Abstract
A dominant genetic male sterility trait obtained through transformation in rapeseed (Brassica napus) was studied in the progenies of 11 transformed plants. The gene conferring the male sterility consists of a ribonuclease gene under the control of a tapetum-specific promoter. Two ribonuclease genes, RNase T1 and barnase, were used. The chimaeric ribonuclease gene was linked to the bialophos-resistance gene, which confers resistance to the herbicide phosphinotricine (PPT). The resistance to the herbicide was used as a dominant marker for the male sterility trait. The study presented here concerns three aspects of this engineered male sterility: genetics correlated with the segregation of the T-DNA in the progenies; expression of the male sterility in relation to the morphology and cytology of the androecium; and stability of the engineered male sterility under different culture conditions. Correct segregation, 50% male-sterile, PPT-resistant plants, and 50% male-fertile, susceptible plants were observed in the progeny of seven transformants. The most prominent morphological change in the male-sterile flowers was a noticeable reduction in the length of the stamen filament. The first disturbances of microsporogenesis were observed from the free microspore stage and were followed by a simultaneous degeneration of microspore and tapetal cell content. At anthesis, the sterile anthers contained only empty exines. In some cases, reversion to fertility of male-sterile plants has been observed. Both ribonuclease genes are susceptible to instability. Instability of the RNase T1-male sterility trait increased at temperatures higher than 25[deg] C. Our results do not allow us to confirm this observation for the barnase male-sterile plants. However, the male-sterile plants of the progeny of two independent RNase T1 transformants were stably male sterile under all conditions studied.
Full Text
The Full Text of this article is available as a PDF (2.9 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alexander M. P. Differential staining of aborted and nonaborted pollen. Stain Technol. 1969 May;44(3):117–122. doi: 10.3109/10520296909063335. [DOI] [PubMed] [Google Scholar]
- Coleman A. W., Goff L. J. Applications of fluorochromes to pollen biology. I. Mithramycin and 4',6-diamidino-2-phenylindole (DAPI) as vital stains and for quantitation of nuclear DNA. Stain Technol. 1985 May;60(3):145–154. doi: 10.3109/10520298509113905. [DOI] [PubMed] [Google Scholar]
- De Block M., De Brouwer D., Tenning P. Transformation of Brassica napus and Brassica oleracea Using Agrobacterium tumefaciens and the Expression of the bar and neo Genes in the Transgenic Plants. Plant Physiol. 1989 Oct;91(2):694–701. doi: 10.1104/pp.91.2.694. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dickinson H. G. The role of plastids in the formation of pollen grain coatings. Cytobios. 1973 Sep-Oct;8(29):25–40. [PubMed] [Google Scholar]
- Hartley R. W. Barnase and barstar: two small proteins to fold and fit together. Trends Biochem Sci. 1989 Nov;14(11):450–454. doi: 10.1016/0968-0004(89)90104-7. [DOI] [PubMed] [Google Scholar]
- Koltunow A. M., Truettner J., Cox K. H., Wallroth M., Goldberg R. B. Different Temporal and Spatial Gene Expression Patterns Occur during Anther Development. Plant Cell. 1990 Dec;2(12):1201–1224. doi: 10.1105/tpc.2.12.1201. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LYNN J. A. RAPID TOLUIDINE BLUE STAINING OF EPON-EMBEDDED AND MOUNTED "ADJACENT" SECTIONS. Am J Clin Pathol. 1965 Jul;44:57–58. doi: 10.1093/ajcp/44.1.57. [DOI] [PubMed] [Google Scholar]
- Quaas R., McKeown Y., Stanssens P., Frank R., Blöcker H., Hahn U. Expression of the chemically synthesized gene for ribonuclease T1 in Escherichia coli using a secretion cloning vector. Eur J Biochem. 1988 May 2;173(3):617–622. doi: 10.1111/j.1432-1033.1988.tb14043.x. [DOI] [PubMed] [Google Scholar]