| In recent years, due to the lack of effective planning and management of the antimonymining activities and irrational use of antimony, the antimony content in the soil, water and airrose sharply, which posed a serious threat to the health of humans and the entire ecosystem.Phytoremediation as an economic, efficient and relatively safe environmental remediationtechnology has broad application prospects. However, the lack of plant materials for antimonyphytoremediation and undefined mechanism about the antimony phytotoxicity andtolerance inplants made the phytoremediation technology for antimony pollution management extremelyrestricted. Therefore, the current research was carried out to analyze the characteristics ofheavy metal accumulation in plants through the antimony mining areas to assess the potentialsof phytoremediaiton in these plants. Besides, antimony-tolerant plant Miscanthus sinensis wasused to study plant physiology, biochemistry and proteomics response under antimony stresswhich provided an effective method for the understanding of the mechanism of antimonyphytotoxicity and tolerance in plant, which provide an effective method for obtaining idealplant material for antimony phytoremediation.The major results are summarized as follows:(1) Research on the characteristics of heavy metal accumulation in plants grown on anantimony mining areas. A field survey of plants and associated soil in an antimony mining areaof Xikuangshan, Hunan Province, China was conducted to identify species that accumulateheavy metals in their tissues. Of the10herbaceous plants, Miscanthus sinensis and Imperatacylindrica exhibited Hg and Cd phytoextraction potentials. Boehmeria longispica was capableof accumulating Sb and As in its shoots. Moreover, Phytolacca americana could be used forthe phytostabilization of Pb and Cd, Amaranthus paniculatus and Miscanthus sinensis could beused for Sb stabilization, Cynodon dactylon had considerable potential for As and Sbstabilization. Additionally, Miscanthus sinensis considered as a potential energy plant couldbring amount of economic value during its Sb phytoremediation, recognized as a ideal material for Sb phytoremediation. Besides, all these Sb accumulation plants could be used for the studyon plant tolerant mechanism of Sb.(2) Comparison of characteristics in antimony accumulation and growth responses underantimony stress between two ecotypes of Miscanthus sinensis. The content of antimonyconcentration in mine and non-mine eco-Miscanthus sinensis roots and leaves increasedsignificantly with increasing concentration in treatments. Antimony in these two plants weremainly accumulated in its roots with transfer coefficient ranges from0.13to0.18. Differentorganizations of the two ecotypes was not significant different in antimony accumulation,indicating that there were not big difference in capacity of antimony uptake. Antimony addedon different ecotypes Miscanthus sinensis caused significant inhibition on its growth andbiomass. Besides the reduction rate of seedling height and root length in mine eco-Miscanthussinensis compared with the control was lower than the non-mine eco-Miscanthus sinensis.Meanwhile, the dry weight of eco-Miscanthus sinensis shoot and root decline less than thenon-mine eco-Miscanthus sinensis compared with the control, which indicate that the mineeco-Miscanthus sinensis possessed a higher antimony tolerance than the non-mineeco-Miscanthus sinensis.(3) Reactive oxygen and osmotic adjustment mechanism of the two eco-Miscanthussinensis under antimony stress. The antimony stress cause a increase content of MDA in botheco-Miscanthus sinensis leaves, which indicated that lipid peroxidation were aggravated.Among them, the MDA accumulation in non-mining eco-Miscanthus sinensis were greaterthan the mining. Meanwile, as to the adjustment process of ROS regulation, SOD, CAT andPOD activities in mining eco-Miscanthus sinensis rose significantly higher while the PODactivities in non-mining eco-Miscanthus sinensis were inhibited.Except for CAT, SODactivities in non-mining eco-Miscanthus sinensis were lower than the mine one. As to theosmotic adjustment process, soluble sugar and proline content increased significantly with theincreased antiomny concentration in both tow ecotypes. Among them, the increasing rate ofsoluble sugar and proline contentin non-mining eco-Miscanthus sinensis were lower than mining one. The results showed that mining eco-Miscanthus sinensis enhanced its antimonytolerance through higher antioxidant enzyme activities and osmotic adjustment matters.(4) Comparative proteomics research on the mining eco-Miscanthus sinensis under antimonystress. In this study, two-dimensional electrophoresis combined with mass spectrometricidentification technology were carry out to analyze proteomic response of miningeco-Miscanthus sinensis to antimony Stress. Comparative proteomics research were carried inboth leaves and roots under antimony stress. A total of48different protein spots were gainedand31spots were successfully identified. The results showed that these proteins were mainlyinvolved in free oxygen regulation, energy metabolism, signal transduction, cell division andcell structure stability, Protein folding and assembling, and transcription. In addition, severaldifferent proteins were upregulated or induced by the antimony stress including active oxygenregulator protein, gamma response proteins, CBS domain protein, zinc finger protein, proteinserine/threonine kinase, heat shock protein Hsp90, ACC oxidase homolog,pathogenesis-related protein PR10. These proteins might playe important roles in enhancingthe antimony tolerance, part of which had been identified to be associated with plantenvironmental stress tolerance.(5) Phytoxicity of Antimony. A large number of active oxygen regulator proteins weredetected through the proteomic study on Miscanthus sinensis responses to antimony stress,including Peroxidase Peroxidase73-like peroxide reductase, ascorbate peroxidase, glutathioneS-transferase enzyme, C-signal protein with oxidoreductase activity. The results clarified thatoxidative stress play a major role in antimony phytotoxicity at the molecular level. |
PDF Full Text Request