The analysis of an Arabidopsis triple knock-down mutant reveals functions for MBF1 genes under oxidative stress conditions

摘要: Transcriptional co-activators of the multiprotein bridging factor 1 (MBF1) type belong to a small multigenic family that controls gene expression by connecting transcription factors and basal machinery. In this report, triple knock-down mutant (abc−) for Arabidopsis thaliana MBF1 genes AtMBF1a, AtMBF1b AtMBF1c was generated. The phenotypic characterization using oxidative agents such as hydrogen peroxide methyl viologen revealed abc− more sensitive stress. mutant, also osmotic stress mediated high concentrations sorbitol. Furthermore, phenotype partially or completely rescued cDNA over-expression (abc− +c) depending on physiological developmental conditions. AtMBF1s regulate ABR1, which is member ethylene-response acts ABA repressor. Thus, we conclude AtMBF1 may function regulatory component cross-talk node between ethylene, signal pathways. higher levels HSP70 mRNA an immunoreactive protein were detected in mutant. participation MBF1c possible negative regulator HSP discussed.