Response of Some Key Enzyme Activities Involved in Nitrogen Metabolism to High Temperature at Filling Stage and Its Relation to Storage Protein Accumulation in Rice Grain Patterns of the Transition of Vacuoles into Protein Bodies in Developing Cotyledon Cells of Soybean Effects of Post-Anthesis High Temperature and Water Stress on Activities of Key Regulatory Enzymes Involved in Protein Formation in Two Wheat Cultivars Protein Accumulation in Grains of Wheat Cultivars Differing in Drought Tolerance and Its Regulation by Nitrogen Application Amount under Irrigated and Dryland Conditions