Investigations on the specific effects of blue light on plants began some fifty years ago. In re cent years the growing awareness of blue-light-in duced phenomena in plants, microorganisms, and animals has accelerat ed and expanded this research into an ever-increasing variety of blue light effects in biological systems. In 1977, J .A. Schiff and W .R. Briggs proposed a specific meeting to present and summarize the various blue-light effects and to discuss their mechanisms and possible photoreceptors. In view of the variety of re sponses and the range of organisms affected by blue light the term Blue Light Syndrome seemed to be the only appropriate one for the meeting. With the help of the International Advisory Committee (W.R. Briggs, Stanford; J. Gressel, Rehovot; W. Kowallik, Bielefeld; S. Miyachi, To kyo; W. Rau, Munich, and J.A. Schiff, Waltham), and the very generous financial support provided by the Deutsche Forschungsgemeinschaft as well as by the Bundesministerium für Forschung und Technologie, the Kultusminister des Landes Hessen, and the Philipps-Universität Marburg, the "International Conference on the Effect of Blue Light in Plants and Microorganisms" was held in July 1979 in the Philipps-Universität Mar burg.

Inhalt
Reviews on Various Fields of Blue Light Action.- The Biological Significance and Evolution of Photosensory Systems.- Short Wavelength Light in Invertebrate Visual Sense Cells Pigments, Potentials and Problems.- Bacteriorhodopsin and its Position in the Blue Light Syndrome.- Chemical Modification of Bacteriorhodopsin by Phenylisothiocyanate: Effect on the Photocycle.- Effects of Blue Light on Movement of Microorganisms.- Blue Light-Induced Intracellular Movements.- Phytochrome and Non-Phytochrome Dependent Blue Light Effects on Intracellular Movements in Fresh-Water Algae.- Interaction Between Blue Light and Phytochrome in Photomorphogenesis.- Sensory Transduction in Phycomyces Photoresponses.- Regulation of Cell Growth and Cell Cycle by Blue Light in Adiantum Gametophytes.- Blue Light and Transcription.- Photoreceptors and Primary Reactions.- Spectroscopic and Photochemical Characterization of Flavoproteins and Carotenoproteins as Blue Light Photoreceptors.- Carotenoids as Primary Photoreceptors in Blue-Light Responses.- On the Nature of the Blue Light Photoreceptor: Still an Open Question.- Conformational Changes Caused by Blue Light.- Interactions of Flavins with Cytochrome C and Oxygen in Excited Artificial Systems.- Artificial Flavin/Membrane Systems; a Possible Model for Physiological Blue Light Action.- Effects of UV and Blue Light on the Bipotential Changes in Etiolated Hypocotyl Hooks of Dwarf Beans.- Blue Light-Controlled Conidiation and Absorbance Change in Neurospora are Mediated by Nitrate Reductase.- Phototropism in Phycomyces: a Photochromic Sensor Pigment?.- Blue and Near Ultraviolet Reversible Photoreaction in Conidial Development of Certain Fungi.- Blue Light Responses in the Siphonaceous Alga Vaucheria.- Cis to Trans Photoisomerization of?-Carotene in Euglena gracilis Var. bacillaris W3BUL: Further Purification and Characterization of the Photoactivity.- Carotenogenesis.- Blue Light-Induced Carotenoid Biosynthesis in Microorganisms.- Photokilling and Protective Mechanisms in Fusarium aquaeductuum.- Dose Response and Related Aspects of Carotenogenesis in Neurospora crassa.- Carbon Metabolism and Respiration.- Effects of Blue Light on Respiration and Non-Photosynthetic CO2 Fixation in Chlorella vulgaris 11h Cells.- Effect of Blue Light on CO2 Fixation in Heterotrophically Grown Scenedesmus obliquus Mutant C-2A'.- Light-Induced Carbon Metabolism in an Early Stage of Greening in Wild Type and Mutant C-2A' Cells of Scenedesmus obliquus.- Enhancement of Carbohydrate Degradation by Blue Light.- Blue Light-Effects on Enzymes of the Carbohydrate Metabolism in Chlorella. 1. Pyruvate Kinase.- Blue Light-Effects on Enzymes of the Carbohydrate Metabolism in Chlorella. 2. Glyceraldehyde 3-Phosphate Dehydrogenase (NADP-Dependent).- Blue Light-Induced Enhancement in Activity of Certain Enzymes in Heterotrophically Grown Cultures of Scenedesmus obliquus.- Effect of 360 nm Light on RuBPCase Products in Vitro Role of Copper in the Reaction.- The Photoinactivation of Micro-Algal Ribulose Bisphosphate Carboxylase; its Physiological and Ecological Significance.- A Rhythmic Change in the Enhancement of the Dark Respiration of Chlorella fusca Induced by a Short Blue-Light Exposure of Low Intensity.- Interaction Between Blue Light and Nitrogen Metabolism.- Regulation by Monochromatic Light of Nitrate Uptake in Chlorella fusca.- Flavin-Mediated Photoreduction of Nitrate by Nitrate Reductase of Higher Plants and Microorganisms.- Effects of Ammonia on Carbon Metabolism in Photosynthesizing Chlorella vulgaris 11 h: theReplacement of Blue Light by Ammonium Ion.- Comparative Studies on the Effect of Ammonia and Blue Light on the Regulation of Photosynthetic Carbon Metabolism in Higher Plants.- The Effect of Blue and Red Light on the Content of Chlorophyll, Cytochrome f, Soluble Reducing Sugars, Soluble Proteins and the Nitrate Reductase Activity During Growth of the Primary Leaves of Sinapis alba.- Chloroplast Development.- Blue Light Effects on Plastid Development in Higher Plants.- Blue Light-Induced Development of Thylakoid Membranes in Isolated Seedling Roots and Cultured Plant Cells.- The Effect of Light Quality and the Mode of Illumination on Chloroplast Development in Etiolated Bean Leaves.- The Importance of Blue Light for the Development of Sun-Type Chloroplasts.- Blue Light and the Photocontrol of Chloroplast Development in Euglena.- Effects of Blue Light on Greening in Microalgae.- Blue Light Regulation of Chloroplast Development in Scenedesmus Mutant C-2A'.- The Action of Blue Light on 5-Aminolevulinic Acid Formation.- Physiology of Blue Light Effects.- Blue-Light Photomorphogenesis in Mushrooms (Basidiomycetes).- Blue Light Induced Differentiation in Phycomyces blakesleeanus.- Effect of Blue Light on Metabolic Processes, Development and Movement in True Slime Molds.- Blue-Light Photoreception in the Inhibition and Synchronization of Growth and Transport in the Yeast Saccharomyces.- Role of Light at Shorter Wavelength in Photobiological Phenomena in Blue-Green Algae.- Blue Light Effects on Some Algae Collected from Subsurface Chlorophyll Layer in the Western Pacific Ocean.- Visible and Spectrophotometrically Detectable Blue Light Responses of Maize Roots.- Synergistic Action of Red and Blue Light on Stomatal Opening of Vicia faba Leaves.- The Blue Light Response ofStomata and the Green Vacuolar Fluorescence of Guard Cells.- Light Induced Changes in the Centrifugability of Chloroplasts Mediated by an Irradiance Dependent Interaction of Respiratory and Photosynthetic Processes.- Growth Rate Patterns Which Produce Curvature and Implications for the Physiology of the Blue Light Response.- Organism Index.