Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR 97331, USA.
Science. 2020 Jun 5;368(6495). doi: 10.1126/science.aba5256.
The accelerated evolution and spread of pathogens are threats to host species. Agrobacteria require an oncogenic Ti or Ri plasmid to transfer genes into plants and cause disease. We developed a strategy to characterize virulence plasmids and applied it to analyze hundreds of strains collected between 1927 and 2017, on six continents and from more than 50 host species. In consideration of prior evidence for prolific recombination, it was surprising that oncogenic plasmids are descended from a few conserved lineages. Characterization of a hierarchy of features that promote or constrain plasticity allowed inference of the evolutionary history across the plasmid lineages. We uncovered epidemiological patterns that highlight the importance of plasmid transmission in pathogen diversification as well as in long-term persistence and the global spread of disease.
病原菌的加速进化和传播对宿主物种构成威胁。根癌农杆菌需要致癌 Ti 或 Ri 质粒才能将基因转移到植物中并引起疾病。我们开发了一种用于鉴定毒性质粒的策略，并将其应用于分析 1927 年至 2017 年间在六大洲收集的数百个菌株，这些菌株来自 50 多种宿主物种。考虑到先前有大量重组的证据，令人惊讶的是，致癌质粒是由少数几个保守谱系衍生而来的。对促进或限制可塑性的一系列特征的表征，使得可以推断质粒谱系的进化历史。我们发现了一些流行病学模式，这些模式强调了质粒在病原体多样化以及疾病的长期存在和全球传播中的传播的重要性。
