7,397 results match your criteria chloroplast electron

Photosynthesis and chloroplast redox signaling in the age of global warming: stress tolerance, acclimation and developmental plasticity.

J Exp Bot 2021 Jun 10. Epub 2021 Jun 10.

Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), 2000 Rosario, Argentina.

Contemporary climate change is characterized by the increased intensity and frequency of environmental stress events such as floods, droughts and heatwaves, which have a debilitating impact on photosynthesis and growth, compromising the production of food, feed and biofuels for an expanding population. The need to increase crop productivity in the context of global warming has fueled attempts to improve several key plant features such as photosynthetic performance, assimilate partitioning and tolerance to environmental stresses. Chloroplast redox metabolism, including photosynthetic electron transport and CO2 reductive assimilation, are primary targets of most stress conditions, leading to excessive excitation pressure, photodamage and propagation of reactive oxygen species. Read More

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Quantum information teleportation through biological wires, gravitational micro-bio-holes and holographic micro-bio-systems: A hypothesis.

Biochem Biophys Rep 2021 Jul 19;26:101011. Epub 2021 May 19.

Faculty of Natural Sciences, Mangosuthu University of Technology, Umlazi, South Africa.

Biological systems like cells, bacteria, chloroplasts and other micro-organisms could exchange quantum particles like electrons, photons and gravitational waves and have large distant information teleportation. This is because that their DNAs and membranes are formed from quantum particles like electrons and protons and by their motions, some currents and waves are emerged. These waves have the main role in information teleportation. Read More

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Standard units for ElectroChromic Shift (ECS) measurements in plant biology.

J Exp Bot 2021 Jun 5. Epub 2021 Jun 5.

Aix Marseille Univ, CEA, CNRS, BIAM, UMR 7265, Photosynthesis and Environment, Saint Paul-Lez-Durance, France.

The absorbance shift of pigments is proportional to the membrane potential (Δψ) in plants, green algae, and many photosynthetic bacteria. It is currently denoted as ElectroChromic Shift (ECS) at 515-520 nm for plant carotenoids. It is increasingly being used for phenotyping plants for traits related to photosynthesis or chloroplast metabolism because it is a non-invasive technique and also because more instruments are now commercially available from various manufacturers. Read More

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GFS9 affects piecemeal autophagy of plastids in young seedlings of Arabidopsis thaliana.

Plant Cell Physiol 2021 Jun 4. Epub 2021 Jun 4.

Department of Plant Biology, Cornell University, Ithaca, New York 14853, USA.

Chloroplasts, and plastids in general, contain abundant protein pools that can be major sources of carbon and nitrogen for recycling. We have previously shown that chloroplasts are partially and sequentially degraded by piecemeal autophagy via the Rubisco-containing body (RCB). This degradation occurs during plant development and in response to the environment; however, little is known about the fundamental underlying mechanisms. Read More

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Flexibility of Oxidized and Reduced States of the Chloroplast Regulatory Protein CP12 in Isolation and in Cell Extracts.

Biomolecules 2021 May 8;11(5). Epub 2021 May 8.

Aix Marseille Univ, CNRS, BIP, UMR7281, F-13402 Marseille, France.

In the chloroplast, Calvin-Benson-Bassham enzymes are active in the reducing environment created in the light by electrons from the photosystems. In the dark, these enzymes are inhibited, mainly caused by oxidation of key regulatory cysteine residues. CP12 is a small protein that plays a role in this regulation with four cysteine residues that undergo a redox transition. Read More

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Dynamic Changes in Protein-Membrane Association for Regulating Photosynthetic Electron Transport.

Cells 2021 May 16;10(5). Epub 2021 May 16.

Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.

Photosynthesis has to work efficiently in contrasting environments such as in shade and full sun. Rapid changes in light intensity and over-reduction of the photosynthetic electron transport chain cause production of reactive oxygen species, which can potentially damage the photosynthetic apparatus. Thus, to avoid such damage, photosynthetic electron transport is regulated on many levels, including light absorption in antenna, electron transfer reactions in the reaction centers, and consumption of ATP and NADPH in different metabolic pathways. Read More

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PRAT Proteins Operate in Organellar Protein Import and Export in .

Plants (Basel) 2021 May 11;10(5). Epub 2021 May 11.

Laboratoire de Génétique Moléculaire des Plantes, Université Grenoble-Alpes, BP53F, 38041 Grenoble, France.

Chloroplasts need to import preproteins and amino acids from the cytosol during their light-induced differentiation. Similarly, chloroplasts have to export organic matter including proteins and amino acids during leaf senescence. Members of the PRAT (preprotein and amino acid transporter) family are candidate transporters for both processes. Read More

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Photosynthetic Linear Electron Flow Drives CO Assimilation in Maize Leaves.

Int J Mol Sci 2021 May 5;22(9). Epub 2021 May 5.

Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.

Photosynthetic organisms commonly develop the strategy to keep the reaction center chlorophyll of photosystem I, P700, oxidized for preventing the generation of reactive oxygen species in excess light conditions. In photosynthesis of C plants, CO concentration is kept at higher levels around ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) by the cooperation of the mesophyll and bundle sheath cells, which enables them to assimilate CO at higher rates to survive under drought stress. However, the regulatory mechanism of photosynthetic electron transport for P700 oxidation is still poorly understood in C plants. Read More

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Single-Walled Carbon Nanotubes Modify Leaf Micromorphology, Chloroplast Ultrastructure and Photosynthetic Activity of Pea Plants.

Int J Mol Sci 2021 May 5;22(9). Epub 2021 May 5.

Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad Georgi Bonchev Str. Bl. 21, 1113 Sofia, Bulgaria.

Single-walled carbon nanotubes (SWCNTs) emerge as promising novel carbon-based nanoparticles for use in biomedicine, pharmacology and precision agriculture. They were shown to penetrate cell walls and membranes and to physically interact and exchange electrons with photosynthetic complexes in vitro. Here, for the first time, we studied the concentration-dependent effect of foliar application of copolymer-grafted SWCNTs on the structural and functional characteristics of intact pea plants. Read More

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Binding and/or hydrolysis of purine-based nucleotides is not required for IM30 ring formation.

FEBS Lett 2021 Jun 1. Epub 2021 Jun 1.

Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany.

IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Read More

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Barley Viridis-k links an evolutionarily conserved C-type ferredoxin to chlorophyll biosynthesis.

Plant Cell 2021 May 29. Epub 2021 May 29.

Department of Biology, Lund University, Sölvegatan 35B, 22362 Lund, Sweden.

Ferredoxins are single-electron carrier proteins involved in various cellular reactions. In chloroplasts, the most abundant ferredoxin accepts electrons from photosystem I and shuttles electrons via ferredoxin NADP+ oxidoreductase to generate NADPH or directly to ferredoxin dependent enzymes. In addition, plants contain other isoforms of ferredoxins. Read More

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Transcriptomes of an oceanic diatom reveal the initial and final stages of acclimation to copper deficiency.

Environ Microbiol 2021 May 24. Epub 2021 May 24.

Department of Biology, McGill University, Montréal, QC, Canada.

Copper (Cu) concentration is greatly reduced in the open sea so that phytoplankton must adjust their uptake systems and acclimate to sustain growth. Acclimation to low Cu involves changes to the photosynthetic apparatus and specific biochemical reactions that use Cu, but little is known how Cu affects cellular metabolic networks. Here we report results of whole transcriptome analysis of a plastocyanin-containing diatom, Thalassiosira oceanica 1005, during its initial stages of acclimation and after long-term adaptation in Cu-deficient seawater. Read More

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Cooperation of chloroplast ascorbate peroxidases and proton gradient regulation 5 is critical for protecting Arabidopsis plants from photooxidative stress.

Plant J 2021 May 24. Epub 2021 May 24.

Graduate School of Natural Science and Technology, Shimane University, Nishikawatsu, Matsue, Shimane, Japan.

High-light (HL) stress enhances the production of H O from the photosynthetic electron transport chain in chloroplasts, potentially causing photooxidative damage. Although stromal and thylakoid membrane-bound ascorbate peroxidases (sAPX and tAPX, respectively) are major H O scavenging enzymes in chloroplasts, their knockout mutants do not exhibit a visible phenotype under HL stress. There are trans-thylakoid ∆pH-dependent mechanisms for controlling H O production from photosynthesis, such as thermal dissipation of light energy and down-regulation of electron transfer between photosystem II and I, which may compensate for the lack of APXs. Read More

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Overexpression of FaHSP17.8-CII improves cadmium accumulation and tolerance in tall fescue shoots by promoting chloroplast stability and photosynthetic electron transfer of PSII.

J Hazard Mater 2021 May 5;417:125932. Epub 2021 May 5.

CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China. Electronic address:

Genetic improvement could play a significant role in enhancing the Cd accumulation, translocation and tolerance in plants. In this study, for the first time, we constructed transgenic tall fescue overexpressing a class II (CII) sHSP gene FaHSP17.8-CII, which enhanced Cd tolerance and the root-to-shoot Cd translocation. Read More

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Stress memory gene FaHSP17.8-CII controls thermotolerance via remodeling PSII and ROS signaling in tall fescue.

Plant Physiol 2021 May 1. Epub 2021 May 1.

CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China.

High-temperature is the most limiting factor in the growth of cool-season turfgrass. To cope with high-temperature stress, grass often adopt a memory response by remembering one past recurring stress and preparing a quicker and more robust reaction to the next stress exposure. However, little is known about how stress memory genes regulate the thermomemory response in cool-season turfgrass. Read More

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In vivo electron donation from plastocyanin and cytochrome c to PSI in Synechocystis sp. PCC6803.

Biochim Biophys Acta Bioenerg 2021 May 15;1862(9):148449. Epub 2021 May 15.

Chloroplast Biology and Light-sensing in Microalgae-UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France. Electronic address:

Many cyanobacteria species can use both plastocyanin and cytochrome c as lumenal electron carriers to shuttle electrons from the cytochrome bf to either photosystem I or the respiratory cytochrome c oxidase. In Synechocystis sp. PCC6803 placed in darkness, about 60% of the active PSI centres are bound to a reduced electron donor which is responsible for the fast re-reduction of Pin vivo after a single charge separation. Read More

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Hidden in plain sight: Morphological and phylogenetic evidence for , a species distinct from (Poaceae, Chloridoideae).

Plant Divers 2021 Apr 10;43(2):125-133. Epub 2020 Oct 10.

Departamento de Biología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Avenida Universidad 940, CP 20131, Aguascalientes, Mexico.

Two varieties of have been recognized, the widespread var. and the more narrowly distributed var. The two varieties differ in inflorescence form even more than that seen between many other closely related species of . Read More

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Rice Ferredoxins localize to chloroplasts/plastids and may function in different tissues.

Plant Signal Behav 2021 May 14:1926813. Epub 2021 May 14.

State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.

Ferredoxins (Fds) play a unique and important role in photosynthetic electron transport. Recently, we characterized the function of Fd1 in rice ( L.), showing that Fd1 is the primary photosynthetic electron transport protein and that Fd1 participates in carbon assimilation. Read More

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Proteomic insights into the photosynthetic divergence between bark and leaf chloroplasts in Salix matsudana.

Tree Physiol 2021 May 13. Epub 2021 May 13.

State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry and grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, PR China.

Bark chloroplasts play important roles in carbon balancing by recycling internal stem CO2 into assimilated carbon. The photosynthetic response of bark chloroplasts to interior stem environments has been studied recently in woody plants. However, the molecular regulatory mechanisms underlying specific characteristics of bark photosynthesis remain unclear. Read More

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Allelochemicals of Alexandrium minutum: Kinetics of membrane disruption and photosynthesis inhibition in a co-occurring diatom.

Harmful Algae 2021 03 18;103:101997. Epub 2021 Feb 18.

Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de la Recherche Scientifique (CNRS), Sorbonne université, 75005 Paris, France. Electronic address:

Allelopathy is an efficient strategy by which some microalgae can outcompete other species. Allelochemicals from the toxic dinoflagellate Alexandrium minutum have deleterious effects on diatoms, inhibiting metabolism and photosynthesis and therefore give a competitive advantage to the dinoflagellate. The precise mechanisms of allelochemical interactions and the molecular target of allelochemicals remain however unknown. Read More

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Heterocapsa busanensis sp. nov. (Peridiniales, Dinophyceae): A new marine thecate dinoflagellate from Korean coastal waters.

Eur J Protistol 2021 Jun 23;79:125797. Epub 2021 Apr 23.

Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea; Department of Oceanography, Pukyong National University, Busan 48513, Republic of Korea. Electronic address:

During daily monitoring in Yongho Bay off Busan, Korea in 2019, an isolate of the dinoflagellate genus Heterocapsa was established in clonal culture. Light and electron microscopic examination revealed that the isolate was ellipsoid in shape, exhibiting a thecal plate arrangement (Po, cp, X, 5', 3a, 7″, 6c, 5s, 5‴, 2'''') consistent with most other Heterocapsa species. A large, elongated nucleus was positioned on the left side of the cell, a single reticulate chloroplast was located peripherally, and a single, starch-sheathed, spherical pyrenoid was present in the episome or near the cingulum. Read More

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Regulation of plasmodesmata in leaves of Arabidopsis: ATP, NADPH and chlorophyll b levels matter.

J Exp Bot 2021 May 11. Epub 2021 May 11.

Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 St.-Petersburg, Russia.

In mature leaves, cell-to-cell transport via plasmodesmata (PD) between mesophyll cells links assimilate production in photosynthesis with their export to sink organs. This study addresses the question how signals derived from chloroplasts and photosynthesis influence PD permeability. Cell-to-cell transport was analyzed in leaves of Arabidopsis chlorophyll b-less ch1-3 mutant, the same mutant complemented with a cyanobacterial CAO gene (PhCAO) over-accumulating chlorophyll b, the trxm3 mutant lacking plastidial thioredoxin m3, and the ntrc mutant lacking functional NADPH : thioredoxin reductase C. Read More

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The Significance of Chloroplast NAD(P)H Dehydrogenase Complex and Its Dependent Cyclic Electron Transport in Photosynthesis.

Front Plant Sci 2021 23;12:661863. Epub 2021 Apr 23.

School of Biological Sciences, The University of Western Australia, Perth, WA, Australia.

Chloroplast NAD(P)H dehydrogenase (NDH) complex, a multiple-subunit complex in the thylakoid membranes mediating cyclic electron transport, is one of the most important alternative electron transport pathways. It was identified to be essential for plant growth and development during stress periods in recent years. The NDH-mediated cyclic electron transport can restore the over-reduction in stroma, maintaining the balance of the redox system in the electron transfer chain and providing the extra ATP needed for the other biochemical reactions. Read More

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Encoding a Ferredoxin Protein With C-Terminus Extension Is Indispensable for Maize Growth.

Front Plant Sci 2021 23;12:646359. Epub 2021 Apr 23.

Agricultural Genomics Institute, Chinese Academy of Agricultural Sciences, Shenzhen, China.

As important electron carriers, ferredoxin (Fd) proteins play important roles in photosynthesis, and the assimilation of CO, nitrate, sulfate, and other metabolites. In addition to the well-studied Fds, plant genome encodes two Fd-like protein members named FdC1 and FdC2, which have extension regions at the C-terminus of the 2Fe-2S cluster. Mutation or overexpression of genes caused alterations in photosynthetic electron transfer rate in rice and Arabidopsis. Read More

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Anatomical and ultrastructural alterations in Ceratopteris pteridoides under cadmium stress: A mechanism of cadmium tolerance.

Ecotoxicol Environ Saf 2021 May 3;218:112285. Epub 2021 May 3.

Department of Environmental Science, Tezpur University, Napaam, Tezpur, Assam, India. Electronic address:

The present research is an appraisal of anatomical and ultrastructural alterations in aquatic fern, Ceratopteris pteridoides under cadmium (Cd) exposure. Plants were cultured hydroponically for 12 consecutive days in different Cd treatments: 10 µM L (CDT1), 20 µM L (CDT2), 40 µM L (CDT3) and 60 µM L (CDT4). Anatomical and ultrastructural changes of different vegetative tissues of C. Read More

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Dissociation Strategies to Maximize Coverage of α-Helical Domains in Top-Down Mass Spectrometry of Integral Membrane Proteins.

J Am Soc Mass Spectrom 2021 Jun 6;32(6):1380-1387. Epub 2021 May 6.

The Pasarow Mass Spectrometry Laboratory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90024, United States.

Transmembrane α-helical domains of membrane proteins tend to remain structured in the gas phase, presenting a challenge for efficient electron capture/transfer dissociation during top-down dissociation mass spectrometry (MS) experiments. In this study, we compare results from different dissociation modes on a modern Orbitrap platform applied to a model integral membrane protein containing two transmembrane helices, the c-subunit of the Fo domain of the chloroplast ATP synthase. Using commercially available options, we compare collisionally activated dissociation (CAD) with the related variant higher-energy collisional dissociation (HCD) and with electron transfer dissociation (ETD). Read More

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Internalization of polystyrene microplastics in Euglena gracilis and its effects on the protozoan photosynthesis and motility.

Aquat Toxicol 2021 Jul 18;236:105840. Epub 2021 Apr 18.

College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, P.R. China.

In this study, effects of polystyrene microplastics (MPS) on Euglena gracilis were investigated via examination on its photosynthesis and motility, two typical properties of the protozoan. No adverse effects were observed after 4-d exposure except for decrease in motility at two high MPS concentrations (5 and 25 mg/L). After 8-d duration, MPS at 1 mg/L had no obvious effects on E. Read More

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Implications of nighttime temperature on metamitron impacts on the photosynthetic machinery functioning of Malus x domestica Borkh.

J Plant Physiol 2021 Jun 16;261:153427. Epub 2021 Apr 16.

Unidade de Geobiociências, Geoengenharias e Geotecnologias (GeoBioTec), Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal; Unidade de Investigação em Biotecnologia e Recursos Genéticos (UIBRG), Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV), 2784-505, Oeiras, Portugal. Electronic address:

Metamitron (MET) is a fruitlet thinning compound for apple trees, needing better understanding of its action on leaf energy metabolism, depending on nighttime temperature. A trial under environmental controlled conditions was set with 'Golden Reinders' potted trees, under 25/7.5 and 25/15 °C (diurnal/nighttime temperature), with (MET, 247. Read More

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Leaf Phenological Stages of Winter Oilseed Rape ( L.) Have Conserved Photosynthetic Efficiencies but Contrasted Intrinsic Water Use Efficiencies at High Light Intensities.

Front Plant Sci 2021 15;12:659439. Epub 2021 Apr 15.

Institute for Genetics, Environment and Plant Protection (IGEPP), National Research Institute for Agriculture, Food and Environment (INRAE), Institut Agro, Université Rennes, Le Rheu, France.

Leaf senescence in source leaves leads to the active degradation of chloroplast components [photosystems, chlorophylls, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)] and plays a key role in the efficient remobilization of nutrients toward sink tissues. However, the progression of leaf senescence can differentially modify the photosynthetic properties of source leaves depending on plant species. In this study, the photosynthetic and respiratory properties of four leaf ranks of oilseed rape describing leaf phenological stages having different sink-source activities were analyzed. Read More

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Changes in Leaf-Level Nitrogen Partitioning and Mesophyll Conductance Deliver Increased Photosynthesis for Leaves Engineered to Accumulate Lipid Carbon Sinks.

Front Plant Sci 2021 9;12:641822. Epub 2021 Mar 9.

Plant Biotechnology Team, AgResearch Ltd, Palmerston North, New Zealand.

Diacylglycerol acyl-transferase (DGAT) and cysteine oleosin (CO) expression confers a novel carbon sink (of encapsulated lipid droplets) in leaves of and has been shown to increase photosynthesis and biomass. However, the physiological mechanism by which DGAT + CO increases photosynthesis remains unresolved. To evaluate the relationship between sink strength and photosynthesis, we examined fatty acids (FA), water-soluble carbohydrates (WSC), gas exchange parameters and leaf nitrogen for multiple DGAT + CO lines varying in transgene accumulation. Read More

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