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Photoacoustics — A Novel Tool for the Study of Aquatic Photosynthesis (Book chapter)

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ISBN: 9789535111610 Year: DOI: 10.5772/56600 Language: English
Publisher: IntechOpen Grant: FP7 Ideas: European Research Council - 249930
Subject: Science (General)
Added to DOAB on : 2019-01-17 11:47:58
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The photoacoustic method allows direct determination of the energy-storage efficiency of photosynthesis by relating the energy stored by it to the total light energy absorbed by the plant material (Canaani et al., 1988; Malkin & Cahen, 1979; Malkin et al., 1990). These authors applied the photoacoustic method to leaves in the gas phase, where brief pulses caused concomitant pulses of oxygen that caused a pressure transient detected by a microphone. This method is based on the conversion of absorbed light to heat. Depending on the efficiency of the photosynthetic system, a variable fraction of the absorbed light energy is stored, thereby affecting the heat evolved and the resulting photoacoustic signal. The higher the photosynthetic efficiency, the greater will be the difference between the stored energy with and without ongoing photosynthesis (Cha & Mauzerall, 1992). These authors collected microalgal cells onto a filter and studied them by an approach similar to that previously used with leaves. In both cases, the oxygen signal is combined with that of thermal expansion resulting from conversion of the fraction of the light energy in the pulse that is not stored by photochemistry.

Structure and Function of Chloroplasts

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889457137 Year: Pages: 279 DOI: 10.3389/978-2-88945-713-7 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Botany
Added to DOAB on : 2019-01-23 14:53:43
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Chloroplasts are plant cell organelles that convert light energy into relatively stable chemical energy via the photosynthetic process. By doing so, they sustain life on Earth. Chloroplasts also provide diverse metabolic activities for plant cells, including the synthesis of fatty acids, membrane lipids, isoprenoids, tetrapyrroles, starch, and hormones. The biogenesis, morphogenesis, protection and senescence of chloroplasts are essential for maintaining a proper structure and function of chloroplasts, which will be the theme of this Research Topic. Chloroplasts are enclosed by an envelope of two membranes which encompass a third complex membrane system, the thylakoids, including grana and lamellae. In addition, starch grains, plastoglobules, stromules, eyespots, pyrenoids, etc. are also important structures of chloroplasts. It is widely accepted that chloroplasts evolved from a free-living photosynthetic cyanobacterium, which was engulfed by a eukaryotic cell. Chloroplasts retain a minimal genome, most of the chloroplast proteins are encoded by nuclear genes and the gene products are transported into the chloroplast through complex import machinery. The coordination of nuclear and plastid genome expressions establishes the framework of both anterograde and retrograde signaling pathways. As the leaf develops from the shoot apical meristem, proplastids and etioplastids differentiate into chloroplasts. Chloroplasts are divided by a huge protein complex, also called the plastid-dividing (PD) machinery, and their division is also regulated by many factors to get an optimized number and size of chloroplasts in the cell. These processes are fundamental for the biogenesis and three-dimensional dynamic structure of chloroplasts.During the photosynthesis, reactive oxygen species (ROS) and other cellular signals can be made. As an important metabolic hub of the plant cell, the chloroplast health has been found critical for a variety of abiotic and biotic stresses, including drought, high light, cold, heat, oxidative stresses, phosphate deprivation, and programmed cell death at sites of infection. Therefore, a better understanding the responses of chloroplasts to these stresses is part of knowing how the plant itself responds. Ultimately, this knowledge will be necessary to engineer crops more resistant to common stresses.With the current global environment changes, world population growth, and the pivotal role of chloroplasts in carbon metabolism, it is of great significance to represent the advancement in this field, for science and society. Tremendous progresses have been made in the field of chloroplast biology in recent years. Through concerted efforts from the community, greater discoveries definitely will emerge in the future.

Current challenges in photosynthesis: From natural to artificial

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192861 Year: Pages: 102 DOI: 10.3389/978-2-88919-286-1 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Botany --- Science (General)
Added to DOAB on : 2015-12-10 11:59:07
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Jules Verne (1828-1905), author of Around the World in Eighty Days (1873) and Journey to the Center of the Earth (1864), wrote in 1875:"I believe that water will one day be used as a fuel, because the hydrogen and oxygen which constitute it, used separately or together, will furnish an inexhaustible source of heat and light. I therefore believe that, when coal (oil) deposits are oxidised, we will heat ourselves by means of water. Water is the fuel of the future". Solar energy is the only renewable energy source that has sufficient capacity for the global energy need; it is the only one that can address the issues of energy crisis and global climate change. A vast amount of solar energy is harvested and stored via photosynthesis in plants, algae, and cyanobacteria since over 3 billion years. Today, it is estimated that photosynthesis produces more than 100 billion tons of dry biomass annually, which would be equivalent to a hundred times the weight of the total human population on our planet at the present time, and equal to a global energy storage rate of about 100 TW. The solar power is the most abundant source of renewable energy, and oxygenic photosynthesis uses this energy to power the planet using the amazing reaction of water splitting. During water splitting, driven ultimately by sunlight, oxygen is released into the atmosphere, and this, along with food production by photosynthesis, supports life on our earth. The other product of water oxidation is “hydrogen” (proton and electron). This ‘hydrogen’ is not normally released into the atmosphere as hydrogen gas but combined with carbon dioxide to make high energy containing organic molecules. When we burn fuels we combine these organic molecules with oxygen. The design of new solar energy systems must adhere to the same principle as that of natural photosynthesis. For us to manipulate it to our benefit, it is imperative that we completely understand the basic processes of natural photosynthesis, and chemical conversion, such as light harvesting, excitation energy transfer, electron transfer, ion transport, and carbon fixation. Equally important, we must exploit application of this knowledge to the development of fully synthetic and/or hybrid devices. Understanding of photosynthetic reactions is not only a satisfying intellectual pursuit, but it is important for improving agricultural yields and for developing new solar technologies. Today, we have considerable knowledge of the working of photosynthesis and its photosystems, including the water oxidation reaction. Recent advances towards the understanding of the structure and the mechanism of the natural photosynthetic systems are being made at the molecular level. To mimic natural photosynthesis, inorganic chemists, organic chemists, electrochemists, material scientists, biochemists, biophysicists, and plant biologists must work together and only then significant progress in harnessing energy via “artificial photosynthesis” will be possible. This Research Topic provides recent advances of our understanding of photosynthesis, gives to our readers recent information on photosynthesis research, and summarizes the characteristics of the natural system from the standpoint of what we could learn from it to produce an efficient artificial system, i.e., from the natural to the artificial. This topic is intended to include exciting breakthroughs, possible limitations, and open questions in the frontiers in photosynthesis research.

Systems biology and ecology of microbial mat communities

Authors: --- --- --- --- et al.
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197934 Year: Pages: 262 DOI: 10.3389/978-2-88919-793-4 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-02-03 17:04:57
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Microbial mat communities consist of dense populations of microorganisms embedded in exopolymers and/or biomineralized solid phases, and are often found in mm-cm thick assemblages, which can be stratified due to environmental gradients such as light, oxygen or sulfide. Microbial mat communities are commonly observed under extreme environmental conditions, deriving energy primarily from light and/or reduced chemicals to drive autotrophic fixation of carbon dioxide. Microbial mat ecosystems are regarded as living analogues of primordial systems on Earth, and they often form perennial structures with conspicuous stratifications of microbial populations that can be studied in situ under stable conditions for many years. Consequently, microbial mat communities are ideal natural laboratories and represent excellent model systems for studying microbial community structure and function, microbial dynamics and interactions, and discovery of new microorganisms with novel metabolic pathways potentially useful in future industrial and/or medical applications. Due to their relative simplicity and organization, microbial mat communities are often excellent testing grounds for new technologies in microbiology including micro-sensor analysis, stable isotope methodology and modern genomics. Integrative studies of microbial mat communities that combine modern biogeochemical and molecular biological methods with traditional microbiology, macro-ecological approaches, and community network modeling will provide new and detailed insights regarding the systems biology of microbial mats and the complex interplay among individual populations and their physicochemical environment. These processes ultimately control the biogeochemical cycling of energy and/or nutrients in microbial systems. Similarities in microbial community function across different types of communities from highly disparate environments may provide a deeper basis for understanding microbial community dynamics and the ecological role of specific microbial populations. Approaches and concepts developed in highly-constrained, relatively stable natural communities may also provide insights useful for studying and understanding more complex microbial communities.

Inter-cellular Electrical Signals in Plant Adaptation and Communication

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889455218 Year: Pages: 120 DOI: 10.3389/978-2-88945-521-8 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Botany --- Physiology
Added to DOAB on : 2019-01-23 14:53:42
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Plants use the Sun's energy to synthesize the basic biomolecules that make up all the organic matter of all organisms of terrestrial ecosystems, including ourselves. Therefore, understanding their adaptive mechanisms to variations of environmental factors, both biotic and abiotic, is fundamental, and particularly relevant in the current context of rapid climate change. Some of the most important adaptive mechanisms of plants are the electrical and chemical signaling systems for the exchange of information between proximally and distally located cells. These signalling systems allow plants to dynamically coordinate the activities of all cells under a diversity of situations. In this Research Topic, we present eight articles that bring up new hypothesis and data to understand the mechanisms of systemic electrical signaling and the central role that it plays in adapting the whole plant to different stresses, as well as new findings on intracellular calcium and nitric oxide-based signaling pathways under stress, which could be extrapolated to non-plant research.

Chloroplast

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ISBN: 9783038973362 / 9783038973379 Year: Pages: 474 DOI: 10.3390/books978-3-03897-337-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biology --- Botany
Added to DOAB on : 2019-02-18 09:52:18
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Chloroplasts are at the front line of many advancements in molecular biology, ranging from evolutionary biology to the mechanism of energy transduction, also including stress responses and programmed leaf death. In addition to the relevance of basic knowledge, advances are unveiling promising insights to improve plant productivity, disease resistance, and environmental control. The production of secondary metabolites and proteins by transformed chloroplasts adds further excitement to applied investigations on chloroplasts.The comparison of the sequences of the chloroplast DNA of different plants provides valuable information on gene content, reordering in the circular chloroplast DNA, and mutational genetic-derive, relevant to the evolution of the chloroplast. Increasing facilities for intense genome sequencing have prompted many laboratories to focus on the chloroplast DNA. Reflecting these efforts, more than half of the articles in this book deal with functional or evolutionary investigations based on sequence analyses of chloroplast DNA. Additional topics treated in the issue include post-transcriptional control, the processing of nuclear encoded preproteins of chloroplasts, the response of photosynthetic machinery to water deficit, turn-over of chloroplast proteins, mechanism of chloroplast division, and chloroplast movements.

Cyanobacteria: The Green E. coli

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198122 Year: Pages: 114 DOI: 10.3389/978-2-88919-812-2 Language: English
Publisher: Frontiers Media SA
Subject: Biotechnology --- General and Civil Engineering
Added to DOAB on : 2016-01-19 14:05:46
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As the world struggles to reduce its dependence on fossil fuels and curb greenhouse gas emissions, industrial biotechnology is also ‘going green.’ Escherichia coli has long been used as a model Gram-negative bacterium, not only for fundamental research, but also for industrial applications. Recently, however, cyanobacteria have emerged as candidate chassis for the production of commodity fuels and chemicals, utilizing CO2 and sunlight as the main nutrient requirements. In addition to their potential for reducing greenhouse gas emissions and lowering production costs, cyanobacteria have naturally efficient pathways for the production metabolites such as carotenoids, which are of importance in the nutraceutical industry. The unique metabolic and regulatory pathways present in cyanobacteria present new challenges for metabolic engineers and synthetic biologists. Moreover, their requirement for light and the dynamic regulatory mechanisms of the diurnal cycle further complicate the development and application of cyanobacteria for industrial applications. Consequently, significant advancements in cyanobacterial engineering and strain development are necessary for the development of a ‘green E. coli’. This Research Topic will focus on cyanobacteria as organisms of emerging industrial relevance, including research focused on the development of genetic tools for cyanobacteria, the investigation of new cyanobacterial strains, the construction of novel cyanobacterial strains via genetic engineering, the application of ‘omics’ tools to advance the understanding of engineered cyanobacteria, and the development of computational models for cyanobacterial strain development.

Assembly of the Photosystem II Membrane-Protein Complex of Oxygenic Photosynthesis

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889452330 Year: Pages: 315 DOI: 10.3389/978-2-88945-233-0 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Science (General)
Added to DOAB on : 2017-10-13 14:57:01
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Photosystem II is a 700-kDa membrane-protein super-complex responsible for the light-driven splitting of water in oxygenic photosynthesis. The photosystem is comprised of two 350-kDa complexes each made of 20 different polypeptides and over 80 co-factors. While there have been major advances in understanding the mature structure of this photosystem many key protein factors involved in the assembly of the complex do not appear in the holoenzyme. The mechanism for assembling this super-complex is a very active area of research with newly discovered assembly factors and subcomplexes requiring characterization. Additionally the ability to split water is inseparable from light-induced photodamage that arises from radicals and reactive O2 species generated by Photosystem II chemistry. Consequently, to sustain water splitting, a “self repair” cycle has evolved whereby damaged protein is removed and replaced so as to extend the working life of the complex. Understanding how the biogenesis and repair processes are coordinated is among several important questions that remain to be answered. Other questions include: how and when are the inorganic cofactors inserted during the assembly and repair processes and how are the subcomplexes protected from photodamage during assembly? Evidence has also been obtained for Photosystem II biogenesis centers in cyanobacteria but do these also exist in plants? Do the molecular mechanisms associated with Photosystem II assembly shed fresh light on the assembly of other major energy-transducing complexes such as Photosystem I or the cytochrome b6/f complex or indeed other respiratory complexes? The contributions to this Frontiers in Plant Science Research Topic are likely to reveal new details applicable to the assembly of a range of membrane-protein complexes, including aspects of self-assembly and solar energy conversion that may be applied to artificial photosynthetic systems. In addition, a deeper understanding of Photosystem II assembly — particularly in response to changing environmental conditions — will provide new knowledge underpinning photosynthetic yields which may contribute to improved food production and long-term food security.

Salinity Tolerance in Plants

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ISBN: 9783039210268 / 9783039210275 Year: Pages: 422 DOI: 10.3390/books978-3-03921-027-5 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Biochemistry
Added to DOAB on : 2019-06-26 10:09:00
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Salt stress is one of the most damaging abiotic stresses because most crop plants are susceptible to salinity to different degrees. According to the FAO, about 800 million Has of land are affected by salinity worldwide. Unfortunately, this situation will worsen in the context of climate change, where there will be an overall increase in temperature and a decrease in average annual rainfall worldwide. This Special Issue presents different research works and reviews on the response of plants to salinity, focused from different points of view: physiological, biochemical, and molecular levels. Although an important part of the studies on the response to salinity have been carried out with Arabidopsis plants, the use of other species with agronomic interest is also notable, including woody plants. Most of the conducted studies in this Special Issue were focused on the identification and characterization of candidate genes for salt tolerance in higher plants. This identification would provide valuable information about the molecular and genetic mechanisms involved in the salt tolerance response, and it also supplies important resources to breeding programs for salt tolerance in plants.

Keywords

Arabidopsis --- Brassica napus --- ion homeostasis --- melatonin --- NaCl stress --- nitric oxide --- redox homeostasis --- Chlamydomonas reinhardtii --- bZIP transcription factors --- salt stress --- transcriptional regulation --- photosynthesis --- lipid accumulation --- Apocyni Veneti Folium --- salt stress --- multiple bioactive constituents --- physiological changes --- multivariate statistical analysis --- banana (Musa acuminata L.) --- ROP --- genome-wide identification --- abiotic stress --- salt stress --- MaROP5g --- rice --- genome-wide association study --- salt stress --- germination --- natural variation --- Chlamydomonas reinhardtii --- salt stress --- transcriptome analysis --- impairment of photosynthesis --- underpinnings of salt stress responses --- chlorophyll fluorescence --- J8-1 plum line --- mandelonitrile --- Prunus domestica --- redox signalling --- salicylic acid --- salt-stress --- soluble nutrients --- Arabidopsis thaliana --- VOZ --- transcription factor --- salt stress --- transcriptional activator --- chlorophyll fluorescence --- lipid peroxidation --- Na+ --- photosynthesis --- photosystem --- RNA binding protein --- nucleolin --- salt stress --- photosynthesis --- light saturation point --- booting stage --- transcriptome --- grapevine --- salt stress --- ROS detoxification --- phytohormone --- transcription factors --- Arabidopsis --- CDPK --- ion homeostasis --- NMT --- ROS --- salt stress --- antioxidant enzymes --- Arabidopsis thaliana --- ascorbate cycle --- hydrogen peroxide --- reactive oxygen species --- salinity --- SnRK2 --- RNA-seq --- DEUs --- flax --- NaCl stress --- EST-SSR --- Salt stress --- Oryza sativa --- proteomics --- iTRAQ quantification --- cell membrane injury --- root activity --- antioxidant systems --- ion homeostasis --- melatonin --- salt stress --- signal pathway --- SsMAX2 --- Sapium sebiferum --- drought, osmotic stress --- salt stress --- redox homeostasis --- strigolactones --- ABA --- TGase --- photosynthesis --- salt stress --- polyamines --- cucumber --- abiotic stresses --- high salinity --- HKT1 --- halophytes --- glycophytes --- poplars (Populus) --- salt tolerance --- molecular mechanisms --- SOS --- ROS --- Capsicum annuum L. --- CaDHN5 --- salt stress --- osmotic stress --- dehydrin --- Gossypium arboretum --- salt tolerance --- single nucleotide polymorphisms --- association mapping. --- n/a

Thioredoxin and Glutaredoxin Systems

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ISBN: 9783038978367 / 9783038978374 Year: Pages: 280 DOI: 10.3390/books978-3-03897-837-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology
Added to DOAB on : 2019-06-26 08:44:06
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This Special Issue features recent data concerning thioredoxins and glutaredoxins from various biological systems, including bacteria, mammals, and plants. Four of the sixteen articles are review papers that deal with the regulation of development of the effect of hydrogen peroxide and the interactions between oxidants and reductants, the description of methionine sulfoxide reductases, detoxification enzymes that require thioredoxin or glutaredoxin, and the response of plants to cold stress, respectively. This is followed by eleven research articles that focus on a reductant of thioredoxin in bacteria, a thioredoxin reductase, and a variety of plant and bacterial thioredoxins, including the m, f, o, and h isoforms and their targets. Various parameters are studied, including genetic, structural, and physiological properties of these systems. The redox regulation of monodehydroascorbate reductase, aminolevulinic acid dehydratase, and cytosolic isocitrate dehydrogenase could have very important consequences in plant metabolism. Also, the properties of the mitochondrial o-type thioredoxins and their unexpected capacity to bind iron–sulfur center (ISC) structures open new developments concerning the redox mitochondrial function and possibly ISC assembly in mitochondria. The final paper discusses interesting biotechnological applications of thioredoxin for breadmaking.

Keywords

methionine --- methionine sulfoxide --- methionine sulfoxide reductase --- physiological function --- protein --- plant --- repair --- redox homeostasis --- signaling --- stress --- mitochondria --- thioredoxin --- iron–sulfur cluster --- redox regulation --- ALAD --- tetrapyrrole biosynthesis --- redox control --- thioredoxins --- posttranslational modification --- chlorophyll --- redox regulation --- thioredoxin --- ferredoxin-thioredoxin reductase --- chloroplast --- H2O2 --- redox signalling --- development --- regeneration --- adult stem cells --- metazoan --- cyanobacteria --- thioredoxin --- photosynthesis --- redox active site --- thioredoxin --- disulfide --- flavin --- NADPH --- X-ray crystallography --- SAXS --- methanoarchaea --- chilling stress --- cold temperature --- posttranslational modification --- regulation --- ROS --- thiol redox network --- thioredoxin --- thioredoxin --- Calvin-Benson cycle --- photosynthesis --- carbon fixation --- chloroplast --- macromolecular crystallography --- protein-protein recognition --- electrostatic surface --- Chlamydomonas reinhardtii --- thioredoxin --- glutaredoxin --- legume plant --- symbiosis --- redox homeostasis --- stress --- thioredoxin --- monodehydroascorbate reductase --- water stress --- protein oxidation --- antioxidants --- ascorbate --- glutathione --- wheat --- thioredoxin --- thioredoxin reductase --- baking --- redox --- dough rheology --- protein oxidation --- methionine oxidation --- methionine sulfoxide reductases --- oxidized protein repair --- ageing --- Chlamydomonas reinhardtii --- cysteine alkylation --- cysteine reactivity --- MALDI-TOF mass spectrometry --- thioredoxin --- X-ray crystallography --- Isocitrate dehydrogenase --- glutathionylation --- nitrosylation --- glutaredoxin --- Arabidopsis thaliana --- thioredoxins --- plastidial --- specificity --- function --- proteomic --- photosynthesis --- Calvin cycle --- n/a

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