Expression of mitochondrial gene fragments within the tapetum induce male sterility by limiting the biogenesis of the respiratory machinery in transgenic tobacco.

Plant mitochondrial genomes (mtDNAs) are large and undergo frequent recombination events. A common phenotype that emerges as a consequence of altered mtDNA structure is cytoplasmic-male sterility (CMS). The molecular basis for CMS remains unclear, but it seems logical that altered respiration activities would result in reduced pollen production.