Xylella fastidiosa subsp. pauca and olive produced lipids moderate the switch adhesive versus non-adhesive state and viceversa

PLoS One. 2020 May 15;15(5):e0233013. doi: 10.1371/journal.pone.0233013. eCollection 2020.

Abstract

Global trade and climate change are re-shaping the distribution map of pandemic pathogens. One major emerging concern is Xylella fastidiosa, a tropical bacterium recently introduced into Europe from America. In last decades, X. fastidiosa was detected in several European countries. X. fastidiosa is an insect vector-transmitted bacterial plant pathogen associated with severe diseases in a wide range of hosts. X. fastidiosa through a tight coordination of the adherent biofilm and the planktonic states, invades the host systemically. The planktonic phase is correlated to low cell density and vessel colonization. Increase in cell density triggers a quorum sensing system based on mixture of cis 2-enoic fatty acids-diffusible signalling factors (DSF) that promote stickiness and biofilm. The lipidome profile of Olea europaea L. (cv. Ogliarola salentina) samples, collected in groves located in infected zones and uninfected zones was performed. The untargeted analysis of the lipid profiles of Olive Quick Decline Syndrome (OQDS) positive (+) and negative (-) plants showed a clustering of OQDS+ plants apart from OQDS-. The targeted lipids profile of plants OQDS+ and OQDS- identified a shortlist of 10 lipids that increase their amount in OQDS+ and X. fastidiosa positive olive trees. These lipid entities, provided to X. fastidiosa subsp. pauca pure culture, impact on the dual phase, e.g. planktonic ↔ biofilm. This study provides novel insights on OQDS lipid hallmarks and on molecules that might modulate biofilm phase in X. fastidiosa subsp. pauca.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesiveness
  • Animals
  • Biofilms / growth & development
  • Host Microbial Interactions / physiology
  • Insect Vectors / microbiology
  • Italy
  • Lipid Metabolism*
  • Lipidomics
  • Olea / metabolism*
  • Olea / microbiology*
  • Plant Diseases / microbiology*
  • Quorum Sensing / physiology
  • Xylella / pathogenicity*
  • Xylella / physiology*

Supplementary concepts

  • Xylella fastidiosa

Grants and funding

The study was funded by MIPAAFT, Project Oli.Di.X.I.It (“OLIvicoltura e Difesa da Xylella fastidiosa e da Insetti vettori in Italia”), D.M. 23773 del 6/09/2017, Project SALVAOLIVI (“Salvaguardia e valorizzazione del patrimonio olivicolo italiano con azioni di ricerca nel settore della difesa fitosanitaria”), D.M. 33437 del 21-12-201 and by Regione Puglia agreement: “Strategie di controllo integrato per il contenimento di Xylella fastidiosa in oliveti pugliesi ed analisi epidemiologiche del complesso del disseccamento rapido dell’olivo (CoDiRO). B.M. and M.Z. were supported by a start-up fund from Boston College and by an Award in Biomedical Excellence from the Smith Family Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.