PT  - JOURNAL ARTICLE
AU  - Talia L. Karasov
AU  - Juliana Almario
AU  - Claudia Friedemann
AU  - Wei Ding
AU  - Michael Giolai
AU  - Darren Heavens
AU  - Sonja Kersten
AU  - Derek S. Lundberg
AU  - Manuela Neumann
AU  - Julian Regalado
AU  - Richard A. Neher
AU  - Eric Kemen
AU  - Detlef Weigel
TI  - <em>Arabidopsis thaliana</em> populations support long-term maintenance and parallel expansions of related <em>Pseudomonas</em> pathogens
AID  - 10.1101/241760
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 241760
4099  - http://biorxiv.org/content/early/2018/01/15/241760.short
4100  - http://biorxiv.org/content/early/2018/01/15/241760.full
AB  - Crop disease outbreaks are commonly associated with the clonal expansion of single pathogenic lineages. To determine whether similar boom-and-bust scenarios hold for wild plant pathogens, we carried out a multi-year multi-site 16S rDNA survey of Pseudomonas in the natural host Arabidopsis thaliana. The most common Pseudomonas lineage corresponded to a pathogenic clade present in all sites. Sequencing of 1,524 Pseudomonas genomes revealed this lineage to have diversified approximately 300,000 years ago, containing dozens of genetically distinct pathogenic sublineages. The coexistence of diverse sublineages suggests that in contrast to crop systems, no single strain has been able to overtake these A. thaliana populations in the recent past. An important question for the future is how the maintenance of pathogenic diversity is influenced by host genetic variation versus an environment with more microbial and abiotic heterogeneity than in agricultural systems.