Behavior of heavy metals in the callus of Brassica juncea, a heavy metal accumulation plant

Abstract

To find a more efficient phytoremediation, the accumulation mechanism of elucidating heavy metals of a hyperaccumulator is important. We measured the behavior and glutathione quantity of the heavy metal accumulation level in calli using Brassica juncea, which is a hyperaccumulator of Pb and Cd. Brassica juncea from a seed was used to grow callus, which was for three months. Then, for two weeks, we conducted long-term exposure to a culture in heavy-metal component culture media (Cr, Cu, Zn, Cd, Pb, Co, Ni). Furthermore, we used a liquid culture medium ; for Pb, we conducted a short-term exposure for five days. As for Cd and Pb, the absorbed dose was high, and the Cd, in particular, showed the absorbed dose to be high at a low concentration (10-100 μM), compared with other heavy-metal classes. There were many things that necrotized, in other heavy metals, the fastness was not found to influence the heavy metal. In the short-term exposure of Pb, the absorption level increased during the early phase. However, 96 hours later, according to the cell cycle, that absorption appeared to be promoted. In addition, in GSH, while a large difference was not recognized, a high concentration level was much contained it. © 2005 The Japan Society for Analytical Chemistry.