Cu Stress Affects The Castor Physiological Reaction And Accumulation Characteristics

Castor is a newly discovered hyperaccumulator for copper, and has broad prospects. Castor has a large biomass, adaptability, and the characteristics of high economic value. It is a kind of oil crops and it is an ideal green plants which has great potential in remediation of heavy metal. In order to alleviate heavy metal contamination, green and safe phytoremediation has become a trend to deal with the increasingly serious environmental problems. In order to investigate the physiological responses and castor accumulation mode under the stress of Cu, we hope to provide some basis for the study of accumulate Cu in the castor. This experiment adopts the hydroponic method to research the castor at different concentrations of Cu stress(0, 50, 100, 200, 500, 1000 umol/L) under the condition of physiological characteristics and accumulation characteristics. Two processing times(3 d and 7 d) were designed. The test of castor root and leaf physiological characteristics and castor accumulation characteristics of root, stem and leaf was analysised.The major results obtained were summarized as follows.(1)The relationship between the accumulation of Cu in castor is stem > root > leaf. DNP and La Cl3 have a certain extent of absorption of Cu castor, indicating that the castor uptake of Cu possibly has zhe active absorption. It is also closely associated with calcium channels.(2) Subcellular distribution of Cu in castor roots, stems and leaves show most of Cu present in the soluble component and nucleus. Cu in different tissues of castor has different forms of existence. In root, the majority of Cu is water soluble inorganic salt, and in the upper Cu mainly is pectic acid or protein binding(3)The content of chlorophyll a and total chlorophyll will has increased with the increase of concentration of heavy metals, and the ratio of chlorophyll a/chlorophyll b presented down trend.(4)When considering MDA, cell membrane permeability, POD, SOD at low concentrations of Cu(Cu≤200μmol / L), there is not significantly difference from the control group. But at high concentrations of Cu, it will significantly increase its activity or content. The activities/contents of proline, CAT, ASA-POD at Cu process have been significantly increased.(5)Castor roots of MDA, proline, POD will significantly improve the activity and content with the Cu concentration increased. The roots of SOD, CAT, ASA-POD is not significantly increased its activity or content with the Cu concentration.Castor at low Cu concentrations(Cu≤200μmol / L), Cu stored in the soluble fraction of cells, and the chemical form of Cu is a mobile water soluble and protein-based state. It did not affect the physiological activity of the cells. Castor can still grow and develop normally at this Cu concentration.