Abstract
The ozone-sensitive and ozone-tolerant tobacco varieties Bel-W3 and Bel-B have been widely used as bioindicator of ozone. However, the mechanisms for the difference in sensitiveness to ozone in above two varieties are not fully understood. Ozone is readily converted other members of reactive oxygen species (ROS) such as superoxide anion. Here, cell suspension cultures were prepared from Bel-B and Bel-W3 plants and propagated for the study of generation and metabolism of ROS. When both cell lines were treated with salicylate (1 mM) and AlCl3 (1 mM), 5-fold greater superoxide generation was observed in Bel-W3 cells compared to Bel-B cells. The in vivo catalase activity was measured by monitoring the H2O2-dependent O2 evolution using a Clark-type oxygen electrode. The in vivo catalase activity in Bel-B cells was ca. 2-fold greater than that in Bel-W3 cells, and apparent Vmax in Bel-B cells was slightly greater than that in Bel-W3 cells.
