Molecular Dynamics Simulation and Biological Evaluation of Chitosan–CERK1 (LysM) Interactions in Enhancing Resistance to Fusarium Dry Rot in Potato Tubers

Abstract

Chitosan is a promising biostimulant for inducing plant resistance, yet its molecular mechanisms against post-harvest pathogens remain poorly understood. This study investigated how chitosan (0.5 g L-1) activates potato resistance against dry rot caused by Fusarium oxysporum during cold storage (5 ±1 °C, 30 days), integrating molecular simulation with experimental bioassays. Molecular docking (MOE) and 100 ns molecular dynamics simulations of the AlphaFold2-modeled CERK1 protein revealed a stable chitosan–LysM interface: the whole protein equilibrated at an overall RMSD of ≈ 4 Å, while the chitin-binding LysM domains remained highly stable (RMSD < 1.5 Å). Experimentally, chitosan-treated tubers showed significantly elevated PAL (+79%), PPO (+58%), and POD (+36%) activities and total phenolic content (+15%), with markedly reduced disease severity; principal component analysis explained 71.1% of the variance. These results indicate an associative link between chitosan-induced defence activation and binding to the CERK1 (LysM) receptor; as no functional validation was performed, this mechanism is proposed rather than confirmed, supporting chitosan as an environmentally safe alternative to synthetic fungicides in sustainable post-harvest management.