TaWRKY70 transcription factor in wheat QTL-2DL regulates downstream metabolite biosynthetic genes to resist Fusarium graminearum infection spread within spike

Sci Rep. 2017 Feb 15:7:42596. doi: 10.1038/srep42596.

Abstract

A semi-comprehensive metabolomics was used to identify the candidate metabolites and genes to decipher mechanisms of resistance in wheat near-isogenic lines (NILs) containing QTL-2DL against Fusarium graminearum (Fg). Metabolites, with high fold-change in abundance, belonging to hydroxycinnamic acid amides (HCAAs): such as coumaroylagmatine, coumaroylputrescine and Fatty acids: phosphatidic acids (PAs) were identified as resistance related induced (RRI) metabolites in rachis of resistant NIL (NIL-R), inoculated with Fg. A WRKY like transcription factor (TF) was identified within the QTL-2DL region, along with three resistance genes that biosynthesized RRI metabolites. Sequencing and in-silico analysis of WRKY confirmed it to be wheat TaWRKY70. Quantitative real time-PCR studies showed a higher expression of TaWRKY70 in NIL-R as compared to NIL-S after Fg inoculation. Further, the functional validation of TaWRKY70 based on virus induced gene silencing (VIGS) in NIL-R, not only confirmed an increased fungal biomass but also decreased expressions of downstream resistance genes: TaACT, TaDGK and TaGLI1, along with decreased abundances of RRI metabolites biosynthesized by them. Among more than 200 FHB resistance QTL identified in wheat, this is the first QTL from which a TF was identified, and its downstream target genes as well as the FHB resistance functions were deciphered.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomass
  • Chromatography, Liquid
  • Chromosome Mapping
  • Disease Resistance / genetics*
  • Fusarium
  • Gene Knockdown Techniques
  • Gene Silencing
  • Genetic Association Studies
  • High-Throughput Nucleotide Sequencing
  • Host-Pathogen Interactions / genetics*
  • Mass Spectrometry
  • Metabolic Networks and Pathways* / genetics
  • Metabolome
  • Metabolomics
  • Phylogeny
  • Plant Diseases / genetics
  • Plant Diseases / microbiology
  • Promoter Regions, Genetic
  • Protein Transport
  • Quantitative Trait Loci*
  • Quantitative Trait, Heritable
  • Transcription Factors / metabolism*
  • Triticum / microbiology*
  • Triticum / physiology*

Substances

  • Transcription Factors