| Acknowledgements | 第11-12页 |
| Abstract | 第12-15页 |
| 摘要 | 第16-19页 |
| List of Abbreviations | 第19-31页 |
| Chapter 1 General Introduction | 第31-35页 |
| 1.1 Background information | 第31-34页 |
| 1.2 General objectives | 第34页 |
| 1.3 Specific objectives | 第34-35页 |
| Chapter 2 Literature review | 第35-63页 |
| 2.1 Overview of plant stress and its consequences | 第35-40页 |
| 2.1.1 Crop plant stress | 第35-36页 |
| 2.1.2 What is heavy metal? | 第36页 |
| 2.1.3 Historical notes and discovery of cadmium | 第36页 |
| 2.1.4 Sources of Cadmium | 第36-37页 |
| 2.1.5 Soil factors affecting mobility and uptake of Cd by plants | 第37-38页 |
| 2.1.6 Cadmium and human health | 第38-40页 |
| 2.2 Cadmium toxicity and its consequences in plants | 第40-46页 |
| 2.2.1 Effect on plant growth and development | 第40页 |
| 2.2.2 Biomass accumulation | 第40-41页 |
| 2.2.3 Cd-induced inhibition of plant photosynthesis | 第41-42页 |
| 2.2.4 Nutrient uptake | 第42页 |
| 2.2.5 Generation of ROS an oxidative challenge in crop plants | 第42-44页 |
| 2.2.6 Lipid Peroxidation | 第44-45页 |
| 2.2.7 DNA damage | 第45-46页 |
| 2.2.8 Cell ultrastructure | 第46页 |
| 2.3 Cadmium toxicity and plant adaptation | 第46-54页 |
| 2.3.1 Antioxidant enzymes activity | 第46-48页 |
| 2.3.2 Proline accumulation | 第48-49页 |
| 2.3.3 Sulphate uptake and metabolism | 第49-50页 |
| 2.3.4 Glutathione (GSH) in plant adaptation | 第50-51页 |
| 2.3.5 Phytochelatins (PCs) | 第51-53页 |
| 2.3.6 Immobilization and compartmentalization of toxic Cd | 第53-54页 |
| 2.4 Melatonin and its overview in plants | 第54-63页 |
| 2.4.1 Melatonin in crop plants; History and biosynthetic pathway | 第54-55页 |
| 2.4.2 Method of detection | 第55-56页 |
| 2.4.3 Crop growth conditions and melatonin content | 第56页 |
| 2.4.4 Melatonin as a plant growth regulator | 第56-58页 |
| 2.4.5 Melatonin in plant as an antioxidant | 第58-59页 |
| 2.4.6 Modulation of antioxidant enzyme and stress gene | 第59-60页 |
| 2.4.7 Genotoxicity | 第60-61页 |
| 2.4.8 Exogenous melatonin and plant stress tolerance | 第61-62页 |
| 2.4.9 Melatonin in plant Cd stress | 第62-63页 |
| Chapter 3 Resonse and mechanisms of tomatoplants to Cd stress and roles of | 第63-93页 |
| 3.1 Introduction | 第64-66页 |
| 3.2 Materials and Methods | 第66-74页 |
| 3.2.1 Plant material and experimental design | 第66-67页 |
| 3.2.2 Gas exchange, chlorophyll fluorescence and pigment contents measurements | 第67页 |
| 3.2.3 Determination of H_2O_2, malondialdehyde and electrolyte leakage in leaves | 第67页 |
| 3.2.4 Staining of H_2O_2 and O_2~(·-) in leaves and ROS in roots | 第67-68页 |
| 3.2.5 Nitric oxide quantification | 第68页 |
| 3.2.6 Saville-Griess assays | 第68页 |
| 3.2.7 Extraction and assay of enzymes | 第68-69页 |
| 3.2.8 Measurement of proline and H~+ ATPase activity | 第69-70页 |
| 3.2.9 Measurements ofthiol compounds | 第70页 |
| 3.2.10 Separation of tissue fractionations and measurement of Cd and micro-nutrient | 第70-71页 |
| 3.2.11 Extraction of total RNA and quantitative real-time PCR analyses | 第71页 |
| 3.2.12 Statistical Analysis | 第71-74页 |
| 3.3 Results | 第74-89页 |
| 3.3.1 The responses and mechanisms of tomato plant to Cd stress | 第74-77页 |
| 3.3.2 Reduced glutathione (GSH) alleviated toxicity of Cd to tomato plants | 第77-79页 |
| 3.3.3 Ameliorating Cd stress by GSH was associated with improvement of nutrient status of microelements | 第79-81页 |
| 3.3.4 Ameliorating the Cd toxicity by GSH is associated with changes in Cd subcellular compartmentation | 第81页 |
| 3.3.5 GSH-mediated Cd compartmentation was associated with enhanced production of phytochelatins | 第81-83页 |
| 3.3.6 GSH modulate the cellular redox status in response to Cd stress | 第83-86页 |
| 3.3.7 Involvement of GSH in the regulation of antioxidant enzymes under Cd stress | 第86页 |
| 3.3.8 GSH is involved in the transcriptional regulation of detoxification and antioxidant genes | 第86-89页 |
| 3.4 Discussion | 第89-92页 |
| 3.5. Conclusion | 第92-93页 |
| Chapter 4 Cadmium induced melatonin biosynthesis in vegetables separation and | 第93-111页 |
| 4.1 Introduction | 第94-97页 |
| 4.2 Materials and methods | 第97-103页 |
| 4.2.1 Chemicals | 第97页 |
| 4.2.2 Plant material and growing conditions | 第97-98页 |
| 4.2.3 Analyis of Cd content in plants | 第98页 |
| 4.2.4 Extraction of plant melatonin | 第98页 |
| 4.2.5 Preparation of standard | 第98-99页 |
| 4.2.6 Instrumentation | 第99页 |
| 4.2.7 Chromatographic conditions | 第99-101页 |
| 4.2.8 LC/MS | 第101-103页 |
| 4.2.9 Statistical analysis | 第103页 |
| 4.3 Results | 第103-106页 |
| 4.4 Discussion | 第106-110页 |
| 4.5 Conclusion | 第110-111页 |
| Chapter 5 Melatonin alleviates cadmium (Cd) induced phytotoxicity by improving | 第111-135页 |
| 5.1 Introduction | 第112-114页 |
| 5.2 Materials and methods | 第114-120页 |
| 5.2.1 Plant material and experimental design | 第114页 |
| 5.2.2 Gas exchange and chlorophyll fluorescence measurements | 第114页 |
| 5.2.3 Determination of H_2O_2,lipid peroxidation and electrolyte leakage in leaf extracts | 第114-115页 |
| 5.2.4 Histochemical staining of H_2O_2 and O_2~(·-) in leayes | 第115页 |
| 5.2.5 Extraction and assay of enzymes | 第115页 |
| 5.2.6 Measurement of proline and H~+ ATPase activity | 第115-116页 |
| 5.2.7 Extraction and quantification of endogenous melatonin by HPLC | 第116页 |
| 5.2.8 Extraction,derivatization and separation of thiol compounds by HPLC | 第116页 |
| 5.2.9 Virus-induced gene silencing(VIGS)of TDC and histochemical localization of Cd | 第116-117页 |
| 5.2.10 Separation of tissue fractionations | 第117页 |
| 5.2.11 Determination of Cd and micronutrients | 第117-118页 |
| 5.2.12 Extraction of total RNA and quantitative real-time PCR analyses | 第118页 |
| 5.2.13 Statistical Analysis | 第118-120页 |
| 5.3 Results | 第120-131页 |
| 5.3.1 Effect of melatonin on plant growth,photosynthesis and plant biomass accumulation against Cd stress | 第120-122页 |
| 5.3.2 Effect of melatonin on Cd-induced ROS accumulation,lipid peroxidation and electrolyte leakage | 第122-124页 |
| 5.3.3 Effect of melatonin on antioxidant enzymes activities under Cd stress | 第124页 |
| 5.3.4 Effect of melatonin on H~+ ATPase activity,proline and endogenous melatonin content | 第124-127页 |
| 5.3.5 Effect of melatonin on detoxified compounds accumulation and relative gene expressions under Cd stress | 第127-128页 |
| 5.3.6 Role of melatonin on absorption,subcellular distribution and localization of Cd | 第128-130页 |
| 5.3.7 Role of melatonin on micronutrient uptake | 第130-131页 |
| 5.4 Discussion | 第131-134页 |
| 5.5 Conclusion | 第134-135页 |
| Chapter 6 Melatonin promotes tolerance to cadmium stress by improving sulfur uptake,assimilation andredox homeostasisin tomato plants | 第135-157页 |
| 6.1 Introduction | 第136-138页 |
| 6.2 Materials and Methods | 第138-145页 |
| 6.2.1 Plant materials and experimental design | 第138-139页 |
| 6.2.2 Virus-induced gene silencing(VIGS)construct and Agrobacterium-mediated transformation | 第139-140页 |
| 6.2.3 Gas exchange,chlorophyll fluorescence and photosynthetic pigment measurements | 第140页 |
| 6.2.4 Quantification of H_2O_2 and lipid peroxidation and histochemical and cytochemical H_2O_2 detection | 第140页 |
| 6.2.5 Study of cell ultrastructure by transmission electron microscpy | 第140-141页 |
| 6.2.6 Determination of Cd and S contents | 第141页 |
| 6.2.7 Western blot analysis of 2-Cys peroxiredoxin | 第141页 |
| 6.2.8 ATP-sulfurylase activity assay | 第141-142页 |
| 6.2.9 Determination of adenosine 5'-phosphosulfate(APS)reductase and sulfide reductase (SiR)activities | 第142页 |
| 6.2.10 Assay of O-acetylserine(thiol)lyase(OASTL)activities | 第142-143页 |
| 6.2.11 Detection of plant endogenous melatonin | 第143页 |
| 6.2.12 Extraction,derivatization and separation of thiol compounds by HPLC | 第143页 |
| 6.2.13 Extraction of total RNA and quantitative real-time PCR analyses | 第143-145页 |
| 6.2.14 Statistical analysis | 第145页 |
| 6.3 Results | 第145-152页 |
| 6.3.1 Melatonin ameliorates Cd-induced inhibitionof growth and S assimilation | 第145-147页 |
| 6.3.2 Melatonin reduces ROS accumulation and chloroplast damage by modulating the cellular redox status in response to Cdstress | 第147-149页 |
| 6.3.3 Melatonin induced sulfur metabolic enzymatic activity under Cd stress | 第149-150页 |
| 6.3.4 Melatonin influences the concentration of thiol compounds and the redox state of 2-Cys peroxiredoxin(2-CP)protein | 第150-152页 |
| 6.4 Discussion | 第152-156页 |
| 6.5 Conclusion | 第156-157页 |
| Chapter 7 Conclusion and Future Perspectives | 第157-160页 |
| 7.1 Conclusion | 第157-159页 |
| 7.2 Future perspectives | 第159-160页 |
| References | 第160-190页 |
| Personel and publication informations | 第190页 |
