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.

Draft genome sequence of an inbred line ofChenopodium quinoa, an allotetraploid crop with great environmental adaptability and outstanding nutritional properties

“…However, N. benthamiana is usually systemically infected with viruses, whereas quinoa is either locally or systemically infected, as shown in Figure 2E and F. Although mutations in Rdr1 , which is involved in antiviral defence, have provided intriguing clues as to the mechanism by which a wide range of viruses can amplify well in N. benthamiana , 80 , 81 it remains unknown why a broad range of viruses can infect quinoa. We therefore analysed the RDR1 genes in quinoa.…”

Highly Efficient Agroinoculation Method for Tomato Plants with <i>Tomato Yellow Leaf Curl Kanchanaburi Virus</i>

“…Inoculation of TYLCKaV to N. benthamiana N. benthamiana, categorized as a Solanaceae species along with tomatoes and capsicums, is the most widely used experimental host in plant virology, mainly because of the large number of diverse plant viruses that can successfully infect it (Bally et al, 2015;Goodin et al, 2008). Partial tandem repeats of TYLCKaV DNA A and DNA B were constructed, and their infectivity was tested on N. benthamiana.…”

Narrow-Leafed Lupin (Lupinus angustifolius) β1- and β6-Conglutin Proteins Exhibit Antifungal Activity, Protecting Plants against Necrotrophic Pathogen Induced Damage from Sclerotinia sclerotiorum and Phytophthora nicotianae

“…Plant experiments were conducted with Nicotiana benthamiana accession “lab” (Bally et al, 2015) in temperature controlled growth rooms as described by Petrie et al (2010). Plants were grown under a 16-h light/8-h dark cycle at 22°C.…”