o:36211 Outer membrane vesicles of plant beneficial bacterial strain Paraburkholderia phytofirmans PsJN make a contact with Arabidopsis thaliana rooots en ABSTRACT Extracellular vesicles (EVs) are recognized as important mediators of intercellular communication in both eukaryotes and prokaryotes. These lipid membrane-coated spherical nanoparticles carry proteins, nucleic acids and other cellular products, and facilitate exchange of these biomolecules among cells within an organism, but also between cells of different organisms, belonging to different species and even kingdoms. Outer membrane vesicles (OMVs), EVs produced by Gram-negative bacteria, are a significant mediator of microbial communication, involved in biofilm formation, virulence, and modulation of host immunity. OMVs of both pathogenic and plant beneficial bacteria have been shown to elicit plant immune responses. Investigations on the modes of OMV-plant cells interactions are still in their infancy, but gain rising attention. Aiming to monitor the interaction between OMVs of Paraburkholderia phytofirmans PsJN, a plant growth promoting bacteria, and Arabidopsis thaliana roots, we isolated OMVs from bacterial culture in mineral medium, using an ion-exchange chromatography system. Isolated OMVs were labeled with lipid binding fluorescent dye Vybrant™ DiD and unbound dye was removed by washing vesicles on ultrafiltration columns. The same dye concentration in phosphate buffer saline, equivalently washed, was used as a control. A. thaliana roots, grown on Murashige and Skoog medium, were incubated with DiD-OMVs or control dye/buffer mixture, washed and observed under confocal laser scanning microscope. Red signals were observed in root hairs and epidermis in DiD-OMV treated plants, while in control-treated roots the same signals were missing. outer membrane vesicles (omvs); Paraburkholderia phytofirmans Ps-JN; intercellular communication 1552100 978-86-7078-178-8 1552102 https://www.icgeb.org/trends-in-microbial-solutions-workshop-serbia-2023/ 2025-05-29T09:13:51.439Z 44 yes 46 Sofija Nešić University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Laboratory for Plant Molecular Biology, Belgrade, Serbia Aleksandra Divac Rankov University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Laboratory for Plant Molecular Biology, Belgrade, Serbia person Vesna Spasovski University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Laboratory for Plant Molecular Biology, Belgrade, Serbia person Maja Kosanović University of Belgrade, Institute for the Application of Nuclear Energy INEP, Serbia doktor bioloških nauka person 0000-0002-1143-1805 Dragana Nikolić University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Laboratory for Plant Molecular Biology, Belgrade, Serbia person application/pdf 1795499 https://phaidrabg.bg.ac.rs/o:36211 no yes 1 70 92000004 11A26 11A2606 11A29 11A2904 ICGEB WORKSHOP-Trends in microbial solutions for sustainable agriculture, 13–15 September 2023, Belgrade, Serbia 89 University of Belgrade, Faculty of Biology, Belgrade, Serbia 2023