發(fā)布時間：2018-07-02 08:25

  本文選題：H2A.Z + 組蛋白變體��； 參考：《華中農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：組蛋白修飾、DNA甲基化、組蛋白變體和核小體排布等表觀修飾是調(diào)控基因表達(dá)的重要方式。固著生長的高等植物,在逆境脅迫下,可以通過自身的逆境應(yīng)答機(jī)制感知環(huán)境的變化并且做出相應(yīng)的應(yīng)激反應(yīng),以利于自身在逆境中的生存。表觀修飾因子在調(diào)控植物逆境脅迫應(yīng)答中扮演了非常重要的角色。H2A.Z是組蛋白H2A的一種變體,具有自身獨(dú)特的分子調(diào)控機(jī)制和功能,在調(diào)控植物開花、環(huán)境應(yīng)答、生長發(fā)育、免疫應(yīng)答、有絲分裂、DNA修復(fù)以及溫度感應(yīng)等方面均發(fā)揮了重要作用。本課題的主要研究內(nèi)容是圍繞組蛋白變體H2A.Z及相關(guān)染色質(zhì)重塑因子PIE1和INO80在水稻適應(yīng)非生物逆境脅迫中的功能研究而展開的。所獲得的主要結(jié)果如下:1.表達(dá)譜的分析發(fā)現(xiàn)OsH2A.Z、OsPIE1、OsINO80、OsARP6均為組成型表達(dá)基因,它們的表達(dá)量受鹽、干旱和脅迫激素(ABA、SA、JA)的影響。說明以上H2A.Z及相關(guān)的基因可能參與水稻的脅迫反應(yīng)。2.轉(zhuǎn)基因材料染色質(zhì)重塑因子的編碼基因OsPIE1 RNAi、H2A.Z的編碼基因OsHTA705RNAi、染色質(zhì)重塑因子的編碼基因OsINO80RNAi均表現(xiàn)出抽穗期比野生型晚2-3周;OsPIE1RNAi同時還表現(xiàn)出穗稀疏,而且植株變矮,莖節(jié)長度變短,籽粒變長且不飽滿等表型,OsPIE1可能參與種子的發(fā)育。3.通過苗期NaCl脅迫處理,發(fā)現(xiàn)OsPIE1RNAi和OsHTA705RNAi比野生型更耐鹽,OsINO80RNAi比野生型對鹽更敏感,并且適宜的NaCl濃度可以提高OsPIE1RNAi和OsHTA705RNAi的發(fā)芽率。4.通過用200 mmol/L NaCl處理的12 d野生型全苗做Ch IP-PCR和RT-qPCR檢測比較ChIP-seq數(shù)據(jù),結(jié)果顯示經(jīng)過NaCl處理后,H2A.Z在鹽誘導(dǎo)全基因組上的富集減少,并且鹽誘導(dǎo)基因受誘導(dǎo)表達(dá)。正常狀態(tài)下,在OsINO80RNAi中的H2A.Z鹽誘導(dǎo)基因的富集高于野生型;在OsPIE1RNAi中的H2A.Z在鹽誘導(dǎo)基因上的富集低于野生型。當(dāng)OsINO80表達(dá)量被抑制后,NaCl處理過程中H2A.Z并不能被有效地去除,導(dǎo)致鹽誘導(dǎo)基因的表達(dá)量弱于野生型;說明正常狀態(tài)下,H2A.Z在鹽誘導(dǎo)基因的富集對該基因的表達(dá)起到抑制作用;PIE1和INO80在分配H2A.Z上有不同的功能;高鹽下,INO80可能通過影響H2A.Z去除來調(diào)控基因表達(dá)。
[Abstract]:Histone modification including DNA methylation, histone variant and nucleosome arrangement are important ways to regulate gene expression. Under the stress, the higher plants can perceive the change of environment and make corresponding stress response through their own stress response mechanism, so as to benefit their survival in adversity. Epidermal modifier plays a very important role in regulating plant stress response. H2A.Z is a variant of histone H2A, which has its own unique molecular regulation mechanism and function in regulating plant flowering, environmental response, growth and development. Immune response, mitotic DNA repair and temperature sensing all play an important role. The main contents of this study were focused on the function of histone variant H2A.Z and related chromatin remodeling factors PIE1 and INO80 in adapting rice to abiotic stress. The main results are as follows: 1. It was found that OsH2A.ZHPIE1 and OsINO80 OsARP6 were constitutive expression genes, and their expression levels were affected by salt, drought and stress hormones (ABA SAJA). These results suggest that the above H2A.Z and related genes may be involved in the stress response of rice. OsPIE1 RNAi, a coding gene of chromatin remodeling factor, and OsHTA705 RNAi, a coding gene of chromatin remodeling factor, and OsINO80 RNAi, which were encoded by chromatin remodeling factor, showed that OsPIE1RNAi also showed sparse spike, shorter plant and shorter stem node length than wild type. OsPIE1 may be involved in seed development. It was found that OsPIE1RNAi and OsHTA705RNAi were more sensitive to salt than wild type, and the suitable concentration of NaCl could increase the germination rate of OsPIE1RNAi and OsHTA705RNAi. ChIP-seq data were compared with Ch IP-PCR and RT-qPCR in wild type seedlings treated with 200 mmol / L NaCl for 12 days. The results showed that the concentration of H2A.Z in the whole salt-induced genome was decreased after NaCl treatment, and the salt-induced gene expression was induced. Under normal condition, the enrichment of H2A.Z salt induced genes in OsINO80 RNAi was higher than that in wild type, and the concentration of H2A.Z in OsPIE1 RNAi was lower than that in wild type. When the expression of OsINO80 was inhibited, H2A.Z could not be effectively removed during NaCl treatment, which resulted in a weaker expression of salt-induced genes than that of wild type. The results indicated that the enrichment of H2A.Z in salt induced gene inhibited the expression of H2A.Z under normal condition. PIE1 and INO80 had different functions in the distribution of H2A.Z, and the gene expression might be regulated by the effect of H2A.Z removal under high salt condition.
【學(xué)位授予單位】：華中農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S511

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本文編號：2089521