本文選題：擬南芥　切入點：EFD　出處：《上海師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：花粉的形成對被子植物的生殖繁衍至關(guān)重要,而花粉壁各層結(jié)構(gòu)的正常發(fā)育對于產(chǎn)生成熟而有活力的花粉起到關(guān)鍵作用。花粉壁的結(jié)構(gòu)組成由外到內(nèi)分為外壁和花粉內(nèi)壁,花粉外壁又可分為外壁外層和外壁內(nèi)層�；ǚ郾诘慕Y(jié)構(gòu)因物種不同而差異很大。此花粉壁的特殊結(jié)構(gòu)稱之為花粉壁模式。影響花粉壁模式建成的主要因素有:胼胝質(zhì)形成、初生外壁沉積、質(zhì)膜波浪狀形成、孢粉素沉積(花粉外壁外層的原料)等因素。目前已經(jīng)發(fā)現(xiàn)很多影響這些過程的重要因子缺失會影響花粉壁模式建成,進(jìn)而影響花粉育性。例如:影響胼胝質(zhì)形成的Cal S5;影響花粉初生外壁形成的基因有NPU、RPG1、DEX1、NEF1等;影響孢粉素合成的基因CYP703A2、MS2、LAP5、LAP6等;以及影響花粉外壁內(nèi)層形成的基因TEK、AGP6、AGP11、AGP23、AGP40等。但這些因素之間的關(guān)系以及調(diào)控花粉壁模式建成的分子機(jī)理仍然很不清楚。最新報道的擬南芥EFD基因編碼一個核定位DNA甲基轉(zhuǎn)移酶。該基因的缺失導(dǎo)致雄性不育,并對擬南芥花藥發(fā)育過程中胼胝質(zhì)的形成、初生外壁的形成以及外壁內(nèi)層的形成等方面都有很大影響。此外,efd背景下大量重要基因的表達(dá)明顯下調(diào)。本論文中,我們以efd突變體為切入點,將對應(yīng)每個受到影響的生物學(xué)過程中的關(guān)鍵基因回補(bǔ)入efd突變體后,發(fā)現(xiàn)外壁內(nèi)層表型未恢復(fù),初生外壁回補(bǔ)植株表型恢復(fù)不顯著,而外壁外層回補(bǔ)植株表型恢復(fù)。因此孢粉素合成過程的異常對efd花粉壁發(fā)育的影響最為關(guān)鍵。另外針對DNA甲基轉(zhuǎn)移酶的轉(zhuǎn)錄沉默功能以及efd背景下與花藥發(fā)育相關(guān)的基因呈現(xiàn)明顯下調(diào)趨勢,猜想EFD下游存在一個轉(zhuǎn)錄抑制因子負(fù)調(diào)控下游花粉壁發(fā)育的相關(guān)基因。我們將efd突變體背景下芯片數(shù)據(jù)中一個表達(dá)量上調(diào)顯著的轉(zhuǎn)錄因子HBF在野生型野生型中過表達(dá)之后,HBF過表達(dá)植株在24℃時并未有明顯表型,但在26℃時HBF過表達(dá)植株出現(xiàn)了一定程度的育性下降。hbf突變體背景下花藥發(fā)育相關(guān)基因出現(xiàn)一定程度上調(diào),而且efd hbf雙突植株恢復(fù)了育性,由此初步推測該HBF轉(zhuǎn)錄因子是EFD下游與花藥發(fā)育相關(guān)的很重要的一個轉(zhuǎn)錄因子。
[Abstract]:Pollen formation is very important for reproduction and reproduction of angiosperms, and the normal development of pollen wall layers plays a key role in producing mature and active pollen. The structure of pollen wall is divided into outer wall and inner wall from outside to inside. The structure of pollen wall is very different from species to species. The special structure of pollen wall is called pollen wall pattern. The main factors influencing the formation of pollen wall model are: callose formation. Factors such as primary outer wall deposition, plasma membrane wavy formation, sporopollen deposition (the raw material for the outer layer of pollen wall) and other factors have been found to affect the formation of pollen wall model. For example: Cal S5, which affects the formation of corpus callosum, the genes that influence the formation of pollen primary outer wall, the gene CYP703A2, the gene CYP703A2, the gene CYP703A2, the gene CYP703A2, the gene CYP703A2, LAP5, LAP6, and so on. The relationship between these factors and the molecular mechanism of regulating pollen wall pattern formation is still unclear. The newly reported Arabidopsis EFD gene encodes a nucleated DNA. Methyltransferase. The deletion of the gene leads to male sterility. The formation of corpus callosum, the formation of primary outer wall and the formation of inner wall of outer wall of Arabidopsis thaliana have great influence on the anther development of Arabidopsis thaliana. In addition, the expression of a large number of important genes in Arabidopsis thaliana is down-regulated. Using the efd mutants as the entry point, we added the key genes corresponding to each affected biological process into the efd mutants. We found that the phenotype of the inner layer of the outer wall did not recover, and the phenotype of the primary outer wall repair plant was not significant. Therefore, the abnormal process of sporopollen synthesis has the most important effect on the development of pollen wall of efd. In addition, the transcriptional silencing function of DNA methyltransferase and the anther development phase under efd background are the most important. The related genes showed a down-regulation trend. We conjectured the existence of a transcription suppressor gene associated with the negative regulation of downstream pollen wall development in the downstream of EFD. We have up-regulated the expression of a significant transcription factor HBF in wild-type wild type in the microarray data of efd mutants. After expression, there was no obvious phenotype of HBF overexpressed plants at 24 鈩，

本文編號：1581593