Kadmiyum İle Kirlenmiş Toprakların Fitoektraksiyonla Arıtımında Transgenik Tütün Bitkisinin Kullanımının Araştırılması

Abstract

Cadmium is one of the environmentally problematic heavy metals, because of its high mobility in soils, its ease and fast uptake by plant and very high toxic potential even at very low concentration. Thus its extraction from the polluted sites is environmentally important. Cadmium can be extracted from the soils either any of expensive remediation methods or phytoextraction which is a method with easy application, natural, and increasing usage. In this study, for fast and efficient removal of heavy metals, including Cd, Metallothionein II (MTII) gene isolated from Saccharomyces cerevisiae (Sc) and Sporamin vacuolar targeting signal gene isolated from sweet potatoes were added for bearing transgenic plant. The experiment was set up in spilt-plot in completely randomized design with three replications. Then the non-transgenic (Nicotiana tabacum L. cv Petit Havana SR1) and transgenic tobacco plants (p-S-ScMTII) were grown in pots containing 0, 0.2, 0.4, 0.8 and 1.6 mg/kg Cd up to flowering stage. Cadmium addition resulted in a slight decrease in growth but no toxicity symptoms were observed. There were no statistical differences in transgenic and non-transgenic plants for dry biomas and Cd concentration. However, Cd concentrations of shoots of both plants were increased upon increasing Cd concentration of soil. For 1.6 mg/kg Cd treatment, Cd concentration of transgenic and non-transgenic plants increased 13.8- 32.9 fold, respectively comparing to the control. Results suggested that S-ScMTII gene bearing transgenic plant did not improve Cd uptake in the studied range of soil Cd concentration. The efficiency of ScMTII gene for accumulation of Cd in shoots should be investigated at higher Cd concentration.