Expression profiling across wild and cultivated tomatoes supports the relevance of early miR482/2118 suppression for Phytophthora resistance

Proc Biol Sci. 2018 Feb 28;285(1873):20172560. doi: 10.1098/rspb.2017.2560.

Abstract

Plants possess a battery of specific pathogen resistance (R-)genes. Precise R-gene regulation is important in the presence and absence of a pathogen. Recently, a microRNA family, miR482/2118, was shown to regulate the expression of a major class of R-genes, nucleotide-binding site leucine-rich repeats (NBS-LRRs). Furthermore, RNA silencing suppressor proteins, secreted by pathogens, prevent the accumulation of miR482/2118, leading to an upregulation of R-genes. Despite this transcriptional release of R-genes, RNA silencing suppressors positively contribute to the virulence of some pathogens. To investigate this paradox, we analysed how the regulation of NBS-LRRs by miR482/2118 has been shaped by the coevolution between Phytophthora infestans and cultivated and wild tomatoes. We used degradome analyses and qRT-PCR to evaluate and quantify the co-expression of miR482/2118 and their NBS-LRR targets. Our data show that miR482/2118-mediated targeting contributes to the regulation of NBS-LRRs in Solanum lycopersicum. Based on miR482/2118 expression profiling in two additional tomato species-with different coevolutionary histories with P. infestans-we hypothesize that pathogen-mediated RNA silencing suppression is most effective in the interaction between S. lycopersicum and P. infestans Furthermore, an upregulation of miR482/2118 early in the infection may increase susceptibility to P. infestans.

Keywords: Solanum; evolution; miRNA signalling; plant immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Coevolution
  • Disease Resistance / genetics
  • Lycopersicon esculentum / genetics*
  • Lycopersicon esculentum / microbiology*
  • MicroRNAs / genetics*
  • Phytophthora / physiology*
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology
  • RNA, Plant / genetics*

Substances

  • MicroRNAs
  • RNA, Plant

Associated data

  • figshare/10.6084/m9.figshare.c.4002592