Characterization of a JAZ7 activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen Fusarium oxysporum

Louise F Thatcher, Volkan Cevik, Murray Grant, Bing Zhai, Jonathan D G Jones, John M Manners, Kemal Kazan

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

In Arabidopsis, jasmonate (JA)-signaling plays a key role in mediating Fusarium oxysporum disease outcome. However, the roles of JASMONATE ZIM-domain (JAZ) proteins that repress JA-signaling have not been characterized in host resistance or susceptibility to this pathogen. Here, we found most JAZ genes are induced following F. oxysporum challenge, and screening T-DNA insertion lines in Arabidopsis JAZ family members identified a highly disease-susceptible JAZ7 mutant (jaz7-1D). This mutant exhibited constitutive JAZ7 expression and conferred increased JA-sensitivity, suggesting activation of JA-signaling. Unlike jaz7 loss-of-function alleles, jaz7-1D also had enhanced JA-responsive gene expression, altered development and increased susceptibility to the bacterial pathogen PstDC3000 that also disrupts host JA-responses. We also demonstrate that JAZ7 interacts with transcription factors functioning as activators (MYC3, MYC4) or repressors (JAM1) of JA-signaling and contains a functional EAR repressor motif mediating transcriptional repression via the co-repressor TOPLESS (TPL). We propose through direct TPL recruitment, in wild-type plants JAZ7 functions as a repressor within the JA-response network and that in jaz7-1D plants, misregulated ectopic JAZ7 expression hyper-activates JA-signaling in part by disturbing finely-tuned COI1-JAZ-TPL-TF complexes.

Original languageEnglish
Pages (from-to)2367-2386
Number of pages20
JournalJournal of Experimental Botany
Volume67
Issue number8
DOIs
Publication statusPublished - Apr 2016

Keywords

  • Amino Acid Motifs
  • Arabidopsis
  • Arabidopsis Proteins
  • Co-Repressor Proteins
  • Cyclopentanes
  • DNA, Bacterial
  • Disease Resistance
  • Disease Susceptibility
  • Flowers
  • Fusarium
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Models, Biological
  • Mutagenesis, Insertional
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • Oxylipins
  • Phenotype
  • Plant Diseases
  • Plants, Genetically Modified
  • Protein Binding
  • Pseudomonas syringae
  • RNA, Messenger
  • Repressor Proteins
  • Up-Regulation
  • Journal Article
  • Research Support, Non-U.S. Gov't

Fingerprint Dive into the research topics of 'Characterization of a<em> JAZ7</em> activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen <em>Fusarium oxysporum</em>'. Together they form a unique fingerprint.

  • Cite this