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Meeting Abstract

SICB+    Two Genomes is Company, Three is a Plant: How MtDNA Copy Number May Influence Organelle Rates of Evolution in Plant Lineages Maclaine, KD*; Tressel, LG; Wu, Z; Kan, SL; Mower, JP; Sloan, DB; Ruhlman, TA; Jansen, RK; Havird, JC; The University of Texas at Austin; The University of Texas at Austin; Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences; Institute of Botany, Chinese Academy of Sciences; University of Nebraska-Lincoln; Colorado State Univeristy; The University of Texas at Austin; The University of Texas at Austin; The University of Texas at Austin

Plants have particularly complex genomic interactions, as they have nuclear, mitochondrial, and plastid genomes. Rates of evolution can vary widely in these genomes across species. Specifically, Silene is a genus of wild, flowering plants that shows variation in mitochondrial DNA (mtDNA) evolutionary rates. Previous work has demonstrated that this variation in mtDNA evolutionary rate may be negatively correlated with the mtDNA copy number in Silene. The “fast” mtDNA species, Silene conica shows a lower copy number than “slow” mtDNA species, Silene latifolia. Since plant mtDNA can undergo homologous recombination, it is possible that lower organelle copy numbers may result in less-efficient double-stranded break repair due to a lack of templates. We expanded on this previous work to address whether similar trends would be found in Plantago, Geraniaceae, and Gymnosperm lineages, which show appreciable variation in rates of organellar evolution. Preliminary data suggests that the trend observed in Silene is consistent with some, but not all lineages. Expanding these findings can help address the cause of mtDNA evolutionary rate variation on a broader level.