Abstract
During culture, Brassica napus leaf protoplasts become swollen and finally degrade. Both morphological and biochemical approaches revealed that the process through which the death occurred were subjected to apoptotic-like manner. This suggests that the recalcitrance of B. napus leaf protoplasts might be explained by apoptosis. The amounts of hydrogen peroxide and superoxide present in the medium during the isolation of leaf protoplasts from recalcitrant B. napus and regenerating Petunia hybrida were measured. This data showed that both active oxygen species (AOS) accumulated to greater levels in P. hybrida. Addition of radical scavengers to the isolation medium of B. napus protoplasts had no effect on the cell death. This suggests that neither of the two AOS generated during the isolation of leaf protoplasts might be involved in triggering apoptosis in B. napus leaf protoplasts. Intracellular ROS generated during the culture need to be further elucidated.
