Molecular cloning of WRKY transcription factor sequences in wild emmer wheat (Triticum dicoccoides)

WRKY transcription factors are one of the largest families of transcriptional regulators in plants and the WRKY gene family is involved in several diverse pathways. WRKY genes contain one or two highly conserved DNA binding domains called WRKY domain interrupted by an intron. In this study, 20 sequence fragments with WRKY genes/proteins were identified by a pair of degenerate primer (WRKY 1 FP + WRKY 2 RP) from wild emmer wheat (Triticum dicoccoides), which were represented fragments of 7 unique WRKY loci. The T. dicoccoides WRKY (TdWRKY) putative loci ranged in size from 207 bp (TdWRKY-7) to 562 bp (TdWRKY-2). Size differences among the 7 TdWRKY putative loci were primarily due to variations in the length of the intron contained within the WRKY domain. These introns ranged in size from 97 bp (TdWRKY-7) to 449 bp (TdWRKY-2). According to the group assignments of 7 TdWRKY domains with 38 AtWRKY domains and the position of the putative intron for the TdWRKY loci, the 5 TdWRKY loci (TdWRKY-1, TdWRKY-3, TdWRKY-4, TdWRKY-5 and TdWRKY-7) belonged to WRKY group I domains; and the rest 2 loci’s domains (TdWRKY-2 and TdWRKY-6) were clustered into WRKY group IIb. This research provide some useful information for studying the WRKY transcriptional factors families in the genus Triticum L.