ORFH79 impairs mitochondrial function via interaction with a subunit of electron transport chain complex III in Honglian cytoplasmic male sterile rice
Article first published online: 25 FEB 2013
No claim to original Chinese government works New Phytologist © 2013 New Phytologist Trust
Volume 198, Issue 2, pages 408–418, April 2013
How to Cite
Wang, K., Gao, F., Ji, Y., Liu, Y., Dan, Z., Yang, P., Zhu, Y. and Li, S. (2013), ORFH79 impairs mitochondrial function via interaction with a subunit of electron transport chain complex III in Honglian cytoplasmic male sterile rice. New Phytologist, 198: 408–418. doi: 10.1111/nph.12180
- Issue published online: 20 MAR 2013
- Article first published online: 25 FEB 2013
- Manuscript Accepted: 6 JAN 2013
- Manuscript Received: 6 NOV 2012
- National 973 Project. Grant Numbers: 2007CB109005, 2011CB100102
- National Natural Science Foundation. Grant Number: 31070303
- cytoplasmic male sterility;
- electron transport chain complex III;
- Oryza sativa
- Cytoplasmic male sterility (CMS) has attracted great interest because of its application in crop breeding. Despite increasing knowledge of CMS, not much is understood about its molecular mechanisms. Previously, orfH79 was cloned and identified as the CMS gene in Honglian rice, but how the ORFH79 protein causes pollen abortion is still unknown.
- Through bacterial two-hybrid library screening, P61, a subunit of the mitochondrial electron transport chain (ETC) complex III, was selected as a candidate that interacts with ORFH79. Bimolecular fluorescence complementation (BiFC) and coimmunoprecipitation (coIP) assays verified their interaction inside mitochondria. Blue native polyacrylamide gel electrophoresis (BN-PAGE) and western blotting showed ORF79 and P61 colocalized in mitochondrial ETC complex III of CMS lines.
- Compared with the maintainer line, Yuetai B (YB), a significant decrease of enzyme activity was detected in mitochondrial complex III of the CMS line, Yuetai A (YA), which resulted in decreased ATP concentrations and an increase in the reactive oxygen species (ROS) content.
- We propose that the CMS protein, ORFH79, can bind to complex III and decrease its enzyme activity through interaction with P61. This defect results in energy production dysfunction and oxidative stress in mitochondria, which may work as retrograde signals that lead to abnormal pollen development.