In an attempt to improve communication between disciplines in this field, we have aimed to cover what we perceive to be all relevant aspects of photooxidative stress: from primary reactions to molecular genetics and the devising of strategies for engineering stress tolerance in plants. We hope to achieve a forum for new ideas, concepts, and approaches. The intellectual challenge also arose because we wished to produce a work that was accessible to both specialist and nonspecialist. We have encouraged our authors to provide personal perspectives of their topics while discussing them in depth. To this end, the nonspecialist will find that some chapters include relatively simple introductions and conclusions, e.g., Foyer and Harbinson (Chapter 1); Gressel and Galun (Chapter 10).