2019-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/682928摘要：在高等生物中，在DNA序列沒有變化的情況下基因表達或細胞表型受表觀遺傳控 制。該調節包括DNA甲基化，組蛋白修飾等。特別是，組蛋白可以進行轉譯後修 飾，包括甲基化，乙醯化，SUMOlation，磷酸化等。組蛋白乙醯化由組蛋白乙醯 轉移&#37238;（HATs）催化，而去乙醯化由組蛋白去乙醯化&#37238;（HDA）催化。這些修飾 可以通過非生物性逆境和離層酸（ABA）調節基因表達來調節。然而，分子機制卻 鮮為人知。我們的實驗室之前的初步結果，發現HDA6可以與阿拉伯芥中的轉錄因 子WRKY25結合。而且，我們發現過表達WRKY25增加鹽逆境耐受性，但側根密 度變少。我們假設HDA6可以與WRKY25結合並調節鹽逆境和ABA反應。我們將以 阿拉伯芥作為本研究的模型系統。我們的目的是研究HDA6與WRKY25結合參與鹽 逆境和ABA反應的功能。我們將使用共免疫沉澱確認HDA6是否可以與WRKY25結 合。我們將通過反式激活試驗測試HDA6與WRKY25結合是否影響轉錄活性。此外 ，我們還將通過反式激活試驗測試ABA處理條件下HDA6與WRKY25結合是否影響 植物中ABA相關標記基因的表達。另外，通過使用染色質免疫沉澱及PCR分析 ，我們將分析鹽和ABA處理條件下HDA6 及WRKY25的共調控基因。最後，我們以 突變體和過表達株之雜交株來測試鹽和ABA反應。還將在交品系中測試下游鹽和 ABA相關標誌物基因表達以及共同調控基因之表達。在正常情況下、鹽和ABA處理 下的側根研究方面，將分析細胞週期相關的基因表達。也將引進生長素報告基因 DR5 :: GUS，以確定生長素的分佈和水平。最後，並將處理生長素和生長素極向 運輸抑製劑NPA以觀察側根表型是否改變。該項目的意義在於深入了解組蛋白修飾 在鹽逆境和植物中ABA反應的表觀遺傳調控中的功能和機制。在長期目標中，我們 希望將該系統引入作物（如水稻）以抵抗鹽逆境並提高作物產量。<br> Abstract: In higher organisms, epigenetic control of gene expression or cellular phenotype occurs without changes in DNA sequence. This regulation includes DNA methylation, histone modifications etc. In particular, histone proteins can be posttranslationally modified, including methylation, acetylation, SUMOlation, phosphorylation etc. Histone acetrylation is mediated by histone acetyltransferases (HATs), and deacetylation is mediated by histonedeacetylases (HDAs). These modifications can be modulated by abiotic stresses and abscisic acid (ABA) in regulating the gene expression. However, the molecular mechanism is little known. It was reported that is involved in salt and ABA responses in Arabidopsis. Our lab found that overexpression of WRKY25 confers salt stress tolerance, but reduced lateral root density. In addition, we found that HDA6 can interact with WRKY25. We hypothesize that HDA6 can interact with WRKY25 in regulating salt stress and ABA responses. We will introduce Arabidopsis as model systems for this study. We aim to investigate the function of HDA6 interaction with WRKY25 in salt stress and ABA responses. We will confirm if HDA6 can interact with WRKY25 by use of co-immunoprecipitation. We will test whether HDA6 binding to WRKY25 affects TF activity by transactivation assay. In addition, we will also test whether the binding affects ABA-related marker gene expression in planta under ABA treatment condition by transactivation assay. Moreover, by use of chromatic-immunoprecipitation followed by PCR analysis, HDA6 and WRKY25 co-targeted genes under salt and ABA-treatment conditions will be profiled. Finally, we will cross HDA6 mutant line and WRKY25 overexpression lines to test salt and ABA responses. Downstream salt and ABA-related marker gene expression, and co-target gene expression will also be tested in the cross lines. In terms of lateral root study of the cross lines under normal, salt and ABA treatment, cell cycle-related gene expression will be analyzed. Auxin reporter DR5::GUS line will be introduced to determine auxin distribution and level. In addition, auxin and auxin polar transport inhibitor NPA will be treated to see if lateral root phenotype is changed. The significance of the project is to gain insight of the functions and mechanism of histone modification in epigenetic regulation in salt stress and ABA responses in plants. In long term goal, we hope to introduce the system to crops (i.e. rice) against salt stress and improve crop yield.組蛋白乙醯化離層酸鹽根表觀遺傳學 計Epigeneticssaltabscisic acidroothistone acetylation