tailieunhanh - báo cáo khoa học: " Roles of arabidopsis WRKY18, WRKY40 and WRKY60 transcription factors in plant responses to abscisic acid and abiotic stress"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Roles of arabidopsis WRKY18, WRKY40 and WRKY60 transcription factors in plant responses to abscisic acid and abiotic stress | Chen et al. BMC Plant Biology 2010 10 281 http 1471-2229 10 281 BMC Plant Biology RESEARCH ARTICLE Open Access Roles of arabidopsis WRKY18 WRKY40 and WRKY60 transcription factors in plant responses to abscisic acid and abiotic stress 1 2 1 w X - 1 Z- 2 X - X 1 Han Chen Zhibing Lai Junwei Shi Yong Xiao Zhixiang Chen Xinping Xu Abstract Background WRKY transcription factors are involved in plant responses to both biotic and abiotic stresses. Arabidopsis WRKY18 WRKY40 and WRKY60 transcription factors interact both physically and functionally in plant defense responses. However their role in plant abiotic stress response has not been directly analyzed. Results We report that the three WRKYs are involved in plant responses to abscisic acid ABA and abiotic stress. Through analysis of single double and triple mutants and overexpression lines for the WRKY genes we have shown that WRKY18 and WRKY60 have a positive effect on plant ABA sensitivity for inhibition of seed germination and root growth. The same two WRKY genes also enhance plant sensitivity to salt and osmotic stress. WRKY40 on the other hand antagonizes WRKY18 and WRKY60 in the effect on plant sensitivity to ABA and abiotic stress in germination and growth assays. Both WRKY18 and WRKY40 are rapidly induced by ABA while induction of WRKY60 by ABA is delayed. ABA-inducible expression of WRKY60 is almost completely abolished in the wrky18 and wrky40 mutants. WRKY18 and WRKY40 recognize a cluster of W-box sequences in the WRKY60 promoter and activate WRKY60 expression in protoplasts. Thus WRKY60 might be a direct target gene of WRKY18 and WRKY40 in ABA signaling. Using a stable transgenic reporter effector system we have shown that both WRKY18 and WRKY60 act as weak transcriptional activators while WRKY40 is a transcriptional repressor in plant cells. Conclusions We propose that the three related WRKY transcription factors form a highly interacting regulatory network that modulates gene .