The hnRNP-Q protein LIF2 participates in the plant immune response

PLoS One. 2014 Jun 10;9(6):e99343. doi: 10.1371/journal.pone.0099343. eCollection 2014.

Abstract

Eukaryotes have evolved complex defense pathways to combat invading pathogens. Here, we investigated the role of the Arabidopsis thaliana heterogeneous nuclear ribonucleoprotein (hnRNP-Q) LIF2 in the plant innate immune response. We show that LIF2 loss-of-function in A. thaliana leads to changes in the basal expression of the salicylic acid (SA)- and jasmonic acid (JA)- dependent defense marker genes PR1 and PDF1.2, respectively. Whereas the expression of genes involved in SA and JA biosynthesis and signaling was also affected in the lif2-1 mutant, no change in SA and JA hormonal contents was detected. In addition, the composition of glucosinolates, a class of defense-related secondary metabolites, was altered in the lif2-1 mutant in the absence of pathogen challenge. The lif2-1 mutant exhibited reduced susceptibility to the hemi-biotrophic pathogen Pseudomonas syringae and the necrotrophic ascomycete Botrytis cinerea. Furthermore, the lif2-1 sid2-2 double mutant was less susceptible than the wild type to P. syringae infection, suggesting that the lif2 response to pathogens was independent of SA accumulation. Together, our data suggest that lif2-1 exhibits a basal primed defense state, resulting from complex deregulation of gene expression, which leads to increased resistance to pathogens with various infection strategies. Therefore, LIF2 may function as a suppressor of cell-autonomous immunity. Similar to its human homolog, NSAP1/SYNCRIP, a trans-acting factor involved in both cellular processes and the viral life cycle, LIF2 may regulate the conflicting aspects of development and defense programs, suggesting that a conserved evolutionary trade-off between growth and defense pathways exists in eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / immunology*
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Botrytis
  • Cyclopentanes / metabolism
  • Gene Expression Regulation, Plant
  • Gene Ontology
  • Glucosinolates / metabolism
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism*
  • Models, Biological
  • Mutation / genetics
  • Oxylipins / metabolism
  • Plant Diseases / genetics
  • Plant Diseases / microbiology
  • Plant Immunity* / genetics
  • Pseudomonas syringae / physiology
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Salicylic Acid / metabolism
  • Signal Transduction / genetics
  • Stress, Physiological / genetics
  • Transcriptome / genetics

Substances

  • Arabidopsis Proteins
  • Cyclopentanes
  • Glucosinolates
  • Heterogeneous-Nuclear Ribonucleoproteins
  • LIF2 protein, Arabidopsis
  • Oxylipins
  • RNA-Binding Proteins
  • jasmonic acid
  • Salicylic Acid

Grants and funding

CLR was supported by an INRA CJS PhD fellowship. SDP was supported by PhD fellowships provided by the European Commission Seventh Framework-People-2012-ITN project EpiTRAITS (Epigenetic regulation of economically important plant traits, no-316965). Furthermore, this work was supported by the ANR (ANR/08/BLAN-0200) from the French Research Ministry and by INRA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.