Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long...Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg-1 respectively. DTPA-extractablc metals were correlated positively and significantly with total metals, CEC, and organic C (except for DTPA-extractable Cd), while they were negatively and highly significantly correlated with pH, total Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C mineralization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some "linked" microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incuba.tion, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone.展开更多
Type I interferon(IFN-I)provides an important first line to protect avian species against pathogens invasion.IFN regulatory factor 7(IRF7)has been identified as the most important regulator for both DNA and RNA virus-...Type I interferon(IFN-I)provides an important first line to protect avian species against pathogens invasion.IFN regulatory factor 7(IRF7)has been identified as the most important regulator for both DNA and RNA virus-induced IFN-I production in chickens.Although four splicing variants of IRF7 have been identified in mammals,it is still unclear whether alternative splicing patterns and the function of IRF7 isoform(s)exist in chickens.In this study,we reported a novel short transcript isoform of chicken IRF7(chIRF7),termed chIRF7-iso,which contained an intact N-terminal DNA-binding domain(DBD)and 14 amino acids different from chIRF7 in the C-terminal.Overexpression of chIRF7 in chicken leghorn male hepatocellular(LMH)cells activated the IFN-βpromoter and significantly inhibited Newcastle disease virus(NDV)and fowl adenovirus serotype 4(FAdV-4)replication.Conversely,overexpression of chIRF7-iso blocked the IFN-βpromoter activity and was favorable for NDV and FAdV-4 replication in vitro.Collectively,our results confirm that a novel chIRF7 isoform-mediated negative regulates IFN-βproduction,which will contribute to understanding the role of chIRF7 in innate antiviral response in chicken.展开更多
基金Project supported by the France-China. Advanced Research Programme, France (No. PRA E03-03) and Natural ScienceFoundation of Guangdong Province (No. 032255).
文摘Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg-1 respectively. DTPA-extractablc metals were correlated positively and significantly with total metals, CEC, and organic C (except for DTPA-extractable Cd), while they were negatively and highly significantly correlated with pH, total Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C mineralization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some "linked" microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incuba.tion, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone.
基金supported by the grants from the National Natural Science Foundation of China(32002259)the Natural Science Foundation of Henan Province,China(202300410198).
文摘Type I interferon(IFN-I)provides an important first line to protect avian species against pathogens invasion.IFN regulatory factor 7(IRF7)has been identified as the most important regulator for both DNA and RNA virus-induced IFN-I production in chickens.Although four splicing variants of IRF7 have been identified in mammals,it is still unclear whether alternative splicing patterns and the function of IRF7 isoform(s)exist in chickens.In this study,we reported a novel short transcript isoform of chicken IRF7(chIRF7),termed chIRF7-iso,which contained an intact N-terminal DNA-binding domain(DBD)and 14 amino acids different from chIRF7 in the C-terminal.Overexpression of chIRF7 in chicken leghorn male hepatocellular(LMH)cells activated the IFN-βpromoter and significantly inhibited Newcastle disease virus(NDV)and fowl adenovirus serotype 4(FAdV-4)replication.Conversely,overexpression of chIRF7-iso blocked the IFN-βpromoter activity and was favorable for NDV and FAdV-4 replication in vitro.Collectively,our results confirm that a novel chIRF7 isoform-mediated negative regulates IFN-βproduction,which will contribute to understanding the role of chIRF7 in innate antiviral response in chicken.
