Virus-mediated export of chromosomal DNA in plants

Abstract

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. However, virus-mediated acquisition of host genetic material, as deduced from historical events, appears to be rare. Here, we report spontaneous and surprisingly efficient generation of hybrid virus/host DNA molecules in the form of minicircles during infection of Beta vulgaris by Beet curly top Iran virus (BCTIV), a single-stranded DNA virus. The hybrid minicircles replicate, become encapsidated into viral particles, and spread systemically throughout infected plants in parallel with the viral infection. Importantly, when co-infected with BCTIV, B. vulgaris DNA captured in minicircles replicates and is transcribed in other plant species that are sensitive to BCTIV infection. 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.

A Panicum‐derived chromosomal segment captured by Hordeum a few million years ago preserves a set of stress‐related genes

“…However, the question arises if this mechanism truly represents an HGT, as it does not involve integration of foreign genetic material into the recipient genome. Hypothetically, transfer mediated by a common parasite (Yoshida et al, 2010), an endophytic fungus (Ambrose et al, 2014), or a virus (Catoni et al, 2018) could be envisaged. According to a weak-link model (Huang, 2013), HGT may have been facilitated by asexual reproduction in multicellular eukaryotes, as foreign genes need not to be passed through specialized reproductive cells (germ lines) to be transmitted to offspring.…”

Lateral Gene Transfer Mechanisms and Pan-genomes in Eukaryotes

“…At least some viruses can infect a wide range of hosts and/or change hosts (e.g., [19]) and some eukaryotes harbour multiple divergent viruses, each of which may enable gene exchange beyond species boundaries. The virus-mediated export of nuclear DNA in plants was recently documented in real time by Catoni et al [20], where Beta vulgaris chromosomal DNA integrated into the viral genome of a singlestranded DNA virus during infection was encapsidated into viral particles and spread throughout the plant population via subsequent viral infections. Notably, the B. vulgaris DNA present in the hybrid minicircles was replicated and transcribed in the newly infected host.…”

Identification and distribution of novel badnaviral sequences integrated in the genome of cacao (Theobroma cacao)

“…In summary, the data generated in this study add to the growing evidence for the dynamic status of plants (and other) genomes 35 , such as evidence for the role of plant viruses as agents for horizontal gene transfer between species 36 , and the role of such diversity in determining the response of plants to the continuous battle between plants and their pathogens.…”