Study the mechanisms of histone deacetylase HD2s in response to drought stress in plants

在真核生物中，核小体是染色质的基本功能单位。核小体由DNA和组蛋白组成，DNA包裹在组蛋白八聚体上。组蛋白的n端尾部经常遭受不同的翻译后修饰，如乙酰化。组蛋白乙酰化受组蛋白乙酰转移酶（HAT）和组蛋白去乙酰化酶（hdac）调控，前者催化超乙酰化，后者通过去除核心组蛋白上的乙酰基来催化去乙酰化。研究表明，hdac控制着植物的许多基本生物过程，特别是植物的发育和对环境胁迫的反应。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。植物含有一组特定的HDACs， HD2s。HD2s与其他HDAC家族在序列和结构上的相似性较低，HD2s似乎在不同类型的植物中都有很好的保守性。研究表明，HD2s参与植物对干旱等非生物胁迫的反应。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，利用分子生物学方法开展一系列研究，研究HD2在植物对非生物胁迫，特别是干旱的响应中的不同方面。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成员在干旱胁迫下的关系和潜在的相互作用。我们将研究HD2s在脱落酸（ABA）介导的干旱响应途径中的作用。此外，我们将研究HD2s如何调控干旱响应基因。我们的长期研究目标是揭示HD2s以及其他类型的hdac在植物对不同环境胁迫反应中调控基因表达的见解和机制。研究成果可用于植物和作物的非生物抗逆性开发。

In eukaryotes, the nucleosome is the basic and functional unit of chromatin. The nucleosome consists of DNA and histone proteins and DNA wraps on the histone octamer. The N-terminal tails of histone proteins are often subjected to different posttranslational modifications, such as acetylation. Histone acetylation is regulated by histone acetyltransferases (HAT) that catalyze hyper acetylation and histone deacetylases (HDACs) that catalyze deacetylation by removing the acetyl group from the core histones. Research has shown that the HDACs control a number of fundamental biological processes in plants, especially plant development and response to environmental stresses. Histone deacetylases are an ancient group of enzymes that are widely present in various organisms. Plants contain a specific group of HDACs, HD2s. HD2s show low levels of similarity in sequence and structure with other HDAC families and it appears HD2s are well conserved in different types of plants. Research has shown that HD2s involve in plant response to abiotic stresses, such as drought. Currently, 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 using molecular biology approaches to study different aspects of HD2 in plants in response to abiotic stresses, specifically, in response to drought. We will study gene expression patterns of different HD2s in plants. We will then reveal the relationship and potential interactions of different HD2 members in response to drought stress. The involvement of HD2s in abscisic acid (ABA)-mediated drought responsive pathway will be investigated. Moreover, we will study how HD2s regulate drought response genes. Our long term research goals are to reveal the insights and mechanisms of HD2s as well as other types HDACs in regulating gene expression in plant response to different environmental stresses. The knowledge and findings generated from the research can be used for development of plants and crops for abiotic stress tolerance.