组蛋白变体H2A.Z和相关重塑因子在水稻逆境中的功能研究

发布时间：2018-07-02 08:25

本文选题：H2A.Z + 组蛋白变体　；参考：《华中农业大学》2017年硕士论文

【摘要】：组蛋白修饰、DNA甲基化、组蛋白变体和核小体排布等表观修饰是调控基因表达的重要方式。固着生长的高等植物,在逆境胁迫下,可以通过自身的逆境应答机制感知环境的变化并且做出相应的应激反应,以利于自身在逆境中的生存。表观修饰因子在调控植物逆境胁迫应答中扮演了非常重要的角色。H2A.Z是组蛋白H2A的一种变体,具有自身独特的分子调控机制和功能,在调控植物开花、环境应答、生长发育、免疫应答、有丝分裂、DNA修复以及温度感应等方面均发挥了重要作用。本课题的主要研究内容是围绕组蛋白变体H2A.Z及相关染色质重塑因子PIE1和INO80在水稻适应非生物逆境胁迫中的功能研究而展开的。所获得的主要结果如下:1.表达谱的分析发现OsH2A.Z、OsPIE1、OsINO80、OsARP6均为组成型表达基因,它们的表达量受盐、干旱和胁迫激素(ABA、SA、JA)的影响。说明以上H2A.Z及相关的基因可能参与水稻的胁迫反应。2.转基因材料染色质重塑因子的编码基因OsPIE1 RNAi、H2A.Z的编码基因OsHTA705RNAi、染色质重塑因子的编码基因OsINO80RNAi均表现出抽穗期比野生型晚2-3周;OsPIE1RNAi同时还表现出穗稀疏,而且植株变矮,茎节长度变短,籽粒变长且不饱满等表型,OsPIE1可能参与种子的发育。3.通过苗期NaCl胁迫处理,发现OsPIE1RNAi和OsHTA705RNAi比野生型更耐盐,OsINO80RNAi比野生型对盐更敏感,并且适宜的NaCl浓度可以提高OsPIE1RNAi和OsHTA705RNAi的发芽率。4.通过用200 mmol/L NaCl处理的12 d野生型全苗做Ch IP-PCR和RT-qPCR检测比较ChIP-seq数据,结果显示经过NaCl处理后,H2A.Z在盐诱导全基因组上的富集减少,并且盐诱导基因受诱导表达。正常状态下,在OsINO80RNAi中的H2A.Z盐诱导基因的富集高于野生型;在OsPIE1RNAi中的H2A.Z在盐诱导基因上的富集低于野生型。当OsINO80表达量被抑制后,NaCl处理过程中H2A.Z并不能被有效地去除,导致盐诱导基因的表达量弱于野生型;说明正常状态下,H2A.Z在盐诱导基因的富集对该基因的表达起到抑制作用;PIE1和INO80在分配H2A.Z上有不同的功能;高盐下,INO80可能通过影响H2A.Z去除来调控基因表达。
[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.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S511

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