Study the mechanisms of histone deacetylases -HD2s for drought response in plants

在真核生物中，核小体是染色质的功能单位。核小体由DNA和组蛋白组成，DNA包裹在组蛋白八聚体上，该八聚体含有组蛋白H2A、H2B、H3和H4的两个拷贝。组蛋白的n端尾部经常遭受不同的翻译后修饰，如乙酰化。组蛋白乙酰化由组蛋白乙酰转移酶（HAT）和组蛋白去乙酰化酶（HDACs）控制。组蛋白去乙酰化酶是一组古老的酶，广泛存在于各种生物体中。研究表明，hdac控制着植物的一系列重要生物过程，特别是植物的发育和对环境胁迫的反应。植物含有一组特定的HDACs， HD2s。HD2s与其他HDAC家族在结构上几乎没有相似性，HD2s似乎在植物中具有较好的保守性。研究表明，控制HD2的表达可以提高植物对某些非生物胁迫的耐受性。目前，关于HD2s如何调节基因表达以应对环境胁迫的分子机制知之甚少。在本研究中，我们将以拟南芥为模式植物，开展一系列研究，研究植物在非生物胁迫下HD2在不同方面的功能。我们将研究不同HD2s在植物中的基因表达模式。然后我们将揭示不同HD2成员对干旱胁迫的响应关系。HD2s参与脱落酸（ABA）介导的非生物反应途径将被研究。最后，我们将揭示HD2s调控应激反应基因，并探讨HD2s调控应激反应基因的机制。我们的长期研究目标是揭示不同类型的hdac在植物对环境胁迫反应中调控基因表达的见解和机制。该研究的成果和知识可用于开发具有非生物抗性的植物和作物。

In eukaryotes, the nucleosome is the functional unit of chromatin. The nucleosome consists of DNA and histone proteins and DNA wraps on the histone octamer that contains two copies of histone H2A, H2B, H3 and H4. The N-terminal tails of histone proteins are often subjected to different posttranslational modifications, such as acetylation. Histone acetylation is controlled by histone acetyltransferases (HAT) and histone deacetylases (HDACs). Histone deacetylases are an ancient group of enzymes that are widely present in various organisms. Research has shown that the HDACs control a range of important biological processes in plants, especially plant development and response to environmental stresses. Plants contain a specific group of HDACs, HD2s. HD2s show little similarity in structure with other HDAC families and it appears HD2s are well conserved in plants. Research has indicated that control of HD2 expression can increase plant tolerance to certain abiotic stress. At this time, little is known about the molecular mechanisms of how HD2s regulate gene expression in response to environmental stresses. In this research, we will use Arabidopsis as model plant and conduct a series of research to study different aspects of HD2 functions in plants in response to abiotic stresses. We will study gene expression patterns of different HD2s in plants. We will then reveal the relationship of different HD2 members in response to drought stress. The involvement of HD2s in abscisic acid (ABA)-mediated abiotic responsive pathway will be investigated. Finally, we will reveal HD2s regulated stress response genes and investigate how HD2s regulate stress response genes. Our long term research goals are to reveal the insights and mechanisms of different types HDACs in regulating gene expression in plant response to environmental stresses. The results and knowledge generated from the research can be used for development of plants and crops for abiotic stress tolerance.