Biology subjects

Vidal-Villarejo, M.

Publications and source records attributed to Vidal-Villarejo, M..

3 recordsLinked to original sources

bioRxiv2024

Regional Diversity and Leaf Microbiome Interactions of the Fungal Maize Pathogen Exserohilum turcicum in Switzerland: AMetagenomic Analysis

The spread and adaptation of fungal plant pathogens in agroecosystems are facilitated by environmental homogeneity. Metagenomic sequencing of infected tissues allows to monitor eco-evolutionary dynamics and interactions betwen host, pathogen and the plant microbiome. Exserohilum turcicum, the causal agent of northern corn leaf blight (NCLB) in maize, is distributed in multiple clonal lineages throughout Europe. To characterize regional pathogen diversity, we conducted metagenomic DNA sequencing on 241 infected leaf samples from the highly susceptible Swiss maize landrace Rheintaler Ribelmais, collected over three years (2016-2018) from an average of 14 agricultural farms within the Swiss Rhine Valley. All major European clonal lineages of E. turcicum were identified. Lineages differ by their mating types which indicates potential for sexual recombination and rapid evolution of new pathogen strains, although we found no evidence of recent recombination. The associated eukaryotic and prokaryotic leaf microbiome exhibited variation in taxonomic diversity between years and locations and is likely influenced by local weather conditions. A network analysis revealed distinct clusters of eukaryotic and prokaryotic taxa that correlates with the frequency of E. turcicum sequencing reads, suggesting causal interactions. Notably, the yeast genus Metschnikowia exhibited a strongly negative correlation, supporting its known potential as biological control agent against fungal pathogens. Our findings show that metagenomic sequencing is a useful tool for analyzing the role of environmental factors and potential pathogen-microbiome interactions in shaping pathogen dynamics and evolution, suggesting their potential for effective pathogen management strategies.

plant biology↗

bioRxiv2020

Population history of the Northern corn leaf blight fungal pathogen Setosphaeria turcica in Europe

Modern agricultural practices and the climate change foster the rapid spread of plant pathogens like the maize fungal pathogen Setosphaeria turcica, which causes Northern corn leaf blight and expanded into Central Europe since the 1980s. To investigate the rapid expansion of S. turcica we sequenced 121 isolates from Europe and Kenya. Population genomic inference revealed a single genetically diverse cluster in Kenya and three clonal lineages with low diversity and one cluster of multiple clonal sublineages in Europe. Phylogenetic dating suggests that all European lineages originated by sexual reproduction outside Europe and subsequently were subsequently introgressed multiple times. In contrast to Kenyan isolates, European isolates did not show sexual recombination despite the presence of both MAT1-1 and MAT1-2 mating types. Coalescent analysis of the geographically most widespread European lineage supported a neutral, strongly exponential population growth model over models with natural selection caused by host defence resistance or environmental adaptation. Within clonal lineages, we observed phenotypic variation in virulence to different monogenic resistances that may originate from repeated mutations in virulence genes. Association mapping between genetic clusters did not identify genomic regions associated with pathogen races but uncovered strongly differentiated genomic regions between clonal lineages that harbor putative effector genes. In conclusion, the expansion and population growth of S. turcica in Europe was mainly driven by the expansion of maize cultivation area and not by rapid adaptation. Significance statementThe geographic expansion and plant pathogens caused by modern agricultural practices and climate change is a major problem in modern agriculture. We investigated the rapid spread of the maize fungal pathogen Setosphaeria turcica by whole genome sequencing of isolates from Kenya and Europe and demonstrated that the rapid expansion in Central Europe since the 1980s mainly reflects the rapid growth of the maize cultivation area in this region and not a rapid adaptation to resistant maize varieties. Our analyses show that by monitoring whole genome sequence diversity of plant pathogens and their invasion history, agricultural management and breeding strategies can be developed to control the evolution and future spread of plant pathogens.

evolutionary biology↗

bioRxiv2019

Convergent seed color adaptation during repeated domestication of an ancient new world grain

Out of the almost 2,000 plants that have been selected as crops, only few are fully domesticated, and many intermediates between wild plants and domesticates exist. Genetic constraints might be the reason why incompletely domesticated plants have few characteristic crop traits, and retained numerous wild plant features. Here, we investigate the incomplete domestication of an ancient grain from the Americas, amaranth. We sequenced 121 genomes of the crop and its wild ancestors to show that grain amaranth has been selected three times independently from a single wild ancestor, but has not been fully domesticated. Our analysis identified a MYB-like transcription factor gene as key regulator for seed color variation and shows that the trait was independently converted in Central and South America. We suggest a low effective population size at the time of domestication as potential cause for the lack of adaptation of complex domestication traits. Our results show how genetic constraints influenced domestication and might have set the fate of hundreds of crops.

evolutionary biology↗