Abstract
Dormant seeds do not germinate when imbibed in water even when conditions are favorable for germination. These hydrated seeds remain viable, but growth-arrested for weeks due to unknown restrictions within the embryo. As a model system for the study of the molecular processes occurring in dormant seeds, we have chosen to examine gene expression in Bromus secalinas, a grass species that produces seeds with high levels of embryonic dormancy. Using differential screening for mRNAs present in hydrated dormant embryos, we have identified a cDNA clone, pBS128, that encodes a mRNA transcript found in the embryos of hydrated seeds of B. secalinus as well as in embryos from mature dry seeds. Striking differences in pBS128 transcript levels appear upon hydration of dormant and nondormant seeds. Upon imbibition pBS128 transcript levels increase over four-fold in dormant seeds, but rapidly decline and disappear in nondormant seeds, which subsequently germinate. The pBS128 transcript appears to be embryo-specific since the transcript is not detectable in either non-stressed or dehydrated seedling tissue. Application of 50μM ABA to nondormant seeds arrests germination and enhances pBS 128 transcript levels. The nucleotide sequence of the nearly full-length pBS128 cDNA shows no homology to other reported genes, and the putative protein sequence does not exhibit the hydrophilic characteristics of the ABA-responsive LEA (late embryogenesis abundant) proteins.
Similar content being viewed by others
References
Bewley JD, Black M: Seeds: Physiology of Development and Germination, pp. 190–192. Plenum Press, New York (1985).
Bradley JE, Bishop GA, St. John T, Frelinger JA: Asimple rapid method for the purification of Poly A+ RNA. Biotechniques 6: 114–116 (1988).
Bray EA: Regulation of gene expression by endogenous ABA during drought stress. In: WJ Davies, HG Jones (eds), Abscisic Acid, Physiology and Biochemistry, pp. 81–98. Bios, Oxford, UK (1991).
Campbell WH, Gowri G: Codon usage in higher plants, green algae, and cyanobacteria. Plant Physiol 92: 1–11 (1990).
Close TJ, Kortt AA, Chandler PM: A cDNA-based comparison of dehydration-induced proteins (dehydrins) in barley and corn. Plant Mol Biol 13: 95–108 (1989).
Curry J, Morris CF, Walker-Simmons MK: Sequence analysis of a cDNA encoding a Group 3 LEA mRNA inducible by ABA or dehydration stress in wheat. Plant Mol Biol 16: 1073–1076 (1991).
Devereux J, Haeberli P, Smithies O: A comprehensive set of sequence analysis programs for the VAX. Nucl Acids Res 12: 387–395 (1984).
Dure LIII, Crouch M, Harada J, Ho TD, Mundy J, Quatrano R, Thomas T, Sung ZR: Common amino acid sequence domains among the LEA proteins of higher plants. Plant Mol Biol 12: 475–486 (1989).
Fawcett TW, Bartlett SG: An effective method for eliminating ‘artifact banding’ when sequencing doublestranded DNA templates. Biotechniques 9: 46–48 (1990).
Gubler U, Hoffman BJ: A simple and very efficient method for generating cDNA libraries. Gene 25: 263–269 (1983).
Hatzopoulos P, Fong F, Sung ZR: Abscisic acid regulation of DC 8, a carrot embryonic gene. Plant Physiol 94: 690–695 (1990).
Karssen CM, Brinkhorst-van der Swan D, Breekland AE, Koornneef M: Induction of dormancy during seed development by endogenous abscisic acid: studies on abscisic acid deficient genotypes of Arabidopsis thaliana (L.) Heynh. Planta 157: 158–165 (1983).
Morris CF, Anderberg RJ, Goldmark PJ, Walker-Simmons MK. Molecular cloning and expression of abscisic acid-responsive genes in embryos of dormant wheat seeds. Plant Physiol 95: 814–821 (1991).
Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY (1989).
Sanger F, Nicklen S, Coulson AR: DNA sequencing with chain termination inhibitors. Proc Natl Acad Sci USA 74: 5463–5467 (1977).
Simpson GM: Seed Dormancy in Grasses. Cambridge University Press, Cambridge, UK (1990).
Skiver K, Mundy J: Gene expression in response to abscisic acid and osmotic stress. Plant Cell 2: 503–512 (1990).
Vance VB, Huang AHC: Expression of lipid body protein gene during maize seed development. J Biol Chem 263: 1476–1481 (1988).
Walker-Simmons M: ABA levels and sensitivity in developing wheat embryos of sprouting resistant and susceptible cultivars. Plant Physiol 84: 61–66 (1987).
Walker-Simmons M: Dormancy in cereals—levels of and response to abscisic acid. In: Pharis RP, Rood SB (eds) Plant Growth Substances 1988, pp. 400–406. Springer-Verlag. New York (1990).
Walker-Simmons MK, Abrams SR: Uses of ABA Immunoassay. In: Davies WJ, Jones HG (eds) Abscisic Acid, Physiology and Biochemistry, pp. 53–61. Bios, Oxford, UK (1991).
Walker-Simmons M, Chandler PM, Sesing J, Ried JL, Morris CF: Comparison of responses to ABA in embryos end dehydrating seedlings of sprouting-resistant and susceptible wheat cultivars. In: Ringlund K, Mosleth E, Mares DJ (eds) Fifth International Symposium on Pre-Harvest Sprouting in Cereals, pp. 119–129. Westview Press, Boulder, CO (1990).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Goldmark, P.J., Curry, J., Morris, C.F. et al. Cloning and expression of an embryo-specific mRNA up-regulated in hydrated dormant seeds. Plant Mol Biol 19, 433–441 (1992). https://doi.org/10.1007/BF00023391
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00023391