Separation and determination of components of xanthophyll cycle and preparation of violaxanthin in large quantity Xanthophyil Cycle and Its Molecular Mechanism in Photoprotection EFFECTS OF TEMPERATURE AND LIGHT TREATMENT ON VIOLAXANTHIN DE-EPOXIDASE ACTIVITY AND XANTHOPHYLL CYCLE-DEPENDENT ENERGY DISSIPATION IN WHEAT LEAVES Regulation of Xanthophyll Cycle of Photosystem by Antenna Proteins and Thylakoid Membrane Lipids Overexpression and Suppression of Violaxanthin De-epoxidase Affects the Sensitivity of Photosystem II Photoinhibition to High Light and Chilling Stress in Transgenic Tobacco