Xylella seminar: Rational assembly of Bacterial SynCom for the management of olive vascular diseases

Xylella Seminar: Rational assembly of Bacterial Synthetic Communities for the management of olive vascular diseases.
Lluis A. Moll and Lucia Alonso from the Institute for Sustainable Agriculture (IAS-CSIC), Córdoba, Spain
Olive vascular diseases caused by the bacterium Xylella fastidiosa and the fungus Verticillium dahliae pose major threats to olive production and other economically important crops. Aligned with the EU Green Deal’s emphasis on sustainable agriculture, this study investigates the use of Synthetic Bacterial Communities (SynComs) composed of xylem-inhabiting bacteria from olive trees as a biocontrol strategy. Over 100 bacterial isolates were screened for stress tolerance (e.g., antibiotics, low pH, salinity), plant growth-promoting traits (e.g., siderophore and IAA production), antimicrobial enzyme production, and in vitro antagonism against both pathogens. Compatibility assays among the most promising strains led to the assembly of two SynComs, each comprising three compatible members. Their potential to control vascular diseases was assessed through in vitro assays (dual cultures and microfluidic chambers) and currently in planta experiments are being carried out using Nicotiana benthamiana and olive. Preliminary results in X. fastidiosa-infected plants are promising, showing reduced pathogen levels and improved plant fitness compared to untreated controls.