The maize CMS-C fertility restore gene ZmRf4b encodes a SPL transcription factor that represses ZmMAP1D-mediated co-translational turnover of mitochondrial toxic ATP6C protein.
The promising CMS-C/Rf system has not been applied on a large scale in maize hybrid breeding due to the unclear restoration mechanism for the primary restorer ZmRf4b. In CMS-C maize, the mitochondrial chimeric gene atp6c encodes a cytotoxic variant of ATP6 that over-accumulates and disrupts the assembly of mitochondria...