The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L.to different dosages of UV-B irradiation was investigated.Results showed that superoxide dimutase （SOD） and peroxida...The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L.to different dosages of UV-B irradiation was investigated.Results showed that superoxide dimutase （SOD） and peroxidase （POX） increased and then maintained at a relatively stable level when subjected to UV-B irradiation.Catalase （CAT） activity under medium dosage of UV-B irradiation （Muv） and high dosage of UV-B irradiation （Huv） treatments were significantly decreased.Ascorbate peroxidase （APX） activity first remained unaltered and then increased in Huv treatment.In addition,the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis （PAGE）.The activities of some SOD isoforms were altered by UV-B.Two new bands （POX V and POX VII） appeared upon exposure to all three UV-B dosages.CAT III activity was increased by low dosage of UV-B irradiation （Luv）,whereas CAT III and CAT IV disappeared when the alga was exposed to Muv and Huv.Two bands of APX （APX VI and APX VII） were increased and a new band （APX X） was observed under Huv exposure.H 2 O 2 and thiobarbituric acid reacting substance （TBARS） increased under Muv and Huv treatments.Overall,UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C.officinalis.展开更多
Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can a...Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors （temperature, salinity, light, and pH） on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels： temperature （15, 20, 25, and 30℃）, salinity （10, 20, 30, and 40）, light （20, 100, 200 and 400 gmol/（m2.s））, and pH （5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments （temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH）. Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature （15 ℃）, low salinity （10）, high-intensity light （400umol/（m2.s））, and high pH （10） treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments： 15℃ and salinity of 40, 25℃ and pH 10, 25℃ with medium- to high-intensity light at 200-400 umol/（m2.s）, 400umol/（m2.s） and salinity of 10, 400 gmol/（m2·s） and pH 10, and pH 10 with a salinity of 40.展开更多
Intertidal macroalgae can cope with the dual effects of UV-B irradiation and allelopathy.To study the impacts of the two stressors,we co-cultured Corallina pilulifera with Sargassum thunbergii in 1:1 and 1:10 ratios u...Intertidal macroalgae can cope with the dual effects of UV-B irradiation and allelopathy.To study the impacts of the two stressors,we co-cultured Corallina pilulifera with Sargassum thunbergii in 1:1 and 1:10 ratios under different doses of UV-B radiation.The response of the antioxidant defense system,focusing on activities of superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POX)and glutathione reductase(GR),was monitored.In addition,isoenzyme patterns were analyzed using nondenaturing poly acry lamide gel electrophoresis.The results show that the activities of SOD,APX,and GR were all significantly affected by both UV-B radiation and allelopathy,and the effect of their interaction was significant.However,POX activity was only influenced by UV-B radiation.The enzymatic assay revealed four distinct bands of SOD.The SODⅢband weakened significantly when the co-cultures were exposed to extremely high dosage of UV-B irradiation under both co-culturing ratios of 1:1 and 1:10.When the coculturing ratio was 1:10,both POXⅡand APXⅡenzy me activities increased with different UV-B doses.GR activity was at its greatest when the co-culture ratio was 1:10 and exposure was to the higher UV-B doses.The activities of GRⅢand GRⅣwere elevated under all UV treatments whereas the activities of GRI and GRII were reduced under the lower UV-B treatments but were elevated under the higher UV-B treatments.However,lipid peroxidation,as indicated by the thiobarbituric acid-reacting substance(TBARS)assay,increased significantly under the dual stressors.Our data sugge st that allelopathy and UV-B radiation stre ss can each affect the antioxidant enzyme activities of C.pilulifera.Critically,the adverse effects of UV-B on C.pilulifera were intensified by the compounding effects of allelopathy.展开更多
Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. Corallina Paraamphiroa siniansis gen. et sp. nov....Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. Corallina Paraamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of Siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, China. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae.展开更多
Concentrations of Fe, Cu, Pb, Zn, Cd and Ni were determined in the red alga Corallina officinalis (Linnaeus, 1758), the green alga Ulva lactuca (Linnaeus, 1753) and sediment sampled in four stations of the coastline o...Concentrations of Fe, Cu, Pb, Zn, Cd and Ni were determined in the red alga Corallina officinalis (Linnaeus, 1758), the green alga Ulva lactuca (Linnaeus, 1753) and sediment sampled in four stations of the coastline of Hona?ne (extreme Western Algeria). The abundance of metal concentrations in algae and sediment samples, is in the following order: Fe > Zn > Pb > Ni > Cu > Cd. The schematic representation by PCA reflects a strong correlation of the corallina with Cd and Pb, the ulva with Zn and Ni and sediment with Cu and Fe, in addition, to homogeneity of rehearsals in each matrix. The results of this study validate the use of these species as reliable tools for biomonitoring of metal pollution of coastal ecosystems, even if the levels of heavy metals in sediment and algae from the coastline of Hona?ne are in general, very low compared with those from other geographic areas and by guidelines.展开更多
基金supported by the National Natural Science Foundation of China (No. 30270258)the Natural Science Foundation of Shandong Province (No.2007ZRB01903)
文摘The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L.to different dosages of UV-B irradiation was investigated.Results showed that superoxide dimutase （SOD） and peroxidase （POX） increased and then maintained at a relatively stable level when subjected to UV-B irradiation.Catalase （CAT） activity under medium dosage of UV-B irradiation （Muv） and high dosage of UV-B irradiation （Huv） treatments were significantly decreased.Ascorbate peroxidase （APX） activity first remained unaltered and then increased in Huv treatment.In addition,the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis （PAGE）.The activities of some SOD isoforms were altered by UV-B.Two new bands （POX V and POX VII） appeared upon exposure to all three UV-B dosages.CAT III activity was increased by low dosage of UV-B irradiation （Luv）,whereas CAT III and CAT IV disappeared when the alga was exposed to Muv and Huv.Two bands of APX （APX VI and APX VII） were increased and a new band （APX X） was observed under Huv exposure.H 2 O 2 and thiobarbituric acid reacting substance （TBARS） increased under Muv and Huv treatments.Overall,UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C.officinalis.
基金Supported by the National Natural Science Foundation of China(No.31200400)
文摘Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors （temperature, salinity, light, and pH） on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels： temperature （15, 20, 25, and 30℃）, salinity （10, 20, 30, and 40）, light （20, 100, 200 and 400 gmol/（m2.s））, and pH （5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments （temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH）. Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature （15 ℃）, low salinity （10）, high-intensity light （400umol/（m2.s））, and high pH （10） treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments： 15℃ and salinity of 40, 25℃ and pH 10, 25℃ with medium- to high-intensity light at 200-400 umol/（m2.s）, 400umol/（m2.s） and salinity of 10, 400 gmol/（m2·s） and pH 10, and pH 10 with a salinity of 40.
基金Supported by the National Natural Science Foundation of China(Nos.31971546,31300326)。
文摘Intertidal macroalgae can cope with the dual effects of UV-B irradiation and allelopathy.To study the impacts of the two stressors,we co-cultured Corallina pilulifera with Sargassum thunbergii in 1:1 and 1:10 ratios under different doses of UV-B radiation.The response of the antioxidant defense system,focusing on activities of superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POX)and glutathione reductase(GR),was monitored.In addition,isoenzyme patterns were analyzed using nondenaturing poly acry lamide gel electrophoresis.The results show that the activities of SOD,APX,and GR were all significantly affected by both UV-B radiation and allelopathy,and the effect of their interaction was significant.However,POX activity was only influenced by UV-B radiation.The enzymatic assay revealed four distinct bands of SOD.The SODⅢband weakened significantly when the co-cultures were exposed to extremely high dosage of UV-B irradiation under both co-culturing ratios of 1:1 and 1:10.When the coculturing ratio was 1:10,both POXⅡand APXⅡenzy me activities increased with different UV-B doses.GR activity was at its greatest when the co-culture ratio was 1:10 and exposure was to the higher UV-B doses.The activities of GRⅢand GRⅣwere elevated under all UV treatments whereas the activities of GRI and GRII were reduced under the lower UV-B treatments but were elevated under the higher UV-B treatments.However,lipid peroxidation,as indicated by the thiobarbituric acid-reacting substance(TBARS)assay,increased significantly under the dual stressors.Our data sugge st that allelopathy and UV-B radiation stre ss can each affect the antioxidant enzyme activities of C.pilulifera.Critically,the adverse effects of UV-B on C.pilulifera were intensified by the compounding effects of allelopathy.
文摘Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. Corallina Paraamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of Siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, China. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae.
文摘Concentrations of Fe, Cu, Pb, Zn, Cd and Ni were determined in the red alga Corallina officinalis (Linnaeus, 1758), the green alga Ulva lactuca (Linnaeus, 1753) and sediment sampled in four stations of the coastline of Hona?ne (extreme Western Algeria). The abundance of metal concentrations in algae and sediment samples, is in the following order: Fe > Zn > Pb > Ni > Cu > Cd. The schematic representation by PCA reflects a strong correlation of the corallina with Cd and Pb, the ulva with Zn and Ni and sediment with Cu and Fe, in addition, to homogeneity of rehearsals in each matrix. The results of this study validate the use of these species as reliable tools for biomonitoring of metal pollution of coastal ecosystems, even if the levels of heavy metals in sediment and algae from the coastline of Hona?ne are in general, very low compared with those from other geographic areas and by guidelines.
