Enhancing tomato growth and early blight disease resistance through green-synthesized silver nanoparticles: Insights into plant physiology

Tomato (Solanum lycopersicum) isa globally significant crop, but its cultivation is challenged by the devastating Early Blight disease caused by Alternaria solani, leading to substantial yield losses. Silver nanoparticles (AgNPs) have emerged as potential antifungal agents, garnering increasing attention. In this study, we investigated the impact of biogenic AgNPs on tomato plant defense mechanisms during a three-way interaction with plant pathogens and nanoparticles. Additionally, the study explored the integration of biochemical markers to assess plant response. Histochemical analyses confirmed the presence of oxidative stress markers (H2O2 and O-2), as well as callose and lignin deposition, supporting the involvement of defensive responses in this study. Metabolic profiling revealed that tomato plants exposed to 20 ppm AgNPs exhibited maximal accumulation levels of various secondary metabolites compared to the control group. Remarkably, the concurrent application of AgNPs and plants resulted in enhanced plant resistance against biotic stress, as evidenced by reduced stress parameters and stress enzyme activity. The antioxidant enzymes (PO, SOD, CAT, LPX) exhibited significant variations among treatments, emphasizing the influence of AgNPs on maintaining reactive oxygen species (ROS) homeostasis in plant cells. These findings highlight the potential of nanotechnology-based approaches in bolstering food supply and promoting sustainable agriculture. Our study underscores the significance of integrating biochemical markers to monitor and assess plant response during the interaction with nanoparticles and pathogens. This integration offers a promising avenue for elucidating the underlying mechanisms of plant defense and optimizing agricultural practices. In conclusion, our research elucidates the potential of silver nanoparticles in augmenting plant resistance against Early Blight disease in tomato, ultimately contributing to sustainable agriculture. The incorporation of biochemical markers further advances our understanding of the intricate interplay between nanoparticles, plant pathogens, and plant defense mechanisms. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.