Evidence for genomic changes in transgenic rice (Oryza sativa L.) recovered from protoplasts
- 75 Downloads
The occurrence of genomic modifications in transgenic rice plants recovered from protoplasts and their transmission to the self-pollination progeny has been verfied with the random amplified polymorphic DNA (RAPD) approach. The plant was the Indica-type rice (Oryza sativa L.) cultivar Chinsurah Boro II. The analysed material was: (1) microspore-derived embryogenic rice cells grown in suspension culture, (2) transgenic plants recovered from protoplasts produced from the cultured cells and (3) the self-pollination progeny (two successive generations) of the transgenic plants. DNA purified from samples of these materials was PCR-amplified with different random oligonucleotide primers and the amplification products were analysed by agarose gel electrophoresis. Band polymorphism was scored and used in band-sharing analyses to produce a similarity matrix. Relationships among the analysed genomes were expressed in a dendrogram.
The extensive DNA changes evidenced in cultured cells demonstrate the occurrence of somaclonal variation in the material used to produce protoplasts for gene transfer. Quantitatively reduced DNA changes were also found in the resulting transgenic plants and i their self-pollination progenies.
While confirming the stability of the foreign gene in transgenic plants, this work gives molecular evidence for the occurrence of stable genomic changes in transgenic plants and points toin vitro cell culture as the causative agent. RAPDs are shown to be a convenient tool to detect and estimate the phenomenon at the molecular level. The methodology is also proposed as a fast tool to select those transgenic individuals that retain the most balanced genomic structure and to control the result of back-crosses planned to restore the original genome.
KeywordsTransgenic rice PCR-RAPD arbitrary DNA primers genomic changes somaclonal variation
Unable to display preview. Download preview PDF.
- Castiglionc, S., Wang, G., Damiani, G., Bandi, C., Bisoffi, S. and Sala, F. (1993) RAPD Fingerprints for identificiation and for taxonomic studies of elite poplar (Populus spp.) clones.Theor. Appl. Genet. 85, 54–9.Google Scholar
- Christou, P., Ford, T.L. and Kofron, M. (1991) Production of transgenic rice (Oryza sativa L.) plants from agronomically important Indica and Japonica varieties via electric discharge particle acceleration of exogenous DNA into immature zygotic embryos.Bio/Technology 9, 957–62.CrossRefGoogle Scholar
- Christou, P., Ford, T.L. and Kofron, M. (1992) The development of a variety-independent gene-transfer method for rice.Tibtech. 10, 239–46.Google Scholar
- Crawford, R. (1991) Gene mapping Japan's number one crop.Science 252, 1611.Google Scholar
- Datta, S.K., Datta, K. and Potrykus, I. (1990a) Fertile Indica rice plants regenerated from protoplasts isolated from microspore derived cell suspensions.Pl. Cell Rep. 9, 253–6.Google Scholar
- Davey, M.R., Kothari, S.L., Zhang, H.M., Rech, E.L., Cocking, E.C. and Lynch, P.T. (1991) Transgenic rice: characterisation of protoplast-derived plants and their seed progeny.J. Exp. Bot. 42, 1159–69.Google Scholar
- Sneath, P.H.A. and Sokal, R.R. (1973)Numerical Taxonomy. San Francisco, USA: Freeman.Google Scholar
- Walbot, V. and Cullis, C.A. (1983) The plasticity of the plant genome. Is it a requirement for success?Pl. Mol. Biol. Rep. 1, 3–11.Google Scholar
- Wang, G., Castiglione, S., Chen, Y., Li, L., Han, Y., Tian, Y., Gabriel, D.W., Han, Y., Mang, K. and Sala, F. (1996) Poplar (Populus nigra L.) plants transformed with aBacillus thuringiensis toxin gene: insecticidal activity and genomic analysisTransgenic Res. 5, in press.Google Scholar
- Zhang, H.M., Yang, H., Rech, E.L., Golds, T.J., Davis, A.S., Mulligan, B.J., Cocking, E.C. and Davey, M.R. (1988) Transgenic rice plants produced by electroporation-mediated plasmid uptake into protoplasts.Pl. Cell Rep. 7, 379–84.Google Scholar