| Programmed cell death (PCD) is a genetically regulated process in which cells activate their own demise. In plants, PCD takes place during development, in such processes as senescence, flower development, and in response to pathogen infection. Among PCD-related genes identified in animals, two share sequence similarities with plant genes: the Dad1 gene (defender against cell death) and the BI 1-gene (bax-like inhibitor). In this study, the pattern of expression of the Dad1-like gene of Arabidopsis thaliana (At-Dad1) was analyzed by mRNA in situ hybridization. Intense signal was observed in young tissues fated to undergo PCD. Subsequent reduction of the signal was noticeable at the onset of death in these tissues, supporting the idea that At-Dad1 functions as a plant cell death regulator. |
