How European vineyards dodged a devastating American disease

• Study reveals how Europe escaped Pierce's disease and warns of increasing risk due to climate change 

A team of researchers, including researchers from IFISC (UIB-CSIC), has revealed the reasons why European vineyards escaped the devastating Pierce's disease, caused by the bacterium Xylella fastidiosa, which has devastated crops in North America. The study, published in Proceedings of the Royal Society B, combines phylogenetic analysis, historical data and epidemiological models to explain this lucky escape and warn about future risks. 

The research reveals that the massive importation of American grapevines to France to combat the phylloxera plague in the late 19th century occurred just before the Pierce's disease-causing bacterium spread across the United States. The authors suggest that the grapevines exported to Europe were probably free of the bacterium. 

However, the key factor that prevented establishment of the disease in Europe was climate. The researchers demonstrated that climatic conditions in continental Europe between 1870 and 1990 were not conducive to the development of epidemics. In other words, the climate acted as a natural barrier. But this situation is changing rapidly. The team of scientists has detected an increased risk of outbreaks in southern Europe since the 1990s, coinciding with global warming. The model proposed indicates an inadvertent expansion of risk that is accelerating with climate change. 

This pioneering study analyzes the risk of pathogen establishment over more than 150 years, shedding light on how climatic factors, rather than phytosanitary measures, have so far protected European vineyards. However, the scenario is changing rapidly as with global warming, Europe faces an imminent risk of epidemics, especially in southern wine regions. The authors state that it is crucial for the wine industry and authorities to be prepared to face this emerging challenge. 

The study underlines the importance of understanding historical and biogeographical processes in plant disease management, especially in a context of global climate change.

Moralejo E, Giménez-Romero À, Matías MA. 2024 Linking intercontinental biogeographic events to decipher how European vineyards escaped Pierce’s disease. Proc. R. Soc. B 291: 20241130. https://doi.org/10.1098/rspb.2024.1130