CGMS involves interaction between:
Cytoplasmic-genic male sterility arises from antagonistic interaction between mitochondrial genome carrying sterility causing chimeric open reading frames and nuclear genome harboring restorer of fertility Rf genes. Mitochondrial ORFs such as orf79 in rice WA cytoplasm, orf138 in Brassica Ogu cytoplasm resulting from rearrangement generate cytotoxic peptides disrupting mitochondrial electron transport complex assembly reducing ATP supply critical for high energy demand of tapetal cells during microsporogenesis. Cytoplasm S with ORF confers sterility when nuclear background homozygous for non-r
Ref: Hanson MR Bentolila Annu Rev Genetics CMS molecular basis; Fujii PPR restorer mechanism Plant Cell; Singh BD CGMS interaction.