Seed dormancy cycling in Arabidopsis: chromatin remodelling and regulation of DOG1 in response to seasonal environmental signals.
Seed dormancy cycling in Arabidopsis: chromatin remodelling and regulation of DOG1 in response to seasonal environmental signals.
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DOI：
10.1111/tpj.12735
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发表时间：
2015-02
期刊：
影响因子：
--
通讯作者：
Finch-Savage WE
中科院分区：
文献类型：
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作者：
Footitt S;Müller K;Kermode AR;Finch-Savage WE
人们对染色质重塑在土壤种子库（SSB）休眠周期中的参与知之甚少。利用冬季和夏季一年生拟南芥生态型 Cvi 和 Bur 之间的自然变异来研究通过组蛋白 2B (H2B) 泛素化/去泛素化和组蛋白乙酰化/脱乙酰化、抑制性组蛋白甲基转移酶 CURLY LEAF (CLF) 和 SWINGER (SWN) 以及基因沉默阻遏物 ROS1 (REPRESSOR OF) 参与染色质重塑的基因的表达。 SILENCING1) 和沉默 KYP/SUVH4 (KRYPTONITE) 的启动子，在 SSB 的休眠周期期间。 ROS1 表达与休眠呈正相关，而 CLF 和 KYP/SUVH4 则相反。我们提出ROS1依赖性沉默抑制以及CLF和KYP/SUVH4依赖性基因抑制和沉默的连续要求，以在休眠周期期间维持和抑制休眠。 H2B 修饰基因的季节性表达与温度呈负相关，与 DOG1 表达呈正相关，组蛋白乙酰转移酶基因也是如此，组蛋白脱乙酰酶与温度呈正相关。在休眠周期期间，Cvi 中的 DOG1（发芽延迟 1）组蛋白标记 H3K4me3 和 H3K27me3 发生变化。 H3K4me3 激活标记沿着 DOG1 保持稳定。在解除休眠期间，H3K27me3 抑制标记缓慢积累，并在暴露于光线时加速，完成休眠丧失。我们建议 DOG1 上的这些标记在休眠周期期间充当热传感机制，为休眠的光抑制做准备。总体而言，染色质重塑通过基因表达的调节在时间感知中发挥着至关重要的作用。
The involvement of chromatin remodelling in dormancy cycling in the soil seed bank (SSB) is poorly understood. Natural variation between the winter and summer annual Arabidopsis ecotypes Cvi and Bur was exploited to investigate the expression of genes involved in chromatin remodelling via histone 2B (H2B) ubiquitination/de-ubiquitination and histone acetylation/deacetylation, the repressive histone methyl transferases CURLY LEAF (CLF) and SWINGER (SWN), and the gene silencing repressor ROS1 (REPRESSOR OF SILENCING1) and promoter of silencing KYP/SUVH4 (KRYPTONITE), during dormancy cycling in the SSB. ROS1 expression was positively correlated with dormancy while the reverse was observed for CLF and KYP/SUVH4. We propose ROS1 dependent repression of silencing and a sequential requirement of CLF and KYP/SUVH4 dependent gene repression and silencing for the maintenance and suppression of dormancy during dormancy cycling. Seasonal expression of H2B modifying genes was correlated negatively with temperature and positively with DOG1 expression, as were histone acetyltransferase genes, with histone deacetylases positively correlated with temperature. Changes in the histone marks H3K4me3 and H3K27me3 were seen on DOG1 (DELAY OF GERMINATION1) in Cvi during dormancy cycling. H3K4me3 activating marks remained stable along DOG1. During relief of dormancy, H3K27me3 repressive marks slowly accumulated and accelerated on exposure to light completing dormancy loss. We propose that these marks on DOG1 serve as a thermal sensing mechanism during dormancy cycling in preparation for light repression of dormancy. Overall, chromatin remodelling plays a vital role in temporal sensing through regulation of gene expression.