籽粒大小是決定水稻產(chǎn)量的主要因素之一。籽粒的長度和寬度與粒重的呈正相關,改良粒型對提高水稻產(chǎn)量具有十分重要的作用。作為重要的農(nóng)藝性狀,粒型是由多基因控制的數(shù)量性狀,遺傳基礎比較復雜,易受到環(huán)境影響。目前一些控制水稻粒長、粒寬和粒重的基因已被克隆,但控制粒型的分子和遺傳調(diào)控網(wǎng)絡仍不清楚。擬南芥DA1基因編碼一個泛素受體蛋白,能夠通過調(diào)控細胞分裂影響擬南芥器官和種子大小。DA1包含兩個LIM結(jié)構(gòu)域,分別位于位于N端和C端。DA1通過LIM結(jié)構(gòu)域與泛素相互作用。擬南芥中有7個DA1的同源基因,其編碼蛋白被命名為DA1相關(DAR)蛋白。在水稻中DA1的同源基因有4個分別命名為OsDA1、OsDAR2、OsDAR3和OsDAR4。本論文通過對水稻DA1相關(DAR)基因的研究表明:OsDAR2、OsDAR3和OsDAR4可以調(diào)節(jié)水稻粒寬和粒長,增加水稻的千粒重和單株產(chǎn)量。本研究表明過表達OsDAR2、OsDAR3和OsDAR4基因可以導致水稻粒寬和粒長同時增加從而導致千粒重和單株總粒重增加,而CAS9敲除株系則表現(xiàn)完全相反的表型,籽粒的長度和寬度同時減小進而千粒重和單株總粒重同時減少。這表明O...

【文章頁數(shù)】：81 頁

【學位級別】：博士

【文章目錄】：
摘要
abstract
CHAPTER 1 INTRODUCTION
    1.1 Rice, an important cereal crop
    1.2 Rice a model plant for genetics and breeding aspects
    1.3 Seed formation mechanism and final seed size
        1.3.1 Zygotic and maternal factors regulate organ size in plants
    1.4 Superior grain quality with high grain yield
        1.4.1 Superior grain quality
        1.4.2 High grain yield
    1.5 VP16 and EAR
        1.5.1 Domain structure and interacting proteins of VP
        1.5.2 EAR transcription suppression domain
    1.6 DA1 and DAR Genes(Research Progress)
        1.6.1 Control of final seed and organ size by the DA1 gene family in Arabidopsisthaliana
        1.6.2 The ubiquitin receptor DA1 interacts with the E3 ubiquitin ligase DA2 toregulate seed and organ size in Arabidopsis
        1.6.3 Control of root meristem size by DA2 in Arabidopsis
        1.6.4 The ubiquitin receptor DA1 regulates seed and organ size by modulating thestability of the ubiquitin-specific protease UBP15/SOD2 in Arabidopsis
        1.6.5 The ubiquitin receptors DA1, DAR1, and DAR2 redundantly regulateendoreduplication by modulating the stability of TCP14/15
        1.6.6 Genetic and molecular network for maternal control of seed size
CHAPTER 2 MATERIALS AND METHODS:
    2.1 PCR primers
        2.1.1 Tips for a good primer design
    2.2 DNA extraction
        2.2.1 DNA extraction by CTAB method
    2.3 RNA extraction
    2.4 c DNA synthesis
    2.5 Full length c DNA amplification
    2.6 Gel electrophoresis
        2.6.1 Agarose gel electrophoresis
        2.6.2 SDS-PAGE
    2.7 Western blotting
    2.8 DNA agarose gel recovery
    2.9 E. coli transformation
        2.9.1 Heat-shock transformation
        2.9.2 Single colony culture
        2.9.3 PCR assay
    2.10 Plasmid extraction
    2.11 Agrobacterium electroporation
    2.12 Gateway reactions
    2.13 Chemical preparation
CHAPTER 3 RESULTS
    3.1 DAR genes in Arabidopsis and Rice
        3.1.1 LOC_Os03g16090
        3.1.2 LOC_Os12g40490
        3.1.3 LOC_Os03g42820
    3.2 DARs-VP16 transgenic lines
        3.2.1 Expression level of DARs- VP16 in transgenic lines
        3.2.2 DARs fused with VP16 enhances grain size in rice
        3.2.3 DARs-VP16 lines showed compact panicle and more spikelets
        3.2.4 DARs-VP16 lines showed no obvious architecture phenotype
    3.3 DARs-EAR transgenic lines
        3.3.1 Expression level of DARs-EAR in transgenic lines
        3.3.2 DARs fused with EAR reduces grain size and KGW in rice
        3.3.3 DARs fused with EAR reduces number of spikelets per panicle fused
        3.3.4 DARs-EAR lines showed no obvious architecture phenotype
    3.4 DARs Over expression (DAR-OEX) lines
        3.4.1 Expression level of DARs in DARs-OEX lines
        3.4.2 DARs-OEX enhances grain length and width
        3.4.3 DARs-OEX lines showed more spikelets with normal seed setting rate
        3.4.4 DAR-OEX lines shows no significant change in plant height
    3.5 DAR4-CAS9 knock out lines
        3.5.1 Knockout of DAR4 reduces grain length and width in rice
        3.5.2 DAR4 knockout lines reduces number of spikelets per panicles
        3.5.3 Plant architecture of knockout lines was similar with wild type
    3.6 Expression level of DARs in rice plant tissues at different stages
CHAPTER 4 DISCUSSION
CHAPTER 5 CONCLUSIONS
REFERENCE
Acknowledgement
Resume



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