Plant-to-plant horizontal gene transfer

Horizontal gene transfer (HGT) is the transfer of genetic material between distinct species, a process that plays a major role in the evolution of a genome. There is an increasing body of evidence for the transfer of genes between eukaryotes, but the complexities of transcription and translation regulation in eukaryotes have always been thought to be a barrier to HGT. In the July 10 Nature, Ulfar Bergthorsson and colleagues at Indiana University show that standard mitochondrial genes are subject to frequent HGT between distantly related angiosperms, implying the presence of a mechanism for transfer of DNA between unrelated plants (Nature, 424:197-201, July 10, 2003).

Bergthorsson et al. surveyed the mitochondrial gene content of a number of angiosperms and found distribution anomalies. Phylogenetic analysis of two mitochondrial ribosomal protein genes—rps2 and rps11—resulted in the identification of four cases of plant-to-plant HGT, suggesting that the frequency of HGT...