On Detrimental Effects of High Light Intensities on the Photosynthetic Mechanism

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

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Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions

Functional Plant Biology ◽

10.1071/fp06078 ◽

2006 ◽

Vol 33 (11) ◽

pp. 1037 ◽

Cited By ~ 54

Author(s):

Dirk Büssis ◽

Uritza von Groll ◽

Joachim Fisahn ◽

Thomas Altmann

Keyword(s):

Arabidopsis Thaliana ◽

Stomatal Conductance ◽

Stomatal Density ◽

Co2 Assimilation ◽

High Light ◽

Stomatal Aperture ◽

Photochemical Quenching ◽

Light Conditions ◽

Wild Type ◽

Light Intensities

Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (Fv / Fm) and quantum yield of photosystem II (Φ PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, Fv / Fm and Φ PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.

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Stress-induced production of volatile halogenated organic compounds inEucheuma denticulatum(Rhodophyta) caused by elevated pH and high light intensities

European Journal of Phycology ◽

10.1080/09670269600651241 ◽

1996 ◽

Vol 31 (1) ◽

pp. 89-95 ◽

Cited By ~ 67

Author(s):

Matern S.P. Mtolera ◽

Jonas Collén ◽

Marianne Pedersén ◽

Anja Ekdahl ◽

Katarina Abrahamsson ◽

...

Keyword(s):

Organic Compounds ◽

High Light ◽

Halogenated Organic Compounds ◽

Light Intensities ◽

Volatile Halogenated Organic Compounds

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Transcriptome analysis of genes and pathways associated with metabolism in Scylla paramamosain under different light intensities during indoor overwintering

BMC Genomics ◽

10.1186/s12864-020-07190-w ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Na Li ◽

Junming Zhou ◽

Huan Wang ◽

Changkao Mu ◽

Ce Shi ◽

...

Keyword(s):

Energy Metabolism ◽

Light Intensity ◽

Differentially Expressed Genes ◽

High Light ◽

Differentially Expressed ◽

Scylla Paramamosain ◽

Strong Impact ◽

Low Light ◽

Light Intensities ◽

Light Group

Abstract Background Scylla paramamosain is one of the commercially crucial marine crustaceans belonging to the genus Scylla, which is commonly distributed along the coasts of China, Vietnam, and Japan. Genomic and transcriptomic data are scarce for the mud crab. Light intensity is one of the ecological factors that affect S. paramamosain during indoor overwintering. To understand the energy metabolism mechanism adapted to light intensity, we analyzed the transcriptome of S. paramamosain hepatopancreas in response to different light intensities (0, 1.43, 40.31 μmol·m− 2·s− 1). Results A total of 5052 differentially expressed genes were identified in low light group (LL group, 3104 genes were up-regulated and 1948 genes were down-regulated). A total of 7403 differentially expressed genes were identified in high light group (HL group, 5262 genes were up-regulated and 2141 genes were down-regulated). S. paramamosain adapts to different light intensity environments through the regulation of amino acids, fatty acids, carbon and energy metabolism. Different light intensities had a strong impact on the energy generation of S. paramamosain by influencing oxygen consumption rate, aerobic respiration, glycolysis/gluconeogenesis pathway, the citrate cycle (TCA cycle) and fatty acid degradation. Conclusion Low light is more conducive to the survival of S. paramamosain, which needs to produce and consume relatively less energy to sustain physiological activities. In contrast, S. paramamosain produced more energy to adapt to the pressure of high light intensities. The findings of the study add to the knowledge of regulatory mechanisms related to S. paramamosain metabolism under different light intensities.

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ChemInform Abstract: ORGANIC PHOTOCHEMISTRY: THE LASER VS. THE LAMP. THE BEHAVIOR OF DIPHENYLCARBENE GENERATED AT HIGH LIGHT INTENSITIES

Chemischer Informationsdienst ◽

10.1002/chin.198043085 ◽

1980 ◽

Vol 11 (43) ◽

Author(s):

N. J. TURRO ◽

M. AIKAWA ◽

J. A. JUN. BUTCHER ◽

G. W. GRIFFIN

Keyword(s):

High Light ◽

Light Intensities ◽

Organic Photochemistry

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Interactions entre mitochondries et chloroplastes dans la cellule. II. Action du DBMIB, de l'antimycine A et du FCCP sur la spore de Funaria hygrometrica

Canadian Journal of Botany ◽

10.1139/b77-193 ◽

1977 ◽

Vol 55 (12) ◽

pp. 1650-1659 ◽

Cited By ~ 4

Author(s):

D. Chevallier ◽

R. Douce ◽

F. Nurit

Keyword(s):

Cytochrome Oxidase ◽

Dark Respiration ◽

High Light ◽

Light Conditions ◽

Oxygen Production ◽

Low Light ◽

Funaria Hygrometrica ◽

Light Intensities

The effect of DBMIB, antimycine A, and FCCP on respiration and photosynthesis of intact chlorophyllic moss (Funaria hygrometrica) spore was investigated.Antimycine A (1 μM) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values), and stimulated photosynthesis at low light intensities (below the saturation plateau values).DBMIB (3 μM) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 μM) partially inhibited oxygen production at high light intensities. In this case, the inhibition observed was partially relieved by 1 μM antimycine A or 30 μM of KCN; higher concentration of FCCP totally inhibited the oxygen production.It seems likely, therefore, that in the chlorophyllic moss spore the cytochrome oxidase pathway is not functioning under high light intensities and that this inhibition of respiration is attributable to the low cytoplasmic ADP:ATP ratio.

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