Sequence Analysis Of WRKY Gene Family And Their Response To Powdery Mildew Fungus In Wheat

The WRKY protein is an important superfamily of transcription factors in plants.WRKY domains were initially defined by a nearly 60 amino acid long motif possessing the well-conserved amino acid signature WRKYGQK at their N-terminus and containing a zinc-finger-like motif at its C-terminal end.WRKY transcription factors can be classified into several groups on the basis of both the number of WRKY domains and the features of their zinc-finger-like motif.They can regulate expression of target gene by cognate cis-acting W box elements presenting in the promoters of many plant genes that are associated with defense. Evidence is accumulating to suggest that the WRKY proteins play a very important role in response to biotic and abiotic stress.Now there has not systematic study to WRKY transcription factors in wheat.We conducted a study using full length cDNA library:Sequence analysis of the wheat WRKY gene family.61 wheat WRKY transcription factors were obtained by full-cDNA sequence.The unrooted phylogenetic tree was depicted by wheat domain use Clustal X,Jalview 2.0,MEGA 4 software.The wheat WRKY gene family can be classified as four main groups and seven subgroups.Phylogenetic tree of wheat WRKY gene family and others species WRKY responded to pathogens induced in order to predicted functional of wheat WRKY genes.WRKY transcription factors play important roles in plant defense signaling network.Ta WRKY34 gene was identified in response to wheat powdery mildew fungus by cDNA macroarray and semi-quantitative RT-PCR.It encodes 464 amino acid residues,and was mapped onto wheat 1BS using electronic mapping strategy.Multiple sequence alignments of proteins indicated that TaWRKY34 was closely related to WRKY transcription factors responding to pathogens in Arabidopsis,rice and barely,and had highest homology with AtWRKY25 in Arabidopsis and HvWRKY46 in barley.The expression profiles of TaWRKY34 induced by powdery mildew fungus,SA and JA were significantly different between resistant and susceptible Pm16/Beijing837~7 near-isogenic lines of wheat powdery mildew.The results implied that TaWRKY34 was involved in different modulation in resistant and susceptible near-isogenic lines of wheat powdery mildew.This study provides basis for to know interaction between Pm16 and TaWRKY34.