The discovery of the reversible red far-red control of plant growth and development and the subsequent in vivo identification and isolation of the photoreceptor pigment, phyto chrome, constitutes one of the great achievements in modern biology. It was primarily a group of investigators at the Plant Industry Station, Beltsville, Mary land, headed by the botanist H.A. BORTHWICK and the physical chemist S.B. HENDRICKS, who made the basic discoveries and developed a theoretical framework on which the current progress in the field of phytochrome is still largely based. While the earlier development of the phytochrome concept has been covered by a num ber of excellent articles by the original investigators [104,105,33,238] as well as by others who joined the field of phytochrome research later [72, 109, 219], a comprehensive and up-to-date treatment of photomorphogenesis is not available at present. Since it seems to be needed for teaching as well as for researchers I have tried to summarize the present state of the field, reviewing the historical aspects of the phytochrome story only insofar as they are required to understand the present situation. The emphasis of my treatment will be on developmental physiology ("photomorphogenesis") rather than on phytochrome per se.

With contributions by numerous experts

Plants as sessile organisms have evolved fascinating capacities to adapt to changes in their natural environment. Arguably, light is by far the most important and variable environmental factor. The quality, quantity, direction and duration of light is monitored by a series of photoreceptors covering spectral information from UVB to near infrared. The response of the plants to light is called photomorphogenesis and it is regulated by the concerted action of photoreceptors. The combined techniques of action spectroscopy and biochemistry allowed one of the important photoreceptors – phytochrome – to be identified in the middle of the last century. An enormous number of physiological studies published in the last century describe the properties of phytochrome and its function and also the physiology of blue and UV-B photoreceptors, unidentified at the time. This knowledge was summarized in the advanced textbook “Photomorphogenesis in Plants” (Kendrick and Kronenberg, eds., 1986, 1994). With the advent of molecular biology, genetics and new molecular, cellular techniques, our knowledge in the field of photomorphogenesis has dramatically increased over the last 15 years.

Annual European Symposium on Photomorphogenesis, Volume 27: Photochemistry and Photobiology covers the proceedings of the 1977 Annual European Symposium on Photomorphogenesis, held in Bet Dagan, Israel. This book is divided into 25 chapters and begins with an examination of different forms of phytochrome in extracts of etiolated oat seedlings. The succeeding chapters review the involvement and interaction of membranes, hormones, and the circadian clock. These chapters also look into the effects of light on oscillations of enzyme activity in extracts and the differential effects of calcium on Mougeotia chloroplast movement. These topics are followed by discussions of in vitro transcription and translation of light; the concept of plastid photomorphogenesis; and the photocontrol of plant growth. The final chapters explore the blue light effects on lower and higher plants and the photomorphogenesis in microorganisms, algae, and mosses. This book will be of great value to photochemists, photobiologists, and researchers.

The fIrst edition of the Science 0/ Photobiology edited by Kendric C. Smith (plenum Press, 1977) was a comprehensive textbook of photobiology, devoting a chapter to each of the subdisciplines of the fIeld. At the end of many of these chapters there were brief descriptions of simple experiments that students could perform to demonstrate the principles discussed. In the succeeding years some photobiologists felt that a more complete publica tion of experiments in photobiology would be a useful teaching tool. Thus, in the 1980s the American Society for Photobiology (ASP) attempted to produce a laboratory manual in photobiology. Cognizant of these efforts, Kendric Smith elected to publish the second edition of The Science o/Photobiology (1989) without experiments; anticipating the comple tion of the ASP laboratory manual. Unfortunately, the initial ASP efforts met with limited success, and several years were to pass before a photobiology laboratory manual became a reality. One of the major stumbling blocks to production of an accurate and reliable laboratory manual was the requirement that the experiments be tested, not just by the author who is familiar with the techniques, but by students who may be quite new to photobiology. How could this be accomplished with limited resources? Many ideas were considered and discarded, before a workable solution was found. The catalyst that enabled the careful screening of all experiments in this book was a NATO Advanced Study Institute (ASI) devoted entirely to this purpose.