Direct interaction of AGL24 and SOC1 integrates flowering signals in Arabidopsis
Direct interaction of AGL24 and SOC1 integrates flowering signals in Arabidopsis
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DOI：
10.1242/dev.020255
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发表时间：
2008-04-15
期刊：
影响因子：
4.6
通讯作者：
Yu, Hao
中科院分区：
文献类型：
--
作者：
Liu, Chang;Chen, Hongyan;Yu, Hao
在从营养生长向生殖生长过渡的过程中，开花植物的茎分生组织获得花序身份以产生花而不是营养组织。AGAMOUS-LIKE 24（AGL 24）是一种MADS盒转录因子，是拟南芥中促进花序同一性的重要调节因子。使用功能性雌二醇诱导系统结合微阵列分析，我们确定了AGL 24诱导的基因，包括CO 1（SOC 1），花途径集成商的过度表达的供应商。染色质免疫沉淀（ChIP）分析功能性AGL 24 - 6 HA标记的细胞系揭示了AGL 24 - 6 HA与SOC 1的调节区的体内结合。SOC 1启动子中AGL 24结合位点的突变降低了ProSOC 1：GUS的表达，并损害了SOC 1促进开花的功能。我们的研究结果表明，SOC 1是AGL 24的直接目标之一，并且SOC 1的表达上调AGL 24在茎尖在花的过渡阶段。使用功能性SOC 1 - 9 myc标记的细胞系和启动子诱变分析的ChIP测定也揭示了SOC 1 - 9 myc与AGL 24的调节区的体内结合以及SOC 1在茎尖处对AGL 24的上调。此外，我们发现，在其他开花的遗传途径，赤霉素对开花短日照条件下的影响是由AGL 24和SOC 1之间的相互作用介导的。这些观察结果表明，在花的过渡，一个正反馈回路赋予的直接转录调控之间的AGL 24和SOC 1在茎尖集成开花信号。
During the transition from vegetative to reproductive growth, the shoot meristem of flowering plants acquires the inflorescence identity to generate flowers rather than vegetative tissues. An important regulator that promotes the inflorescence identity in Arabidopsis is AGAMOUS-LIKE 24 (AGL24), a MADS-box transcription factor. Using a functional estradiol-inducible system in combination with microarray analysis, we identified AGL24- induced genes, including SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), a floral pathway integrator. Chromatin immunoprecipitation (ChIP) analysis of a functional AGL24- 6HA-tagged line revealed in vivo binding of AGL24- 6HA to the regulatory region of SOC1. Mutagenesis of the AGL24 binding site in the SOC1 promoter decreased ProSOC1: GUS expression and compromised SOC1 function in promoting flowering. Our results show that SOC1 is one of the direct targets of AGL24, and that SOC1 expression is upregulated by AGL24 at the shoot apex at the floral transitional stage. ChIP assay using a functional SOC1-9myc-tagged line and promoter mutagenesis analysis also revealed in vivo binding of SOC1-9myc to the regulatory regions of AGL24 and upregulation of AGL24 at the shoot apex by SOC1. Furthermore, we found that as in other flowering genetic pathways, the effect of gibberellins on flowering under short-day conditions was mediated by the interaction between AGL24 and SOC1. These observations suggest that during floral transition, a positive-feedback loop conferred by direct transcriptional regulation between AGL24 and SOC1 at the shoot apex integrates flowering signals.