[Distribution of Pb and Zn in transgenic metallothionein tobacco]

Transgenic metallothionein (MT) plant can clear the heavy metals from soil and environment, but the distribution of metals in plants has not been studied systematically. The Pb and Zn contents in different parts of transgenic MT tobacco plant of sixth generation and traditional plant (same culture variety as control) were analyzed. The Pb and Zn contents in total transgenic plant were 21.8% and 27.2% higher than control, respectively. The distribution of Pb and Zn in different organs varied in these two types of plants. The Pb and Zn contents in old leaves, stem and root in transgenic plants were significantly higher than those in wild type tobacco, while there was no significant difference in young leaves. The Pb contents in old leaves and root were 30.2% and 47.8% higher than those in the control, and the Zn contents in old leaves, stem and root were 4.7%, 29.2% and 21.6% higher than those in the control. These data showed that Pb was accumulated in old leaves and root easily, while Zn was accumulated in old leaves and stem easily.