AOBPreview originally published online on March 13, 2006
Annals of Botany 2006 97(6):1145-1149; doi:10.1093/aob/mcl057
The Mitochondrial Fission Regulator DRP3B Does Not Regulate Cell Death in Plants
1 Institute of Molecular and Cellular Biosciences and 2 Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan and 3 Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan
* For correspondence. E-mail mkawai{at}iam.u-tokyo.ac.jp
Received: 14 November 2005 Returned for revision: 6 January 2006 Accepted: 30 January 2006 Published electronically: 13 March 2006
Background and Aims Recent reports have described dramatic alterations in mitochondrial morphology during metazoan apoptosis. A dynamin-related protein (DRP) associated with mitochondrial outer membrane fission is known to be involved in the regulation of apoptosis. This study analysed the relationship between mitochondrial fission and regulation of plant cell death.
Methods Transgenic plants were generated possessing Arabidopsis DRP3B (K56A), the dominant-negative form of Arabidopsis DRP, mitochondrial-targeted green fluorescent protein and mouse Bax.
Key Results Arabidopsis plants over-expressing DRP3B (K56A) exhibited long tubular mitochondria. In these plants, mitochondria appeared as a string-of-beads during cell death. This indicates that DRP3B (K56A) prevented mitochondrial fission during plant cell death. However, in contrast to results for mammalian cells and yeast, Bax-induced cell death was not inhibited in DRP3B (K56A)-expressing plant cells. Similarly, hydrogen peroxide-, menadione-, darkness- and salicylic acid-induced cell death was not inhibited by DRP3B (K56A) expression.
Conclusions These results indicate that the systems controlling cell death in animals and plants are not common in terms of mitochondrial fission.
Key words: Arabidopsis, Bax, cell death, DRP3B, fission, mitochondria