Rapid systemic accumulation of transcripts encoding a tobacco WRKY transcription factor upon wounding

Abstract

An immediate-early, transiently activated wound-responsive gene was identified in tobacco by fluorescent differential display screening. The full-length cDNA encodes a polypeptide of 356 amino acids with a relative molecular mass of 39,082 Da. The deduced amino acid sequence shows two characteristic features; a leucine-zipper motif found in the more N-terminal region and a WRKY domain containing a zinc-finger motif located in the central region. The gene was designated as wizz (wound-induced leucine zipper zinc finger). Northern analysis showed that upon wounding wizz transcripts were locally and systemically accumulated within 10 min, reached a maximum level by 30 min, and decreased thereafter to the basal level. Analyses of a WIZZ-GFP fusion protein clearly indicated that WIZZ is a nuclear factor. WIZZ specifically binds to sequences containing two TTGAC core motifs that are separated by a spacer of appropriate length. The binding activity was dependent on bivalent cations, most probably zinc. In transient reporter assays, however, WIZZ did not show transactivation activity in tobacco suspension cells, suggesting that it functions together with other components. The results indicate that WIZZ is a new transcription factor which participates in early stages of the wound response.

Characterization of GaWRKY1, a Cotton Transcription Factor That Regulates the Sesquiterpene Synthase Gene (+)-δ-Cadinene Synthase-A

“…Among the WRKY proteins reported so far, only a subset of members, such as ABF2, WIZZ, PcWRKY4, and PcWRKY5, have putative Leu zippers (Rushton et al, 1995;Eulgem et al, 2000;Hara et al, 2000;Cormack et al, 2002). Function of the Leu zipper has been proposed to mediate dimerization and increase the DNA-binding affinity of WRKY proteins (Cormack et al, 2002).…”

“…2). GaWRKY1 exhibited high sequence identities (41%-45%) to Group IIa WRKY proteins, including PcWRKY4 of parsley (Cormack et al, 2002), AtWRKY18 of Arabidopsis , and Wizz of tobacco (Hara et al, 2000). Alignment of these protein sequences revealed that the WRKY domain, putative Leu zipper, nuclear localization site, and a C-terminal Ala-rich stretch were strictly conserved; outside these regions, however, there was little sequence conservation ( Fig.…”

Deciphering the Role of various cis-acting regulatory elements in controlling SamDC gene expression in Rice

“…There are considerable reports on several WRKY transcription factors being induced by cold, salinity or wounding. 9,10,11 Besides the WRKY another superfamily of transcription factors in plants are the MYBs. In plants the MYB transcription factors contains R2 and R3 domains and the binding sequence varies from four to 14 nucleotides.…”

OsWRKY03, a rice transcriptional activator that functions in defense signaling pathway upstream of OsNPR1

“…Recently, the plant-specific transcription factors, WRKY family proteins containing highly conserved WRKY domain [44], have been found to be involved in the regulation of plant defense response. It has been shown from a number of plants that WRKY genes are rapidly induced by pathogens, pathogen elicitors, or SA treatment [45][46][47]. Arabidopsis WRKY transcriptional factor (AtWRKY52), containing a LRR motif of TIR-NBS-LRR subclass R gene products, has been shown to enhance disease resistance to several strains of Ralstonia solanacearum [48].…”