Unravelling the virome in birch: RNA-Seq reveals a complex of known and novel viruses

PLoS One. 2020 Jun 26;15(6):e0221834. doi: 10.1371/journal.pone.0221834. eCollection 2020.

Abstract

To unravel the virome in birch trees of German and Finnish origin exhibiting symptoms of birch leaf-roll disease (BRLD), high-throughput sequencing (HTS) was employed. In total five viruses, among which three were so far unknown, were detected by RNAseq. One to five virus variants were identified in the transcriptome of individual trees. The novel viruses were genetically-fully or partially-characterized, belonging to the genera Carlavirus, Idaeovirus and Capillovirus and are tentatively named birch carlavirus, birch idaeovirus, and birch capillovirus, respectively. The recently discovered birch leafroll-associated virus was systematically detected by HTS in symptomatic seedlings but not in symptomless ones. The new carlavirus was detected only in one of the three symptomatic seedlings. The novel putative Capillovirus was detected in all seedlings-irrespective of their BLRD status-while the Idaeovirus was identified in a plant without leaf symptoms at the time of sampling. Further efforts are needed to complete Koch's postulates and to clarify the possible association of the detected viruses with the BLR disease. Our study elucidates the viral population in single birch seedlings and provides a comprehensive overview for the diversities of the viral communities they harbor, to date.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Betula / virology*
  • Metagenomics
  • Phylogeny
  • Plant Viruses / genetics*
  • Plant Viruses / physiology
  • RNA-Seq*

Grants and funding

DFG (Deutsche Forschunsgemeinschaft), projects BU890/14-1 (“Modes of transmission of Cherry leaf roll virus: genetic basis of seed transmissibility and investigation of possible arthropod vectors”) and BU890/23-1 (“Modes of vector transmission of Cherry leaf roll virus (CLRV) – molecular basis and potential arthropod vector species”).