“Agroinfection,” an alternative route for viral infection of plants by using the Ti plasmid

Abstract

Most plant viruses are transmitted by insect vectors. We present an alternative method for the introduction of infectious viral DNA that uses the ability of Agrobacterium to transfer DNA from bacterial cells to plants. Cauliflower mosaic virus was chosen to develop this method because it is the best characterized plant DNA virus and can be introduced into plants via aphids, virus particles, viral DNA, or suitably treated cloned DNA. We show that systemic infection of turnips results from wounding and inoculation with strains of Agrobacterium tumefdciens in which more than one genome of cauliflower mosaic virus have been placed tandemly in the T-DNA of thO tumor-induiheg plasmid. Thus such constructions allow escape of the viral genome from the T-DNA once inside the plkuts. The combined use of the tumor-inducing plasmid and viral DNA opens the way to molecular biological approaches that are not possible with either system alone.

Fate of African Cassava Mosaic Virus Coat Protein Deletion Mutants after Agroinoculation

“…Infectivity of the deletion mutants was tested by agroinoculation (Grimsley et aL, 1986(Grimsley et aL, , 1987 ofN. benthamiana.…”

“…Subgenomic forms of TGMV DNA A containing extensive deletions within the coat protein gene are also infectious when introduced into N. benthamiana by agroinoculation (Grimsley et al, 1986(Grimsley et al, , 1987 if DNA B was either co-agroinoculated (Hayes et al, 1988b) or produced in vivo 0000-8911 © 1989 SGM by recombination from multimeric copies integrated into the host genome (Gardiner et al, 1988). On both occasions, symptoms were again delayed and greatly attenuated although, in contrast to infections with ACMV subgenomic DNA A, severe symptoms did not eventually develop.…”

Rice tungro bacilliform virus DNA independently infects rice after Agrobacterium-mediated transfer

“…Agroinoculation is the term given to the process of introducing viral or viroidal genomes into plants by the mediation of the soil bacteria, Agrobacterium tumefaciens or A. rhizogenes resulting in an 'agroinfection' (Grimsley et al, 1986;Boulton et al, 1989). It has been used to produce infections in monocotyledons with cloned viral DNAs of maize streak virus (MSV), digitaria streak 0001-0148 © 1991 SGM virus and wheat dwarf virus, viruses which are solely insect-transmitted Donson et al, 1988;Woolston et al, 1988).…”

T‐DNA recombination and replication in maize cells

“…When T-DNA is presented with more than a unit-length viral genome such as the maize streak virus, recombinant viral genomes are generated leading to the effective viral infection. This process is called agroinfection (Grimsley et al, 1986) and the replicative release of the viral DNA molecules has been postulated as a major recombination pathway (Stenger et al, 1991); however, homologous recombination within T-DNA (Lazarowitz et al, 1989) as well as illegitimate recombination involving the T-DNA border sequences (Bakkeren et al, 1989) has also been implicated in this process. Homologous recombination of T-DNA molecules also occurs during plant gene targeting (Risseeuw et al, 1997;Wang et al, 2001).…”