Effects of Flavonoids and Phenols from Moringa oleifera Leaf Extracts on Biofilm Processes in Xanthomonas campestris pv. campestris

first_pagesettingsOrder Article Reprints Open AccessArticle Effects of Flavonoids and Phenols from Moringa oleifera Leaf Extracts on Biofilm Processes in Xanthomonas campestris pv. campestris by Riccardo Fontana 1,†ORCID,Anna Caproni 1,†,Mariaconcetta Sicurella 2ORCID,Stefano Manfredini 3ORCID,Anna Baldisserotto 3ORCID andPeggy Marconi 1,4,*ORCID 1 Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy 2 Department of Environmental Sciences and Prevention, University of Ferrara, 441211 Ferrara, Italy 3 Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy 4 Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, Ferrara 44121, Italy * Author to whom correspondence should be addressed. † These authors contributed equally to this work. Plants 2023, 12(7), 1508; https://doi.org/10.3390/plants12071508 Received: 5 December 2022 / Revised: 13 March 2023 / Accepted: 21 March 2023 / Published: 30 March 2023 (This article belongs to the Special Issue Plant Extracts as Biological Protective Agents) Download Browse Figures Versions Notes Abstract Xanthomonas campestris pv. campestris is the causal agent of black rot in crucifers, a plant disease with significant economic impact. Xanthomonadaceae is a large family of Gram-negative bacteria that cause symptoms by blocking water flow in plants by invading the xylem. To accomplish this, the main mechanism the bacteria use to adapt to environmental changes and colonize tissues is biofilm formation. In recent years, growing interest in natural antimicrobial compounds has led to the study of different phytocomplexes derived from plants. In this work, Moringa oleifera was selected, as its leaves are rich in phenols, essential oils, and vitamins that exert antibacterial activity. X. campestris pv. campestris biofilm, one of its major virulence factors, was studied. Biofilm formation and removal were analyzed on abiotic and biotic surfaces with and without M. oleifera leaf extracts. The data from the analysis show that Moringa oleifera leaf extracts and single phenols were able to inhibit biofilm growth on abiotic surfaces, but the activity of the whole phytocomplex was significantly higher compared to that of individual phenols. The effect of Moringa oleifera extracts on cabbage leaves in vivo was also found to be very important, as scanning electron microscopy showed that treatment with the extracts led to clear unblocking of the xylem, implying many advantages for use in black rot control.