Whole Genome Sequencing-Based Tracing of a 2022 Introduction and Outbreak of <i>Xanthomonas hortorum</i> pv. <i>pelargonii</i>

Phytopathology · 2022 · 12 citations

• Biology
• Biotechnology
• Genetics

. Eighteen of these strains originated from material sold by a plant breeding company that had notified clients following a release of infected geranium cuttings. Analyses of whole genome sequences revealed epidemiological links among the 27 strains from different growers that confirmed a common source of the outbreak and uncovered likely secondary spread events within facilities that housed plants originating from different plant breeding companies. Whole genome sequencing data were also analyzed to reveal how preparatory and analytical methods can impact conclusions on outbreaks of clonal pathogenic strains. The results demonstrate the potential power of using whole genome sequencing among a network of diagnostic labs and highlight how sharing such data can help shorten response times to mitigate outbreaks more expediently and precisely than standard methods.

Experimental evolution can enhance benefits of rhizobia to novel legume hosts

Proceedings of the Royal Society B Biological Sciences · 2021 · 19 citations

• Biology
• Evolutionary biology
• Botany

genotypes that vary in regulation of nodule formation. We evaluated phenotypic evolution of rhizobia by quantifying fitness, growth effects and histological features on hosts, and molecular evolution via genome resequencing. Rhizobia evolved enhanced host benefits and caused changes in nodule development in one of the four host-symbiont combinations, that appeared to be driven by reduced costs during symbiosis, rather than increased nitrogen fixation. Descendant populations included genetic changes that could alter rhizobial infection or proliferation in host tissues, but lack of evidence for fixation of these mutations weakens the results. Evolution of enhanced rhizobial benefits occurred only in a subset of experiments, suggesting a role for host-symbiont genotype interactions in mediating the evolution of enhanced benefits from symbionts.

Recurrent mutualism breakdown events in a legume rhizobia metapopulation

Proceedings of the Royal Society B Biological Sciences · 2020 · 34 citations

• Biology
• Ecology
• Botany

. The evolutionary and genomic drivers of these mutualism breakdown events remain poorly understood.