H3K9ac, an epigenetic marker, is widely distributed in plant genomes. H3K9ac enhances gene expression, which is highly conserved in eukaryotes. However, genome-wide studies of H3K9ac in monocot species are limited, and the changes in H3K9ac under drought stress for individual genes are still not clear. We analysed changes in the H3K9ac level of Brachypodium distachyon under 20% PEG-6000-simulated drought stress conditions. We also performed chromatin immunoprecipitation, followed by next generation sequencing (ChIP-seq) on H3K9ac to reveal changes in H3K9ac for individual genes at the genome-wide level. Our study showed that H3K9ac was mainly enriched in gene exon regions. Drought increased or decreased the H3K9ac level at specific genomic loci. We identified 40 genes associated with increased H3K9ac levels and 36 genes associated with decreased H3K9ac levels under drought stress. Further, RT-qPCR analyses showed that H3K9ac was positively associated with gene expression of those drought-responsive genes. We conclude that H3K9ac enhances the expression level of a large number of drought-responsive genes under drought stress in B. distachyon. The data presented here will help to reveal the correlation of some specific drought-responsive genes and their enriched H3K9ac levels in the model plant B. distachyon.

中文翻译：

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组蛋白修饰H3K9ac的干旱诱导变化与短枝曲霉（Brachypodium distachyon）中的干旱响应基因表达有关。

H3K9ac是一种表观遗传标记，广泛分布在植物基因组中。H3K9ac增强了基因表达，该基因在真核生物中高度保守。但是，单子叶植物物种中H3K9ac的全基因组研究有限，单个基因在干旱胁迫下H3K9ac的变化仍不清楚。我们分析了在20％PEG-6000模拟的干旱胁迫条件下，短枝曲霉H3K9ac水平的变化。我们还进行了染色质免疫沉淀，然后在H3K9ac上进行了下一代测序（ChIP-seq），以揭示全基因组水平上单个基因在H3K9ac中的变化。我们的研究表明，H3K9ac主要富集于基因外显子区域。干旱会在特定基因组位点增加或降低H3K9ac水平。我们确定了40个与H3K9ac水平升高有关的基因和36个与H3K9ac水平降低有关的基因。此外，RT-qPCR分析显示H3K9ac与那些干旱反应基因的基因表达呈正相关。我们得出的结论是，H3K9ac增强了B. distachyon干旱胁迫下大量干旱响应基因的表达水平。此处提供的数据将有助于揭示模型植物B. distachyon中某些特定的干旱响应基因及其丰富的H3K9ac水平的相关性。distachyon。此处提供的数据将有助于揭示模型植物B. distachyon中某些特定的干旱响应基因及其丰富的H3K9ac水平的相关性。distachyon。此处提供的数据将有助于揭示模型植物B. distachyon中某些特定的干旱响应基因及其丰富的H3K9ac水平的相关性。