A fungal cell wall elicitor from Neopestalotiopsis clavispora induces systemic defense in Ginkgo Biloba

Sustainable management of tree diseases requires harnessing the plant’s own immune system. Leaf blight caused by Neopestalotiopsis clavispora (N. clavispora) affects the ornamental value of Ginkgo biloba (G. biloba) and the accumulation of its medicinal components. Elicitors, as a novel biological control method, hold potential application value in the prevention and management of G. biloba leaf blight. We demonstrate that a cell wall elicitor extracted from the fungal pathogen N. clavispora potently induces systemic resistance against leaf blight in the ancient gymnosperm G. biloba. The elicitor exhibited no direct antifungal activity, confirming that its protective function is mediated exclusively through plant innate immunity. Pre-treatment with the elicitor resulted in over 80% disease control, outperforming commercial resistance inducers and matching the efficacy of carbendazim fungicide. This resistance was associated with a primed state, characterized by a rapid and sustained burst in key defense enzyme activities (POD, PAL, PPO), accelerated accumulation of lignin and phenolics, and mitigated oxidative damage. Metabolomic analyses revealed that the elicitor triggers a change of the defense landscape. We identified coordinated upregulation of the phenylpropanoid pathway, which was directly mirrored by the accumulation of defensive flavonoids and flavonols. Furthermore, tryptophan metabolism and glycerophospholipid pathways were significantly altered, indicating a comprehensive reconfiguration of primary and secondary metabolism. Our findings uncover a multifaceted defense strategy in G. biloba, wherein the fungal elicitor acts as a priming agent to establish a state of alert, enabling a robust, integrated metabolic response that effectively restricts pathogen invasion. This work provides a molecular framework for elicitor-induced resistance in trees and validates a sustainable, vaccine-like strategy for forest protection.