Virus Host Jumping Can Be Boosted by Adaptation to a Bridge Plant Species.

Understanding biological mechanisms that regulate emergence of viral diseases, in particular those events engaging cross-species pathogens spillover, is becoming increasingly important in virology. Species barrier jumping has been extensively studied in animal viruses, and the critical role of a suitable intermediate host in animal viruses-generated human pandemics is highly topical. However, studies on host jumping involving plant viruses have been focused on shifting intra-species, leaving aside the putative role of "bridge hosts" in facilitating interspecies crossing.

Streamlined generation of plant virus infectious clones using the pLX mini binary vectors.

Recent metagenomic surveys have provided unprecedented amounts of data that have revolutionized our understanding of virus evolution and diversity. Infectious clones are powerful tools to aid the biological characterization of viruses. We recently described the pLX vectors, a set of mini binary T-DNA vectors (∼3 kb) that includes strong bacterial terminators and a minimal replicon from the broad-host-range plasmid pBBR1, which replicate autonomously in both Escherichia coli and Agrobacterium.

Visual tracking of plant virus infection and movement using a reporter MYB transcription factor that activates anthocyanin biosynthesis.

Insertion of reporter genes into plant virus genomes is a common experimental strategy to research many aspects of the viral infection dynamics. Their numerous advantages make fluorescent proteins the markers of choice in most studies. However, the use of fluorescent proteins still has some limitations, such as the need of specialized material and facilities to detect the fluorescence.

Simultaneous equimolar expression of multiple proteins in plants from a disarmed potyvirus vector.

The use of viral vectors for expression of heterologous proteins in plants is hampered by some limitations including the amount of exogenous genetic information that can be incorporated, difficulties with coexpression of stoichiometric amounts of multiple polypeptides and the risk that infectious clones could escape to environment. Here, a new plant viral vector is described which overcomes these limitations. The technology is based on the replacement of the viral RNA polymerase (NIb) cistron of a potyvirus by a cassette for the coexpression of multiple heterologous proteins.

Stability of Tobacco etch virus infectious clones in plasmid vectors.

Tobacco etch virus (TEV) has been traditionally used as a model to research many aspects of the molecular biology of plant RNA virus and, more recently, experimental evolution. However, the only plasmid of this virus species with an infectious clone that has been commonly available to research (pTEV7DA) is rather unstable when propagated in the bacterium Escherichia coli. Here, the TEV infectious clone contained in pTEV7DA is used to construct three new plasmids that allowed infecting the host plants from RNA transcripts synthesized in vitro (pMTEV), directly from plasmid DNA (p35TEV) and by agroinoculation (pGTEV).