Biodegradation of Juglone by Xanthomonas arboricola pv. juglandis, the Causal Agent of Walnut (Juglans regia L.) Bacterial Blight

Marco Scortichini; Antonio Fiorentino; Elvira Ferrara; Milena Petriccione; Brigida D'Abrosca

doi:10.1002/cbdv.202403299

Biodegradation of Juglone by Xanthomonas arboricola pv. juglandis, the Causal Agent of Walnut (Juglans regia L.) Bacterial Blight

Chem Biodivers. 2025 Apr 7:e202403299. doi: 10.1002/cbdv.202403299. Online ahead of print.

Authors

Marco Scortichini¹, Antonio Fiorentino², Elvira Ferrara^{2

3}, Milena Petriccione³, Brigida D'Abrosca²

Affiliations

¹ Research Centre for Olive, Fruit and Citrus Crops, Council for Agricultural Research and Economics, Roma, Italy.
² Department of Environmental Biological and Pharmaceutical Sciences and Technologies, DiSTABiF University of Campania Luigi Vanvitelli, Caserta, Italy.
³ Research Centre for Olive, Fruit and Citrus Crops, Council for Agricultural Research and Economics, Caserta, Italy.

PMID: 40194923
DOI: 10.1002/cbdv.202403299

Abstract

Xanthomonas arboricola pv. juglandis is the causal agent of walnut blight, a disease affecting Juglans regia L. cultivations by causing severe economic losses worldwide. The content of phenolic compounds in J. regia cultivars plays an important role in determining the resistance or susceptibility to the infection. In this study, the assessment of antimicrobial activity against several phytopathogenic X. arboricola and Pseudomonas strains revealed that X. a. pv. juglandis was less susceptible to juglone at higher concentrations, suggesting a potential resistance mechanism. To explore the antibacterial results, the biodegradation of juglone in the presence of X. a. pvs. juglandis and pruni were assessed at three different collecting times by NMR. The NMR analysis clearly showed the ability of X. a pv. juglandis NCPPB1659 to degrade juglone. On the contrary, X. a. pv. pruni NCPPB2588 was ineffective. The seasonal variation of juglone collected in leaves and husks of walnuts was determined.

Keywords: HPLC; Juglans regia L. cv Sorrento; NMR; Xanthomonas arboricola pv. juglandis; juglone.