Accumulation Characteristics And Subcellular Distributions To Cd Of Dongting Lake Dominant Plants Artemisia Selengensis Turcz

For the status of the heavy metals cadmium (Cd) pollution is serious in the Dongting Lake wetland soils. In this study, the materials is Artemisia selengensis Turz, through the soil pot experiment, different concentrations of Cd, we have reaearched Artemisia selengensis to Cd stress response, and Cd’s distribution and chemical form in subcellular. And through the analysis of plant Cd content in the body and other relevant indicators, to evaluate their enrichment characteristics and temediation effect. It’s purpose was to ascertain the toxicity mechanism of Cd on plant, and provide a theoretical research for the Artemisia selengensis enrichment mechanism of Cd. Reference to the restoration of soil cadmium pollution of Dongting Lake wetland management.The main conclusions of the study are as follows:(1) Low Cd (5to15mg/kg) promote Artemisia selengensis growth, high concentrations of Cd (>90mg/kg) will inhibit the growth. In Artemisia selengensis roots, stems, leaves three kind of nutrition organs in the distribution of the Cd significant differences, the root of enrichment highest concentration, the enrichment, relatively low concentration; Leaf biomass is far less than the stems and roots, so the actual amount of the Cd enrichment of smaller, Artemisia selengensis roots, stems, leaves in the Cd enrichment amount as Cd processing increased concentration of rising trend, the distribution of the significant higher than the rate stems and leaves, Artemisia selengensis main extraction repair organs and fixed repair organs are the stems and roots.(2) Low Cd (5to15mg/kg) stress range, Artemisia selengensis body of the soluble protein content rise, in Artemisia selengensis body that there might be a detoxification mechanism of specific protein, this is Artemisia selengensis resistance to the poison of Cd a detoxification mechanism. No matter in seedling stage or at maturity, POD, SOD the2kinds of enzyme activity in the root Artemisia selengensis rise by significantly greater than the leaves, it shows that Artemisia selengensis root Cd to a greater extent than by the damage of the leaf. Along with the increase of stress concentration Cd, the content of MDA Artemisia selengensis body are higher than those of the control, visible to Artemisia selengensis Cd membrane system a certain degree of damage effect. Artemisia selengensis leaf in the content of chlorophyll a and chlorophyll a/b value is reduced, low stress concentration Cd early days (5mg/kg-15mg/kg), was promoted blade growth, with the increase of the concentration of the treatment, Artemisia selengensis leaf in the chlorophyll content decrease,40mg/kg condition began to appear, gray leaf quantity to reduce the withered and yellow phenomenon, to110mg/kg stress concentration, chlorophyll content to lowest, the leaves and plants basic wither.(3) Cd in Artemisia selengensis roots, leaves the cells of the distribution of the show, Artemisia selengensis cells Cd is mainly distributed in the cell walls of components, of total45%-61%, and soluble component is the second smallest, and of total25%-40%, and other organelles (such as chloroplasts, mitochondrial) content in less, allowing the cell vacuole isolation is fixed and Artemisia selengensis tolerance of high concentration Cd stress mainly detoxification mechanism, the root cells surrounding the role of the area lies between to give priority to, leaf cells to cell wall precipitation function mainly. In Artemisia selengensis body, the extraction state to the different proportion of Cd distribution, in roots with water extraction Cd main state (FW) primarily, followed by sodium chloride extraction state (FNaC1) and acetic acid extraction state (FHAC) and how in the most Cd with organic acid salt, pectin acid salt and heavy metal phosphate form existence, and various forms of trend performance:root> stem> leaf, this and may in Artemisia selengensis root Cd is of high enrichment related.