Formation of Floral Organs
The formation of floral organs on the meristem follows on the heels of evocation and overlaps with evocation. The conventional angiosperm flower is made up of four whorls of modified leaves constituting the sterile and fertile parts. The sterile parts consist of an outer whorl of sepals that are usually green and enclose the rest of the flower before it opens, and an inner whorl of brightly colored petals that aid in attracting insects and other pollinators. Aggregates of sepals and petals in a flower are known, respectively, as the calyx and the corolla. The fertile organs of the flower directly concerned with sexual reproduction are the stamens, representing the male units, and the carpels (or the pistil, consisting of one or more carpels), representing the female units. Collectively, the stamens and carpels constitute, respectively, the androecium and the gynoecium. These four whorls are produced in acropetal sequence by the floral meristem in the correct numbers of units and are precisely determined according to a blueprint characteristic of each species.
KeywordsFloral Organ Floral Meristem Homeotic Gene Floral Organ Identity Stamen Primordia
Unable to display preview. Download preview PDF.
- Angenent, G.C., Franken J., Busscher M., Colombo L., and van Tunen, A.J. 1993. Petal and stamen formation in Petunia is regulated by the homeotic gene fbp1. Plant J. 4: 101–112.Google Scholar
- Bommineni, V.R., Atkinson, B.G., Greyson, R.I., and Walden, D.B. 1990. Polypeptides synthesized during the maturation of flower organs from tassel and ear inflorescences of Zea maysL. Maydica 35: 195–201.Google Scholar
- Clark, S.E., Running, M.P., and Meyerowitz, E.M. 1995. CLAVATA3is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATA1. Development 121: 2057–2067.Google Scholar
- Eames, A.J. 1961. Morphology of the Angiosperms. New York: McGraw-Hill Book Co.Google Scholar
- Gifford, E.M., and Foster, A.S. 1989. Morphology and Evolution of Vascular Plants, 3rd Ed. New York: W.H. Free-man.Google Scholar
- Heslop-Harrison, J. 1964. Sex expression in flowering plants. In Meristems and Differentiation. Brookhaven Symp. Biol 16: 109–125.Google Scholar
- Leyser, H.M.O., and Furner, I.J. 1992. Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana. Development 116: 397–403.Google Scholar
- Sawhney, V.K., Chen, K., and Sussex, I.M. 1985. Soluble proteins of the mature floral organs of tomato (Lycopersicon esculentumMill). J. Plant Physiol. 121: 265–271.Google Scholar
- Schwarz-Sommer, Z., Hue I., Huijser P., Flor, P.J., Hansen, R., Tetens, R, Lönnig, W.-E., Saedler, H., and Sommer, H. 1992. Characterization of the Antirrhinumfloral homeotic MADS-box gene deficiens:evidence for DNA binding and autoregulation of its persistent expression throughout flower development. EMBO J. 11: 251–263.PubMedGoogle Scholar
- Stebbins, G.L. 1967. Gene action, mitotic frequency, and morphogenesis in higher plants. In Control Mechanisms in Developmental Processes. M. Locke, ed. New York: Academic Press, pp. 113–135.Google Scholar