Inducible high-level mRNA amplification system by viral replicase in transgenic plants

Citation
M. Mori et al., Inducible high-level mRNA amplification system by viral replicase in transgenic plants, PLANT J, 27(1), 2001, pp. 79-86
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
0960-7412 → ACNP
Volume
27
Issue
1
Year of publication
2001
Pages
79 - 86
Database
ISI
SICI code
0960-7412(200107)27:1<79:IHMASB>2.0.ZU;2-H
Abstract
We have constructed a new system for inducible high-level expression of mRN A for foreign genes in transgenic plants by introducing a glucocorticoid-in ducible transcription system into the previously developed 'mRNA amplificat ion system' where target mRNA can be amplified as a subgenomic RNA by the r eplicase of a plant tripartite RNA virus, Brome mosaic virus (BMV). In the new amplification system, the amplification of mRNA is tightly regulated by the expression of a subunit of the BMV replicase. Transgenic Nicotiana ben thamiana plants (designated GVG1 x 2FR) were produced that contained cDNA o f BMV RNA1 coding a subunit of replicase under the control of a tightly reg ulated, glucocorticoid-inducible promoter. In addition GVG1 x 2FR plants co ntain cDNAs of BMV RNA2 coding another subunit of the replicase, and a repl icable engineered BMV RNA3 derivative (FCP2IFN) carrying the human gamma in terferon (IFN) gene under the control of the Cauliflower mosaic virus 35S p romoter. When transgenic plants were treated with dexamethasone (DEX), a st rong synthetic glucocorticoid, induction of replication and amplification o f the 35S-driven FCP2IFN and synthesis of subgenomic mRNA for IFN were obse rved. Accumulation levels of amplified FCP2IFN were over 300 times higher t han those of the 35S-driven FCP2IFN in the GVG1 x 2FR plant without the tre atment and those of the mRNA for IFN were 30-230 times higher than in the p revious, non-inducible mRNA amplification system. Without DEX treatment, no subgenomic mRNA for IFN was detected in the GVG1 x 2FR plant. The advantag es and potential uses of this system are also discussed.