Abstract
Although relatively little is known about the mechanistic details of cell death in plants, some aspects of the molecular machinery are conserved between plants and animals. We recently presented the evidence that the anti-apoptotic protein AtBI-1 (Arabidopsis Bax inhibitor-1) is biologically active in suppressing the lethal action of mammalian Bax in yeast and plant. Transgenic Arabidopsis expressing Bax exhibited marked cell death at the whole plant level. The plants possessing both Bax and AtBI-1 were able to maintain growth. Furthermore, tobacco suspension cells (BY-2) expressing AtBI-1 reduced hydrogen peroxide- or SA- induced cell death. To study the cellular localization of AtBI-1, a fusion protein with GFP was expressed in yeast and tobacco suspension cells. Microscopic analysis revealed that such protein was localized to the ER in each system. Involvement of ER-localized membrane protein in the response for oxidative stress will be discussed.
