while infected plants showed severe cellular damage. Conclusion: These findings suggest that AgNPs act through a dual mechanism: activation of molecular defense pathways and preservation of cellular ultrastructure, thereby presenting an effective and environmentally safe strategy to control Fusarium wilt in pepper plants.