Book excerpt: This unique resource reviews progress made by scientists researching into how ambient changes in the wavelength, intensity, direction and duration of light environment affect plant growth and development. It explains how combinations of new research with classical photobiology and physiology have made it feasible to interpret intriguing light dependent phenomena such as phototropism, determination of flowering time, shade avoidance etc. at molecular level. Written by over 20 leading experts in the field the book covers major breakthroughs achieved in the last decade. It is generously referenced with more than 2389 bibliographic citations.