The Small Subunit Genes of Petunia: A Well-Characterized Plant Multigene Family
Many key proteins in both plants and animals are specified by multigene families. The evolutionary significance of multigeny appears to be several-fold. On the one hand, gene dosage may be necessary to meet requirements of copious expression over short developmental times. An example of this is the deposition of seed storage proteins during the latter phase of seed maturation; multigene families for such plant proteins have been described (13,17). A second evolutionary basis for multigene families seems to be the requirement for multiple peptides with similar, yet distinct, functions. In plants, the chlorophyll a/b binding proteins of the light-harvesting complex represent such an example (11). A requirement for the expression of identical products in different tissues is yet a third basis for multigeny. In Drosophila, the actin genes (12) show a tissue-specific expression of this type. Tissue-specific expression of specific actin genes in soybean may be inferred from the results of Hightower and Meagher (15). Finally, individual genes in multigene families may be required at different stages of development. Although this has been shown to be true in animal systems, e.g., the actin genes in Drosophila, such a demonstration has not yet been made in higher plants.
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- 4.Cashmore, A.R. (1983) Nuclear genes encoding the small subunit of ribulose-1,5-bisphosphate carboxylase. In Genetic Engineering of Plants, T. Kosuge, C.P. Meredith, and A. Hollaender, eds. Plenum Press, New York, pp. 29–38.Google Scholar
- 13.Goldberg, B., R. Fischer, J. Harada, D. Jofuku, and J. Okamuro (1983) Organization of soybean seed protein genes and their flanking regions. In Structure and Function of Plant Genomes, O. Ciferri and L. Dure, eds. Plenum Press, New York, pp. 37–46.Google Scholar
- 17.Larkins, B., K. Pedersen, M. Marks, D. Wilson, and P. Argos (1983) Structure and expression of zein genes in maize endosperm. In Structure and Function of Plant Genomes, O. Ciferri and L. Dure, eds. Plenum Press, New York, pp. 73–84.Google Scholar
- 20.Wimpee, C.F., W.J. Stiekema, and E.M. Tobin (1983) Sequence heterogeneity in the RuBP carboxylase small subunit gene family of Lemna gibba. In Plant Molecular Biology (UCLA Symposium on Molecular and Cellular Biology, New Series, Vol. 12), R.B. Goldberg, ed. A.R. Liss, Inc., New York, pp. 391–401.Google Scholar