Protochlorophyllide Reduction and Greening


Book Description

Proceedings of a Meeting held at the University of Liège, Belgium, 8-9 August 1983




Photoreduction of Protochlorophyllide a to Chlorophyllide a During the Biogenesis of the Photosynthetic Apparatus in Highter Plants


Book Description

This thesis is divided into 4 chapters summarizing this contribution on selected topics related to chlorophyll biosynthesis and biogenesis of the photosynthetic apparatus. The first chapter deals with the state of Pchlide in nonilluminated leaves. The comparison of the photoactive Pchlide absorbance spectra throughout the development in the dark, reveals that the proportion of P638-645 and P650-657 is not much modified during this period. The Gaussian deconvolutions of 77 K fluorescence spectra of nonphotoactive and photoactive Pchlide indicated the presence of three and 5 spectral forms, respectively. None of the nonphotoactive Pchlide forms is accumulated during the dark-growth. In constrast, photoactive Pchlide P650-657 is particularly accumulated. In the second chapter, we describe the photoreduction of Pchlide to Chlide. We conclude that the mechanism of photoreduction is independent on the leaf developmental stage. Using 77 K fluorescence spectroscopy, the Chlide spectral forms corresponding to the three photoactive Pchlides were identified. In leaves with proplastids, C670-675 is mainly formed whereas in leaves with etioplasts C684-696 is produced. During the 1st hour of greening, the newly formed Chlide molecules are not protected by carotenoids. The evidence for the involvement of a photocycle involving two spectral forms of Chlide in protection of newly formed Chlide is presented. In the third chapter, a method for the isolation of photoactive Pchlide yielding complexes characterized by spectral properties similar to those found in intact leaves is described. In the fourth chapter, it is explained that the different fates of the first products of the photoreduction, described in the 2nd chapter, influence the greening process. In fact, C684-696 is only produced in small amounts in plants with proplastids. Therefore the increase of the photosynthetic activity of these leaves is delayed. Nevertheless, during the first 8 h of greening, a weak photosynthetic activity is detected in these leaves. Fluorescence measurements reveal that a large part of the Chl remains nonintegrated to the photosystems. In young leaves, rapid Chl integration into the photosynthetic units occurs when both carotenoids and Chl are massively synthesized.




Handbook of Plant and Crop Physiology


Book Description

With contributions from over 70 international experts, this reference provides comprehensive coverage of plant physiological stages and processes under both normal and stressful conditions. It emphasizes environmental factors, climatic changes, developmental stages, and growth regulators as well as linking plant and crop physiology to the production of food, feed, and medicinal compounds. Offering over 300 useful tables, equations, drawings, photographs, and micrographs, the book covers cellular and molecular aspects of plant and crop physiology, plant and crop physiological responses to heavy metal concentration and agrichemicals, computer modeling in plant physiology, and more.




The Porphyrin Handbook


Book Description

The Porphyrin Handbook, Volume 12: The Iron and Cobalt Pigments: Biosynthesis, Structure, and Degradation provides information pertinent to every aspect of the chemistry, synthesis, spectroscopy, and structure of phthalocyanines. This book presents the biochemical and clinical aspects of genetically transmitted or drug-induced diseases associated with errors in heme metabolism. Organized into eight chapters, this volume begins with an overview of the comparison of regulatory principles in animal and plant tetrapyrrole biosynthesis. This text then examines the biology and medical implications of porphyrin systems. Other chapters consider the transformation of hemes into bile pigments, the organic synthesis of bilins, and the pathways of degradation of chlorophyll in senescent plants. This book discusses as well the biosynthesis of porphyrins, vitamin B12, and chlorophylls. The final chapter deals with genome sequencing projects that provide sources of genes encoding the enzymes needed for the synthesis of the intermediates. This book is a valuable resource for research scientists, engineers, and clinicians.




Pigment—Protein Complexes in Plastids


Book Description

Pigment-Protein Complexes in Plastids: Synthesis and Assembly covers the different aspects of biosynthesis, assembly, and function of pigment-protein complexes. This book focuses on the molecular biology and physiological relevance of chlorophyll-protein complexes. The regulation and biosynthesis of chlorophyll proteins that involve a coordinated expression of nuclear and plastid genes and require communication among the cell organelles to respond properly to changing light and temperature conditions are also deliberated. This publication is intended for researchers in the fields of plant molecular biology, genetics, plant physiology and biochemistry, and cell biology, as well as students and teachers in agriculture, horticulture, biology, and biochemistry interested in pigment-protein complexes.




Annual Plant Reviews, Plant Pigments and their Manipulation


Book Description

Annual Plant Reviews, Volume 14 It is difficult to over-state the importance of plant pigments in biology. Chlorophylls are arguably the most important organic compounds on earth, as they are required for photosynthesis. Carotenoids are also necessary for the survival of both plants and mammals, through their roles in photosynthesis and nutrition, respectively. The other plant pigment groups, such as flavonoids and betalains, have important roles in both the biology of plants and the organisms with which plants interact. This book provides an overview of pigment chemistry and biology, together with an up-to-date account of the biosynthesis of pigments and the modification of their production using biotechnology. The chapters cover a wide scope of pigmentation research - from the importance of structural diversity in generating the range of colours seen in plants, through to improving human health properties of crops by increasing pigment levels in transgenic plants. The volume is directed at researchers and professionals in plant biochemistry, molecular biology and genetics.




Recent Advances in Biological Membrane Studies


Book Description

A NATO Advanced Study Institute on "New Developments and Methods in Membrane Research and Biological Energy Transduction" was held in order to consider some of the most recent developments in membrane research methodologies and results, with particular emphasis on studies of biological energy transduction. The partic ipants in the Institute dealt with three general areas of membrane study: membrane structure (with emphasis on lipid and protein components), membrane component assembly (with particular emphasis on mitochondria and chloroplasts), and the specialized functions of certain membrane systems. This last area included discussions of topics such as drug transformation, the role of membrane electron transport in the generation of oxygen radicals, the effect of oxygen radicals on cellular homeostasis and on the structure, organization and function of the acetylcholine receptor. Lectures and posters were concerned with two central questions: what is the function of membrane structure in energy transduction and how can energy trans duction be effectively measured and assessed? This text presents the content of the major lectures and important posters presented during the Institute's program. In issuing this book, the editor hopes to convey the proceedings of the Institute to a larger audi ence and to offer a comprehensive account of those developments in membrane research that were considered on the Island of Spetsai between August 16 and August 29, 1984. L. Packer Berkeley, California February 1985 v CONTENTS I. STRUCTURE AND BIOGENSIS Membrane Structure: Neutron Diffraction and Small Angle Scattering Studies •••••••••• 1 G.




Primary Processes of Photosynthesis


Book Description

This volume forms part of a two-volume set and is not available for individual purchase. Please view the complete pack (ISBN: 978-0-85404-364-4) for purchase options.




Protein Reviews


Book Description

The aim of the Protein Reviews is to serve as a publication vehicle for review articles that focus on crucial current vigorous aspects of protein structure, function, evolution and genetics. Volume 17 of Protein Reviews is the beginning of a new publication format. The volumes will appear online before they are published in a printed book. Articles will be selected according to their importance to the understanding of biological systems, their relevance to the unravelling of issues associated with health and disease or their impact on scientific or technological advances and developments. The chapters in this volume are authored by experts in the field. They deal with aspects of structure and biological activity of selected proteins. Specific chapters deal with the aggregation of FET proteins (FUS, EWSR1, TAF15) as a pathological change in amyotrophic lateral sclerosis, structural changes fundamental to gating of the cystic fibrosis transmembrane conductance regulator anion channel pore, the dual roles for epithelial splicing regulatory proteins 1 (ESRP1) and 2 (ESRP2) in cancer progression, controlling autolysis during flagella insertion in Gram-negative bacteria, the regulation of skeletal muscle myoblast differentiation and the proliferation by pannexins, hyaluronidase and chondroitinase, factors that control mitotic spindle elongation, how secreted phospholipase A2 type IIA (sPLA2-IIA) activates integrins in an allosteric manner, the simple and unique allosteric machinery of Thermus caldophilus lactate dehydrogenase, and the reduction of chemically stable multibonds: Nitrogenase-like biosynthesis of tetrapyrroles. This volume is intended for research scientists, clinicians, physicians, and graduate students in fields of biochemistry, cell biology, molecular biology microbiology, immunology and genetics.




Current Research in Photosynthesis


Book Description

These four volumes with close to one thousand contributions are the proceedings from the VIIIth International Congress on Photosynthesis, which was held in Stockholm, Sweden, on August 6- 11, 1989. The site for the Congress was the campus of the University of Stockholm. This in itself was an experiment, since the campus never before had been used for a conference of that size. On the whole, it was a very sucessful experiment. The outcome of a congress depends on many contributing factors, one major such factor being the scientific vigour of the participants, and I think it is safe to say that the pariticipants were vigourous indeed. Many exciting new fmdings were presented and thoroughly dicussed, indoors in the discussion sessions as well as outdoors on the lawns. For the local organizing committee it was very rewarding to participate in these activities, and to watch some of our younger colleagues for the first time being subjected to the impact of a large international congress. The stimulating effect of this event on the local research atmosphere has been substantial. As was the case with the proceedings from both the 1983 and 1986 Congresses these proceedings have been compiled from camera ready manuscripts, and the editing has mainly consisted of finding the proper place for each contribution and distributing the manuscripts into four volumes with some int~rnal logic in each. In this I have had the invaluable help from Dr.