Cytoplasmic Male Sterility and Fertility Restoration by Nuclear Genes

Abstract

Cytoplasmically inherited male sterility (CMS) the maternally inherited failure to produce or shed functional pollen, has been reported in a wide range of plant species. In many cases, the genetic basis for this trait has been traced to the mitochondrial genome. Although male fertility is affected in all cases, the developmental features are varied, as are the molecular mechanisms that produce them. While mitochondrial genomes encode CMS, nuclear restorer-of-fertility genes can suppress or compensate for the expression of mitochondrial CMS genes, thereby conditioning male fertility. Molecular mechanisms of fertility restoration are also varied. CMS and fertility restoration provide a unique set of molecular - genetic tools for the investigation of interactions between nuclear and mitochondrial genetic systems.