Seminarios IHSM La Mayora - Víctor Carrión (IHSM La Mayora UMA-CSIC)

Unlocking the secrets of plant microbiomes Plant roots are colonized by an astonishing number of microbes, not merely externally (rhizosphere) but also internally (endosphere). In the past years, extensive research has revealed the role of specific members of the plant microbiome to the improvement of plant tolerance to (a)biotic stress factors. However, the molecular mechanisms underlying these functions remain largely elusive. This in turn has raised new questions such as how endophytic bacteria colonize and protect plants against pathogens; and which genes are essential for being pathogenic or beneficial for the plant? In other words, are there genetic markers associated with specific microbial lifestyles? Here, our newest results are presented to shed light on these outstanding questions. We used in-depth metagenomic sequencing of the endosphere to discover that chitinase and novel NRPS and PKS genes were only activated in endophytic microbes upon pathogen infection. We also developed a new computational tool (MicroLife) to explore large-scale genomic datasets and to identify genes as well as biosynthetic gene clusters (BGCs) associated with specific microbial lifestyles. Using MicroLife, we were able to dig into the microbial dark matter to discover novel genes and BGCs involved in pathogenesis and endophytic lifestyles. Collectively, our results provide new exciting insights into the largely unexplored functional potential of the plant microbiome and the chemical secrets of the endosphere. Biography Víctor studied Biology and did his MSc and PhD at the University of Málaga (Spain). During his PhD he used molecular microbiology techniques to characterize virulence factors in Pseudomonas syringae, under the supervision of Prof. Antonio de Vicente and Prof. Francisco M. Cazorla. In October 2012 he joined the group of Prof. Jos M. Raaijmakers, at the Wageningen university and later at the Netherlands Institute of Ecology, in Wageningen (The Netherlands), where he studied how the endophytic microbiome can protect plants against fungal diseases. Since September 2020 he leads the group of Metagenomics and Plant-Microbe Interactions at Leiden University. His research program focuses on understanding the underlying mechanisms of plant protection against (a)biotic stresses mediated by microorganisms, and the use of bioinformatic tools for the prediction of bacterial lifestyles.