Research interest

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Bacterial plant diseases cause significant economic losses, while available antimicrobials remain limited and increasingly ineffective due to resistance. Climate change further elevates the risk of disease outbreaks, highlighting the urgent need for sustainable control strategies. Our research focuses on the early infection stages of phytopathogenic bacteria, during which pathogens colonize plant surfaces and, under favorable conditions, enter the apoplast via natural openings or wounds, triggering virulence mechanisms. These initial steps are critical for infection success and represent key intervention targets.

Our research aims to elucidate how phytopathogenic bacteria detect and respond to plant and environmental cues during early infection. Focusing on Pseudomonas syringae pv. tomato DC3000 (hemibiotroph) and Dickeya dadantii 3937 (necrotroph), our studies emphasize the role of chemosensory systems in host entry and infection establishment, aiming to identify molecular targets for sustainable disease control.

 

 

 

Chemosensory functions and pathogenicity

       

Chemosensory pathways represent one of the primary bacterial signal transduction systems, are widely distributed among bacteria and exert a key role in signal transduction processes associated with the response to environmental cues. This system controls the direction of flagellar rotation and ultimately bacterial motility. Although most chemosensory pathways appear to be involved in chemotaxis, this system also regulates other key processes involved in bacterial physiology (c-di-GMP levels, type IV pili motility, etc.). 

Characterization of bacterial chemoreceptors involved in plant interaction

We have carried out a comprehensive phylogenomic analysis of the full CR repertoire from a wide collection of microbial genomes. We have identified CR ligand-binding domains (LBDs) with high degree of plant association that are shared across distant taxonomic ranges and are postulated to be strong biomarkers for the plant-associated lifestyle. We work with selected chemoreceptors from our two model bacteria for an in-depth biochemical and functional characterization, especially in the context of bacterial pathogenesis and virulence. A detailled knowledge of chemoreceptors functions allow us to propose efficient interfering strategies to control bacterial infections. Overall, our results point to the potential use of non-metabolizable chemoeffectors as interfering tools to prevent bacterial infection. In our model we have characterized  bacteria CRs for compounds like different amino acids abundant in plant hosts or nitrato/nitrite.

 

 

Biochemical and functional characterization of selected chemoreceptors

 

"Energy taxis" and bacterial pathogenesis

“Energy taxis” is a process which allows the navigation to niches that support maximum energy levels. We are working on determining how phytobacteria deal with the perception of poor nutritional environments and how bacteria transduce the information regarding redox status through chemosensory pathways. Both PsPto and Dd3937 show chemoreceptors with cytoplasmic domains which could be involved in perception of the energy status driving specific responses during infection. We are working on their characterization through functional and biochemical approaches.

Chemosensory signal transduction

While Dd3937 shows a unique chemosensory pathway, PsPto encodes four different chemosensory pathways. We are working to understand their role in pathogenesis through the construction and functional characterization of mutant strains altered at different levels of these pathways. Our results point to the existence of a crosstalk among them to regulate pathogenesis-related traits.

Ecology of chemoreceptors: a global genomic and metagenomic study

In collaboration with the Comparative Genomics and Metagenomics group of the CBGP led by Dr. Jaime Huerta Cepas we are working on the description of the chemoreceptor profiles in different environments from metagenomic data. We are particularly interested in figuring out if the bacterial CR profile is a signature of a crop microbiome and therefore if we can predict and diagnose bacterial-plant interactions using CR profiles. With that purpose we are working on a sequence capture methodology to study CRs in crop samples.

 

 

 

POMATO: Strategies to manage emerging bacterial pathogens in tomato and potato crops

Clavibacter sepedonicus (Cs), causal organism of bacterial ring rot of potato, and Ralstonia solanacearum (Rs), responsible for bacterial wilt of potato and tomato, pose severe economic and environmental risks and are classified as EPPO A2 quarantine pathogens. The POMATO project (https://pomato.eu/#) aims to protect potato and tomato health through four main strategies:

1. Isolation of bacteria and molecular characterisation studies.
2. Developing early detection technologies using artificial intelligence (AI) and digital tools.
3. Development of natural bio-control solutions for seed, plant and soil.
4. Implementing and refining Integrated Pest Management (IPM) strategies.
   
   

 

 

 

Other research lines

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1. MULTILEVEL INTERFERENCE OF SEED TRANSMISSION FOR A SUSTAINABLE MANAGEMENT OF CROP VIRAL DISEASES (SEEDPROTECT). In collaboration with Dr. Israel Pagán and Dr. Fernando García-Arenal from the CBGP, we are analyzing the effect of bacterial and viruses mixed infection on viral seed transmission.
2. PLANT-PATHOGEN BIOTECHNOLOGY AND GENOMICS MEET FLUID DYNAMICS MIT-UPM seed projects. In collaboration with Dr. Lydia Borouiba from the Massachusetts Institute of Technology, Boston (USA), we are working on the dynamic of bacterial plant infection transmission through the analysis of bacterial dispersion in fluids in the plant environment.