WRKY Transcription Factor Family

WRKY transcription factors are one of the largest multigene families of transcriptional regulators in plants but are absent from prokaryotes, animals and fungi . Each WRKY protein has at least one WRKY domain of approximately 60 amino acids containing the conserved amino acid sequence WRKYGQK at its N-terminus (from which the factors take their name) and a novel zinc finger motif at its C-terminus . The WRKYGQK amino acid sequence forms a ß-strand that directly contacts the binding site on the promoters of target genes . Usually, this binding site is the W box (C/T)TGAC(T/C), an element found in the promoters of many stress-related plant genes . The ancestral-type WRKY transcription factor (group I) contains two WRKY domains (N-terminal and C-terminal). All other genes contain one WRKY domain and are classified into groups IIa, IIb, IIc, IId, IIe and III based on their primary amino acid sequence and structure of their zinc finger motifs . Rushton et al. (1996) presented the first evidence that WRKY transcription factors play roles in plant defence. There is now considerable evidence that they play roles in responses not only to biotic stresses but also abiotic stresses such as wounding, drought and cold adaptation and in Arabidopsis, most of the 74 WRKY genes are transcriptionally upregulated by defence-related stimuli. This suggests that a major role of WRKY genes in flowering plants is to mediate defence responses . It has recently been suggested that WRKY DNA-binding domains are related to the widespread GCM1 superfamily as both contain a four-stranded fold . However, any relatedness is distant as the primary amino acid sequences show very little similarity.
  • 198 predicted putative WRKY TF peptide, CDS, and cDNA sequences; blast HSP, and gene level multiple sequence alignment in Soy - TFKB.
  • WRKY domain peptide sequences with alignment and phylogeny tree in branching style or in phylogeny tree in radiation style.
  • 106 WRKY protein and DNA sequences with annotations for soybean in PlantTFDB. Most are partial sequences.
    Last updated by Dr. Jeff Chen on July 15, 2009.