Shindo Chikako, Lister Clare, Crevillen Pedro, Nordborg Magnus, Dean Caroline
Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom.
Genes Dev. 2006 Nov 15;20(22):3079-83. doi: 10.1101/gad.405306.
Vernalization, the cold-induced acceleration of flowering, involves the epigenetic silencing of the floral repressor gene FLOWERING LOCUS C (FLC). We investigated the molecular basis for variation in vernalization in Arabidopsis natural accessions adapted to different climates. A major variable was the degree to which different periods of cold caused stable FLC silencing. In accessions requiring long vernalization, FLC expression was reactivated following nonsaturating vernalization, but this reactivation was progressively attenuated with increasing cold exposure. This response was correlated with the rate of accumulation of FLC histone H3 Lys 27 trimethylation (H3K27me3). Thus, variation in epigenetic silencing of FLC appears to have contributed to Arabidopsis adaptation.
春化作用,即低温诱导的开花加速,涉及到 floral repressor 基因 FLOWERING LOCUS C(FLC)的表观遗传沉默。我们研究了适应不同气候的拟南芥自然群体中春化作用变异的分子基础。一个主要变量是不同时长的低温导致 FLC 稳定沉默的程度。在需要长时间春化作用的群体中,不饱和春化处理后 FLC 表达会重新激活,但随着低温暴露时间增加,这种重新激活会逐渐减弱。这种反应与 FLC 组蛋白 H3 赖氨酸 27 三甲基化(H3K27me3)的积累速率相关。因此,FLC 表观遗传沉默的变异似乎促成了拟南芥的适应性。