A root-bag experiment was conducted to study the effects of insoluble Zn, Cd, and ethylenediaminetetraacetic acid （EDTA） on the plant growth, activities of antioxidant enzymes, proline, glutathione （GSH）, water-so...A root-bag experiment was conducted to study the effects of insoluble Zn, Cd, and ethylenediaminetetraacetic acid （EDTA） on the plant growth, activities of antioxidant enzymes, proline, glutathione （GSH）, water-soluble proteins and malondialdehyde （MDA） of Vetiveria zizanioides. The V. zizanioides uptake capacity of Zn and Cd also determined. The results showed that plant growth of V. zizanioides was inhibited by Zn and Cd. The shoot dry weight （SDW） and root dry weight （RDW） decrease by 14.2%, 14.1%, 17.0% and 17.3%, 32.5%, 35.7%, respectively, compared to the control without EDTA addition. After adding EDTA, shoot and root dry weight decreased over 10% and 15%, respectively. The toxicity from insoluble Zn and Cd in soil on SDW and RDW of V. zizanioides was in order： Zn＋Cd 〉 Cd 〉 Zn. The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT）, and contents of MDA and proline increased significantly, while the contents of GSH and water-soluble proteins decreased markedly with increasing Zn and Cd toxicity. With EDTA, shoot and root Zn concentrations increased in the Zn treatment by 7.3% and 37.4%, and Cd concentrations in the combined Zn and Cd treatment increased by 18.6% and 391.9% compared to the treatment without EDTA. However, Zn and Cd concentrations in shoot and roots decreased in the Cd treatment compared to the plants grown in absence of EDTA, with exception of root Cd concentration in the presence of EDTA.展开更多
Soil organic carbon(SOC)is the largest terrestrial carbon(C)stock,and the capacity of soils to preserve organic C(OC)varies with many factors,including land use,soil type,and soil depth.We investigated the effect of l...Soil organic carbon(SOC)is the largest terrestrial carbon(C)stock,and the capacity of soils to preserve organic C(OC)varies with many factors,including land use,soil type,and soil depth.We investigated the effect of land use change on soil particulate organic matter(POM)and mineral-associated organic matter(MOM).Surface(0–10 cm)and subsurface(60–70 cm)samples were collected from paired sites(native and cropped)of four contrasting soils.Bulk soils were separated into POM and MOM fractions,which were analyzed for mineralogy,OC,nitrogen,isotopic signatures,and14C.The POM fractions of surface soils were relatively unaffected by land use change,possibly because of the continuous input of crop residues,whereas the POM fractions in corresponding subsurface soils lost more OC.In surface soils,MOM fractions dominated by the oxides of iron and aluminum(oxide-OM)lost more OC than those dominated by phyllosilicates and quartz,which was attributed to diverse organic matter(OM)input and the extent of OC saturation limit of soils.In contrast,oxide-OM fractions were less affected than the other two MOM fractions in the subsurface soils,possibly due to OC protection via organo-mineral associations.The deviations in isotopic signature(linked with vegetation)across the fractions suggested that fresh crop residues constituted the bulk of OM in surface soils(supported by greater14C).Increased isotopic signatures and lower14C in subsurface MOM fractions suggested the association of more microbially processed,aged OC with oxide-OM fractions than with the other MOM fractions.The results reveal that the quantity and quality of OC after land use change is influenced by the nature of C input in surface soils and by mineral-organic association in subsurface soils.展开更多
基金supported by the National Natural Sci-ence Foundation of China (No. 20477032).
文摘A root-bag experiment was conducted to study the effects of insoluble Zn, Cd, and ethylenediaminetetraacetic acid （EDTA） on the plant growth, activities of antioxidant enzymes, proline, glutathione （GSH）, water-soluble proteins and malondialdehyde （MDA） of Vetiveria zizanioides. The V. zizanioides uptake capacity of Zn and Cd also determined. The results showed that plant growth of V. zizanioides was inhibited by Zn and Cd. The shoot dry weight （SDW） and root dry weight （RDW） decrease by 14.2%, 14.1%, 17.0% and 17.3%, 32.5%, 35.7%, respectively, compared to the control without EDTA addition. After adding EDTA, shoot and root dry weight decreased over 10% and 15%, respectively. The toxicity from insoluble Zn and Cd in soil on SDW and RDW of V. zizanioides was in order： Zn＋Cd 〉 Cd 〉 Zn. The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT）, and contents of MDA and proline increased significantly, while the contents of GSH and water-soluble proteins decreased markedly with increasing Zn and Cd toxicity. With EDTA, shoot and root Zn concentrations increased in the Zn treatment by 7.3% and 37.4%, and Cd concentrations in the combined Zn and Cd treatment increased by 18.6% and 391.9% compared to the treatment without EDTA. However, Zn and Cd concentrations in shoot and roots decreased in the Cd treatment compared to the plants grown in absence of EDTA, with exception of root Cd concentration in the presence of EDTA.
基金the financial support of the International Postgraduate Research Scholarships and Postgraduate Research Support Scheme of the University of Sydneythe Australian Institute of Nuclear Science and Engineering for providing a research grant(No.ALNGRA15536)for accelerator mass spectrometry14C analysis。
文摘Soil organic carbon(SOC)is the largest terrestrial carbon(C)stock,and the capacity of soils to preserve organic C(OC)varies with many factors,including land use,soil type,and soil depth.We investigated the effect of land use change on soil particulate organic matter(POM)and mineral-associated organic matter(MOM).Surface(0–10 cm)and subsurface(60–70 cm)samples were collected from paired sites(native and cropped)of four contrasting soils.Bulk soils were separated into POM and MOM fractions,which were analyzed for mineralogy,OC,nitrogen,isotopic signatures,and14C.The POM fractions of surface soils were relatively unaffected by land use change,possibly because of the continuous input of crop residues,whereas the POM fractions in corresponding subsurface soils lost more OC.In surface soils,MOM fractions dominated by the oxides of iron and aluminum(oxide-OM)lost more OC than those dominated by phyllosilicates and quartz,which was attributed to diverse organic matter(OM)input and the extent of OC saturation limit of soils.In contrast,oxide-OM fractions were less affected than the other two MOM fractions in the subsurface soils,possibly due to OC protection via organo-mineral associations.The deviations in isotopic signature(linked with vegetation)across the fractions suggested that fresh crop residues constituted the bulk of OM in surface soils(supported by greater14C).Increased isotopic signatures and lower14C in subsurface MOM fractions suggested the association of more microbially processed,aged OC with oxide-OM fractions than with the other MOM fractions.The results reveal that the quantity and quality of OC after land use change is influenced by the nature of C input in surface soils and by mineral-organic association in subsurface soils.
