The interaction of copper, zinc and cadmium on the uptake of heavy metals in Nicotiana benthamiana

• Main Authors: Hsiang-Jen Cheng, 鄭翔仁
• Other Authors: 陳建德
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/33118588886944178568

碩士 === 臺灣大學 === 農業化學研究所 === 95 === Copper, zinc and cadmium are common heavy metal pollutants in Taiwan. In the resent studies of phytoremediation, most of them were focus on the act of single heavy metal in soil, but in many cases, heavy metal pollution was the combination of multielement. Thus, whether the interaction of multiple heavy metals was an antagonistic effect or a synergistic effect needed to be discussed. The aims of this study assess the interaction of copper, zinc and cadmium to the uptake of heavy metal in tobacco. In this study, Nicotiana benthamiana was the test plant and grew in greenhouse with sunlight, and with temperature controlled between 24 to 30 ℃. After grew in the soilless culture for six weeks, tobacco was treated with heavy metal solution where copper, zinc and cadmium were added singly or in the combination of copper with zinc or cadmium. The growth of tobacco was monitored with plant wilting level, fresh weight and dry weight. The physiological status was expressed with chlorophyll content, protein content, proline content and lipid peroxidation level. The metal ion contents were also analyzed at the end of experiment. The result showed that plant wilting level increased with the increase of copper concentration. Cadmium increased plant wilting level only under 10 mM cadmium treatment and zinc did not affect plant wilting level, that implying copper was more toxic than cadmium and zinc to tobacco. Cadmium could reduce Cu-induced plant wilting level. Zinc also ccould reduce Cu-induced plant wilting level, but only at 10 mM copper treatment. Surprisingly, cadmium or zinc also increased copper content in Cu-treated tobacco leaf and stem, suggesting cadmium and zinc reduce Cu-induce plant wilting level was not due to the competition with Cu absorption, but the interfering on Cu toxicity. Chlorophyll content, protein content and lipid peroxidation level did not change after treated with heavy metal for 3d. It’s seemed that it was not the shoot affected by heavy metal after 3d treatment, but the root. Proline content was highly correlated with plant wilting level, thus the proline accumulation may relate to plant wilting level. Copper increased zinc content in Zn-treated tobacco leaf and stem. Copper also increased cadmium content in Cd-treated tobacco stem, but not in leaf. The combined heavy metals treatments also increased the content of potassium, calcium, magnesium, iron and manganese in tobacco.