Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: WRKY Transcription Factors Involved in Activation of SA Biosynthesis Genes | van Verk et al. BMC Plant Biology 2011 11 89 http 1471-2229 11 89 BMC Plant Biology RESEARCH ARTICLE Open Access WRKY Transcription Factors Involved in Activation of SA Biosynthesis Genes Marcel C van Verk John F Bol and Huub JM Linthorst Abstract Background Increased defense against a variety of pathogens in plants is achieved through activation of a mechanism known as systemic acquired resistance SAR . The broad-spectrum resistance brought about by SAR is mediated through salicylic acid SA . An important step in SA biosynthesis in Arabidopsis is the conversion of chorismate to isochorismate through the action of isochorismate synthase encoded by the ICS1 gene. Also AVRPPHB SUSCEPTIBLE 3 PBS3 plays an important role in SA metabolism as pbs3 mutants accumulate drastically reduced levels of SA-glucoside a putative storage form of SA. Bioinformatics analysis previously performed by us identified WRKY28 and WRKY46 as possible regulators of ICS1 and PBS3. Results Expression studies with ICS1 promoter Ị3-glucuronidase GUS genes in Arabidopsis thaliana protoplasts cotransfected with 35S WRKY28 showed that over expression of WRKY28 resulted in a strong increase in GUS expression. Moreover qRT-PCR analyses indicated that the endogenous ICS1 and PBS3 genes were highly expressed in protoplasts overexpressing WRKY28 or WRKY46 respectively. Electrophoretic mobility shift assays indentified potential WRKY28 binding sites in the ICS1 promoter positioned -445 and -460 base pairs upstream of the transcription start site. Mutation of these sites in protoplast transactivation assays showed that these binding sites are functionally important for activation of the ICS1 promoter. Chromatin immunoprecipitation assays with haemagglutinin-epitope-tagged WRKY28 showed that the region of the ICS1 promoter containing the binding sites at -445 and -460 was highly enriched in the immunoprecipitated DNA. Conclusions The results obtained here confirm results from our .
