The first evidence of a host-to-parasite mitochondrial gene transfer in Orobanchaceae

Several parasitic plants are known to have acquired mitochondrial genes via a horizontal transfer from their hosts. However, mitochondrial gene transfer in this direction has not yet been found in the parasite-rich family Orobanchaceae. Based on a phylogenetic analysis of the mitochondrial atp6 gene in selected species of Orobanche s.l., we provide evidence of a host-to-parasite transfer of this gene in O. coerulescens, which is a Eurasiatic species that parasitises Artemisia (Asteraceae). We did not find the original Orobanche atp6 gene in this species, which suggests that it has been replaced by a gene that was acquired from Asteraceae. In addition, our data suggest the occurrence of a second HGT event in the atp6 sequence – from Asteraceae to Phelipanche. Our results support the view that the transfer of genetic material from hosts to parasites influences the mitochondrial genome evolution in the latter.