IBAM   22618
INSTITUTO DE BIOLOGIA AGRICOLA DE MENDOZA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Widespread horizontal transfer of mitochondrial DNA in a holoparasitic plant
Autor/es:
GARCIA, LE; SANCHEZ PUERTA, MV; CERIOTTI, F; WOHLFEILER, J
Lugar:
Buenos Aires
Reunión:
Congreso; XXXV Annual Meeting of the Willi Hennig Society; 2016
Institución organizadora:
Willi Hennig Society (USA)
Resumen:
Horizontal gene transfer (HGT) is the lateral transmission of genetic material between unrelated organisms and contrasts with the more familiar transfer through sexual or asexual reproduction. HGT among flowering plant mitochondria occurs frequently but in most cases leads to nonfunctional transgenes in the recipient genome. Parasitic plants are particularly prone to this phenomenon, but their mitochondrial genomes (mtDNA) have been largely unexplored. We undertook a large-scale genomic study of the holoparasitic plant Lophophytum mirabile, which belongs to the poorly studied family Balanophoraceae. Comprehensive phylogenetic analyses were performed to address the frequency, origin, and impact of HGT. The sequencing of the complete mtDNA of L. mirabile revealed the unprecedented acquisition of host-derived mitochondrial genes, representing 79% of the protein-coding gene content. All but one of these foreign genes replaced the native homologs and are probably functional in energy metabolism. The genome consists of 54 circular-mapping chromosomes, 26 of which carry no intact genes. Unlike other angiosperm mitochondria, all plastid sequences in L. mirabile mtDNA are foreign, as a natural consequence of the putative loss of the native plastid genome. The likely functional replacement of up to 26 genes in L. mirabile represents a stunning example of the potential effect of rampant HGT on plant mitochondria. The use of host-derived genes may have a positive effect on the host-parasite relationship, but could also be the result of nonadaptive forces.