Metatranscriptomic dynamics after Verticillium dahliae infection and root damage in Olea europaea

BMC Plant Biol. 2020 Feb 17;20(1):79. doi: 10.1186/s12870-019-2185-0.

Abstract

Background: The olive tree is of particular economic interest in the Mediterranean basin. Researchers have conducted several studies on one of the most devastating disorders affecting this tree, the Verticillium wilt, which causes substantial economic losses in numerous areas. We analyzed metatranscriptomic samples taken from a previous study conducted on leaves and roots of Olea europaea that were infected with Verticillium dahliae. In addition, we also analyzed mechanically damaged roots. The aim of our approach is to describe the dynamics of the root microbiome after severe perturbations.

Results: Our results not only describe the dynamics of the microbial community associated with the disturbance, but also show the high complexity of these systems and explain how this can lead to a conflicting assignment of the various types of parasitism observed in a specific organism.

Conclusions: Our findings indicate that this infection, although led by Verticillium, is driven not by a single species, but by a polymicrobial consortium that also includes natural endophytes of the olive tree. This community contains both biotrophic and necrotrophic organisms that alternate and live together during the infection. In addition, opportunistic organisms appear that take profit not from plant tissues, but from new emerging populations of microorganisms. Therefore, this system can be described as a complex biological system composed of different interacting communities. Notably, our work has important considerations when it comes to classifying the type of parasitism of a given species.

Keywords: Biotroph; Endophytes; Hemibiotroph; Necrotroph; Olea europaea; Polymicrobial infection; Rank dynamics; Root damage; Temporal metatranscriptomics; Verticillium dahliae; Verticillium wilt of olive.

MeSH terms

  • Microbiota*
  • Olea / genetics*
  • Olea / metabolism
  • Olea / microbiology
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Leaves / microbiology
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Plant Roots / microbiology
  • Transcriptome*
  • Verticillium / physiology*