John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
Cell. 2010 Jan 8;140(1):136-47. doi: 10.1016/j.cell.2009.11.006.
Plants are highly sensitive to temperature and can perceive a difference of as little as 1 degrees C. How temperature is sensed and integrated in development is unknown. In a forward genetic screen in Arabidopsis, we have found that nucleosomes containing the alternative histone H2A.Z are essential to perceiving ambient temperature correctly. Genotypes deficient in incorporating H2A.Z into nucleosomes phenocopy warm grown plants, and show a striking constitutive warm temperature transcriptome. We show that nucleosomes containing H2A.Z display distinct responses to temperature in vivo, independently of transcription. Using purified nucleosomes, we are able to show that H2A.Z confers distinct DNA-unwrapping properties on nucleosomes, indicating a direct mechanism for the perception of temperature through DNA-nucleosome fluctuations. Our results show that H2A.Z-containing nucleosomes provide thermosensory information that is used to coordinate the ambient temperature transcriptome. We observe the same effect in budding yeast, indicating that this is an evolutionarily conserved mechanism.
植物对温度非常敏感，能够感知到 1 摄氏度的微小差异。目前尚不清楚温度是如何被感知并整合到发育中的。在拟南芥的正向遗传筛选中，我们发现含有组蛋白 H2A.Z 的核小体对于正确感知环境温度是必不可少的。缺乏将 H2A.Z 纳入核小体的基因型表现出类似于在温暖条件下生长的植物的表型，并显示出显著的组成性温暖温度转录组。我们表明，含有 H2A.Z 的核小体在体内对温度表现出独特的反应，而不依赖于转录。使用纯化的核小体，我们能够表明 H2A.Z 赋予核小体独特的 DNA 解缠绕特性，这表明通过 DNA-核小体波动来感知温度的直接机制。我们的结果表明，含有 H2A.Z 的核小体提供热感觉信息，用于协调环境温度转录组。我们在 budding yeast 中观察到相同的效果，表明这是一种进化保守的机制。
