Bacterial phytopathology is not limited to simple, bilateral interactions between a pathogen and its host. Instead, it arises from complex multipartite interactions that also involve plant-beneficial microorganisms and environmental stressors. Plant Growth-Promoting Rhizobacteria (PGPR), such as certain strains of the genus Bacillus, play a protective role by inhibiting pathogen colonization and/or strengthening plant defenses. However, the mechanistic basis of plant protection by PGPR remains only partially understood.

Our research focuses on the interactions between phytopathogenic bacterial strains of the genus Xanthomonas, PGPR strains of the genus Bacillus, and their host plants. We aim to decipher the inter- and intra-organismic mechanisms that determine pathogen infection or plant resistance, under environmental stress. A key aspect of this work is to examine how climatic factors influence the dynamics of these interactions.

To address these questions, we employ an integrative and holistic approach that combines advanced biophysical and molecular techniques. These include next-generation biosensors, microfluidics, high-resolution fluorescence imaging, and a wide range of omics analyses. Together, these tools allow us to investigate host-microbe interactions with fine spatiotemporal resolution under conditions that closely mimic natural environments while remaining highly controlled.

At the core of our research lies the hypothesis that microbes colonize host plants to create favorable conditions for their multiplication. Thus, our investigations center on how these unicellular organisms establish communication networks both among themselves and with the host in order to facilitate colonization, resource acquisition, and proliferation within the unique environment of plant tissues.

Microbial survival often depends on their ability to manipulate host resources efficiently while simultaneously outpacing host defenses in a continuous evolutionary race. Understanding these processes requires us to immerse ourselves as close observers within the system an objective that is both technically and intellectually challenging.

To this end, we use biosensors and microfluidic devices to detect changes associated with signaling, nutrient transport, metabolism within microbes, within plant hosts, and at their interface. This enables us to gain deeper insights into communication networks and microbial feeding strategies and, as well as the molecular mechanisms that drive their success. The combination of these approaches with comprehensive omics technologies provides a powerful framework for understanding plant-microbe interactions at the highest resolution.

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