Wood Craig C, Robertson Masumi, Tanner Greg, Peacock W James, Dennis Elizabeth S, Helliwell Chris A
Division of Plant Industry, Commonwealth Scientific and Industrial Research Organization, GPO Box 1600, Canberra, ACT 2601, Australia.
Proc Natl Acad Sci U S A. 2006 Sep 26;103(39):14631-6. doi: 10.1073/pnas.0606385103. Epub 2006 Sep 18.
In Arabidopsis thaliana, the promotion of flowering by cold temperatures, vernalization, is regulated via a floral-repressive MADS box transcription factor, FLOWERING LOCUS C (FLC). Vernalization leads to the epigenetic repression of FLC expression, a process that requires the polycomb group (PcG) protein VERNALIZATION 2 (VRN2) and the plant homeodomain protein VERNALIZATION INSENSITIVE 3 (VIN3). We demonstrate that the repression of FLC by vernalization requires homologues of other Polycomb Repressive Complex 2 proteins and VRN2. We show in planta that VRN2 and VIN3 are part of a large protein complex that can include the PcG proteins FERTILIZATION INDEPENDENT ENDOSPERM, CURLY LEAF, and SWINGER. These findings suggest a single protein complex is responsible for histone deacetylation at FLC and histone methylation at FLC in vernalized plants. The abundance of the complex increases during vernalization and declines after plants are returned to higher temperatures, consistent with the complex having a role in establishing FLC repression.
在拟南芥中，低温促进开花即春化作用，是通过一个抑制开花的MADS盒转录因子——开花位点C（FLC）来调控的。春化作用导致FLC表达的表观遗传抑制，这一过程需要多梳蛋白组（PcG）蛋白春化作用2（VRN2）和植物同源结构域蛋白春化不敏感3（VIN3）。我们证明，春化作用对FLC的抑制需要其他多梳抑制复合体2蛋白和VRN2的同源物。我们在植物体内表明，VRN2和VIN3是一个大型蛋白复合体的一部分，该复合体可能包括PcG蛋白非受精胚乳、卷曲叶和摆动蛋白。这些发现表明，在春化处理的植物中，一个单一的蛋白复合体负责FLC位点的组蛋白去乙酰化和FLC位点的组蛋白甲基化。在春化作用期间，该复合体的丰度增加，而在植物恢复到较高温度后其丰度下降，这与该复合体在建立FLC抑制中发挥作用相一致。
