Regulation of pepc gene expression in Anabaena sp. PCC 7120 and its effects on cyclic electron flow around photosystem I and tolerances to environmental stresses Physiological Response to High Light in Cymbidium tracyanum and C.sinense Photosynthetic Acclimation of Erythrophleum guineense and Dalbergia odorifera to Winter Low Temperature in a Marginal Tropical Area Effect of Growth Temperature on the Activity of Cyclic Electron Flow in Tobacco Leaves Effects of Seasonal Drought on Water Status, Leaf Spectral Traits and Fluorescence Parameters in Tarenna depauperata Hutchins, a Chinese Savanna Evergreen Species Physiological Role of Cyclic Electron Flow in Higher Plants