Abstract
We compared the germination of Brassica napus L. embryos at three stages of development-mid-cotyledon, maturation and mature dry-to determine at which stage they acquired the capacity for normal germination and seedling development. Embryos were removed from the seed and cultured on hormone-free medium, allowing them to germinate. The transition from embryogeny to germination was monitored both morphologically and biochemically, using synthesis of 12 S storage protein as a marker of embryogeny. The mature embryos (dry seeds) set the standard for normal seedling development: radicle emergence, hypocotyl extension and cotyledon expansion occurred within 2 d and true leaves were formed within a week of germination. Rocket immunoelectrophoresis indicated that the storage proteins in seedlings from mature dry embryos were completely degraded within a week. In contrast, the midcotyledon-stage embryos appeared to germinate abnormally, retaining many embryonic characteristics. Although the roots emerged, the hypocotyls did not elongate and secondary cotyledons instead of leaves were formed at the shoot apex. Also, the seedlings continued to synthesize and accumulate storage proteins. The maturation-stage embryos did develop into normal-looking seedlings, but complete degradation of storage proteins required several weeks, presumably reflecting continued synthesis and turnover. We conclude that embryogenic and germination-specific processes can occur concurrently and that the capacity to develop as normal seedlings is acquired gradually during the maturation process.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Abbreviations
- dpa:
-
days post anthesis
- EDTA:
-
ethylenedi-aminetetraacetic acid
- FW:
-
fresh weight
References
Ammirato, P.V. (1977) Hormonal control of somatic embryo development from cultured cells of caraway. Plant Physiol. 59, 579–586
Bhatty, R.S., McKenzie, S.L., Finlayson, A.J. (1968) The proteins of rapeseed (Brassica napus L.) soluble in salt solutions. Can. J. Biochem. 46, 1191–1197
Bruskin, A.M., Tyner, A.L., Wells, D.E., Showman, R.M., Klein, W.H. (1981) Accumulation in embryogenesis of five mRNAs enriched in the ectoderm of sea urchin pluteus. Dev. Biol. 87, 308–318
Ching, T.M., Crane, J.M., Stamp, D.L. (1974) Adenylate energy pool and energy charge in maturing rape seeds. Plant Physiol 54, 748–751
Crouch, M.L., Sussex, I.M. (1981) Storage protein synthesis in Brassica napus. Planta 153, 64–74
Crouch, M.L., Tenbarge, K.M., Simon, A.E., Ferl, R. (1983) cDNA clones for Brassica napus seed storage proteins: evidence from nucleotide sequence that both subunits of napin are cleaved from a precursor polypeptide. J. Mol. Appl. Gen. 2, 273–283
Cutter, E.G. (1967) Surgical techniques in plants. In: Methods in developmental biology, pp. 623–634, Wilt, F., Wessels, N., eds. Crowell, New York
Delseny, M., Cooke, R., Penon, P. (1983) Sequence heterogeneity in radish nuclear ribosomal RNA genes. Plant Sci. Lett. 30, 107–119
Finlayson, A.J. (1976) The seed protein contents of some cruciferae. In: The biology and chemistry of the cruciferae, pp. 279–306, Vaughan, J.G., McLeod, A.J., Jones, B.M.G., eds. Academic Press, New York London
Galau, G.A., Legocki, A.B., Greenway, S.C., Dure, L.S. (1981) Cotton messenger RNA sequences exist in both polyadenylated and nonpolyadenylated forms. J. Biol. Chem. 256, 2551–2560
Goding, L.A., Bhatty, R.S., Finlayson, A.J. (1970) The characterization of the 12 S “globulin” from rapeseed and its glycoprotein content. Can. J. Biochem. 48, 1096–1103
Goldberg, R.B., Crouch, M.L., Walling, L. (1983) Regulation of soybean seed protein gene expression. In: Manipulation and expression of genes in eukaroytes, pp. 193–202, Nagley, P., Linnane, A.W., Peacock, W.J., Pateman, J.A., eds. Academic Press, Sydney New York London
Ihle, J.N., Dure, L.S. III (1969) Synthesis of a protease in germinating cotton cotyledons catalyzed by mRNA synthesized during embryogenesis. Biochem. Biophys. Res. Comm 36, 706–710
LaRue, C.D., Avery, G.S., Jr. (1938) The development of the embryo of Zizania aquatica in the seed and in artificial culture. Bull. Torrey Bot. Club 65, 11–21
Long, S.R., Dale, R.M.K., Sussex, I.M. (1981) Maturation and germination of Phaseolus vulgaris embryonic axes in culture. Planta 153, 405–415
Madison, J.T., Thompson, J.F., Muenster, A.E. (1981) Turnover of storage protein in seeds of soybean (Glycine max) and pea (Pisum sativum). Ann. Bot. (London) 47, 65–74
Millerd, A. (1975) Biochemistry of legume seed proteins. Annu. Rev. Plant Physiol. 26, 53–72
Monnier, M. (1976) Culture in vitro de l'embryon immature de Capsella bursa-pastoris Moench (L.). Rev. Cytol. Biol. Vég. 39, 1–120
Taylor, B., Powell, A. (1982) Isolation of plant DNA and RNA. Bethesda Res Lab. Focus 4, 4–6
Thomas, P.S. (1980) Hybridization of denatured RNA and small DNA fragments transferred to nitrocellulose. Proc. Natl. Acad. Sci. USA 77, 5201–5205
Tukey, H.B. (1938) Growth patterns of plants developed from immature embryos in artificial culture. Bot. Gaz. (Chicago) 99, 630–665
Walbot, V., Clutter, M., Sussex, I.M. (1972) Reproductive development and embryogeny in Phaseolus. Phytomorphology 22, 59–68
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Finkelstein, R.R., Crouch, M.L. Precociously germinating rapeseed embryos retain characteristics of embryogeny. Planta 162, 125–131 (1984). https://doi.org/10.1007/BF00410208
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00410208