Maria Sorokina, Yulia Yugay, Anastasia Mironova, Dmitry Bulgakov, Vladimir Silant'ev, Valeria Grigorchuk, Olesya Kudinova, Yulia Yaroshenko, Victor Bulgakov, Yury Shkryl
Physiological and Molecular Plant Pathology 2027; 147: 103553
Outer membrane vesicles (OMVs) are spherical nanostructures secreted by Gram-negative bacteria that encapsulate periplasmic contents along with a diverse array of lipids, proteins, and nucleic acids. Although OMVs are increasingly recognized as important mediators of plant–microbe interactions, their biological effects on plants remain insufficiently understood for many phytopathogenic bacteria. In this study, we provide the first characterization of OMVs produced by Agrobacterium rhizogenes and assess their morphology, protein composition, and effects on the model plant Arabidopsis thaliana. Proteomic analysis revealed membrane-associated proteins, flagellar components, ribosomal proteins, and proteins potentially related to bacterial fitness and host interaction, indicating that protein cargo may contribute to OMV-mediated communication together with other vesicle constituents. In A. thaliana, OMV treatment affected overall plant development and leaf expansion, reduced leaf fresh weight and membrane stability, and altered secondary metabolism, mainly by increasing glucosinolate accumulation. qPCR analysis showed differential expression of genes associated with immune responses and stress-related signaling pathways. In addition, pretreatment of A. thaliana leaves with OMVs reduced Pseudomonas syringae proliferation and disease symptoms. These findings indicate that A. rhizogenes OMVs can modulate host plant physiology and defense responses, highlighting OMVs as previously underappreciated factors in Agrobacterium–plant interactions with potential relevance for understanding and modulating plant defense activation.
