tailieunhanh - báo cáo khoa học: " Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses | Li et al. BMC Plant Biology 2011 11 109 http 1471 -2229 11 109 BMC Plant Biology RESEARCH ARTICLE Open Access Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses 1t X 71 1t 1 1 1 -71 - 2 1 1 Daofeng Li Yunqin Zhang Xiaona Hu Xiaoye Shen Lei Ma Zhen Su Tao Wang and Jiangli Dong Abstract Background Salt stress hinders the growth of plants and reduces crop production worldwide. However different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene MtCBF4 for experimental validation. Results A microarray experiment was conducted using root samples collected 6 24 and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4 which belongs to the AP2-EREBP transcription factor family is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses including salt drought cold and abscisic acid suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis overexpressing MtCBF4 enhanced tolerance to drought and salt stress and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream .