Grafting is common in nature and is familiar as a means of manipulating plants and trees for use in agriculture. Now Ralph Bock and colleagues demonstrate that entire nuclear genomes can be transferred across the graft junction from plant to plant. In grafting experiments between tree tobacco Nicotiana glauca and cigarette tobacco N. tabacum (woody and herbaceous species, respectively), horizontal transfer of nuclear genomes can result in the formation of a new polyploid species - Nicotiana tabauca. This is an example of allopolyploidization, the combination of the genomes from two different species, that has contributed to evolutionary innovation, adaptation, speciation and domestication. This work shows that allopolyploidization can occur through an asexual mechanism that is readily available as a tool for crop improvement.
展开▼
