Skip to main content
NCBI home page
The Plant Cell logoLink to The Plant Cell
. 1997 Aug;9(8):1495–1504. doi: 10.1105/tpc.9.8.1495

A Transcriptionally Active State Is Required for Post-Transcriptional Silencing (Cosuppression) of Nitrate Reductase Host Genes and Transgenes.

H Vaucheret 1, L Nussaume 1, J C Palauqui 1, I Quillere 1, T Elmayan 1
PMCID: PMC157014  PMID: 12237392

Abstract

Using tobacco nitrate reductase cosuppression as a model system of post-transcriptional gene silencing, we analyzed the influence of DNA and RNA dosages both together and independently. For this purpose, zero, one, two, or four active or transcriptionally silenced copies of a cauliflower mosaic virus 35S-Nia2 transgene were combined by transformation and subsequent crosses with zero, one, two, three, or four active, disrupted, or transcriptionally repressed copies of the wild-type host Nia genes. The analysis of the corresponding transgenic lines revealed that (1) the percentage of isogenic plants that are affected by cosuppression depends directly upon the relative dosage of both host gene and transgene; (2) transcriptional silencing of the 35S-Nia transgene impedes cosuppression; and (3) the absence of host gene transcription reduces the frequency of cosuppression or delays its triggering. Taken together, these results indicate that transgene DNA per se is not sufficient to trigger post-transcriptional cosuppression of nitrate reductase host genes and transgenes. The requirement for a transcriptionally active state is discussed with respect to both the RNA dosage and the DNA-DNA pairing hypotheses.

Full Text

The Full Text of this article is available as a PDF (3.0 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Angenent G. C., Franken J., Busscher M., Colombo L., van Tunen A. J. Petal and stamen formation in petunia is regulated by the homeotic gene fbp1. Plant J. 1993 Jul;4(1):101–112. doi: 10.1046/j.1365-313x.1993.04010101.x. [DOI] [PubMed] [Google Scholar]
  2. Dehio C., Schell J. Identification of plant genetic loci involved in a posttranscriptional mechanism for meiotically reversible transgene silencing. Proc Natl Acad Sci U S A. 1994 Jun 7;91(12):5538–5542. doi: 10.1073/pnas.91.12.5538. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dorlhac de Borne F., Vincentz M., Chupeau Y., Vaucheret H. Co-suppression of nitrate reductase host genes and transgenes in transgenic tobacco plants. Mol Gen Genet. 1994 Jun 15;243(6):613–621. doi: 10.1007/BF00279570. [DOI] [PubMed] [Google Scholar]
  4. Dougherty W. G., Parks T. D. Transgenes and gene suppression: telling us something new? Curr Opin Cell Biol. 1995 Jun;7(3):399–405. doi: 10.1016/0955-0674(95)80096-4. [DOI] [PubMed] [Google Scholar]
  5. English J. J., Mueller E., Baulcombe D. C. Suppression of Virus Accumulation in Transgenic Plants Exhibiting Silencing of Nuclear Genes. Plant Cell. 1996 Feb;8(2):179–188. doi: 10.1105/tpc.8.2.179. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Flavell R. B. Inactivation of gene expression in plants as a consequence of specific sequence duplication. Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3490–3496. doi: 10.1073/pnas.91.9.3490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gabard J, Marion-Poll A, Chérel I, Meyer C, Müller A, Caboche M. Isolation and characterization of Nicotiana plumbaginifolia nitrate reductase-deficient mutants: genetic and biochemical analysis of the NIA complementation group. Mol Gen Genet. 1987 Oct;209(3):596–606. doi: 10.1007/BF00331169. [DOI] [PubMed] [Google Scholar]
  8. Hart C. M., Fischer B., Neuhaus J. M., Meins F., Jr Regulated inactivation of homologous gene expression in transgenic Nicotiana sylvestris plants containing a defense-related tobacco chitinase gene. Mol Gen Genet. 1992 Nov;235(2-3):179–188. doi: 10.1007/BF00279359. [DOI] [PubMed] [Google Scholar]
  9. Lindbo J. A., Silva-Rosales L., Proebsting W. M., Dougherty W. G. Induction of a Highly Specific Antiviral State in Transgenic Plants: Implications for Regulation of Gene Expression and Virus Resistance. Plant Cell. 1993 Dec;5(12):1749–1759. doi: 10.1105/tpc.5.12.1749. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Luthe D. S., Quatrano R. S. Transcription in Isolated Wheat Nuclei: I. ISOLATION OF NUCLEI AND ELIMINATION OF ENDOGENOUS RIBONUCLEASE ACTIVITY. Plant Physiol. 1980 Feb;65(2):305–308. doi: 10.1104/pp.65.2.305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Matzke M. A., Matzke AJM. How and Why Do Plants Inactivate Homologous (Trans)genes? Plant Physiol. 1995 Mar;107(3):679–685. doi: 10.1104/pp.107.3.679. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Napoli C., Lemieux C., Jorgensen R. Introduction of a Chimeric Chalcone Synthase Gene into Petunia Results in Reversible Co-Suppression of Homologous Genes in trans. Plant Cell. 1990 Apr;2(4):279–289. doi: 10.1105/tpc.2.4.279. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Palauqui J. C., Vaucheret H. Field trial analysis of nitrate reductase co-suppression: a comparative study of 38 combinations of transgene loci. Plant Mol Biol. 1995 Oct;29(1):149–159. doi: 10.1007/BF00019126. [DOI] [PubMed] [Google Scholar]
  14. Park Y. D., Papp I., Moscone E. A., Iglesias V. A., Vaucheret H., Matzke A. J., Matzke M. A. Gene silencing mediated by promoter homology occurs at the level of transcription and results in meiotically heritable alterations in methylation and gene activity. Plant J. 1996 Feb;9(2):183–194. doi: 10.1046/j.1365-313x.1996.09020183.x. [DOI] [PubMed] [Google Scholar]
  15. Pouteau S., Cherel I., Vaucheret H., Caboche M. Nitrate Reductase mRNA Regulation in Nicotiana plumbaginifolia Nitrate Reductase-Deficient Mutants. Plant Cell. 1989 Nov;1(11):1111–1120. doi: 10.1105/tpc.1.11.1111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Sijen T., Wellink J., Hiriart J. B., Van Kammen A. RNA-Mediated Virus Resistance: Role of Repeated Transgenes and Delineation of Targeted Regions. Plant Cell. 1996 Dec;8(12):2277–2294. doi: 10.1105/tpc.8.12.2277. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Smith C. J., Watson C. F., Bird C. R., Ray J., Schuch W., Grierson D. Expression of a truncated tomato polygalacturonase gene inhibits expression of the endogenous gene in transgenic plants. Mol Gen Genet. 1990 Dec;224(3):477–481. doi: 10.1007/BF00262443. [DOI] [PubMed] [Google Scholar]
  18. Smith H. A., Swaney S. L., Parks T. D., Wernsman E. A., Dougherty W. G. Transgenic plant virus resistance mediated by untranslatable sense RNAs: expression, regulation, and fate of nonessential RNAs. Plant Cell. 1994 Oct;6(10):1441–1453. doi: 10.1105/tpc.6.10.1441. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Thierry D., Vaucheret H. Sequence homology requirements for transcriptional silencing of 35S transgenes and post-transcriptional silencing of nitrite reductase (trans)genes by the tobacco 271 locus. Plant Mol Biol. 1996 Dec;32(6):1075–1083. doi: 10.1007/BF00041391. [DOI] [PubMed] [Google Scholar]
  20. Vaucheret H., Kronenberger J., Lepingle A., Vilaine F., Boutin J. P., Caboche M. Inhibition of tobacco nitrite reductase activity by expression of antisense RNA. Plant J. 1992 Jul;2(4):559–569. [PubMed] [Google Scholar]
  21. Vaucheret H., Marion-Poll A., Meyer C., Faure J. D., Marin E., Caboche M. Interest in and limits to the utilization of reporter genes for the analysis of transcriptional regulation of nitrate reductase. Mol Gen Genet. 1992 Nov;235(2-3):259–268. doi: 10.1007/BF00279369. [DOI] [PubMed] [Google Scholar]
  22. Vaucheret H., Vincentz M., Kronenberger J., Caboche M., Rouzé P. Molecular cloning and characterisation of the two homologous genes coding for nitrate reductase in tobacco. Mol Gen Genet. 1989 Mar;216(1):10–15. doi: 10.1007/BF00332224. [DOI] [PubMed] [Google Scholar]
  23. Vincentz M., Caboche M. Constitutive expression of nitrate reductase allows normal growth and development of Nicotiana plumbaginifolia plants. EMBO J. 1991 May;10(5):1027–1035. doi: 10.1002/j.1460-2075.1991.tb08041.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. de Carvalho Niebel F., Frendo P., Van Montagu M., Cornelissen M. Post-transcriptional cosuppression of beta-1,3-glucanase genes does not affect accumulation of transgene nuclear mRNA. Plant Cell. 1995 Mar;7(3):347–358. doi: 10.1105/tpc.7.3.347. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. van der Krol A. R., Mur L. A., Beld M., Mol J. N., Stuitje A. R. Flavonoid genes in petunia: addition of a limited number of gene copies may lead to a suppression of gene expression. Plant Cell. 1990 Apr;2(4):291–299. doi: 10.1105/tpc.2.4.291. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Plant Cell are provided here courtesy of Oxford University Press

RESOURCES