| Affiliation: | (1) Department of Biology, Indiana University, 47405-3700 Bloomington, IN, USA;(2) Department of Biology, University of Central Florida, 32816 Orlando, FL, USA;(3) Department of Ecology and Evolutionary Biology, University of Michigan, 48109 Ann Arbor, MI, USA;(4) Department of Otolaryngology, University of Washington, 98195 Seattle, WA, USA;(5) Sigma Chemical Co, 3300 S. 2nd St, 63118 St. Louis, MO, USA;(6) Department of Biology, Holyoke Community College, 01040 Holyoke, MA, USA;(7) Department of Biology, Penn State University, 16802-0001 University Park, PA, USA |
| Abstract: | Background Rates of synonymous nucleotide substitutions are, in general, exceptionally low in plant mitochondrial genomes, several times lower than in chloroplast genomes, 10–20 times lower than in plant nuclear genomes, and 50–100 times lower than in many animal mitochondrial genomes. Several cases of moderate variation in mitochondrial substitution rates have been reported in plants, but these mostly involve correlated changes in chloroplast and/or nuclear substitution rates and are therefore thought to reflect whole-organism forces rather than ones impinging directly on the mitochondrial mutation rate. Only a single case of extensive, mitochondrial-specific rate changes has been described, in the angiosperm genus Plantago. |
