Understanding the biology of this microorganism is essential to grasping how it is able to survive in the xylem—a nutrient-poor environment—and its ability to block plant vessels, leading to symptoms of decline and a loss of yield. The research findings have been published in the journal Microbiological Research.

To investigate how it obtains energy and grows under such restrictive conditions, the most comprehensive ‘metabolic map’ of Xylella fastidiosa to date has been reconstructed. This map describes the chemical reactions the bacterium uses to survive and has enabled the identification of a previously unknown mechanism for utilising acetate — a simple molecule present in the xylem — as its sole source of nutrition. The study also demonstrates, for the first time, that this plant-pathogenic bacterium produces polyamines, molecules that may be linked to its ability to infect plants.

The research combines systems biology tools—which enable the simulation of metabolic processes based on genomic data—with laboratory experiments. To construct the metabolic map, the researchers integrated the shared genetic information from 18 representative strains of five subspecies of Xylella fastidiosa. This has enabled them to identify the essential metabolic functions shared across the entire species.

A new way of living on acetate alone
Among the most notable findings, the metabolic model has suggested a possible explanation for a previously unexplained phenomenon: the ability of Xylella fastidiosa to grow using acetate alone as a carbon source. The known pathways that enable this process in other bacteria do not exist in this plant pathogen, but the model proposes an alternative mechanism consistent with the available genomic data, which will need to be confirmed in future experiments.

“Metabolic modelling has enabled us to connect elements which, when analysed in isolation, did not provide a coherent explanation. Tools of this kind are particularly useful for uncovering biological mechanisms that can subsequently be validated in the laboratory,” explains the research team.

First evidence of polyamine production
Another significant contribution of this study is the demonstration, for the first time, that Xylella fastidiosa produces polyamines. These molecules are involved in numerous cellular processes and, in other plant-pathogenic bacteria, have been linked to biofilm formation, resistance to plant defences and the ability to infect their hosts.

The computational model predicted this ability, and experiments carried out with different strains of the bacterium have confirmed the production of three different polyamines. The results also suggest that these molecules may be particularly associated with growth in the form of biofilms – the state in which the bacterium colonises the vascular tissues of plants and also the insects that transmit it.

The research team believes that this discovery opens up a new line of research into the role of polyamines in the pathogenesis of Xylella fastidiosa and in its interaction with the plants it infects.

As well as generating new hypotheses about the bacterium’s biology, the metabolic model has also enabled the design of minimal culture media based on computational predictions, which have been experimentally validated. These formulations provide a new tool to facilitate the study of a microorganism that is particularly difficult to culture in the laboratory—a limitation that has held back research into this pathogen for decades.

Understanding the metabolism of Xylella fastidiosa is key to predicting its behaviour in plants, identifying potential vulnerabilities and guiding future control strategies. Although this study does not provide direct solutions, it lays a solid foundation for the future development of more informed interventions against a pathogen that has a significant socio-economic impact in the Mediterranean.

The authors highlight that the study exemplifies the potential of systems biology to accelerate scientific discovery. Integrating genomic data, computational simulations and experiments enables a better understanding of how plant pathogens function and helps identify new areas of research which, in the future, could contribute to the development of more effective strategies for controlling the diseases they cause.

Article reference: Paola Corbín-Agustí, Miguel Álvarez-Herrera, Miguel Román-Écija, Patricia Álvarez, Marta Tortajada, Blanca B. Landa, Juli Peretó (2026) “A metabolic model based on a pangenome core reveals putative conserved biochemical features of the phytopathogen Xylella fastidiosa”. Microbiological Research. https://doi.org/10.1016/j.micres.2026.128616