Characterization of SOC1's Central Role in Flowering by the Identification of Its Upstream and Downstream Regulators
Characterization of SOC1's Central Role in Flowering by the Identification of Its Upstream and Downstream Regulators
复制标题
DOI：
10.1104/pp.112.202614
复制
发表时间：
2012-09-01
期刊：
影响因子：
7.4
通讯作者：
Angenent, Gerco C.
中科院分区：
文献类型：
--
作者：
Immink, Richard G. H.;Pose, David;Angenent, Gerco C.
从营养生长向生殖生长的转变是植物生活史中最重要的阶段变化之一。这一步骤是由各种环境信号控制的，这些信号通过所谓的花整合子在分子水平上整合。拟南芥中的一个这样的花整合子是MADS结构域转录因子CONSTANS 1（SOC 1）的过表达的提供者。尽管进行了广泛的遗传学研究，但对SOC 1的转录控制知之甚少，我们刚刚开始探索SOC 1转录因子复合物直接控制下的基因网络。在这里，我们表明，几个MADS结构域蛋白，包括SOC 1异二聚体，能够结合SOC 1调控序列。通过ChIP-seq进行的全基因组靶基因分析证实了SOC 1与其自身基因座的结合，并表明它还与大量的开花时间调节基因和花同源异型基因结合。反过来，编码的花同源异型MADS结构域蛋白似乎结合SOC 1调控序列。随后在植物分析显示SOC 1镇压几个花同源异型MADS结构域蛋白，我们表明，从机械上讲，这取决于SOC 1蛋白的存在。总之，我们的数据表明，SOC 1构成了一个主要的枢纽，在调控网络的基础开花时间和花的发育，这些网络是由许多积极和消极的自动调节和反馈回路。后者似乎是一个强大的花诱导信号的产生至关重要的，随后不久，由SOC 1花的整合剂的镇压。
The transition from vegetative to reproductive development is one of the most important phase changes in the plant life cycle. This step is controlled by various environmental signals that are integrated at the molecular level by so-called floral integrators. One such floral integrator in Arabidopsis (Arabidopsis thaliana) is the MADS domain transcription factor SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1). Despite extensive genetic studies, little is known about the transcriptional control of SOC1, and we are just starting to explore the network of genes under the direct control of SOC1 transcription factor complexes. Here, we show that several MADS domain proteins, including SOC1 heterodimers, are able to bind SOC1 regulatory sequences. Genome-wide target gene analysis by ChIP-seq confirmed the binding of SOC1 to its own locus and shows that it also binds to a plethora of flowering-time regulatory and floral homeotic genes. In turn, the encoded floral homeotic MADS domain proteins appear to bind SOC1 regulatory sequences. Subsequent in planta analyses revealed SOC1 repression by several floral homeotic MADS domain proteins, and we show that, mechanistically, this depends on the presence of the SOC1 protein. Together, our data show that SOC1 constitutes a major hub in the regulatory networks underlying floral timing and flower development and that these networks are composed of many positive and negative autoregulatory and feedback loops. The latter seems to be crucial for the generation of a robust flower-inducing signal, followed shortly after by repression of the SOC1 floral integrator.