A Single Amino Acid Change in the Enhancer of Zeste Ortholog CURLY LEAF Results in Vernalization-Independent, Rapid Flowering in Arabidopsis
A Single Amino Acid Change in the Enhancer of Zeste Ortholog CURLY LEAF Results in Vernalization-Independent, Rapid Flowering in Arabidopsis
复制标题
DOI：
10.1104/pp.109.145581
复制
发表时间：
2009-11-01
期刊：
影响因子：
7.4
通讯作者：
Amasino, Richard M.
中科院分区：
文献类型：
--
作者：
Doyle, Mark R.;Amasino, Richard M.
许多拟南芥（Arabidopsis thaliana）需要长时间暴露在寒冷中才能快速开花，这一过程称为春化。拟南芥中的春化作用导致开花抑制子FLOWERNIA LOCUS C（FLC）的抑制。在筛选不再需要春化以快速开花的突变体时，我们鉴定了Zeste E（z）增强子直系同源物卷曲叶（CLF）的显性等位基因clf-59。CLF是Polycomb Group基因，并且clf-59突变蛋白在SET结构域之前的富含半胱氨酸的区域中含有脯氨酸至丝氨酸的转变。突变体植物开花早，FLC表达减少，但与clf功能丧失突变体不同，clf-59突变体不显示额外的多效性表型。clf-59突变体在FLC处对组蛋白H3的赖氨酸27（H3 K27 me 3）具有升高的三甲基化水平。因此，clf-59似乎是一个功能获得性等位基因，该等位基因抑制FLC，而不需要春化介导的抑制所需的一些组分。在这项工作的过程中，我们还确定了在FLC中H3 K27 me 3水平在含有和缺乏FRIGIDA（FRI）基因的植物之间的显著差异。此外，FRI似乎影响CLF占用FLC，因此，我们的工作提供了深入了解的分子作用，FRI在延迟开花的开始。
Many strains of Arabidopsis (Arabidopsis thaliana) require exposure to prolonged cold for rapid flowering, a process known as vernalization. Vernalization in Arabidopsis results in the suppression of FLOWERING LOCUS C (FLC), a repressor of flowering. In a screen for mutants that no longer require vernalization for rapid flowering, we identified a dominant allele of the Enhancer of Zeste E(z) ortholog CURLY LEAF (CLF), clf-59. CLF is a Polycomb Group gene, and the clf-59 mutant protein contains a proline-to-serine transition in a cysteine-rich region that precedes the SET domain. Mutant plants are early flowering and have reduced FLC expression, but, unlike clf loss-of-function mutants, clf-59 mutants do not display additional pleiotropic phenotypes. clf-59 mutants have elevated levels of trimethylation on lysine 27 of histone H3 (H3K27me3) at FLC. Thus, clf-59 appears to be a gain-of-function allele, and this allele represses FLC without some of the components required for vernalization-mediated repression. In the course of this work, we also identified a marked difference in H3K27me3 levels at FLC between plants that contain and those that lack the FRIGIDA (FRI) gene. Furthermore, FRI appears to affect CLF occupancy at FLC; thus, our work provides insight into the molecular role that FRI plays in delaying the onset of flowering.