Oxidative stress tolerance in the filamentous green algae Cladophora glomerata and Enteromorpha ahlneriana

Choo, Kyung‐sil; Snoeijs, Pauli; Pedersén, Marianne

doi:10.1016/j.jembe.2003.08.007

Cited by 144 publications

(94 citation statements)

References 24 publications

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“…This response was not observed in filamentous gametophyte (this study) and in propagules (zoospores and gametes; Roleda et al 2009) of Urospora. Other defense mechanism against UVR-induced oxidative stress includes increase in superoxide dismutase activities reported in several green algae belonging to the genera Chaetomorpha, Cladophora, and Ulva (e.g., Choo et al 2004;Bischof et al 2006). Other targets which may reduce photosynthetic efficiency under UVR and high PAR include the ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco), and structural chloroplast lipids (glycolipids and phosphatidylglycerol; Bischof et al 2002a;Khotimchenko and Yakovleva 2004).…”

Section: Discussionmentioning

confidence: 99%

Physiological, biochemical, and ultrastructural responses of the green macroalga Urospora penicilliformis from Arctic Spitsbergen to UV radiation

2009

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Exposure of the filamentous turf green alga Urospora penicilliformis to ambient and artificial ultraviolet radiation (UVR) revealed a considerable resilient species. This explains the ability of this alga to thrive in the middleupper intertidal zones of the Arctic sea where it is periodically exposed to environmental extremes. A transient UVR effect on photosynthesis under photosynthetically active radiation (PAR) + UV-A and PAR + UV-A + UV-B was found, but dynamic recovery of photoinhibition was observed immediately after reduction of the photon fluence rate of PAR in the absence or presence of background UVR under laboratory and natural solar radiation, respectively. Chlorophylls, carotenoids, and xanthophyll cycle pigments (violaxanthin, antheraxanthin, and zeaxanthin) concentrations were not significantly different between freshly collected samples and filaments exposed to additional laboratory radiation treatment. The ultrastructure of the U. penicilliformis gametophytes showed that the cells are well adapted to UVR. No significant ultrastructural alterations were observed in filaments exposed to different spectral irradiance in the laboratory compared to in situ acclimated specimen. The antioxidant α-tocopherol was detected in minute quantity while the search for flavonoid-like compounds was negative. Other UV screening strategies or certain genetically fixed physiological protective mechanism could be operating in this species responsible for their occurrence in higher shoreline and ecological success. Further molecular and biochemical studies are needed to elucidate the stress resistance in this turf alga. There is an indication that the extremely thick cell wall of U. penicilliformis gametophytes covered with mucilage sheath and dense layer of mineral depositions may provide a shield against unfavorable environmental conditions in general and against UVR in particular.

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Section: Discussionmentioning

confidence: 99%

Physiological, biochemical, and ultrastructural responses of the green macroalga Urospora penicilliformis from Arctic Spitsbergen to UV radiation

2009

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“…The results of this enzymic activity were recorded in units of SOD activity per microgram protein, where 1 U of SOD is defined as the amount of enzyme required for 50% inhibition of cyt c reduction. The method for measurement of CAT activity is described by Choo et al, 2004. 2.4. Total protein, chlorophyll a and oxygen evolution activity Total soluble protein content was determined by Coomassie blue-dye binding assay (Bradford, 1976) using bovine serum albumin as a standard protein.…”

Section: Superoxide Dismutase (Sod) and Catalase (Cat) Assaysmentioning

confidence: 99%

Response of Microcystis to copper stress – Do phenotypes of Microcystis make a difference in stress tolerance?

Gan

Huang

et al. 2007

Environmental Pollution

114

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“…Chlorophyll a was extracted in 90% acetone and measured as described by Nusch (1980). The assay for antioxidant enzyme-catalase (CAT) activity was based on its ability to decompose H 2 O 2 , with the absorbance of supernatant at 240 nm (Choo et al, 2004). Lipid peroxidation products as malodialdehyde (MDA), expressed as mmol of MDA formed by per milligram of total proteins, were measured spectrophotometrically by a method using thiobarbituric acid (Uchimaya & Mihara, 1978).…”

Section: Strains and Culture Conditionmentioning

confidence: 99%

Different tolerances and responses to low temperature and darkness between waterbloom forming cyanobacterium Microcystis and a green alga Scenedesmus

Song

2007

Hydrobiologia

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The dynamics of planktonic cyanobacteria in eutrophicated freshwaters play an important role in formation of annual summer blooms, yet overwintering mechanisms of these water bloom forming cyanobacteria remain unknown. The responses to darkness and low temperature of three strains (unicellular Microcystis aeruginosa FACHB-905, colonial M. aeruginosa FACHB-938, and a green alga Scenedesmus quadricauda FACHB-45) were investigated in the present study. After a 30-day incubation under darkness and low temperature, cell morphology, cell numbers, chlorophyll a, photosynthetic activity (ETR max and I k ), and malodialdehyde (MDA) content exhibited significant changes in Scenedesmus. In contrast, Microcystis aeruginosa cells did not change markedly in morphology, chlorophyll a, photosynthetic activity, and MDA content. The stress caused by low temperature and darkness resulted in an increase of the antioxidative enzymecatalase (CAT) in all three strains. When the three strains re-grew under routine cultivated condition subjected to darkness and low temperature, specific growth rate of Scenedesmus was lower than that of Microcystis. Flow cytometry (FCM) examination indicated that two distinct types of metabolic response to darkness and low temperature existed in the three strains. The results from the present study reveal that the cyanobacterium Microcystis, especially colonial Microcystis, has greater endurance and adaptation ability to the stress of darkness and low temperature than the green alga Scenedesmus.

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Oxidative stress tolerance in the filamentous green algae Cladophora glomerata and Enteromorpha ahlneriana

Cited by 144 publications

References 24 publications

Physiological, biochemical, and ultrastructural responses of the green macroalga Urospora penicilliformis from Arctic Spitsbergen to UV radiation

Physiological, biochemical, and ultrastructural responses of the green macroalga Urospora penicilliformis from Arctic Spitsbergen to UV radiation

Response of Microcystis to copper stress – Do phenotypes of Microcystis make a difference in stress tolerance?

Different tolerances and responses to low temperature and darkness between waterbloom forming cyanobacterium Microcystis and a green alga Scenedesmus

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