This study investigated the transformations of heavy metals(HMs) and polycyclic aromatic hydrocarbons(PAHs) in rhizosphere soils and adaptive responses of rhizobacterial community under the real field conditions durin...This study investigated the transformations of heavy metals(HMs) and polycyclic aromatic hydrocarbons(PAHs) in rhizosphere soils and adaptive responses of rhizobacterial community under the real field conditions during four growth stages(e.g., greening, tillering, heading, and maturity) of early rice(Zhongjiazao 17) and late rice(Zhongyou 9918) in Jiangshe village(JSV) and Yangji village(YJV). Results showed that rhizosphere soils of YJV were mildly polluted by Cd and PAHs compared to that of JSV. The relative abundance of bioavailable Cd(bio-Cd) and bioavailable As(bio-As) in rhizosphere soil increased before the heading stage but decreased at the subsequent growth stage, but the content of ΣPAHs in rhizosphere soil decreased gradually during whole growth period. The dominant rhizobacteria genera at YJV(e.g., Bacillus, Massilia, Sphingomonas, and Geobacter) increased at an abundance level from the tillering to heading stage. Rhizobacteria interacted with the above co-pollutant more intensely at the tillering and heading stage, where genes involved in HM-resistance and PAH-degradation appeared to have a significant enhancement. The contents of bioCd and bio-As in rhizosphere soil of early rice were higher than that of late rice at each growth stage, especially at the heading stage. Bio-Cd, ΣPAHs, and organic matter were key factors influencing the community structure of rhizobacteria. Results of this study provide valuable insights about the interactions between HM-PAH co-pollutant and rhizobacterial community under real field conditions and thus develop in-situ rhizosphere remediation techniques for contaminated paddy fields.展开更多
Phosvitin(PV)was treated with high-temperature,mild pressure(HTMP),and enzyme combination,and then phosvitin phosphopeptides-calcium(PPP-Ca)complexes were prepared.The low-calcium specific pathogen free-Kunming(SPF-KM...Phosvitin(PV)was treated with high-temperature,mild pressure(HTMP),and enzyme combination,and then phosvitin phosphopeptides-calcium(PPP-Ca)complexes were prepared.The low-calcium specific pathogen free-Kunming(SPF-KM)mice were used to determine the effect of PPP-Ca complexes on intestinal calcium absorption and their utilization for bone formation.The serum calcium content was the highest with the HTMP-Enz-PPP-Ca treatment(2.19 mmol/L),and it significantly down-regulated the abnormal elevation of serum alkaline phosphatase(AKP)caused by calcium deficiency.The low-calcium control group had the lowest calcium deposited to the femur(80.41 mg/g)and the lowest femur bone mineral density(BMD)(0.17 g/cm^(3)),while HTMP-Enz-PPP-Ca significantly improved bone calcium content(94.33 mg/g)and BMD(0.29 g/cm^(3)).The micro-computed tomography(MCT)images showed that the femur with the normal control,PV-Ca,and HTMP-Enz-PPP-Ca treatments had a more compact,complete,and thicker trabecular network than the low-calcium and CaCl_(2)treatments.These results indicated that the organic calcium(HTMP-Enz-PPP-Ca)promoted calcium absorption and bone deposition,and the effect of HTMP-Enz-PPP-Ca was better than the inorganic CaCl_(2).展开更多
基金supported by the National Natural Science Foundation of China(No.22176161)the National Natural Science Foundation of China-Hunan Joint Fund(No.U21A20293)+2 种基金the Natural Science Foundation of Hunan Province(No.2021JJ30655)the Innovation Platform Open Fund Project of Hunan Provincial Education Committee(No.19K090)the Program of Shanghai Academic/Technology Research Leader(No.19XD1434900).
文摘This study investigated the transformations of heavy metals(HMs) and polycyclic aromatic hydrocarbons(PAHs) in rhizosphere soils and adaptive responses of rhizobacterial community under the real field conditions during four growth stages(e.g., greening, tillering, heading, and maturity) of early rice(Zhongjiazao 17) and late rice(Zhongyou 9918) in Jiangshe village(JSV) and Yangji village(YJV). Results showed that rhizosphere soils of YJV were mildly polluted by Cd and PAHs compared to that of JSV. The relative abundance of bioavailable Cd(bio-Cd) and bioavailable As(bio-As) in rhizosphere soil increased before the heading stage but decreased at the subsequent growth stage, but the content of ΣPAHs in rhizosphere soil decreased gradually during whole growth period. The dominant rhizobacteria genera at YJV(e.g., Bacillus, Massilia, Sphingomonas, and Geobacter) increased at an abundance level from the tillering to heading stage. Rhizobacteria interacted with the above co-pollutant more intensely at the tillering and heading stage, where genes involved in HM-resistance and PAH-degradation appeared to have a significant enhancement. The contents of bioCd and bio-As in rhizosphere soil of early rice were higher than that of late rice at each growth stage, especially at the heading stage. Bio-Cd, ΣPAHs, and organic matter were key factors influencing the community structure of rhizobacteria. Results of this study provide valuable insights about the interactions between HM-PAH co-pollutant and rhizobacterial community under real field conditions and thus develop in-situ rhizosphere remediation techniques for contaminated paddy fields.
基金supported by the General Program of National Natural Science Foundation of China(32072237)the Hubei Provincial Natural Science Foundation of China(2020CFB583)Fundamental Research Funds for the Central Universities(2662020SPPY006)。
文摘Phosvitin(PV)was treated with high-temperature,mild pressure(HTMP),and enzyme combination,and then phosvitin phosphopeptides-calcium(PPP-Ca)complexes were prepared.The low-calcium specific pathogen free-Kunming(SPF-KM)mice were used to determine the effect of PPP-Ca complexes on intestinal calcium absorption and their utilization for bone formation.The serum calcium content was the highest with the HTMP-Enz-PPP-Ca treatment(2.19 mmol/L),and it significantly down-regulated the abnormal elevation of serum alkaline phosphatase(AKP)caused by calcium deficiency.The low-calcium control group had the lowest calcium deposited to the femur(80.41 mg/g)and the lowest femur bone mineral density(BMD)(0.17 g/cm^(3)),while HTMP-Enz-PPP-Ca significantly improved bone calcium content(94.33 mg/g)and BMD(0.29 g/cm^(3)).The micro-computed tomography(MCT)images showed that the femur with the normal control,PV-Ca,and HTMP-Enz-PPP-Ca treatments had a more compact,complete,and thicker trabecular network than the low-calcium and CaCl_(2)treatments.These results indicated that the organic calcium(HTMP-Enz-PPP-Ca)promoted calcium absorption and bone deposition,and the effect of HTMP-Enz-PPP-Ca was better than the inorganic CaCl_(2).
