Ultraviolet-B radiation (UV-B) has profound effects on plant growth and development, and exposure varies with ozone depletion across geographic regions with ecosystem and agricultural consequences. This book deals with large-scale impacts and how UV-B affects plants at the molecular level. While UV-B radiation can be damaging, it also has a more positive role in plant photomorphogenesis. Consequently, UV-B treatments are being developed as innovative approaches to improve horticulture. This book is a timely synthesis of what we know and need to know about UV-B radiation and plants.