Abstract
Hypersensitive cell death is known as a kind of defense responses and a typical programmed cell death in plants. It has been indicated that cell death signaling is transduced via Hsp90, MAPK (NtMEK2-WIPK/SIPK) cascade and then mitochondria, although almost other factors which function between these steps, are not identified yet. Many pathogenic bacteria utilize the type III secretion system to inject effector proteins into the host cells, and their main role is considered to disturb host defense systems including hypersensitive cell death. We have isolated plural cell death suppressors from type III effectors of Ralstonia solanacearum which is a bacterial pathogen causing severe damage in solanaceous species using tobacco hypersensitive cell death induction systems, and then analyzed the mechanism of the suppression. It is expected that the identification of the targets for cell death suppressors would provide unknown factors involved in hypersensitive cell death signaling.
