Preface

Photosynthesis is integral to plant productivity, both as a source of energy and materials and as a target for feedback regulation by the demand of the whole plant for photosynthate. Photosynthesis is also strongly modulated by the environment multiple environmental conditions result in the absorption of potentially harmful levels of excess light. Photoprotection and the phenomenon of photoinhibition of photosynthesis are thus key responses of plants to the environment as well. However, it...

Sources of Singlet Oxygen

Photosynthesis is the major source of singlet oxygen in plants. Singlet oxygen is mainly formed through energy transfer from the triplet state of excited pigments to triplet oxygen, but is also an intermediate in chemi-excitation, such as occurs in lipid peroxidation. Of course, since photosynthesis involves constant pigment excitation, the potential for singlet oxygen production is always present. Chlorophyll triplets are formed both in the antenna as well as in the photosystems. In the...