声明
Contents
ABBREVIATIONS
FIGURE LEGENDS
LIST OF TABLES
摘要
ABSTARCT
CHAPTER ONE:1.0 General introduction
1.1 General objective
1.2 Specific objectives
CHAPTER TWO:Research background
2.0 Phytophthora capsici
2.1 Lifecycle of Phytophthora capsici
2.2 Phytophthora capsici effectors
2.2.1 RxLR effectors
2.2.2 Crinkler (CRN) effectors
2.3 Molecular Plant-Pathogen Interactions
2.3.1 PAMP Triggered Immunity(PTI).
2.3.2 Effector Triggered Immunity(ETI)
2.4 Localization Phytophthora effectors
CHAPTER THREE:A virulence essential CRN effector of phytophthora capsici suppresses host defense and induces cell death in plant nucleus
3.1 Introduction
3.2 Materials and Methods
3.2.1 Plasmid construction
3.2.2 Agrobacterium tumefaciens infiltration assays
3.2.3 Pathogenicity assay
3.2.4 Phytophthora capsici inoculation and in vitro samples
3.2.5 RNA extraction and real time quantitative RT-PCR
3.2.6 Protein extraction and Western blot
3.2.7 Confocal microscopy
3.2.8 Stable silencing of PcCRN4 in P.capsici
3.2.9 Oxygen burst detection and Callose deposition assay
3.2.10 Trypan blue staining
3.3 Results
3.3.1 Identification of PcCRN4 homologs and cell death induction in three plants
3.3.2 PcCRN4 is expressed at infection stages
3.3.3 PcCRN4 requires nuclear localization to trigger cell death
3.3.4 PcCRN4 enhances Phytophthora virulence on N. benthamiana and decreases ROS accumulation
3.3.5 PcCRN4 is required for full virulence
3.3.6 Silenced line exhibits reduced invasive hyphae,ability to reduce H2O2 accumulation and callose deposition
3.3.7 In planta expression of PcCRN4 recovers virulence of the silenced line
3.3.8 PcCRN4 may manipulate cell death by regulating expression of celldeath-related genes
3.4 Discussion
CHAPTER FOUR:Overexpression of Phytophthoracapsici effector RxLR242 induces cell death,disease and defense responses in Nicotiana benthamiana
4.1 Introduction
4.2 Materials and Methods
4.2.1 Plasmid construction
4.2.2 Agrobacterium tumefaciens infiltration assays
4.2.3 Pathogenicity assay
4.2.4 Phytophthora capsici inoculation and in vitro samples
4.2.5 RNA extraction and real time quantitative RT-PCR
4.2.6 Protein extraction and Western blot
4.2.7 Confocal microscopy
4.2.8 Stable silencing of PcRxLR242 in P.capsici
4.2.9 Oxygen burst detection
4.2.10 Trypan blue staining
4.2.11 Generation of Tobacco Rattle Virus(TRV)-Based Virus-Induced Gene Silencing (VIGs)N.benthamiana plants
4.3 Resuits
4.3.1 Overexpression of PcRxLR242 induce cell death in planta
4.3.2 PcRxLR242 is expressed highly at early infection stages
4.3.3 PcRxLR242 protein localization in the cytosol
4.3.4 Expression of PcRxLR242 reduces plant susceptibility to P.capsici
4.3.5 Silencing PcRxLR242 increases plant susceptibility to P.capsici
4.3.6 PcRxLR242-silenced lines enhances virulence on N.tabacum
4.4 Discussion
CONCLUSIONS AND SUMMARY
REFERENCES
PUBLICATIONS
ACKNOWLEDGEMENTS