Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem fu...Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ecosystems.However,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still unclear.In this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient addition.The short-term nutrient addition had no significant influences on belowground bud density,aboveground shoot density,and MLI of the whole plant community.Plant functional groups showed different responses to soil fertilization.Specifically,N addition significantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no influence on its bud density and MLI.Nutrient addition had significant effects on the three indicators of PB.Our study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit specific responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.展开更多
Biological volatile organic compounds(BVOCs) have a large influence on atmospheric environmental quality, climate change and the carbon cycle. This study assesses the composition and diurnal variation in emission rate...Biological volatile organic compounds(BVOCs) have a large influence on atmospheric environmental quality, climate change and the carbon cycle. This study assesses the composition and diurnal variation in emission rates of BVOCs from Pinus tabuliformis, using an enclosure technique. Environmental parameters(temperature and light intensity) and physiological parameters(net photosynthetic rate, P_n; stomatal conductance, g_s; intercellular CO_2 concentration, C_i; and transpiration rate, T_r) that may affect emission behavior were continuously monitored. The 10 most abundant compound groups emitted by P. tabuliformis were classified by gas chromatography–mass spectrometry. The dominant monoterpenoid compounds emitted were α-pinene, β-myrcene, α-farnesene and limonene. The diurnal emission rate of BVOCs changed with temperature and light intensity, with dynamic analysis of BVOCs emissions revealing that their emission rates were more affected by temperature than light. The variation in monoterpene emission rates was consistent with estimates of P_n, g_s and T_r. Basal emission rates(at 30 °C,) of the main BVOCs ranged from 0.006 to 0.273 μg^(-1)/(hr g),while the basal ER standardization coefficients ranged from 0.049 to 0.144 °C^(-1). Overall, these results provide a detailed reference for the effective selection and configuration of tree species to effectively prevent and control atmospheric pollution.展开更多
Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are d...Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are directly associated with influenzainduced fatal acute lung injury and acute respiratory distress syndrome.Due to the narrow administration window,current antiviral therapies are often inadequate.The efforts to use immunomodulatory agents alone or in combination with antiviral agents in the treatment of influenza in animal models have resulted in the achievement of protective effects accompanied with reduced cytokine production.Currently,there are no immunomodulatory drugs for influenza available for clinical use.Animal models,despite being ideal to study the anti-inflammatory responses to influenza virus infection,are very costly and time-consuming.Therefore,there is an urgent need to establish fast and economical screening methods using cellbased models to screen and develop novel immunomodulatory agents.In this study,we screened seven human cell lines and found that the human monocytic cell U937 supports the replication of different subtypes of influenza viruses as well as the production of the important pro-inflammatory cytokines and was selected to develop the cell-based model.The U937 cell model was validated by testing a panel of known antiviral and immunomodulatory agents and screening a drug library consisting of 1280 compounds comprised mostly of FDA-approved drugs.We demonstrated that the U937 cell model is robust and suitable for the high-throughput screening of immunomodulators and antivirals against influenza infection.展开更多
基金support from the National Natural Science Foundation of China(41877542).
文摘Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ecosystems.However,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still unclear.In this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient addition.The short-term nutrient addition had no significant influences on belowground bud density,aboveground shoot density,and MLI of the whole plant community.Plant functional groups showed different responses to soil fertilization.Specifically,N addition significantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no influence on its bud density and MLI.Nutrient addition had significant effects on the three indicators of PB.Our study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit specific responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.
基金This work was supported by the National Natural Science Foundation of China(32122055 and 32071603)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(ZDBS-LY-DQC034).
基金supported by the Natural Science Foundation of China(Nos.31800377,31470638)the National Key Research and Development Program of China(No.2016YFC0501704)+2 种基金the National Science and Technology Program of China(No.2015BAD07B0502)the National Key Research the Beijing Collaborative Innovation Center for Eco-environmental Improvement with Forestry and Fruit Trees(No.PXM2016014207000038)the Special Foundation for Beijing Common Construction Project
文摘Biological volatile organic compounds(BVOCs) have a large influence on atmospheric environmental quality, climate change and the carbon cycle. This study assesses the composition and diurnal variation in emission rates of BVOCs from Pinus tabuliformis, using an enclosure technique. Environmental parameters(temperature and light intensity) and physiological parameters(net photosynthetic rate, P_n; stomatal conductance, g_s; intercellular CO_2 concentration, C_i; and transpiration rate, T_r) that may affect emission behavior were continuously monitored. The 10 most abundant compound groups emitted by P. tabuliformis were classified by gas chromatography–mass spectrometry. The dominant monoterpenoid compounds emitted were α-pinene, β-myrcene, α-farnesene and limonene. The diurnal emission rate of BVOCs changed with temperature and light intensity, with dynamic analysis of BVOCs emissions revealing that their emission rates were more affected by temperature than light. The variation in monoterpene emission rates was consistent with estimates of P_n, g_s and T_r. Basal emission rates(at 30 °C,) of the main BVOCs ranged from 0.006 to 0.273 μg^(-1)/(hr g),while the basal ER standardization coefficients ranged from 0.049 to 0.144 °C^(-1). Overall, these results provide a detailed reference for the effective selection and configuration of tree species to effectively prevent and control atmospheric pollution.
基金supported by the Important Hubei Science and Technology Innovation Plan 2015ACA062 (to Xulin Chen)the Natural Science Foundation of Hubei Province (2018CFB244, to Jungang Chen)
文摘Severe influenza infections are often associated with the excessive induction of pro-inflammatory cytokines,which is also referred to as"cytokine storms".Several studies have shown that cytokine storms are directly associated with influenzainduced fatal acute lung injury and acute respiratory distress syndrome.Due to the narrow administration window,current antiviral therapies are often inadequate.The efforts to use immunomodulatory agents alone or in combination with antiviral agents in the treatment of influenza in animal models have resulted in the achievement of protective effects accompanied with reduced cytokine production.Currently,there are no immunomodulatory drugs for influenza available for clinical use.Animal models,despite being ideal to study the anti-inflammatory responses to influenza virus infection,are very costly and time-consuming.Therefore,there is an urgent need to establish fast and economical screening methods using cellbased models to screen and develop novel immunomodulatory agents.In this study,we screened seven human cell lines and found that the human monocytic cell U937 supports the replication of different subtypes of influenza viruses as well as the production of the important pro-inflammatory cytokines and was selected to develop the cell-based model.The U937 cell model was validated by testing a panel of known antiviral and immunomodulatory agents and screening a drug library consisting of 1280 compounds comprised mostly of FDA-approved drugs.We demonstrated that the U937 cell model is robust and suitable for the high-throughput screening of immunomodulators and antivirals against influenza infection.