2016-08-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/665828摘要：表觀遺傳學為高等生物在不改變DNA序列之情況下調控基因表現，其中組蛋白之轉譯後修飾，如磷酸 化、乙醯化、甲基化等是植物細胞表觀遺傳重要的調控，其中組蛋白乙醯化受乙醯化及去乙醯化&#37238;調 控，這些修飾可調控逆境中基因的表達。然而，在蛋白質層次上組蛋白修飾受非生物逆境調控的研究 有限。在本研究室早先研究中，我們分析受鹽分處理之阿拉伯芥植株，並利用質譜分析找到組蛋白去 乙醯化&#37238;受鹽分調控之磷酸化位點。已知阿拉伯芥去乙醯化&#37238;會與14-3-3蛋白結合，我們預期在植物 體內找到組蛋白去乙醯化&#37238;磷酸化位點受鹽分調控及參與開花之生理意義，並探討14-3-3蛋白是否在 中間扮演重要角色。我們將以阿拉伯芥為模式植物，找出乙醯化&#37238;5、6、15 及19之磷酸化位點，並 對磷酸化位點進行點突變，進而分析突變體對去乙醯化&#37238;活性之影響，以及植物體內在鹽分逆境下對 下游基因表現及生理之影響，同時也會觀察對開花的影響。另一方面，我們將探討14-3-3蛋白結合對 去乙醯化&#37238;5、6、15 及19活性之影響，及是否影響植物體內在鹽分逆境下對下游標的基因表現及生 理，及對開花的影響。這項研究的特點是，我們將獲得在蛋白質層次上組蛋白修飾在非生物逆境及開 花的反應調節機制的知識。<br> Abstract: Epigenetic control of gene expression or cellular phenotype occurs without changes in DNA sequence. It has been widely found in higher organisms. This regulation includes DNA methylation, histone modifications etc. In particular, histone proteins can be post-translationally modified (PTM). Histone proteins are unclear proteins which are associated with chromosome and forms nucleosome. Histone acetrylation is mediated by histone acetyltransferases (HATs), and deacetylation is mediated by histone deacetylases (HDAs). These modifications can be modulated by abiotic stresses and abscisic acid in regulating the gene expression. In Arabidopsis it was known that HDA5 can interact with 14-3-3 proteins, a scaffold protein for phosphorylated proteins. Genetics studied also showed that HDA6 and HDA19 are involved in salt stress in Arabidopsis. However, histone deacetylase regulation by abiotic stress on the protein level is little studied. We will introduce Arabidopsis as model systems in this proposed project. We aim to investigate the dynamic and function of the phosphorylation of HDA5, HDA6, HDA15, and HDA19 in response to salt or drought stress. We will also check the effect on flowering. In particular, the effect of 14-3-3 binding is the main focus. We will first identify the phosphorylation site of these HDAs. We will then introduce point mutation and investigate whether the activity is affected. We will also test whether the mutation of the phosphorylation site affect flowering gene expression and phenotype in plants under salt or drought condition. On the other hand, we will test whether 14-3-3 binding affect enzyme activity. In addition, we will also test whether 14-3-3 binding affect flowering gene expression and phenotype in planta under salt or drought condition. The importance of the project is to gain insight of the functions and mechanism of histone modification in epigenetic regulation in response to salt or drought stress and flowering in plants.組蛋白去乙醯化&#3723814-3-3鹽分開花阿拉伯芥磷酸化histone deacetylase14-3-3saltfloweringArabidopsisphosphorylation