Titanium dioxide nanoparticle(nano-TiO2),as an excellent UV absorbent and photo-catalyst,has been widely applied in modem industry,thus inevitably discharged into environment.We proposed that nano-TiO2 in soil can pro...Titanium dioxide nanoparticle(nano-TiO2),as an excellent UV absorbent and photo-catalyst,has been widely applied in modem industry,thus inevitably discharged into environment.We proposed that nano-TiO2 in soil can promote crop yield through photosynthetic and metabolic disturbance,therefore,we investigated the effects of nano-TiO2 exposure on related physiologic-biochemical properties of rice(Oryza sativa L.).Results showed that rice biomass was increased>30%at every applied dosage(0.1-100 mg/L)of nano-TiO2.The actual photosynthetic rate(Y(II))significantly increased by 10.0%and 17.2%in the treatments of 10 and 100 mg/L respectively,indicating an increased energy production from photosynthesis.Besides,non-photochemical quenching(Y(NPQ))significantly decreased by 19.8%-26.0%of the control in all treatments respectively,representing a decline in heat dissipation.Detailed metabolism fingerprinting further revealed that a fortified transformation of monosaccharides(D-fructose,D-galactose,and D-talose)to disaccharides(D-cellobiose,and Dlactose)was accompanied with a weakened citric acid cycle,confirming the decrease of energy consumption in metabolism.All these results elucidated that nano-TiO2 promoted rice growth through the upregulation of energy storage in photosynthesis and the downregulation of energy consumption in metabolism.This study provides a mechanistic understanding of the stress-response hormesis of rice after exposure to nano-TiO2,and provides worthy information on the potential application and risk of nanomaterials in agricultural production.展开更多
The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited informati...The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited information on the metabolism relationship between OH-pentaB DEs and MeO-pentaB DEs that were frequently detected with relatively high concentrations in the environment. In this study, the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice, wheat, and soybean plants. All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites, while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean. The conversion of parent compounds was the highest in soybean, followed by wheat and rice. Transformation products were found mainly in the roots, with few metabolites being translocated to the shoots and solution after exposure. The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.21836003 and 21520102009).
文摘Titanium dioxide nanoparticle(nano-TiO2),as an excellent UV absorbent and photo-catalyst,has been widely applied in modem industry,thus inevitably discharged into environment.We proposed that nano-TiO2 in soil can promote crop yield through photosynthetic and metabolic disturbance,therefore,we investigated the effects of nano-TiO2 exposure on related physiologic-biochemical properties of rice(Oryza sativa L.).Results showed that rice biomass was increased>30%at every applied dosage(0.1-100 mg/L)of nano-TiO2.The actual photosynthetic rate(Y(II))significantly increased by 10.0%and 17.2%in the treatments of 10 and 100 mg/L respectively,indicating an increased energy production from photosynthesis.Besides,non-photochemical quenching(Y(NPQ))significantly decreased by 19.8%-26.0%of the control in all treatments respectively,representing a decline in heat dissipation.Detailed metabolism fingerprinting further revealed that a fortified transformation of monosaccharides(D-fructose,D-galactose,and D-talose)to disaccharides(D-cellobiose,and Dlactose)was accompanied with a weakened citric acid cycle,confirming the decrease of energy consumption in metabolism.All these results elucidated that nano-TiO2 promoted rice growth through the upregulation of energy storage in photosynthesis and the downregulation of energy consumption in metabolism.This study provides a mechanistic understanding of the stress-response hormesis of rice after exposure to nano-TiO2,and provides worthy information on the potential application and risk of nanomaterials in agricultural production.
基金supported by the National Basic Research Program (973) of China (No. 2014CB441104)National Natural Science Foundation of China (Nos. 21520102009 and 21137003)the Zhejiang Provincial Natural Science Foundation of China (LY14B070009)
文摘The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited information on the metabolism relationship between OH-pentaB DEs and MeO-pentaB DEs that were frequently detected with relatively high concentrations in the environment. In this study, the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice, wheat, and soybean plants. All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites, while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean. The conversion of parent compounds was the highest in soybean, followed by wheat and rice. Transformation products were found mainly in the roots, with few metabolites being translocated to the shoots and solution after exposure. The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.
