Differential gene expression and physiological changes during acute or persistent plant virus interactions may contribute to viral symptom differences

PLoS One. 2019 May 3;14(5):e0216618. doi: 10.1371/journal.pone.0216618. eCollection 2019.

Abstract

Viruses have different strategies for infecting their hosts. Fast and acute infections result in the development of severe symptoms and may cause the death of the plant. By contrast, in a persistent interaction, the virus can survive within its host for a long time, inducing only mild symptoms. In this study, we investigated the gene expression changes induced in CymRSV-, crTMV-, and TCV-infected Nicotiana benthamiana and in PVX- and TMV-U1-infected Solanum lycopersicum plants after the systemic spread of the virus by two different high-throughput methods: microarray hybridization or RNA sequencing. Using these techniques, we were able to clearly differentiate between acute and persistent infections. We validated the gene expression changes of selected genes by Northern blot hybridization or by qRT-PCR. We show that, in contrast to persistent infections, the drastic shut-off of housekeeping genes, downregulation of photosynthesis-related transcripts and induction of stress genes are specific outcomes with acute infections. We also show that these changes are not a consequence of host necrosis or the presence of a viral silencing suppressor. Thermal imaging data and chlorophyll fluorescence measurements correlated very well with the molecular changes. We believe that the molecular and physiological changes detected during acute infections mostly contribute to virus symptom development. The observed characteristic physiological changes associated with economically more dangerous acute infections could serve as a basis for the elaboration of remote monitoring systems suitable for detecting developing virus infections in crops. Moreover, as molecular and physiological changes are characteristics of different types of virus lifestyles, this knowledge can support risk assessments of recently described novel viruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Regulation, Plant*
  • Host-Pathogen Interactions / genetics*
  • Nicotiana / genetics*
  • Nicotiana / virology
  • Plant Diseases / genetics*
  • Plant Diseases / virology
  • Plant Leaves / genetics
  • Plant Leaves / virology
  • Plant Proteins / genetics*
  • Plant Viruses / physiology*
  • Solanum lycopersicum / genetics*
  • Solanum lycopersicum / virology
  • Virus Replication

Substances

  • Plant Proteins

Grants and funding

This research was funded by the National Research, Development and Innovation Office – NKFIH: PD78049 (EV), K108718 (EV), K119783 (EV), K115934 (TC) and EU EPPN2020 - Grant agreement no.: 731013 (IV) Doctoral Programme of Biological Sciences at Szent István University (RP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.