Floral repressors in Arabidopsis thaliana

花的诱导在拟南芥中已被广泛研究。在过去的十年中，在理解这一重要的发育过程方面取得了巨大的进展，许多促进开花的基因已经被分离出来。然而，花的抑制作用还不太清楚。类似地，目前还不清楚不同的成花诱导途径的输出如何控制控制个体花的身份的基因的表达。我们已经确定了花的阻遏物，SCHLAFMÜTZE（SMZ），它编码的AP 2型转录因子，在光周期途径的下游。SMZ和旁系同源基因SCHNARCHZAPFEN（SNZ）属于六个AP 2家族成员的分支，这些成员是miR 172 micro-RNAs的潜在靶点。我们将详细研究SMZ和SNZ的转录积累是如何调节的，包括miR 172在这一过程中的潜在作用。SMZ和SNZ的转录靶标将使用表达谱以及SMZ/SNZ结合位点的全基因组鉴定来鉴定。分子、生物化学和基因组方法将通过遗传学研究进行补充，包括诱变筛选以鉴定SMZ功能获得性等位基因的增强子和/或抑制子。最后，我们将开始表征另外七个激活标记的系，其中开花被延迟，因此是用于鉴定另外的花阻遏物的候选物。

Floral induction has been studied extensively in Arabidopsis thaliana. Over the last decade, tremendous progress has been made in understanding this important developmental process, and many genes promoting flowering have been isolated. Floral repression, however, is less well understood. Similarly, it has been unclear how output of different floral induction pathways controls the expression of genes that control the identity of individual flowers. We have identified a floral repressor, SCHLAFMÜTZE (SMZ), which encodes an AP2-type transcription factor that acts downstream in the photoperiod pathway. SMZ and the paralogous gene SCHNARCHZAPFEN (SNZ) belong to a clade of six AP2-family members that are potential targets of miR172 micro-RNAs. We will study in detail how transcript accumulation of SMZ and SNZ is regulated, including the potential role of miR172 in this process. Transcriptional targets of SMZ and SNZ will be identified using expression profiling as well as genome-wide identification of SMZ/SNZ bindigs sites. Molecular, biochemical and genomic approaches will be complemented by genetic studies, including mutagenesis screens to identify enhancers and/or suppressors of an SMZ gain-of-function allele. Finally, we will begin to characterize seven additional activation-tagged lines in which flowering is delayed, and which are therefore candidates for identifying additional floral repressors.