The Isolation And Genetic Transformation Of WRKY Gene In Wheat(Triticum Aestivum L.)

WRKY transcription factors are one of the largest families of transcriptional regulaters in plant, which can specifically bind to W-box, and modulate the expression of disease, wound and senescence-related genes expression whose promoters contain W-box elements, thereby extensively involved in the responses to biotic and abiotic stresses in plant.In the present research, based on the conserved protein sequence of WRKY transcription factor, ESTs with high similarity to WRKY in wheat genome sequence database were researched, collected and then assembled into several uni-genes. A full-length cDNA sequence encoding WRKY in wheat was successufully cloned by using gene specific primers via PCR approach. The alignment of this gene in NCBI showed that it had high similarity with that of TaWRKY53a and TaWRKY53b, suggesting that it should be a novel WRKY gene in wheat, and thus designated TaWRKY53c. The bioinformatic analysis of this gene showed that TaWRKY53c has two conserved WRKY domains and zinc-finger structures, indicating that it belongs to GroupⅠin WRKY family. A phylogenetic tree was made by multiple sequence alignment with WRKY GroupⅠproteins in Arabidopsis and TaWRKY53c protein, and it was showed that TaWRKY53c was closely related to AtWRKY33, therefore we could infer that they maybe involved in the similar signaling pathway. It has been reported that AtWRKY33 participated in the salt resistance in Arabidopsis. Spatiotemporal expression pattern and fluorescent quantitation RT-PCR analysis showed that TaWRKY53c was strongly expressed in leaf, moderately in stem and weakly in root. The expression of TaWRKY53c was greatly enhanced after one hour of salt stress in wheat seedlings and returned to the normal level thereafter. Thus AtWRKY33 was considered as one of the important signalling component in response to salt stress in wheat.?In order to verify its function, TaWRKY53c was transformed into wheat by particle bombardment, and a large number of regenerated plants were obtained. These results of the present study provided the bases to clarify the regulation mechanisms and biological functions of WRKY proteins and to breed new transgenetic wheat variety with salt resistance.