Functional characterization of Arabidopsis thaliana WRKY39 in heat stress

Mol Cells. 2010 May;29(5):475-83. doi: 10.1007/s10059-010-0059-2. Epub 2010 Apr 12.

Abstract

Arabidopsis thaliana WRKY39, a transcription factor that is induced by heat stress, is a member of the group II WRKY proteins and responds to both abiotic and biotic stress. Heat-treated seeds and plants of WRKY39 knock-down mutants had increased susceptibility to heat stress, showing reduced germination, decreased survival, and elevated electrolyte leakage compared with wild-type plants. In contrast, WRKY39 over-expressing plants exhibited enhanced thermotolerance compared with wild-type plants. RT-PCR and qRT-PCR analysis of wrky39 mutants and WRKY39 over-expressing plants identified putative genes regulated by WRKY39. Consistent with a role for WRKY39 in heat tolerance, the expression levels of salicylic acid (SA)-regulated PR1 and SA-related MBF1c genes were downregulated in wrky39 mutants. In contrast, over-expression of WRKY39 increased the expression of PR1 and MBF1c. The WRKY39 transcript was induced in response to treatment with SA or methyljasmonate. Analysis of heat stress-induced WRKY39 in defense signaling mutants, including coi1, ein2, and sid2, further indicated that WRKY39 was positively co-regulated by the SA and jasmonate (JA) signaling pathways. Together, these findings reveal that heat stress-induced WRKY39 positively regulates the cooperation between the SA- and JA-activated signaling pathways that mediate responses to heat stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / metabolism*
  • Arabidopsis
  • Arabidopsis Proteins / biosynthesis
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cyclopentanes / metabolism*
  • DNA-Binding Proteins / genetics
  • Gene Expression Regulation, Plant*
  • Gene Knockdown Techniques
  • Germination / genetics
  • Hot Temperature / adverse effects
  • Intramolecular Transferases / genetics
  • Microarray Analysis
  • Mutation / genetics
  • Oxylipins / metabolism*
  • Plant Proteins / biosynthesis
  • Plant Proteins / genetics
  • Receptors, Cell Surface / genetics
  • Salicylic Acid / metabolism*
  • Signal Transduction / genetics
  • Stress, Physiological / genetics
  • Trans-Activators / biosynthesis
  • Trans-Activators / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transgenes / genetics

Substances

  • Acetates
  • Arabidopsis Proteins
  • CONSTANS protein, Arabidopsis
  • Cyclopentanes
  • DNA-Binding Proteins
  • EIN2 protein, Arabidopsis
  • MBF1 protein, Arabidopsis
  • Oxylipins
  • Plant Proteins
  • Receptors, Cell Surface
  • Trans-Activators
  • Transcription Factors
  • WRKY39 protein, Arabidopsis
  • pathogenesis-related proteins, plant
  • methyl jasmonate
  • Intramolecular Transferases
  • isochorismate synthase
  • Salicylic Acid