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Desiccation and the switch from seed development to germination. Alfalfa embryos can synthesize storage proteins after germination if maturation drying is prevented

Published online by Cambridge University Press:  19 September 2008

N. Xu
Affiliation:
Department of Botany, University of Guelph, Ontario, Canada, N1G 2W1
J. D. Bewley*
Affiliation:
Department of Botany, University of Guelph, Ontario, Canada, N1G 2W1
*
* Correspondence

Abstract

Storage proteins (2S, 7S and 11S) are synthesized at the mid- to late stages of development in alfalfa seeds, mainly within the embryos. Mature dry seeds cannot synthesize these proteins upon subsequent germination and growth. When embryos were isolated from the seed during development (stages VII and VIII) and placed on water or nutrient medium, they germinated. They exhibited a pattern of protein synthesis which was identifiable as germinative/post-germinative, and was identical to the pattern synthesized in embryos of germinated dry seeds, and of embryos from seeds that were subjected to drying prematurely at stages VII and VIII. When, after 48 h from the start of imbibition, abscisic acid or osmoticum was introduced to germinated embryos isolated at stage VII and not desiccated, the synthesis of the 11S storage protein was restored to a rate comparable to that of stage-VII embryos before isolation. This was accompanied by an increase in transcription of the 11S storage protein gene. Transfer of germinated stage-VII embryos, which had first been desiccated, to abscisic acid or osmoticum 48 h after imbibition started did not result in any restoration of storage protein synthesis. Thus, desiccation, prematurely or at maturation, off-regulates storage protein synthesis and within the embryos this process is no longer responsive to abscisic acid or osmoticum.

Type
Short Communication
Copyright
Copyright © Cambridge University Press 1994

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References

Bewley, J.D. and Black, M. (1994) Seeds. Physiology of development and germination. 2nd edn. New York, Plenum Press.CrossRefGoogle Scholar
Black, M. (1991) Involvement of ABA in the physiology of developing and maturing seeds. pp 99124 in Davies, W.J. and Jones, H.G. (Eds) Abscisic acid physiology and biochemistry. Oxford, BioScientific Publishers.Google Scholar
Bustos, M.M., Begum, D., Kalkan, F.A., Battraw, M.J. and Hall, T.C. (1991) Positive and negative cis-acting DNA domains are required for spatial and temporal regulation of gene expression by a seed storage protein promoter. EMBO Journal 10, 14691479.CrossRefGoogle ScholarPubMed
Crouch, M.L., Tenbarge, K., Sigmon, A., Finkelstein, R., Scofield, S. and Solberg, L. (1985) Storage protein mRNA levels can be regulated by abscisic acid in Brassica embryos. pp 555566. in van Vloten-Doting, L. et al. (Eds) Molecular form and function of the plant genome. New York, Plenum Press.Google Scholar
Goffner, D., This, P. and Delseny, M. (1990) Effects of abscisic acid and osmotica on helianthinin gene expression in sunflower cotyledons in vitro. Plant Science 66, 211219.CrossRefGoogle Scholar
Kermode, A.R. (1990) Regulatory mechanism involved in the transition from seed development to germination. Critical Reviews in Plant Sciences 9, 155195.CrossRefGoogle Scholar
Kermode, A.R. and Bewley, J.D. (1985a) Role of maturation drying in the transition from development to germination. I. Acquisition of desiccation-tolerance and germinability during development of Ricinus communis L. seeds. Journal of Experimental Botany 36, 19061915.CrossRefGoogle Scholar
Kermode, A.R. and Bewley, J.D. (1985b) Role of maturation drying in the transition from development to germination. II. Post-germinative enzyme production and soluble protein synthetic pattern changes within the endosperm of Ricinus communis L. seeds. Journal of Experimental Botany 36, 19161927.CrossRefGoogle Scholar
Kermode, A.R. and Bewley, J.D. (1985c) Role of maturation drying in the transition from development to germination. III. Insoluble protein synthetic pattern changes within the endosperm of Ricinus communis L. seeds. Journal of Experimental Botany 36, 19281936.CrossRefGoogle Scholar
Krochko, J.E. and Bewley, J.D. (1988) Use of electrophoretic techniques in determining the composition of alfalfa seed storage proteins. Electrophoresis 9, 751763.CrossRefGoogle ScholarPubMed
Murashige, T. and Skoog, F. (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiologia Plantarum 15, 473497.CrossRefGoogle Scholar
Murphy, D.J., Cummins, I. and Ryan, A.J. (1989) Immunocytochemical and biochemical study of the biosynthesis and mobilisation of the major seed storage proteins of Brassica napus. Plant Physiology and Biochemistry 27, 647657.Google Scholar
Olsen, O.A., Jakobsen, K.S. and Schmelzer, E. (1990) Development of barley aleurone cells: temporal and spatial patterns of accumulation of cell-specific mRNAs. Planta 181, 462466.CrossRefGoogle ScholarPubMed
Pramanik, S.K., Reynolds, T.L., Maclsaac, S.A. and Bewley, J.D. (1993) Rapid and efficient purification of seed messenger RNA without phenol:chloroform extraction. Seed Science Research 3, 137139.CrossRefGoogle Scholar
Rerie, W.G., Whitecross, M. and Higgins, T.J.V. (1991) Developmental and environmental regulation of pea legumin genes in transgenic tobacco. Molecular and General Genetics 225, 148157.CrossRefGoogle ScholarPubMed
Schopfer, P., Bajracharya, D. and Plachy, C. (1979) Control of seed germination by abscisic acid. I. Time course of action in Sinapis alba L. Plant Physiology 64, 822827.CrossRefGoogle ScholarPubMed
Schopfer, P. and Plachy, C. (1984) Control of seed germination by abscisic acid. II. Effect on embryo water uptake in Sinapis alba L. Plant Physiology 76, 155160.CrossRefGoogle Scholar
Schopfer, P. and Plachy, C. (1985) Control of seed germination by abscisic acid. III. Effect on embryo growth potential (minimum turgor pressure) and growth coefficient (cell wall extensibility) in Sinapis alba L. Plant Physiology 77, 676686.CrossRefGoogle Scholar
Xu, N. (1993) Regulation of storage protein synthesis in alfalfa (Medicago savita L.) by osmotic potential and abscisic acid. PhD Thesis, University of Guelph.Google Scholar
Xu, N. and Bewley, J.D. (1991) Sensitivity to abscisic acid and osmoticum changes during embryogenesis of alfalfa (Medicago sativa). Journal of Experimental Botany 42, 821826.CrossRefGoogle Scholar
Xu, N., Coulter, K.M. and Bewley, J.D. (1990) Abscisic acid and osmoticum prevent germination of developing alfalfa embryos, but only osmoticum maintains the synthesis of developmental proteins. Planta 182, 382390.CrossRefGoogle ScholarPubMed
Xu, N., Coulter, K.M., Krochko, J.E. and Bewley, J.D. (1991) Morphological stages and storage protein accumulation in developing alfalfa (Medicago sativa L.) seeds. Seed Science Research 1, 119125.CrossRefGoogle Scholar