楊樹是世界上種植面積最為廣泛的經(jīng)濟(jì)林木之一,它不僅被廣泛應(yīng)用于經(jīng)濟(jì)、生態(tài)和環(huán)境保護(hù)等領(lǐng)域,而且作為模式樹種應(yīng)用于木本植物遺傳轉(zhuǎn)化和分子機(jī)制研究。楊樹作為重要的速生樹種,是木材的主要來源。木材的主要成分包括木質(zhì)素(Lignin)、纖維素(Cellulose)和半纖維素(Hemicellulose),其中木質(zhì)素是影響木材材性關(guān)鍵的成分之一。然而楊樹中木質(zhì)素生物合成機(jī)制尚不完全清楚。因此,闡明楊樹中木質(zhì)素合成的分子調(diào)控機(jī)制具有重要的意義。MicroRNA(miRNAs)是一種內(nèi)源單鏈非編碼小RNA,長度約為20-22個(gè)核苷酸,能夠靶向調(diào)控目標(biāo)基因的表達(dá)。大量研究表明,miRNAs在調(diào)控植物生長和發(fā)育過程中發(fā)揮著重要的作用。此外,miRNAs還能夠調(diào)控細(xì)胞壁主要組分,如糖和木質(zhì)素的生物合成。已有研究證實(shí),miR828在柑橘粒化過程中調(diào)控木質(zhì)素的生物合成,在紅薯傷害處理下調(diào)控木質(zhì)素和H₂O₂的積累。目前尚未報(bào)道m(xù)iR828在楊樹木材發(fā)育過程中是否參與木質(zhì)素的生物合成調(diào)控。因此,本研究擬闡明miR828在楊樹中木質(zhì)素生物合成過程中的生物學(xué)功能。具體研究結(jié)...

【文章頁數(shù)】：105 頁

【學(xué)位級別】：博士

【文章目錄】：
摘要
Abstract
Chapter1 Literature Review
    1.1 Function of wood
    1.2 Secondary cell wall
    1.3 Overview of the Lignin
    1.4 MYB transcription factor
    1.5 Biological functions of MYB transcription factor in plants
        1.5.1 Regulation of primary and secondary metabolism
        1.5.2 R2R3-MYB protein regulate plant development
        1.5.3 R2R3-MYB proteins respond to biotic and abiotic stresses
    1.6 MicroRNA
    1.7 MicroRNA biogenesis and processing
    1.8 Origin,conservation,and diversity of miRNAs in plants
    1.9 Biological function of plant microRNA
        1.9.1 MicroRNA in plant growth and development
        1.9.2 MicroRNA and stress response
    1.10 Identification of miRNA targets in plants
Chapter2 Introduction
    2.1 Background
    2.2 Problems and statements
    2.3 Technical route of this study
Chapter3 Cloning and Functional Analysis of miR828a in Poplar
    3.1 Introduction
    3.2 Materials and methods
        3.2.1 Plant materials
        3.2.2 Bacteria and plasmids
        3.2.3 Reagents,enzymes and kits
        3.2.4 Hormone and antibiotics
        3.2.5 Growth media for plants and bacteria
        3.2.6 Other reagents
        3.2.7 Plasmid extract reagents
        3.2.8 Equipment
        3.2.9 Bioinformatic analysis
        3.2.10 DNA extraction
        3.2.11 RNA extraction
        3.2.12 RNA quality detection
        3.2.13 RNA reverse transcription reaction
        3.2.14 miRNA specific reverse transcription reaction
        3.2.15 Quantitative Real-time PCR(qRT-PCR)
        3.2.16 Vector construction
        3.2.17 Enzyme digestion and ligation
        3.2.18 Preparation of chemically competent Escherichia coli(DH5α)
        3.2.19 Transformation of E.coli competent cells
        3.2.20 Confirmation of positive bacterial cloning
        3.2.21 Extraction of plasmid DNA
        3.2.22 Transformation of Agrobacterium tumefaciens
        3.2.23 Transformation of poplar leaves
        3.2.24 Identification of transgenic poplar
        3.2.25 GUS staining assay
        3.2.26 Observation of lignin components
        3.2.27 Lignin content determination
        3.2.28 Isolation of cell wall polysaccharide
        3.2.29 Prediction of miRNA target genes
    3.3 Results
        3.3.1 Isolation and characterization of miR828a in poplar
        3.3.2 Expression analysis of miR828a in poplar
        3.3.3 Construction and overexpression of miR828a
        3.3.4 Identification of the target genes of miR828a in poplar
    3.4 Discussion
Chapter4 Identification and Characterization of miR828a Target MYB
    4.1 Introduction
    4.2 Materials and methods
        4.2.1 Identification of poplar MYB gene
        4.2.2 Vector construction and plant transformation
        4.2.3 Degradome sequencing analysis
    4.3 Results
        4.3.1 MYB is a potential target gene of multiple miRNAs
        4.3.2 Expression analysis of miR828a target MYB genes
        4.3.3 Effect of MYB011 overexpression on secondary wall component in poplar
        4.3.4 MYB011 regulates gene encoding lignin Biosynthesis enzymes
    4.4 Discussion
Chapter5 Conclusion and Prospect
    5.1 Conclusion
    5.2 Prospect
References
Appendix
Acknowledgement
List of Published Papers



本文編號：3799981