| Abstract in Chinese | 第1-8页 |
| Abstract in English | 第8-10页 |
| 1 Introduction | 第10-18页 |
| ·Literature Review | 第10-16页 |
| ·Atrazine occurrence in the ecosystem | 第10页 |
| ·Atrazine Toxicological Effects in the Ecosystem | 第10-11页 |
| ·Abiotic stress responses in plants | 第11-13页 |
| ·Mode of scavenging antioxidative stress related response s in plant cells | 第13-16页 |
| ·Significance of research and hypothesis | 第16-17页 |
| ·Research Route | 第17-18页 |
| 2 Materials and methods | 第18-24页 |
| ·Materials and Methods in Experiment 1 | 第18-19页 |
| ·Plant materials and atrazine stress treatment | 第18页 |
| ·Measurement of the Ascorbate and Glutathione contents | 第18页 |
| ·Determination of Glutathione S-transferase and Glutathione Reductase | 第18-19页 |
| ·Determination of Hydrogen peroxide and superoxide radicals | 第19页 |
| ·Statistical analysis | 第19页 |
| ·Materials and Methods in Experiment 2 | 第19-24页 |
| ·Plant materials and growth conditions | 第19-20页 |
| ·ROS detection by confocal laser scanning fluorescence microscopy (CLSM) | 第20页 |
| ·Enzyme extraction and antioxidant enzymes assays (APX, CAT and POD) | 第20-21页 |
| ·Reactive oxygen species quantificationand Chlorophyll contents analysis | 第21-22页 |
| ·Gene Expression Analysis (c APX, Cc POD, chl Cu/Zn SOD and psb A) | 第22页 |
| ·Atrazine content determination by Gas Chromatography | 第22-23页 |
| ·Statistical analysis | 第23-24页 |
| 3 Result analysis | 第24-37页 |
| ·Experiment 1: Physiological responses of Pennisetumto high atrazine content | 第24-32页 |
| ·Response of Reduced and Oxidized Ascorbate in Pennisetum leaves to atrazine | 第24页 |
| ·Response of Glutathione pools in Pennisetum leaves to atrazine toxicity | 第24-27页 |
| ·Response of Glutathione-S-transferase and Glutathione reductase in Pennisetumleaves to atrazine toxicity | 第27-28页 |
| ·Reactive oxygen species production in Pennisetum seedling exposed to atrazinestress | 第28-30页 |
| ·Correlation pattern between the scavenging antioxidants, reactive oxygen speciesand atrazine concentrations | 第30-32页 |
| ·Experiment 2: Exogenous calcium alleviates oxidative stress in Pennise tum seedlings | 第32-37页 |
| ·Effect of exogenous calcium on ROS and MDA contents | 第32-33页 |
| ·Effect of exogenous calcium on ROS contents in Pennisetum seedlings exposed toatrazine toxicity | 第33-34页 |
| ·Effect of exogenous calcium on chlorophyll contents | 第34-35页 |
| ·Effect of exogenous calcium on antioxidant enzymes activity and transcriptabundance | 第35-36页 |
| ·Effect of exogenous calcium on atrazine accumulation | 第36-37页 |
| 4 Discussion | 第37-45页 |
| ·Effect of atrazine on ascorbate and glutathione levels, glutathione -S-transferase andGlutathione Reductase activities in Pennisetum plants | 第37-39页 |
| ·Correlation pattern between the scavenging antioxidants, reactive oxygen species andatrazine concentrations | 第39页 |
| ·Exogenous calcium suppresses atrazine induced oxidative stress in Pennisetum plants | 第39-40页 |
| ·Exogenous calcium application induced restoration of photosynthetic components afteratrazine-induced oxidative damage | 第40-41页 |
| ·Exogenous calcium upregulated activity of antioxidant enzymes in atrazine stressedplants | 第41-43页 |
| ·Exogenous calcium induced up-regulation of gene transcripts in atrazine stressedplants | 第43-45页 |
| 5 Conclusion | 第45-47页 |
| Acknowledgement | 第47-48页 |
| References | 第48-62页 |
| Appendix | 第62-63页 |
| Papers published in the period of Ph. D education | 第63页 |
