Abstract
The mammalian apoptotic protein Bax has been shown to induce cell death in plants as well as yeast and animal cells. This suggests parallels between PCD in plants and apoptosis in animals. To investigate the morphological changes involved in Bax-induced death in plants, we established the transgenic Arabidopsis possessing Bax and plastid- or mitochondria-targeted GFP. Upon DEX treatment, such plants exhibited morphological changes in mitochondria, the leakage of GFP proteins from chloroplasts, and etiolation of leaves. Interestingly, the transgenic plants treated with DEX under the dark condition showed similar events, but they did not present etiolation, which was the last step of plant cell death. Furthermore, non-photosynthetic Arabidopsis suspension cells expressing Bax were also induced to cell death. These results indicate that the developed chloroplast (or light) is not essential, and morphological changes of organelles occur in the early stage of Bax-induced cell death in plant.
