title: The extremophile Nicotiana benthamiana has traded viral defence for early vigour.
abstract: A single lineage of Nicotiana benthamiana is widely used as a model plant(1) and has been instrumental in making revolutionary discoveries about RNA interference (RNAi), viral defence and vaccine production. It is peerless in its susceptibility to viruses and its amenability in transiently expressing transgenes(2,3). These unparalleled characteristics have been associated both positively and negatively with a disruptive insertion in the RNA-dependent RNA polymerase 1 gene, Rdr1(4-6). For a plant so routinely used in research, the origin, diversity and evolution of the species, and the basis of its unusual abilities, have been relatively unexplored. Here, by comparison with wild accessions from across the spectrum of the species' natural distribution, we show that the laboratory strain of N. benthamiana is an extremophile originating from a population that has retained a mutation in Rdr1 for ∼0.8 Myr and thereby traded its defence capacity for early vigour and survival in the extreme habitat of central Australia. Reconstituting Rdr1 activity in this isolate provided protection. Silencing the functional allele in a wild strain rendered it hypersusceptible and was associated with a doubling of seed size and enhanced early growth rate. These findings open the way to a deeper understanding of the delicate balance between protection and vigour.
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.|School of Molecular Biology, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Julia
authors.initials: J
authors.lastname: Bally
authors.affiliation: School of Molecular Biology, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Kenlee
authors.initials: K
authors.lastname: Nakasugi
authors.affiliation: School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Fangzhi
authors.initials: F
authors.lastname: Jia
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.
authors.forename: Hyungtaek
authors.initials: H
authors.lastname: Jung
authors.affiliation: School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Simon Y W
authors.initials: SY
authors.lastname: Ho
authors.affiliation: School of Molecular Biology, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Mei
authors.initials: M
authors.lastname: Wong
authors.affiliation: School of Molecular Biology, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Chloe M
authors.initials: CM
authors.lastname: Paul
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.|School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Fatima
authors.initials: F
authors.lastname: Naim
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation-Plant Industry, Canberra, Australia.
authors.forename: Craig C
authors.initials: CC
authors.lastname: Wood
authors.affiliation: Mount Albert Research Centre, Plant and Food Research, Auckland, New Zealand.
authors.forename: Ross N
authors.initials: RN
authors.lastname: Crowhurst
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.|Mount Albert Research Centre, Plant and Food Research, Auckland, New Zealand.
authors.forename: Roger P
authors.initials: RP
authors.lastname: Hellens
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.
authors.forename: James L
authors.initials: JL
authors.lastname: Dale
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland 4001, Australia.|School of Molecular Biology, The University of Sydney, Sydney, New South Wales 2006, Australia.|School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Waterhouse