Inducible expression of p50 from TMV for increased resistance to bacterial crown gall disease in tobacco
- 546 Downloads
The dominant tobacco mosaic virus (TMV) resistance gene N induces a hypersensitive response upon TMV infection and protects tobacco against systemic spread of the virus. It has been proposed to change disease resistance specificity by reprogramming the expression of resistance genes or their corresponding avirulence genes. To reprogramme the resistance response of N towards bacterial pathogens, the helicase domain (p50) of the TMV replicase, the avirulence gene of N, was linked to synthetic promoters 4D and 2S2D harbouring elicitor-responsive cis-elements. These promoter::p50 constructs induce local necrotic lesions on NN tobacco plants in an Agrobacterium tumefaciens infiltration assay. A tobacco genotype void of N (nn) was transformed with the promoter::p50 constructs and subsequently crossed to NN plants. Nn F1 offspring selected for the T-DNA develop normally under sterile conditions. After transfer to soil, some of the F1 plants expressing the 2S2D::p50 constructs develop spontaneous necrosis. Transgenic Nn F1 plants with 4D::p50 and 2S2D::p50 expressing constructs upregulate p50 transcription and induce local necrotic leasions in an A. tumefaciens infiltration assay. When leaves and stems of Nn F1 offspring harbouring promoter::p50 constructs are infected with oncogenic A. tumefaciens C58, transgenic lines harbouring the 2S2D::p50 construct induce necrosis and completely lack tumor development. These results demonstrate a successful reprogramming of the viral N gene response against bacterial crown gall disease and highlight the importance of achieving tight regulation of avirulence gene expression and the control of necrosis in the presence of the corresponding resistance gene.
KeywordsDisease resistance N gene Necrosis Synthetic promoter Tobacco mosaic virus Transgenic plants
The technical assistance of Elke Faurie and Erik Hanko with greenhouse work is gratefully acknowledged. We would like to thank Michael Steinert for critically reading the manuscript. This work was supported by the Federal Ministry of Education and Research (BMBF).
- Hehl R, Steffens NO, Wingender E (2004) Isolation and analysis of gene regulatory sequences. In: Christou P, Klee H (eds) Handbook of plant biotechnology. Wiley, Chichester, pp 81–102Google Scholar
- Jaglo KR, Kleff S, Amundsen KL, Zhang X, Haake V, Zhang JZ, Deits T, Thomashow MF (2001) Components of the Arabidopsis C-repeat/dehydration-responsive element binding factor cold-response pathway are conserved in Brassica napus and other plant species. Plant Physiol 127:910–917PubMedCrossRefGoogle Scholar
- Komatsu K, Hashimoto M, Ozeki J, Yamaji Y, Maejima K, Senshu H, Himeno M, Okano Y, Kagiwada S, Namba S (2010) Viral-induced systemic necrosis in plants involves both programmed cell death and the inhibition of viral multiplication, which are regulated by independent pathways. Mol Plant Microbe Interact 23:283–293PubMedCrossRefGoogle Scholar
- Koschmann J (2009) Identifizierung neuer cis-regulatorischer Elemente durch bioinformatische und experimentelle Analyse Pathogen-induzierbarer Gene. Dissertation, Technische Universität BraunschweigGoogle Scholar
- Kuang H, Padmanabhan C, Li F, Kamei A, Bhaskar PB, Ouyang S, Jiang J, Buell CR, Baker B (2009) Identification of miniature inverted-repeat transposable elements (MITEs) and biogenesis of their siRNAs in the Solanaceae: new functional implications for MITEs. Genome Res 19:42–56PubMedCrossRefGoogle Scholar
- Schornack S, Ballvora A, Gürlebeck D, Peart J, Baulcombe D, Ganal M, Baker B, Bonas U, Lahaye T (2004) The tomato resistance protein Bs4 is a predicted non-nuclear TIR-NB-LRR protein that mediates defense responses to severely truncated derivatives of AvrBs4 and overexpressed AvrBs3. Plant J 37:46–60PubMedCrossRefGoogle Scholar