土壤微生物在陆地生态系统的生物地球化学循环中起着重要作用。然而目前尚不清楚氮(N)添加量及其持续时间如何影响土壤微生物群落结构,以及微生物群落结构变化与微生物相对养分限制状况是否存在关联。本研究在亚热带黄山松林开展了N添...土壤微生物在陆地生态系统的生物地球化学循环中起着重要作用。然而目前尚不清楚氮(N)添加量及其持续时间如何影响土壤微生物群落结构,以及微生物群落结构变化与微生物相对养分限制状况是否存在关联。本研究在亚热带黄山松林开展了N添加试验以模拟N沉降,并设置3个处理:对照(CK,0 kg N·hm^(-2)·a^(-1))、低N(LN,40 kg N·hm^(-2)·a^(-1))和高N(HN,80 kg N·hm^(-2)·a^(-1))。在N添加满1年和3年时测定土壤基本理化性质、磷脂脂肪酸含量和碳(C)、N、磷(P)获取酶活性,并通过生态酶化学计量分析土壤微生物的相对养分限制状况。结果表明:1年N添加对土壤微生物群落结构无显著影响,3年LN处理显著提高了革兰氏阳性菌(G^(+))、革兰氏阴性菌(G^(-))、放线菌(ACT)和总磷脂脂肪酸(TPLFA)含量,而3年HN处理对微生物的影响不显著,表明细菌和ACT对N添加可能更为敏感。N添加加剧了微生物C和P限制,而P限制是土壤微生物群落结构变化的最佳解释因子。这表明,N添加诱导的P限制可能更有利于部分贫营养菌(如G^(+))和参与P循环的微生物(如ACT)的生长,从而改变亚热带黄山松林土壤微生物群落结构。展开更多
Variations in temperature and moisture play an important role in soil organic matter(SOM) decomposition. However, relationships between changes in microbial community composition induced by increasing temperature and ...Variations in temperature and moisture play an important role in soil organic matter(SOM) decomposition. However, relationships between changes in microbial community composition induced by increasing temperature and SOM decomposition are still unclear.The present study was conducted to investigate the effects of temperature and moisture levels on soil respiration and microbial communities involved in straw decomposition and elucidate the impact of microbial communities on straw mass loss. A 120-d litterbag experiment was conducted using wheat and maize straw at three levels of soil moisture(40%, 70%, and 90% of water-holding capacity)and temperature(15, 25, and 35?C). The microbial communities were then assessed by phospholipid fatty acid(PLFA) analysis.With the exception of fungal PLFAs in maize straw at day 120, the PLFAs indicative of Gram-negative bacteria and fungi decreased with increasing temperatures. Temperature and straw C/N ratio significantly affected the microbial PLFA composition at the early stage, while soil microbial biomass carbon(C) had a stronger effect than straw C/N ratio at the later stage. Soil moisture levels exhibited no significant effect on microbial PLFA composition. Total PLFAs significantly influenced straw mass loss at the early stage of decomposition, but not at the later stage. In addition, the ratio of Gram-negative and Gram-positive bacterial PLFAs was negatively correlated with the straw mass loss. These results indicated that shifts in microbial PLFA composition induced by temperature, straw quality, and microbial C sources could lead to changes in straw decomposition.展开更多
An incubation experiment(Exp. 1) with three soils, two from Australia and one from Norway, was carried out to investigate the fate of dissolved BorreGro(a lignosulfonate, produced by Borregaard LignoTech Company, Norw...An incubation experiment(Exp. 1) with three soils, two from Australia and one from Norway, was carried out to investigate the fate of dissolved BorreGro(a lignosulfonate, produced by Borregaard LignoTech Company, Norway) at different concentrations(0, 10 and 100 mg C L-1) in soil solutions. A rhizobox experiment(Exp. 2) was also done in a Norwegian clay soil, mixed with four levels of BorreGro-carbon(BG-C) added(0, 2, 20 and 200 mg BG-C kg-1) to test the impact of BorreGro on root growth, rhizosphere chemistry(pH, metals and dissolved organic carbon(DOC)) and the composition of phospholipid fatty acids(PLFAs). The BorreGro addition increased the concentration of Mn due to the high concentrations in BorreGro. The BorreGro addition to soil had an indirect but significant impact on the rhizosphere chemistry and PLFAs. The lowest amounts of added BorreGro facilitated the DOC excretion at plant roots, and thereby increased the bacterial and fungal biomass, likely as an effect of increased Mn solubility from BorreGro in the root zone.展开更多
Zinc finger in the cerebellum 1 （Zicl） is known to regulate neurogenesis and myogenesis in the develop- mental stage and widely used as one of the brown adipocyte-specific markers. In this study, we examined the eff...Zinc finger in the cerebellum 1 （Zicl） is known to regulate neurogenesis and myogenesis in the develop- mental stage and widely used as one of the brown adipocyte-specific markers. In this study, we examined the effect of Zicl on brown adipogenesis. Overexpression of Zicl attenuated the lipid accumulation and the expressions of PPAR72 and C/EBPα in C3H10T1/2 mesenchymal stem cells. The mRNA levels of BAT-specific thermogenic genes （PRDM16, PGC-1α and UCP1） and fatty acid oxidation regulatory genes （PPARα, CPT1α, CPT1β and COX7α1） were suppressed in Zicl-overexpressed cells. Moreover, overexpression of Zicl reduced the mitochondrial oxidative phosphorylation （OXPHOS） regulatory proteins including ATP5α, UQCRC2, SDHB and NDUFB5. These results indicate a potential role of Zicl in the regulation of brown adipogenesis via inhibiting adipogenesis, fatty acid oxidation and mitochondrial OXPHOS.展开更多
文摘土壤微生物在陆地生态系统的生物地球化学循环中起着重要作用。然而目前尚不清楚氮(N)添加量及其持续时间如何影响土壤微生物群落结构,以及微生物群落结构变化与微生物相对养分限制状况是否存在关联。本研究在亚热带黄山松林开展了N添加试验以模拟N沉降,并设置3个处理:对照(CK,0 kg N·hm^(-2)·a^(-1))、低N(LN,40 kg N·hm^(-2)·a^(-1))和高N(HN,80 kg N·hm^(-2)·a^(-1))。在N添加满1年和3年时测定土壤基本理化性质、磷脂脂肪酸含量和碳(C)、N、磷(P)获取酶活性,并通过生态酶化学计量分析土壤微生物的相对养分限制状况。结果表明:1年N添加对土壤微生物群落结构无显著影响,3年LN处理显著提高了革兰氏阳性菌(G^(+))、革兰氏阴性菌(G^(-))、放线菌(ACT)和总磷脂脂肪酸(TPLFA)含量,而3年HN处理对微生物的影响不显著,表明细菌和ACT对N添加可能更为敏感。N添加加剧了微生物C和P限制,而P限制是土壤微生物群落结构变化的最佳解释因子。这表明,N添加诱导的P限制可能更有利于部分贫营养菌(如G^(+))和参与P循环的微生物(如ACT)的生长,从而改变亚热带黄山松林土壤微生物群落结构。
文摘Variations in temperature and moisture play an important role in soil organic matter(SOM) decomposition. However, relationships between changes in microbial community composition induced by increasing temperature and SOM decomposition are still unclear.The present study was conducted to investigate the effects of temperature and moisture levels on soil respiration and microbial communities involved in straw decomposition and elucidate the impact of microbial communities on straw mass loss. A 120-d litterbag experiment was conducted using wheat and maize straw at three levels of soil moisture(40%, 70%, and 90% of water-holding capacity)and temperature(15, 25, and 35?C). The microbial communities were then assessed by phospholipid fatty acid(PLFA) analysis.With the exception of fungal PLFAs in maize straw at day 120, the PLFAs indicative of Gram-negative bacteria and fungi decreased with increasing temperatures. Temperature and straw C/N ratio significantly affected the microbial PLFA composition at the early stage, while soil microbial biomass carbon(C) had a stronger effect than straw C/N ratio at the later stage. Soil moisture levels exhibited no significant effect on microbial PLFA composition. Total PLFAs significantly influenced straw mass loss at the early stage of decomposition, but not at the later stage. In addition, the ratio of Gram-negative and Gram-positive bacterial PLFAs was negatively correlated with the straw mass loss. These results indicated that shifts in microbial PLFA composition induced by temperature, straw quality, and microbial C sources could lead to changes in straw decomposition.
基金Support by the Borregaard LignoTech Company,Norway
文摘An incubation experiment(Exp. 1) with three soils, two from Australia and one from Norway, was carried out to investigate the fate of dissolved BorreGro(a lignosulfonate, produced by Borregaard LignoTech Company, Norway) at different concentrations(0, 10 and 100 mg C L-1) in soil solutions. A rhizobox experiment(Exp. 2) was also done in a Norwegian clay soil, mixed with four levels of BorreGro-carbon(BG-C) added(0, 2, 20 and 200 mg BG-C kg-1) to test the impact of BorreGro on root growth, rhizosphere chemistry(pH, metals and dissolved organic carbon(DOC)) and the composition of phospholipid fatty acids(PLFAs). The BorreGro addition increased the concentration of Mn due to the high concentrations in BorreGro. The BorreGro addition to soil had an indirect but significant impact on the rhizosphere chemistry and PLFAs. The lowest amounts of added BorreGro facilitated the DOC excretion at plant roots, and thereby increased the bacterial and fungal biomass, likely as an effect of increased Mn solubility from BorreGro in the root zone.
基金supported by the Strategic Priority Research Program(XDB13030000)Key Research Program(KJZD-EW-L01-3)+1 种基金the One Hundred Talents Program of the Chinese Academy of Sciences and the Ministry of Science and Technology of China(2012CBA01301 and 2012CB944701,respectively)the National Natural Science Foundation of China(31171131,81370951)
文摘Zinc finger in the cerebellum 1 （Zicl） is known to regulate neurogenesis and myogenesis in the develop- mental stage and widely used as one of the brown adipocyte-specific markers. In this study, we examined the effect of Zicl on brown adipogenesis. Overexpression of Zicl attenuated the lipid accumulation and the expressions of PPAR72 and C/EBPα in C3H10T1/2 mesenchymal stem cells. The mRNA levels of BAT-specific thermogenic genes （PRDM16, PGC-1α and UCP1） and fatty acid oxidation regulatory genes （PPARα, CPT1α, CPT1β and COX7α1） were suppressed in Zicl-overexpressed cells. Moreover, overexpression of Zicl reduced the mitochondrial oxidative phosphorylation （OXPHOS） regulatory proteins including ATP5α, UQCRC2, SDHB and NDUFB5. These results indicate a potential role of Zicl in the regulation of brown adipogenesis via inhibiting adipogenesis, fatty acid oxidation and mitochondrial OXPHOS.
