Abstract
Reactive oxygen species (ROS) accumulation is triggering cell death in plants. We studied mitochondrial changes using mitochondria-targeted GFP (S65T) under a CaMV 35S promoter (mt-GFP) in plant cells. With the treatment of Arabidopsis leaves by hydrogen peroxide (H2O2), paraquat (Pq), and menadione (MD), a series of morphological changes from bacilli form to a round shape was seen in mitochondria, where cytoplasmic streaming was also blocked. Mitochondrial size was also reduced to about half by ROS stress. Dominant-negative mutant DRP3B (K56A) protein in Arabidopsis cells showed a significant fusion and tubulation of mitochondria, which lacked division ability. This mutant plants co-expressing mt-GFP were treated with hydrogen peroxide. Arabidopsis plants with dominant-negative mutant DRP3B showed the alteration of mitochondira to string-with-bead form under the ROS stresses, suggesting the occurrance of mitochodrial fission.
