保守的DNA修饰及其与玉米基因表达和表型性状的关联

发布时间：2024-04-23 02:46

　　玉米(Zea mays L.)是模式植物之一,也是重要的C4作物,广泛用于揭示全基因组遗传变异和表观遗传调控,其基因组具有高密度的转座因子(TEs)。C4植物的生产力取决于植株的生长和发育,生长季节的净光合作用速率以及光合产物分离到谷物中的效率。C4植物具有高效的光合作用,使植物能够在更加多样化的生态系统中生存。作为能量利用机制的光合作用通常可以分为暗反应和光反应,这些过程主要受内源和外源因素的影响。最近的研究表明,除了遗传学的差异,表观遗传变异也可能参与C4植物光合效率、基因表达。本研究统计了12个近交玉米品系中叶色、气体交换、叶绿素荧光、叶绿素含量等生理参数,C4植物光合相关基因的表达量,以及包括5-甲基胞嘧啶(5mC)和N6-甲基腺嘌呤(6mA)在内的DNA甲基化修饰的含量分析,以期揭示与光合作用相关的基因及表观修饰变异。1.使用LI-6800便携式光合作用系统估算了近交玉米品系的叶色、气体交换值、叶绿素荧光和光合色素的表型评估。玉米叶色含量揭示了氮含量足够、不足或过量。基于气体交换和叶绿素荧光的进一步测定显示,从光合作用测量获得的大多数参数在近交系中是统计学上是存在差异的。气体...

【文章页数】：92 页

【学位级别】：博士

【文章目录】：
摘要
abstract
Abbreviation
Chapter1 Introduction
    1.1 Maize(Zea mays L.)
    1.2 C4 Photosynthesis pathway
        1.2.1 Photosynthetic pigments
        1.2.2 Gas exchange processes
        1.2.3 Fluorescence processes
        1.2.4 Genetics regulation and evolution of C4 pathways in Maize
        1.2.5 Epigenetic regulation of C4 Pathways in Maize
    1.3 DNA methylation
        1.3.1 N5-methylcytosine(5mC)
        1.3.2 N6-methyladenine(6mA)
        1.3.3 Plant DNA methyltransferases and demethylases
    1.4 Approaches for estimating DNA Methylation
        1.4.1 HPLC-UV
        1.4.2 ELISA-Based Methods
        1.4.3 LC-MS/MS
        1.4.4 Restriction specific enzymes
        1.4.5 Immunoprecipitation of methylated DNA(meDIP)
        1.4.6 Sodium Bisulfite treatment
    1.5 Maize methylome
        1.5.1 Genomic Distribution of DNA Methylation in Maize
        1.5.2 Methylated Domains across the Maize Genome
        1.5.3 DNA Methylation profiling at Maize Genes
        1.5.4 DNA Methylation Profiling among TEs in Maize
        1.5.5 Sources of variation for the Maize Methylome and Inheritance
Chapter2 Phenotypic evaluation of maize inbred lines
    2.1 Introduction
    2.2 Material and Methods
        2.2.1 Plant material and growth conditions
        2.2.2 Gas Exchange and Chlorophyll fluorescence measurements
        2.2.3 Chlorophyll Content
        2.2.4 Statistical analysis
    2.3 Results
        2.3.1 Leaf color variation
        2.3.2 Photosynthesis related trait variation
        2.3.3 Chlorophyll contents
    2.4 Discussion
        2.4.1 Environmental cues mainly affect the photosynthesis efficiency
        2.4.2 Chlorophyll Fluorescence efficiency
        2.4.3 Chlorophyll accumulation
Chapter3 Characterization of the C4 pathway enzymes genes in Maize
    3.1 Introduction
    3.2 Material and Methods
        3.2.1 Plant materials and growth conditions
        3.2.2 Gene identification and sequence analysis
        3.2.3 RNA isolation
        3.2.4 cDNA synthesis
        3.2.5 Quantitative real time PCR
    3.3 Results
        3.3.1 Expression profiling of C4 photosynthetic genes
        3.3.2 Genomic analysis of Rubisco activase
        3.3.3 Expression profiling of Rubisco activase and subunits
        3.3.4 Expression profiling of classical C4 genes in maize
        3.3.5 Photosynthetic transcriptional factors
    3.4 Discussion
        3.4.1 Rubisco activase and their subunits are transcriptionally repressed in maize Leaves
        3.4.2 Classical genes are key C4 photosynthesis regulators
        3.4.3 Photosynthetic regulatory network
Chapter4 Estimation of global and photosynthetic gene specific associated methylation levels in Maize
    4.1 Introduction
    4.2 Material and Methods
        4.2.1 Plant materials and growth conditions
        4.2.2 DNA extraction
        4.2.3 Dot blot assay
        4.2.4 Liquid chromatography-mass spectrometry(LC-MS/MS)assay
        4.2.5 Bisulfite conversion and sequencing
        4.2.6 Primer designing
        4.2.7 PCR amplification
        4.2.8 Cloning and sequencing of the amplicon
        4.2.9 Data analysis
    4.3 Results
        4.3.1 Dot Blot analysis of DNA modifications
        4.3.2 LC-MS/MS analysis of DNA modifications
        4.3.3 Bisulfite Sequencing
    4.4 Discussion
        4.4.1 DNA modifications are dynamic in plants
        4.4.2 Contribution of methylation levels with phenotypic traits and gene expression
Conclusion
References
ACKNOWLEDGEMENTS
CV



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