The late flowering phenotype of fwa mutants is caused by gain-of-function epigenetic alleles of a homeodomain gene
The late flowering phenotype of fwa mutants is caused by gain-of-function epigenetic alleles of a homeodomain gene
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DOI：
10.1016/s1097-2765(05)00090-0
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发表时间：
2000-10-01
期刊：
影响因子：
16
通讯作者：
Peeters, AJM
中科院分区：
文献类型：
--
作者：
Soppe, WJJ;Jacobsen, SE;Peeters, AJM
在fwa突变体植物中，拟南芥向开花的过渡延迟。FWA是通过FWA突变体正常开花复合体的功能缺失突变鉴定出来的，它编码一个含有同源结构域的转录因子。fwa基因组区野生型和突变型等位基因的DNA序列完全一致。此外，FWA基因在FWA突变体中异位表达，而在成熟的野生型植物中沉默。这种沉默与基因5'区两个直接重复序列的广泛甲基化有关。在ddm1低甲基化背景下，延迟开花表型、异位FWA表达和重复序列的低甲基化也被诱导。讨论了FWA表观遗传标记的建立和维持机制。
The transition to flowering in Arabidopsis thaliana is delayed in fwa mutant plants. FWA was identified by loss-of-function mutations in normally flowering revertants of the fwa mutant, and it encodes a homeodomain-containing transcription factor. The DNA sequence of wild-type and fwa mutant alleles was identical in the genomic region of FWA. Furthermore, the FWA gene is ectopically expressed in fwa mutants and silenced in mature wild-type plants. This silencing is associated with extensive methylation of two direct repeats in the 5' region of the gene. The late flowering phenotype, ectopic FWA expression, and hypomethylation of the repeats were also induced in the ddm1 hypomethylated background. Mechanisms for establishment and maintenance of the epigenetic mark on FWA are discussed.