植物會(huì)因?yàn)樗募净驎円沟臏囟茸兓{(diào)整生長狀態(tài)，那么它們靠什么來感知外界溫度變化呢,？英國研究人員說,，植物在基因?qū)用嬗幸粋€(gè)特殊的“溫度計(jì)”。這一發(fā)現(xiàn)將有助于研究人員培育出更能適應(yīng)當(dāng)前氣候變化的植物新品種,。
英國約翰·英尼斯中心的研究人員在最新一期《細(xì)胞》雜志上報(bào)告說,，他們利用擬南芥這種植物進(jìn)行了實(shí)驗(yàn)。研究人員使用可以導(dǎo)致這種植物發(fā)光的基因手段,，使其在溫度越高的環(huán)境下能發(fā)出越多的光,。
研究人員發(fā)現(xiàn)，一種名為H2A．Z的組蛋白是植物的“溫度計(jì)”,。當(dāng)植物生長的環(huán)境溫度較低時(shí),，這種組蛋白會(huì)綁在DNA（脫氧核糖核酸）上，使得一些基因無法發(fā)揮作用,，從而抑制植物生長,；而當(dāng)溫度升高時(shí)，它就會(huì)松開DNA,，相關(guān)基因就可以發(fā)揮作用,，指導(dǎo)植物生長。研究人員認(rèn)為,，一些植物隨著天氣冷暖而延后或提前開花,，都是受這套系統(tǒng)控制。
但如果這種組蛋白因變異而出現(xiàn)問題時(shí),，植物就可能無法感知到外界溫度變化,。研究人員說，因?yàn)橹参餆o法移動(dòng),，如果它不能迅速適應(yīng)某個(gè)地方的氣溫變化,，就有在當(dāng)?shù)販缃^的危險(xiǎn)。研究人員希望在了解植物溫控系統(tǒng)的特點(diǎn)后,，能培育出更能適應(yīng)氣候變化的植物新品種,。（生物谷Bioon.com）
生物谷推薦原始出處：
Cell, Volume 140, Issue 1, 136-147, 8 January 2010 DOI:10.1016/j.cell.2009.11.006
H2A.Z-Containing Nucleosomes Mediate the Thermosensory Response in Arabidopsis
S. Vinod Kumar, Philip A. Wigge
Plants are highly sensitive to temperature and can perceive a difference of as little as 1°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.
