Virus-mediated export of chromosomal DNA in plants

A new study, published in Nature Communications (https://www.nature.com/articles/s41467-018-07775-w), performed by the Institute for Sustainable Plant Protection of CNR and the University of Cambridge, documents the initial steps of virus-mediated horizontal transfer of chromosomal DNA between plant species. The propensity of viruses to acquire genetic material from relatives and possibly from infected hosts makes them excellent candidates as vectors for horizontal gene transfer. We report spontaneous and surprisingly efficient generation of hybrid virus/host DNA molecules in the form of minicircles during infection of sugar beet by a single-strand DNA virus. The hybrid minicircles replicated, became encapsidated into viral particles, and spread systemically throughout infected plants in parallel with the viral infection. Importantly, when co-infected with the virus, sugar beet DNA captured in minicircles replicated and was transcribed in other plant species. Thus, we have likely documented in real time the initial steps of a possible path of virus-mediated horizontal transfer of chromosomal DNA between plant species.