In the heart of Spain, researchers are unraveling the genetic secrets of one of the world’s most devastating plant pathogens, with implications that stretch far beyond the agricultural sector. María Pilar Velasco-Amo, a scientist at the Institute for Sustainable Agriculture, Consejo Superior de Investigaciones Científicas (CSIC) in Córdoba, has led a team that has sequenced the complete genomes of several strains of Xylella fastidiosa subsp. multiplex, a bacterium that has wreaked havoc on olive groves, vineyards, and citrus orchards across the globe.
The bacterium, originally from the Americas, has spread to more than 20 countries, causing billions of dollars in damage. In Europe, it’s listed as a priority pest, threatening not just the continent’s agricultural heritage but also its economy. “The socio-economic and ecological impacts of Xylella are immense,” Velasco-Amo explains. “Understanding its genetics is crucial for developing effective control strategies.”
The team’s work, published in Phytopathologia Mediterranea, which translates to Mediterranean Phytopathology, focuses on the multiplex subspecies, known for its wide range of host plants. By comparing the genomes of these strains, the researchers hope to understand how the bacterium adapts to new environments and hosts. This could pave the way for targeted treatments and preventative measures, protecting crops and the industries that depend on them.
The energy sector, in particular, has a lot to gain from this research. Olive oil is a significant source of biodiesel, and citrus peels are used to produce bioethanol. The spread of Xylella threatens these renewable energy sources, making the development of resistant crop varieties and effective treatments a priority.
The team used a hybrid assembly approach, combining Illumina and Oxford Nanopore technologies, to sequence the genomes. This method allowed them to identify and close several plasmid sequences, as well as prophage sequences and contigs outside the chromosomes, annotated as phages. These findings could provide insights into the bacterium’s evolution and host adaptation mechanisms, as well as the potential emergence of novel strains.
The new genomes, along with those already in GenBank, will facilitate further exploration of Xylella’s evolutionary dynamics. This could lead to the development of new control strategies, protecting crops and the industries that depend on them. As Velasco-Amo puts it, “The more we understand about Xylella’s genetics, the better equipped we’ll be to fight it.”
The research also highlights the potential of hybrid assembly approaches in genomics. By combining different sequencing technologies, researchers can gain a more comprehensive view of an organism’s genome, leading to new insights and discoveries. This could have implications for the study of other plant pathogens, as well as human and animal diseases.
As the world grapples with the challenges of climate change and food security, the need for sustainable and resilient agriculture has never been greater. This research is a step towards that goal, providing valuable insights into one of the world’s most destructive plant pathogens. The findings could shape future developments in the field, from the development of new treatments to the creation of resistant crop varieties. As the energy sector looks to diversify its sources, the protection of these crops becomes even more critical. The work of Velasco-Amo and her team is a testament to the power of scientific research in addressing real-world problems, and a beacon of hope in the fight against Xylella.