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The mitochondrial fission regulator DRP3B does not regulate cell death in plants
Keiko Yoshinaga1, Masaru Fujimoto, Shin-Ichi Arimura
1Institute of Molecular and Cellular Biosciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Tokyo 113-0032, Japan.
Annals of Botany
|March 15, 2006
Summary
Plant cell death involves mitochondrial fission, but unlike in animals, inhibiting this process with DRP3B (K56A) did not prevent cell death. This suggests distinct mechanisms regulate plant and animal cell death pathways.
Area of Science:
- Plant Biology
- Cell Biology
- Molecular Biology
Background:
- Mitochondrial morphology changes are observed during metazoan apoptosis.
- Dynamin-related proteins (DRPs) regulate mitochondrial outer membrane fission and apoptosis.
- The role of mitochondrial fission in plant cell death is not well understood.
Purpose of the Study:
- To investigate the relationship between mitochondrial fission and plant cell death regulation.
- To determine if inhibiting mitochondrial fission affects plant cell death pathways.
Main Methods:
- Generated transgenic Arabidopsis plants expressing a dominant-negative form of Arabidopsis DRP3B (K56A).
- Utilized mitochondrial-targeted green fluorescent protein and mouse Bax for cellular analysis.
- Observed mitochondrial morphology and assessed cell death induction under various stimuli.
Main Results:
- Overexpression of DRP3B (K56A) resulted in long, tubular mitochondria and a string-of-beads appearance during cell death, indicating prevention of fission.
- Unlike in mammalian cells and yeast, Bax-induced cell death was not inhibited in DRP3B (K56A)-expressing plant cells.
- DRP3B (K56A) expression did not inhibit cell death induced by hydrogen peroxide, menadione, darkness, or salicylic acid.
Conclusions:
- Mitochondrial fission is involved in plant cell death, but its regulation differs from that in animals.
- The mechanisms controlling cell death, particularly concerning mitochondrial fission, are not conserved between plants and animals.
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