scholarly journals Coordinated downregulation of the photosynthetic apparatus as a protective mechanism against UV exposure in the diatom Corethron hystrix

2018 ◽  
Author(s):  
Robert W. Read ◽  
David C. Vuono ◽  
Iva Neveux ◽  
Carl Staub ◽  
Joseph J. Grzymski
Keyword(s):  
Photosystem Ii ◽  
Photosynthetic Efficiency ◽  
Photosynthetic Apparatus ◽  
Turnover Time ◽  
Uv Exposure ◽  
Protective Mechanism ◽  
Repair Mechanisms ◽  
Electron Transport Complexes ◽  
Related Reaction

AbstractThe effect of ultraviolet radiation (UVR) on photosynthetic efficiency and the resulting mechanisms against UV exposure employed by phytoplankton are not completely understood. To address this knowledge gap, we developed a novel close-coupled, wavelength-configurable platform designed to produce precise and repeatable in vitro irradiation of Corethron hystrix, a member of a genera found abundantly in the Southern Ocean where UV exposure is high. We aimed to determine its metabolic, protective, mutative, and repair mechanisms as a function of varying levels of specific electromagnetic energy. Our results show that the physiological responses to each energy level of UV have a negative linear decrease in the photosynthetic efficiency of photosystem II proportional to UV intensity, corresponding to a large increase in the turnover time of quinone re-oxidation. Gene expression changes of photosystem II related reaction center proteins D1, CP43 and CP47 showed coordinated downregulation whereas the central metabolic pathway demonstrated mixed expression of up and downregulated transcripts after UVR exposure. These results suggest that while UVR may damage photosynthetic machinery, oxidative damage may limit production of new photosynthetic and electron transport complexes as a result of UVR exposure.

scholarly journals Impact of saline solution on growth and photosystem II during in vitro cultivation of Bromelia antiacantha (Bromeliaceae)

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Rosiane Cipriano ◽  
João Paulo Rodrigues Martins ◽  
Luiz Carlos de Almeida Rodrigues ◽  
Antelmo Ralph Falqueto ◽  
Andreia Barcelos Passos Lima Gontijo
Keyword(s):  
Photosystem Ii ◽  
Saline Solution ◽  
Growth Traits ◽  
Photosynthetic Apparatus ◽  
Solution Culture ◽  
In Vitro Cultivation ◽  
Ms Medium ◽  
Number Of Leaves ◽  
Positive Effect

Abstract In vitro cultivation is a technique with wide application for micropropagation. However, each species has specific mineral needs for this type of cultivation. The objective was to assess the impacts of the saline solution culture medium on the performance of the photosynthetic apparatus and growth of Bromelia antiacantha during in vitro cultivation, and thus to elucidate the mitigation of the nutritional imbalance that can interfere in the electron transport in the plants. Plants were cultivated in a salt concentration gradient of MS medium (0%, 25%, 50%, 75% or 100%). The growth traits and fluorescence a chlorophyll were analyzed. Intermediate concentrations of MS medium resulted in plants with a larger number of leaves and longer root length. The OJIP curves and results of the JIP test showed that the plants grown without MS salts presented less efficient photosystem II (PSII), as indicated by the performance index [Pi(total)]. In contrast, the intermediate concentrations (MS 25% and 50%) had a positive effect on the performance of the photosynthetic apparatus. The MS 25% medium can be used for in vitro cultivation of B. antiacantha, enabling the development of plants with suitable physiological qualities for planting in the field.

scholarly journals Morphophysiological responses of Billbergia zebrina Lindl. (Bromeliaceae) in function of types and concentrations of carbohydrates during conventional in vitro culture

2020 ◽  
Vol 26 (1) ◽  
pp. 18-34 ◽  
Author(s):  
Elizangela Rodrigues Santos ◽  
João Paulo Rodrigues Martins ◽  
Luiz Carlos de Almeida Rodrigues ◽  
Andreia Barcelos Passos Lima Gontijo ◽  
Antelmo Ralph Falqueto
Keyword(s):  
Photosystem Ii ◽  
In Vitro Culture ◽  
Leaf Anatomy ◽  
Culture Medium ◽  
Stomatal Density ◽  
Photosynthetic Apparatus ◽  
Fluorescence Transient ◽  
Chlorophyll A Fluorescence Transient ◽  
Concentration Interval

Abstract When propagated in vitro, explants receive all the nutrients needed for their growth, including carbohydrates, from the culture medium. However, it is not well understood how the type and concentration of carbohydrates can affect the functioning of the photosynthetic apparatus (particularly photosystem II) of these plants. The aim was to assess the morphophysiological responses of Billbergia zebrina plants in function of sources and concentrations of carbohydrates during in vitro culture. Side shoots of plants previously established in vitro were individualized and transferred to a culture medium containing fructose, glucose or sucrose in four concentrations (0, 15, 30 or 45 g L−1). After growth for 55 days, the chlorophyll a fluorescence transient, leaf anatomy and growth were analyzed. The concentration and type of carbohydrate employed during in vitro culture did not decrease the photosynthetic apparatus performance. However, concentrations above 30 g L−1 led to anatomical modifications, revealing some degree of stress suffered by the plants. When grown in concentrations of 15 and 30 g L−1, irrespective of the carbohydrate used, the plants presented greater stomatal density. The supplementation of the culture medium with monosaccharides caused alterations in the development of the xylem vessels, such as increased number and diameter, allowing adjustment to the microenvironmental conditions. The in vitro conditions influenced the photosynthetic and anatomical responses of plants. The concentration interval from 15 to 30 g L−1 sucrose had a better effect by not causing large changes in the performance of the photosynthetic apparatus and anatomy of plants.

Effect of enucleation on protein synthesis during maturation of bovine oocytes in vitro

1997 ◽  
Vol 9 (6) ◽  
pp. 603 ◽  
Author(s):  
J. C. Bell ◽  
L. C. Smith ◽  
R. Rumpf ◽  
A. K. Goff
Keyword(s):  
Protein Synthesis ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Germinal Vesicle ◽  
Uv Exposure ◽  
One Dimensional ◽  
Repair Mechanisms ◽  
Bovine Oocytes

The role of the nucleus in protein synthesis reprogramming during oocyte maturation was examined in immature or mature bovine oocytes, enucleated at the germinal vesicle (GV) stage or the metaphase II (MII) stage. Cumulusoocyte complexes (COCs) were denuded before or after maturationin vitro. Denuded oocytes were (i) enucleated at the GV or MII stage (after DNA staining and ultraviolet (UV) exposure), (ii) stained and exposed to UV but not enucleated, or (iii) used as controls. After treatment, oocytes were labelled for 4 h with35S-methionine or were matured for 24 h before labelling. GV- or MII- karyoplasts and small portions of cytoplasm (cytoplasts), removed during enucleation, were also labelled. Labelled oocytes, karyoplasts or cytoplasts were prepared for one-dimensional polyacrylamide gel electrophoresis. Incorporation of labelled methionine into oocyte protein was measured. Enucleation did not affect protein synthesis reprogramming, but incorporation of 35S-methionine in immature UV-stained oocytes was high-possibly due to nuclear repair mechanisms. Protein proles of GV- and MII- karyoplasts differed from those of immature and mature oocytes. In conclusion, normal protein synthesis reprogramming in the cytoplasm can occur in the absence of the nucleus, and specic proteins are synthesized in the nuclear region.

scholarly journals Healthy Photosynthetic Mechanism Suggests ISR Elicited by Bacillus spp. in Capsicum chinense Plants Infected with PepGMV

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 455
Author(s):  
Blancka Yesenia Samaniego-Gámez ◽  
René Garruña ◽  
José M. Tun-Suárez ◽  
Oscar A. Moreno-Valenzuela ◽  
Arturo Reyes-Ramírez ◽  
...  
Keyword(s):  
Photosynthetic Efficiency ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Capsicum Chinense ◽  
Yield And Quality ◽  
Bacillus Spp ◽  
Use Efficiency ◽  
Photochemical Quantum Yield ◽  
Quantum Yield Of Psii

The aim of this study was to evaluate the effect of inoculation with Bacillus spp. isolates on the photosynthetic apparatus of Capsicum chinense plants infected with PepGMV. In vitro and greenhouse experiments were performed to evaluate whether the inoculation improved plants’ performance through the increase in photosynthetic efficiency to control PepGMV. The results showed that despite PepGMV infection, the plants inoculated with some isolates of Bacillus spp. had a healthy photosynthetic mechanism, as the photochemical parameters and gas exchange increased. The maximum photochemical quantum yield of PSII (Fv/Fm) of plants with PepGMV and inoculated with Bacillus isolates (M9, K46, and K47) increased (7.85, 7.09, and 7.77%, respectively) with respect to uninoculated controls. In inoculated plants, the CO2 assimilation rate increased and the transpiration rate decreased, therefore indicating an increased water use efficiency. This effect was reflected by the less severe symptoms caused by PepGMV in the plants obtained from seeds inoculated with different Bacillus spp. Plants inoculated with K47 isolates showed an increase in fruit yield and quality. This study suggests that it is possible to protect, at the greenhouse level, C. chinense plants from PepGMV through selected rhizobacteria inoculation.

scholarly journals Coordinated downregulation of the photosynthetic apparatus as a protective mechanism against UV exposure in the diatom Corethron hystrix

2019 ◽  
Vol 103 (4) ◽  
pp. 1837-1850
Author(s):  
Robert W. Read ◽  
David C. Vuono ◽  
Iva Neveux ◽  
Carl Staub ◽  
Joseph J. Grzymski
Keyword(s):  
Photosynthetic Apparatus ◽  
Uv Exposure ◽  
Protective Mechanism

scholarly journals Interference of Cd2+ in functioning of the photosynthetic apparatus of higher plants

2014 ◽  
Vol 55 (2) ◽  
pp. 291-304 ◽  
Author(s):  
Tadeusz Baszyński
Keyword(s):  
Photosystem Ii ◽  
Thylakoid Membrane ◽  
Higher Plants ◽  
Photosynthetic Apparatus ◽  
Light Phase ◽  
Membrane Degradation ◽  
Transport Chain ◽  
Photosystem Ii Activity

The actual opinions concerning the role of Cd<sup>2+</sup> in inhibition of photosynthesis have been reviewed. The light phase of photosynthesis, particularly the site of Cd<sup>2+</sup> action in the photosynthetic transport chain has been given the greatest attention. Cd<sup>2+</sup>-induced inhibition of Photosystem II activity as the result of thylakoid membrane degradation has been discussed. The present studies on Cd<sup>2+</sup>-inhibited dark reactions occurring in stroma has been analysed. Attention has been drawn to the fact that the results of studies in vitro are not always compatible with the changes found in the photosynthetic apparatus of higher plants growing in a Cd2 containing medium.

Bestimmung der DNA-Schädigung in vitro

2010 ◽  
Vol 49 (S 01) ◽  
pp. S64-S68
Author(s):  
E. Dikomey
Keyword(s):  
Dna Damage ◽  
Cell Lines ◽  
Chromosome Aberrations ◽  
Genetic Factors ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Cell Inactivation ◽  
Repair Mechanisms ◽  
Break Repair

SummaryIonising irradiation acts primarily via induction of DNA damage, among which doublestrand breaks are the most important lesions. These lesions may lead to lethal chromosome aberrations, which are the main reason for cell inactivation. Double-strand breaks can be repaired by several different mechanisms. The regulation of these mechanisms appears be fairly different for normal and tumour cells. Among different cell lines capacity of doublestrand break repair varies by only few percents and is known to be determined mostly by genetic factors. Knowledge about doublestrand break repair mechanisms and their regulation is important for the optimal application of ionising irradiation in medicine.

Changes in the Stoichiometry of Photosystem II Components as an Adaptive Response to High-Light and Low-Light Conditions during Growth

1986 ◽  
Vol 41 (5-6) ◽  
pp. 597-603 ◽  
Author(s):  
Aloysius Wild ◽  
Matthias Höpfner ◽  
Wolfgang Rühle ◽  
Michael Richter
Keyword(s):  
Photosystem Ii ◽  
Functional Organization ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Molar Ratio ◽  
Light Conditions ◽  
Low Light ◽  
Pigment System ◽  
Transport Chain ◽  
The One

The effect of different growth light intensities (60 W·m-2, 6 W·m-2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light conditions was found. For P-680 as well as for Oᴀ and Oв protein the molar ratio between high-light and low-light plants was 1.4 whereas the respective concentrations per chlorophyll showed some variations for P-680 and Oᴀ on the one and Oв protein on the other hand.In addition to the study of photosystem II components, the concentrations of PQ, Cyt f, and P-700 were measured. The light regime during growth had no effect on the amount of P-700 per chlorophyll but there were large differences with respect to PQ and Cyt f. The molar ratio for Cyt f and PQ between high- and low-light leaves was 2.2 and 1.9, respectively.Two models are proposed, showing the functional organization of the pigment system and the electron transport chain in thylakoids of high-light and low-light leaves of mustard plants.

scholarly journals The protective mechanism of Ginkgolides and Ginkgo flavonoids on the TNF-α induced apoptosis of rat hippocampal neurons and its mechanisms in vitro

Heliyon ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. e00020 ◽  
Author(s):  
Maojuan Guo ◽  
Yanrong Suo ◽  
Qing Gao ◽  
Huan Du ◽  
Wenyun Zeng ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Protective Mechanism ◽  
Tnf Α ◽  
Induced Apoptosis

scholarly journals In Vitro Synthesis and Assembly of Photosystem II Core Proteins

1995 ◽  
Vol 270 (43) ◽  
pp. 25685-25695 ◽  
Author(s):  
Klaas J. van Wijk ◽  
Sophie Bingsmark ◽  
Eva-Mari Aro ◽  
Bertil Andersson
Keyword(s):  
Photosystem Ii ◽  
In Vitro Synthesis ◽  
Core Proteins
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