A hydroponics experiment was conducted to investigate the effect of copper （Cu） on cadmium （Cd）, calcium （Ca）, iron （Fe）, and zinc （Zn） uptake by several rice genotypes. The experiment was carried out as a 2...A hydroponics experiment was conducted to investigate the effect of copper （Cu） on cadmium （Cd）, calcium （Ca）, iron （Fe）, and zinc （Zn） uptake by several rice genotypes. The experiment was carried out as a 2×2×4 factorial with four rice genotypes and two levels of Cu and Cd in nutrient solution. Plants were grown in a growth chamber with controlled environment. The results showed a significant difference between the biomass of different rice genotypes （P 〈 0.001）. The Cd and Cu concentration in the solution had no significant effect on the biomass. The addition of Cu significantly decreased Cd uptake by shoots and roots of rice （P 〈 0.001）. The Cd concentration did not significantly influence Ca uptake by plants, whereas the Cu concentration did （P = 0.034）. There was a significant influence of Cd on Fe uptake by shoots and roots （P 〈 0.001, P = 0.003, respectively）. Zn uptake decreased significantly as the addition of Cd and Cu increased in shoots. We concluded that Cu had significant influence on Cd uptake. The possible mechanisms were discussed.展开更多
Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter ...Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter in the world, is committed to introducing an ETS to reduce emissions. Here we reviewed existing ETSs and sustainable energy policies worldwide as well as China's pilot programs. These studies were conducted in order to propose recommendations for national initiatives and strategies to be implemented in China in relation to climate change adaptation and mitigation. It has been shown that setting emission caps in the context of a national emission intensity target is difficult. However, implementing reliable systems for measurement, reporting, and verification of emissions are essential. A two-level management system(by central and provincial governments) for carbon trading is beneficial to ensure uniform standards and compliance while maintaining flexibility. Persistent political support from, and effective coordination of, policies by the government are crucial. In addition, strengthening of institutional innovation, and the establishment of a national GHG emissions information system, are of equal importance. This vital information could provide a great opportunity for China to re-define its economic growth and take global leadership in combatting climate change.展开更多
Arsenic(As) is a metalloid toxic to organisms including humans.Arsenic in rice represents a significant exposure pathway for the general population,particularly for those subsisting on rice.Arsenic transformation,name...Arsenic(As) is a metalloid toxic to organisms including humans.Arsenic in rice represents a significant exposure pathway for the general population,particularly for those subsisting on rice.Arsenic transformation,namely reduction,oxidation and methylation,in soil-rice systems has fundamental impacts on its mobility and toxicity.In addition to soil chemical properties(pH,Eh,metallic oxides,organic matter),microorganisms play critical roles in As transformation and mobility in paddy soil,such as through ArsM(As(III) S-adenosylmethyltransferase) and interactions with iron oxides or organic matters.Arsenic species in paddy soil directly influence As speciation in rice grain because the methylated As species in rice are mainly derived from microbial methylation in paddy soil.This paper aims to provide an overview on the status of the knowledge and gaps on the chemical aspects of As transformation in soil-rice system in conjunction with microbial ecology and functional genes.In addition,potential pathways(manipulation of microorganisms in paddy soil and genetic engineering) to decrease total As and/or inorganic As in rice grain are proposed.展开更多
Soil is an essential part of the critical zone,and soil-microbe-plant system serves as a key link among lithosphere,biosphere,atmosphere and hydrosphere.As one of the habitats with the richest biodiversity,soil plays ...Soil is an essential part of the critical zone,and soil-microbe-plant system serves as a key link among lithosphere,biosphere,atmosphere and hydrosphere.As one of the habitats with the richest biodiversity,soil plays a critical role in element biogeochemistry on the earth surface(weathered crust).Here we review the soil biological processes that are relevant to mineral weathering,element cycling,and transformation,with an emphasis on rock weathering mediated by soil microbes,plant root and the rhizosphere.展开更多
基金supported by the National Natural Science Foundation of China(No.40225002,20207012)the National Basic Research Program(973)of China(No.2002CB410808).
文摘A hydroponics experiment was conducted to investigate the effect of copper （Cu） on cadmium （Cd）, calcium （Ca）, iron （Fe）, and zinc （Zn） uptake by several rice genotypes. The experiment was carried out as a 2×2×4 factorial with four rice genotypes and two levels of Cu and Cd in nutrient solution. Plants were grown in a growth chamber with controlled environment. The results showed a significant difference between the biomass of different rice genotypes （P 〈 0.001）. The Cd and Cu concentration in the solution had no significant effect on the biomass. The addition of Cu significantly decreased Cd uptake by shoots and roots of rice （P 〈 0.001）. The Cd concentration did not significantly influence Ca uptake by plants, whereas the Cu concentration did （P = 0.034）. There was a significant influence of Cd on Fe uptake by shoots and roots （P 〈 0.001, P = 0.003, respectively）. Zn uptake decreased significantly as the addition of Cd and Cu increased in shoots. We concluded that Cu had significant influence on Cd uptake. The possible mechanisms were discussed.
基金Under the auspices of the National Key Research & Development Program of China(No.2017YFA0604700)
文摘Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter in the world, is committed to introducing an ETS to reduce emissions. Here we reviewed existing ETSs and sustainable energy policies worldwide as well as China's pilot programs. These studies were conducted in order to propose recommendations for national initiatives and strategies to be implemented in China in relation to climate change adaptation and mitigation. It has been shown that setting emission caps in the context of a national emission intensity target is difficult. However, implementing reliable systems for measurement, reporting, and verification of emissions are essential. A two-level management system(by central and provincial governments) for carbon trading is beneficial to ensure uniform standards and compliance while maintaining flexibility. Persistent political support from, and effective coordination of, policies by the government are crucial. In addition, strengthening of institutional innovation, and the establishment of a national GHG emissions information system, are of equal importance. This vital information could provide a great opportunity for China to re-define its economic growth and take global leadership in combatting climate change.
基金supported by the National Natural Science Foundation of China (40973058,21077100)
文摘Arsenic(As) is a metalloid toxic to organisms including humans.Arsenic in rice represents a significant exposure pathway for the general population,particularly for those subsisting on rice.Arsenic transformation,namely reduction,oxidation and methylation,in soil-rice systems has fundamental impacts on its mobility and toxicity.In addition to soil chemical properties(pH,Eh,metallic oxides,organic matter),microorganisms play critical roles in As transformation and mobility in paddy soil,such as through ArsM(As(III) S-adenosylmethyltransferase) and interactions with iron oxides or organic matters.Arsenic species in paddy soil directly influence As speciation in rice grain because the methylated As species in rice are mainly derived from microbial methylation in paddy soil.This paper aims to provide an overview on the status of the knowledge and gaps on the chemical aspects of As transformation in soil-rice system in conjunction with microbial ecology and functional genes.In addition,potential pathways(manipulation of microorganisms in paddy soil and genetic engineering) to decrease total As and/or inorganic As in rice grain are proposed.
基金supported by Major Program of National Natural Science Foundation of China(Grant No.41090282)
文摘Soil is an essential part of the critical zone,and soil-microbe-plant system serves as a key link among lithosphere,biosphere,atmosphere and hydrosphere.As one of the habitats with the richest biodiversity,soil plays a critical role in element biogeochemistry on the earth surface(weathered crust).Here we review the soil biological processes that are relevant to mineral weathering,element cycling,and transformation,with an emphasis on rock weathering mediated by soil microbes,plant root and the rhizosphere.
