Abstract
The development of Brassica napus L. cv Tower embryos of different ages cultured in vitro with and without high osmoticum (0.48 and 0.69 molar sorbitol) was compared with normal development in situ to investigate the role of a drying environment in embryo maturation. Sensitivity to osmoticum was assayed in terms of its ability to mimic normal development, i.e. to both suppress germination and maintain 12 S storage protein (cruciferin) synthesis at levels comparable to those seen in the developing seed. The osmotic conditions used block germination of predesiccation stage embryos but were not sufficient to prevent desiccation stage embryos from taking up water and germinating. At all stages tested, the osmotically treated embryos had approximately normal levels of cruciferin mRNA. Measurements of endogenous abscisic acid (ABA) levels by radioimmunoassay indicated that the osmotic effects on germination and gene expression were not mediated by elevated embryonic ABA. Comparison of the kinetics of osmotic and ABA effects on gene expression showed that the osmotic effect is more rapid. These results are consistent with the hypothesis that ABA acts by inhibiting water uptake, which mechanically prevents germination and affects gene expression in some unknown manner.
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- Bray E. A., Beachy R. N. Regulation by ABA of beta-Conglycinin Expression in Cultured Developing Soybean Cotyledons. Plant Physiol. 1985 Nov;79(3):746–750. doi: 10.1104/pp.79.3.746. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Finkelstein R. R., Tenbarge K. M., Shumway J. E., Crouch M. L. Role of ABA in Maturation of Rapeseed Embryos. Plant Physiol. 1985 Jul;78(3):630–636. doi: 10.1104/pp.78.3.630. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Galau G. A., Legocki A. B., Greenway S. C., Dure L. S., 3rd Cotton messenger RNA sequences exist in both polyadenylated and nonpolyadenylated forms. J Biol Chem. 1981 Mar 10;256(5):2551–2560. [PubMed] [Google Scholar]
- Schopfer P., Plachy C. Control of Seed Germination by Abscisic Acid : II. Effect on Embryo Water Uptake in Brassica napus L. Plant Physiol. 1984 Sep;76(1):155–160. doi: 10.1104/pp.76.1.155. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stewart C. R., Voetberg G. Relationship between Stress-Induced ABA and Proline Accumulations and ABA-Induced Proline Accumulation in Excised Barley Leaves. Plant Physiol. 1985 Sep;79(1):24–27. doi: 10.1104/pp.79.1.24. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Uknes S. J., Ho T. H. Mode of action of abscisic Acid in barley aleurone layers : abscisic Acid induces its own conversion to phaseic Acid. Plant Physiol. 1984 Aug;75(4):1126–1132. doi: 10.1104/pp.75.4.1126. [DOI] [PMC free article] [PubMed] [Google Scholar]