A new variant of Xylella fastidiosa subspecies multiplex detected in different host plants in the recently emerged outbreak in the region of Tuscany, Italy

EUROPEAN JOURNAL OF PLANT PATHOLOGY | https://doi.org/10.1007/s10658-019-01736-9

Authors

Maria Saponari¹, Giusy D’Attoma¹, Raied Abou Kubaa¹, Giuliana Loconsole², Giuseppe Altamura¹, Stefania Zicca¹, Domenico Rizzo³, Donato Boscia¹

The vector-borne bacterial pathogen Xylella fastidiosa is widely distributed in the Americas; in the last decade it has emerged as a serious threat for agricultural crops, natural environment and landscape in Europe. Following the first EU outbreak in 2013 in southern Italy, associated with a severe disease in olive trees, annual mandatory surveys are now in place in the Member States, leading to the discovery of bacterial outbreaks in different countries. Among the latest findings, an outbreak has been reported in the Italian region of Tuscany, with infections identified in seven different plant species. In this work, we report the isolation and the genetic characterization of isolates associated with this newly discovered outbreak.

Multilocus sequence typing approach revealed the occurrence of isolates harbouring a new sequence type, denoted ST87, genetically related to strains of subsp. multiplex, but different from the genotypes of this subspecies previously characterized in Europe. Five cultured strains were successfully recovered from four of the seven host plants, an important achievement for advancing the studies on genomics and pathogenicity of these isolates and thus assess their potential threat for European agriculture.

The present work has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 727987 – XF-ACTORS “Xylella Fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy”.