Expression of the animal pro-apoptotic protein Bid in Arabidopsis thaliana and Nicotiana tabacum

Bid is a BH3-only member of the Bcl-2 family that regulates cell death at the level of mitochondrial membranes. Full length Bid protein (flBid) becomes activated after a proteolytic cleavage catalyzed by apical caspases (tBid). The cleaved protein then promotes mitochondrial membrane permeabilization by interaction with lipids and other Bcl-2 proteins. flBid also has pro-apoptotic potential in vivo, when ectopically expressed in cells, or in vitro. Although no homologues of Bcl-2 proteins have been identified in plant genomes to date, recent evidence suggests that both Bcl-2 and Bax can fulfil similar roles when introduced into plant cells. In this study, we have constitutively expressed either flBid or tBid in plants to explore the possible cross-talk of this regulatory protein with cell death signalling pathway in Arabidopsis thaliana and Nicotiana tabacum plants.