Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen...Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.展开更多
Napier grass （Pennisetum purpureum Schumach）, a C4 tropical plant, has high dry matter productivity and sustainability without the need for renovating every year due to good overwintering ability and the absence of ...Napier grass （Pennisetum purpureum Schumach）, a C4 tropical plant, has high dry matter productivity and sustainability without the need for renovating every year due to good overwintering ability and the absence of serious pathogens or insects injury. This grass is suitable for multipurpose use, providing forage, bioethanol feedstock and phytoremediation of cadmium （Cd） contaminated soil in Kyushu, Japan. When two cultivars of Napier grass （Wruk wona, WK and Merkeron, ME） were grown in Cd-contaminated soils, dry matter yield and the concentration and uptake of herbage Cd were higher in WK than in ME, and soil Cd concentration was reduced by 14% in a single season of cultivation. A dwarf variety of late-heading type （DL）, Napier grass had superior sustainability for more than 5 years in Miyazaki, Japan, and has gradually increased in cultivation areas for both cut-and-carry and grazing herbage production in cooperation with regional communities. Through the extension in several Kyushu areas, DL Napier grass required temperatures above -6.2 ~C for sustainability in winter, based on its threshold response to the lethal minimum temperature. DL Napier grass pasture can be utilized by grazing beef cattle even in early spring with temperate Italian ryegrass inter-sown into its inter-row spaces. Organic digested animal manure or sun-dried leguminous leaves as green manure can replace chemical fertilizers to reduce energy consumption and allow comparable productivity.展开更多
基金financially supported by the National Key R&D Program of China(2019YFD0900200,2018YFD0900400)Supported by the earmarked fund for CARS(CARS-45)+2 种基金National Natural Science Foundation of China for Outstanding Youth Science Foundation(31922086)the Young Top-Notch Talent Support ProgramSichuan Science and Technology Program(2019YFN0036)。
文摘Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.
文摘Napier grass （Pennisetum purpureum Schumach）, a C4 tropical plant, has high dry matter productivity and sustainability without the need for renovating every year due to good overwintering ability and the absence of serious pathogens or insects injury. This grass is suitable for multipurpose use, providing forage, bioethanol feedstock and phytoremediation of cadmium （Cd） contaminated soil in Kyushu, Japan. When two cultivars of Napier grass （Wruk wona, WK and Merkeron, ME） were grown in Cd-contaminated soils, dry matter yield and the concentration and uptake of herbage Cd were higher in WK than in ME, and soil Cd concentration was reduced by 14% in a single season of cultivation. A dwarf variety of late-heading type （DL）, Napier grass had superior sustainability for more than 5 years in Miyazaki, Japan, and has gradually increased in cultivation areas for both cut-and-carry and grazing herbage production in cooperation with regional communities. Through the extension in several Kyushu areas, DL Napier grass required temperatures above -6.2 ~C for sustainability in winter, based on its threshold response to the lethal minimum temperature. DL Napier grass pasture can be utilized by grazing beef cattle even in early spring with temperate Italian ryegrass inter-sown into its inter-row spaces. Organic digested animal manure or sun-dried leguminous leaves as green manure can replace chemical fertilizers to reduce energy consumption and allow comparable productivity.
