声明
Chapter 1 Introduction
1.1 Background
1.2 Cadmium
1.2.1 Cadmium in the Soil
1.2.2 Cadmium Mobilization,Uptake,and Transport
1.2.3 Plant Response to CdT oxicity
1.2.4 Factor Effecting Cd Uptake and Accumulation
1.3 Silicon
1.3.1 Silicon and Plants
1.3.2 Silicon Role in Wheat Plants
1.3.3 Silicon Role Against Abiotic Stress
1.4 Need for the Project
1.5Significance of Research
1.6Research Aims
Chapter 2 Materials and Methods
2.1Plant Culture and Experimental Design
2.1.1Recipe of Hoagland’s Solution
2.1.2Recipe of SiTreatment
2.2 Experimental Layout
2.2.1 Experiment 01
2.2.2 Experiment 02
2.2.3 Experiment 03
2.2.4 Experiment 04
2.2.5 Experiment 05
2.3Determination of Plant Growth and Biomass
2.4Measurements of Photosynthetic Pigments
2.5Biochemical Analysis
2.6Electrolyte Leakage
2.7Determination of Nutrient Elements in Plant Tissues
Chapter 3 The Effect of Silicon Foliar and Root Application on Growth, Physiology,and Antioxidant Enzymes Activity of Wheat Plants under Cadmium Toxicity
3.1 Introduction
3.2 Results
3.2.1 Growth Parameters
3.2.2 Photosynthetic Pigments
3.2.3Reactive Oxygen Species (ROS)
3.2.4Enzymatic and Non-enzymatic Antioxidants in Wheat Seedlings
3.2.5Essential Nutrients in Wheat
3.3 Discussion
3.4 Conclusion
Chapter 4 Mechanisms of Silicon-Mediated Enhancement of Cadmium Tolerance in Wheat (Triticum AestivumL.) Grown in Cadmium Contaminated Acidic Nutrient Solution
4.1 Introduction
4.2 Results
4.2.1 Biomass Production
4.2.2 Photosynthetic Pigments
4.2.3Enzymatic Antioxidants
4.2.4Non-enzymatic Antioxidants
4.2.5 Osmoprotectants
4.2.6 Protein Contents
4.2.7Relative Water Contents and Membrane Stability Index
4.2.8Reactive Oxygen Species (ROS)Production and Lipid Peroxidation
4.2.9 Nutrient Concentrations
4.2.10Tissue-specific Cadmium Concentration
4.2.11Tissue-specific Silicon Concentration
4.3 Discussions
4.4 Conclusions
Chapter 5 Silicon Attenuates Acidic and Alkaline Stress in the Wheat Plant by Improving Nutrient Availability,Membrane Stability Index and Antioxidative Defense System
5.1 Introduction
5.2 Results
5.2.1Biomass Production
5.2.2 Photosynthetic Pigments
5.2.3 Antioxidative Enzymes
5.2.4Reactive Oxygen Species(ROS)Production and Lipid Peroxidation
5.2.5 Nutrients Concentration
5.2.6Tissue-specific Silicon Concentration
5.3 Discussion
5.4 Conclusion
Chapter 6 Interactions of pH and Cadmium Toxicity inTheir Effect on Growth,Membrane Stability, and Antioxidant Defense Systems of Triticum Aestivum (L.)
6.1 Introduction
6.2 Results
6.2.1 Biomass Production
6.2.2 Photosynthetic Pigments
6.2.3Enzymatic and Non-enzymatic Antioxidants
6.2.4Reactive Oxygen Species (H2O2, EL, and MDA)Production and Lipid Peroxidation
6.2.5Nutrient Concentration
6.2.6 Tissue-specific Cadmium Concentration
6.3 Discussion
6.4 Conclusion
Chapter 7 Alleviatory Effects of Siliconon the Physiology, Morphology and Antioxidative Mechanisms of Wheat (Triticum Aestivum L.) Roots under Cadmium Stress in Acidic Nutrient Solution
7.1 Introduction
7.2 Results
7.2.1Effect of Silicon and Cadmium on Root Biomass
7.2.2Effect of Silicon and Cadmium on Root Volume and Average Diameter
7.2.3Effect of Silicon and Cadmium onTotal Root Length and Root Tips
7.2.4Effect of Silicon and Cadmium on Enzymatic Antioxidant and Protein Contents
7.2.5Effect of Silicon and Cadmium on Non-enzymatic Antioxidants
7.2.6Effect of Silicon and Cadmium on Osmoprotectants
7.2.7Effect of Silicon and Cadmium on Reactive Oxygen Species
7.2.8Effect of Silicon and Cadmium on Nutrient Concentrations in Roots of Wheat Plants
7.2.9Tissue-specific Silicon Concentration in Roots
7.2.10Tissue-specific Cadmium Concentration in Roots
7.3 Discussion
7.4 Conclusion
Chapter 8 Conclusion
8.1SiliconSoil and Foliar Application Alleviates Cd Toxicity
8.2Silicon Alleviates Alone as well as Combines Effects of Cd and Acidic pH Toxicities in Wheat Plants
8.3Silicon Alleviates Acidic and Alkine pH Toxicities in Wheat Plants
8.4Silicon Improves Morphology and Physiology of Roots of Wheat Plants Grown under Cd-contaminated Acidic Nutrient Solution
8.5Cadmium Uptake and Accumulation in Different Levels of pHs
参考文献
致谢
Curriculum Vitae
Malik Shafeeq-ur-Rahman
中国农业科学院;
