Programmed cell death in Datura innoxia Mill. callus cultures cultivated in light and in dark

It has been established that dimedone in solid culture medium influenced th e growth of Datura innoxia Mill. callus tissues and the apoptotic processes of cells. This formaldehyde (HCHO) capture reagent appears to modify the m etabolism of plant cells, resulting in quantitative changes in the apoptoti c index (A(i)). Apoptotic cells were detected in six-week-old callus tissue s by the TUNEL reaction. The amount of TUNEL positive nuclei showed a chara cteristic spatial distribution. Enhanced DNA fragmentation was observed in the cell layers close to the surface of the cultures. Elevated A(i) was det ermined in cultures grown in the dark compared to the tissues grown in the light. High doses of dimedone considerably decreased apoptosis in tissue cu ltures under both light and dark conditions.