scholarly journals Copper excess-induced large reversible and small irreversible adaptations in a population of Chlamydomonas reinhardtii CW15 (Chlorophyta)

2018 ◽  
Vol 87 (1) ◽  
Author(s):  
Bartosz Pluciński ◽  
Andrzej Waloszek ◽  
Joanna Rutkowska ◽  
Kazimierz Strzałka
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Copper Concentration ◽  
Photosynthetic Apparatus ◽  
Cellular Level ◽  
Copper Tolerance ◽  
Control Population ◽  
Copper Stress ◽  
Elevated Concentration ◽  
Adaptive Value ◽  
Dim Light

<p>Two <em>Chlamydomonas reinhardtii</em> CW15 populations modified by an excess of copper in growth medium were obtained: a “Cu” population that was continuously grown under the selection pressure of 5 µM Cu<sup>2+</sup> (for at least 48 weeks) and the “Re” population, where a relatively short (9 week) exposure to elevated copper, necessary for acquiring tolerance, was followed by a prolonged period (at least 39 weeks) of cultivation at a normal (0.25 µM) copper concentration.</p><p>Cells of the Cu population were able to multiply at a Cu<sup>2+</sup> concentration 16 times higher than that of the control population at a normal light intensity and at a Cu<sup>2+</sup> concentration 64 times higher when cultivated in dim light. The potential quantum yield of photosystem II (F<sub>V</sub>/F<sub>M</sub> ratio) under copper stress was also significantly higher for the Cu population than for Re and control populations.</p><p>The Re population showed only residual tolerance towards the elevated concentration of copper, which is revealed by an F<sub>V</sub>/F<sub>M</sub> ratio slightly higher than in the control population under Cu<sup>2+</sup> stress in dim light or in darkness.</p><p>We postulate that in the <em>Chlamydomonas populations</em> studied in this paper, at least two mechanisms of copper tolerance operate. The first mechanism is maintained during cultivation at a standard copper concentration and seems to be connected with photosynthetic apparatus. This mechanism, however, has only low adaptive value under excess of copper. The other mechanism, with a much higher adaptive value, is probably connected with Cu<sup>2+</sup> homeostasis at the cellular level, but is lost during cultivation at a normal copper concentration.</p>

scholarly journals PGRL1 Participates in Iron-induced Remodeling of the Photosynthetic Apparatus and in Energy Metabolism in Chlamydomonas reinhardtii

2009 ◽  
Vol 284 (47) ◽  
pp. 32770-32781 ◽  
Author(s):  
Dimitris Petroutsos ◽  
Aimee M. Terauchi ◽  
Andreas Busch ◽  
Ingrid Hirschmann ◽  
Sabeeha S. Merchant ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Chlamydomonas Reinhardtii ◽  
Photosynthetic Apparatus

scholarly journals Nitric Oxide Remodels the Photosynthetic Apparatus upon S-Starvation in Chlamydomonas reinhardtii

2018 ◽  
Vol 179 (2) ◽  
pp. 718-731 ◽  
Author(s):  
Marcello De Mia ◽  
Stéphane D. Lemaire ◽  
Yves Choquet ◽  
Francis-André Wollman
Keyword(s):  
Nitric Oxide ◽  
Chlamydomonas Reinhardtii ◽  
Photosynthetic Apparatus

scholarly journals Association of Ferredoxin:NADP+ oxidoreductase with the photosynthetic apparatus modulates electron transfer in Chlamydomonas reinhardtii

2017 ◽  
Vol 134 (3) ◽  
pp. 291-306 ◽  
Author(s):  
Laura Mosebach ◽  
Claudia Heilmann ◽  
Risa Mutoh ◽  
Philipp Gäbelein ◽  
Janina Steinbeck ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Chlamydomonas Reinhardtii ◽  
Photosynthetic Apparatus

Changes in the photosynthetic apparatus and lipid droplet formation in Chlamydomonas reinhardtii under iron deficiency

2018 ◽  
Vol 139 (1-3) ◽  
pp. 253-266 ◽  
Author(s):  
Elsinraju Devadasu ◽  
Dinesh Kumar Chinthapalli ◽  
Nisha Chouhan ◽  
Sai Kiran Madireddi ◽  
Girish Kumar Rasineni ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Chlamydomonas Reinhardtii ◽  
Lipid Droplet ◽  
Photosynthetic Apparatus ◽  
Droplet Formation ◽  
Lipid Droplet Formation

scholarly journals Thylakoid membrane biogenesis in Chlamydomonas reinhardtii 137+. II. Cell-cycle variations in the synthesis and assembly of pigment.

1982 ◽  
Vol 93 (2) ◽  
pp. 411-416 ◽  
Author(s):  
D R Janero ◽  
R Barrnett
Keyword(s):  
Cell Cycle ◽  
Chlamydomonas Reinhardtii ◽  
Thylakoid Membrane ◽  
Direct Analysis ◽  
Cellular Level ◽  
Periodic Pattern ◽  
Cell Cycle Time ◽  
Pigment Synthesis ◽  
Thylakoid Biogenesis ◽  
Kinetics Of

Synthesis of the chlorophyll and the major carotenoid pigments and their assembly into thylakoid membrane have been studied throughout the 12-h light/12-h dark vegetative cell cycle of synchronous Chlamydomonas reinhardtii 137+ (wild-type). Pulse exposure of cells to radioactive acetate under conditions in which labeling accurately reflects lipogenesis, followed by cellular fractionation to purify thylakoid membrane, allowed direct analysis of the pigment synthesis and assembly attendant to thylakoid biogenesis. All pigments are synthesized and assembled into thylakoids continuously, but differentially, with respect to cell-cycle time. Highest synthesis and assembly rates are confined to the photoperiod (mid-to-late G1) and support chlorophyll and carotenoid accretion before M-phase. The lower levels at which these processes take place during the dark period (S, M, and early-to-mid G1) have been ascribed to pigment turnover. Within this general periodic pattern, pigment synthesis and assembly occur in a "multi-step" manner, i.e., by a temporally-ordered, stepwise integration of the various pigments into the thylakoid membrane matrix. The cell-cycle kinetics of pigment assembly at the subcellular level mirror the kinetics of pigment synthesis at the cellular level, indicating that pigment synthesis not only provides chlorophyll and carotenoid for thylakoid biogenesis but may also serve as a critical rate-determinant to pigment assembly.

scholarly journals Copper Stress on Photosynthesis of Black Mangle (Avicennia germinans)

2013 ◽  
Vol 85 (2) ◽  
pp. 665-670 ◽  
Author(s):  
DANIEL GONZALEZ-MENDOZA ◽  
FRANCISCO ESPADAS y GIL ◽  
FERNANDO ESCOBOZA-GARCIA ◽  
JORGE M. SANTAMARIA ◽  
OMAR ZAPATA-PEREZ
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Apparatus ◽  
Copper Toxicity ◽  
Net Photosynthesis ◽  
Avicennia Germinans ◽  
Copper Stress ◽  
Photosynthetic Gas Exchange ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Photosynthetic Activities

The effects of copper toxicity on the photosynthetic activities of Avicennia germinans was investigated using two CuSO4 concentrations (0.062 and 0.33 M) added in Hoagland's solution in an aerated hydroponic system. Photosynthesis and chlorophyll fluorescence were measured after 30 h of copper stress. Results obtained in this study show that increasing levels of Cu+2 of 0.062 and 0.33 M Cu+2 resulted in a general reduction of the stomatal conductance (28 and 18%, respectively) and 100% of inhibition of net photosynthesis. Additionally, at these concentrations of Cu+2, reductions of chlorophyll fluorescence parameters were also observed. These changes suggested that the photosynthetic apparatus of Avicennia germinans was the primary target of the Cu+2 action. It is concluded that Cu+2 ions causes a drastic decline in photosynthetic gas exchange and Chlorophyll fluorescence parameters in A. germinans leaves.

scholarly journals The Surface-Associated and Secreted MopE Protein of Methylococcus capsulatus (Bath) Responds to Changes in the Concentration of Copper in the Growth Medium

2003 ◽  
Vol 69 (4) ◽  
pp. 2386-2388 ◽  
Author(s):  
Odd A. Karlsen ◽  
Frode S. Berven ◽  
Graham P. Stafford ◽  
Øivind Larsen ◽  
J. Colin Murrell ◽  
...  
Keyword(s):  
Growth Medium ◽  
Copper Concentration ◽  
Copper Ions ◽  
Copper Stress ◽  
Secreted Protein ◽  
Methylococcus Capsulatus ◽  
Methanotrophic Bacterium ◽  
In Cells

ABSTRACT Expression of surface-associated and secreted protein MopE of the methanotrophic bacterium Methylococcus capsulatus (Bath) in response to the concentration of copper ions in the growth medium was investigated. The level of protein associated with the cells and secreted to the medium changed when the copper concentration in the medium varied and was highest in cells exposed to copper stress.

scholarly journals Overexpression of mqsR in Xylella fastidiosa Leads to a Priming Effect of Cells to Copper Stress Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Isis Gabriela Barbosa Carvalho ◽  
Marcus Vinicius Merfa ◽  
Natália Sousa Teixeira-Silva ◽  
Paula Maria Moreira Martins ◽  
Marco Aurélio Takita ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Xylella Fastidiosa ◽  
Cell Formation ◽  
Cell Aggregation ◽  
Plant Diseases ◽  
Copper Tolerance ◽  
Copper Stress ◽  
Economic Damage ◽  
Environmental Damage

Copper-based compounds are widely used in agriculture as a chemical strategy to limit the spread of multiple plant diseases; however, the continuous use of this heavy metal has caused environmental damage as well as the development of copper-resistant strains. Thus, it is important to understand how the bacterial phytopathogens evolve to manage with this metal in the field. The MqsRA Toxin–Antitoxin system has been recently described for its function in biofilm formation and copper tolerance in Xylella fastidiosa, a plant-pathogen bacterium responsible for economic damage in several crops worldwide. Here we identified differentially regulated genes by X. fastidiosa MqsRA by assessing changes in global gene expression with and without copper. Results show that mqsR overexpression led to changes in the pattern of cell aggregation, culminating in a global phenotypic heterogeneity, indicative of persister cell formation. This phenotype was also observed in wild-type cells but only in the presence of copper. This suggests that MqsR regulates genes that alter cell behavior in order to prime them to respond to copper stress, which is supported by RNA-Seq analysis. To increase cellular tolerance, proteolysis and efflux pumps and regulator related to multidrug resistance are induced in the presence of copper, in an MqsR-independent response. In this study we show a network of genes modulated by MqsR that is associated with induction of persistence in X. fastidiosa. Persistence in plant-pathogenic bacteria is an important genetic tolerance mechanism still neglected for management of phytopathogens in agriculture, for which this work expands the current knowledge and opens new perspectives for studies aiming for a more efficient control in the field.

scholarly journals Excess copper induces structural changes in cultured photosynthetic soybean cells

2006 ◽  
Vol 33 (11) ◽  
pp. 1001 ◽  
Author(s):  
María Bernal ◽  
Pilar Sánchez-Testillano ◽  
María del Carmen Risueño ◽  
Inmaculada Yruela
Keyword(s):  
Cell Wall ◽  
Structural Changes ◽  
Copper Tolerance ◽  
Copper Stress ◽  
Induced Response ◽  
Cytoplasmic Vacuole ◽  
Cell Nuclei ◽  
Short Term ◽  
Excess Copper

Soybean [Glycine max (L.) Merr.] cell suspensions have the capacity to develop tolerance to excess copper, constituting a convenient system for studies on the mechanisms of copper tolerance. The functional cell organisation changes observed in these cell cultures after both short-term (stressed cells) and long-term (acclimated cells) exposure to 10 μm CuSO4 are reported from structural, cytochemical and microanalytical approaches. Cells grown in the presence of 10 μm CuSO4 shared some structural features with untreated cells, such as: (i) a large cytoplasmic vacuole, (ii) chloroplasts along the thin layer of cytoplasm, (iii) nucleus in a peripheral location exhibiting circular-shaped nucleolus and a decondensed chromatin pattern, and (iv) presence of Cajal bodies in the cell nuclei. In addition, cells exposed to 10 μm CuSO4 exhibited important differences compared with untreated cells: (i) chloroplasts displayed rounded shape and smaller size with denser-structured internal membranes, especially in copper-acclimated cells; (ii) no starch granules were found within chloroplasts; (iii) the cytoplasmic vacuole was larger, especially after long-term copper exposure; (iv) the levels of citrate and malate increased. Extracellular dark-coloured deposits with high copper content attached at the outer surface of the cell wall were observed only in cells exposed to a short-term copper stress. Structural cell modifications, mainly affecting chloroplasts, accompanied the short-term copper-induced response and were maintained as stable characters during the period of adaptation to excess copper. Vacuolar changes accompanied the long-term copper response. The results indicate that the first response of soybean cells to excess copper prevents its entry into the cell by immobilising it in the cell wall, and after an adaptive period, acclimation to excess copper may be mainly due to vacuolar sequestration.

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