Skip to main content
ISMPMI Congress 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.

Poster

Session: Session 1 Presenting Authors at Posters (Odds)

P-313 - Dual Role of Xylella fastidiosa Extracellular Vesicles in Gene Transfer and sRNA-Mediated Plant Immunity Regulation

Monday, July 14, 2025
13:30 - 15:15  
Location: Confex Hall 3
RNA on the move: Advances in Cross-Species communiation &Translational Research
Abstract Text:

Xylella fastidiosa is a Gram-negative bacterial plant pathogen responsible for severe diseases in a variety of economically important crops. A critical aspect of its virulence is the production of extracellular vesicles (EVs). We discovered that non-ribosomal RNA-binding proteins and DNA-binding proteins are abundant in the corona of X. fastidiosa (Xf)-EVs. RNA sequencing revealed a distinct pattern of non-coding RNAs enriched in EVs, including four homologous small RNAs designated sXFs. DNA-seq revealed enrichment of three genomic islands in EVs, which carry molecular signatures indicative of horizontal gene transfer. The most abundant genomic island encodes five sXFs. Both RNA and DNA appear to be associated to the EV membrane. Target prediction of sXFs in bacteria suggests regulation of horizontal gene transfer. Predicted targets in plants include NLRs, one of which is downregulated in response to Xf-EVs. We propose a model where X. fastidiosa releases at least two types of nucleic acid carrying EVs: one with RNA-related cargo to regulate gene expression in both bacterial and plant cells, and a second type containing DNA-related cargo for the genetic transfer of genomic islands. We highlight island-encoded sXFs as potential virulence factors reprogramming stress responses and vesiduction as a mechanism of horizontal gene transfer of sXFs in X. fastidiosa. Our data on Xf-EV cargoes provide a molecular framework for understanding the virulence of X. fastidiosa.