Induction of flowering

The rapid vegative growth, which includes development of shoots, leaves, and flowers, is controlled by a variety of transcription factors.483 Among these are homeodomain proteins that control differentiation of meristem cells 484-486 The induction of flowering is... 

Additive effects of daminozide and ethephon on the induction of flowers on one-year-old trees of apple cv. Cox s Orange Pippin. 

Mesken, M., Induction of flowering, seed production, and evaluation of seedlings and clones of Jerusalem artichoke (Helianthus tuberosus L.), in Topinambour (Jerusalem Artichoke), Grassi, G. and Grosse, G Eds., Report EUR 11855, CEC, Luxembourg, 1988, pp. 137-144. 

Zeevaart JAD (1969) In Evans LT (ed) The induction of flowering some case histories. Cornell University Press, Ithaca, NY, p 435... 

Compounds that release ethylene when sprayed on plants have become of major economic importance, being used to accelerate diverse ethylene responses such as induction of flowering, stimulation of latex flow, leaf and branchlet abscission, fruit ripening, fruit abscission, and pod dehiscence. Novel aspects of application of these materials in agriculture are reviewed. 

Jacobs WP (1978 a) Does the induction of flowering by photoperiodic change the polarity or other characteristics of lAA transport in petioles for the short-day plant Xanthium Plant Physiol 61 307-310... 

Heslop-Harrison J (1969) Cannabis sativa L. In Evans LT (ed) The induction of flowering. Cornell Univ. Press, Ithaca. NY, pp 205-226 Heslop-Harrison J (1972) Sexuality in angiosperms. In Steward FC (ed) Plant physiology A treatise, Vol VIC. Academic, New York, pp 133-289 Hill TA (1973) Endogenous plant growth substances. Edward Arnold, London Hohmann P, Robey RA, Gurley LR (1975) Cell-cycle-dependent phosphorylation of serine and threonine in Chinese hamster cell FI histones. Biochem Biophys Res Com-mun 63 126-133... 

Nitsch, C. and Nitsch, J.P. (1967) Tlie induction of flowering in vitro in stem segment of Plumago indica Planta 72, 355-370. 

Ethene is the hydrocarbon commercially produced in the greatest quantity in the United States. It is used in the synthesis of many plastics and commercially important alcohols. Ethene is also an important plant hormone. Induction of flowering and the ripening of fruit, as shown in Figure 2.10, are effects of ethene hormone action that can be manipulated by commercial growers. 

Induction of Flower Formation. In the case of long day plants and a number of cold-requiring plants gibberellins can induce the formation of flowers under conditions under which this does not normally occur. We shall discuss this phenomenon later (page 304). 

By induction of flowering we mean all those processes that cause the cells of the shoot meristem to switch from the course of development that they have hitherto pursued and now form the leaf organs of the flower instead of leaves. Once this pivotal event has been initiated, the switches are thrown so that the processes of differentiation leading to flowers or inflorescences foWo w (Fig. 230). The induction of flowering is of particular interest to the physiologist and the plant grower. This is because differentiation follows the induction of flowering almost automatically. Control of flower... 

But now to return to Streptocarpus. It has been shown that 2-thiouracil, a structural analogue of uracil (page 22), is incorporated into RNA in Streptocarpus, If the plant is now treated with 2-thiouracil during the induction of flowering, the formation of flowers is completely blocked or, at least, seriously delayed, whereas the growth of the leaf is not impaired. Thus, flower formation is selectively inhibited (Fig. 237, cf. see below). 

We have just learned that interruption of the dark period of short day plants can prevent the induction of flowering. These light breaks involve... 

The administration of antimetabolities of transcription and translation inhibits the induction of flowering in plants that are dependent on the length of day just as it does in those requiring vernalization. The inhibitors produce their effect partly in the leaf, partly in the shoot meristem. As far as their activity in the leaf is concerned, it may be assumed that they impair the activity of the genes that are involved in the synthesis of the flowering hormone. At least in part their effectiveness in the shoot meristem has to do with subsequent flower differentiation rather than with flower induction the activity of the genes for flower differentiation is interferred with. 

Furthermore, older findings of Salisbury and Bonner on Xanthium strumarium and more recent ones (1969) of Krekule on Chrysanthemum rubrum, another short day plant, suggest that antimetabolites such as 5-fluorodeoxyuridine might inhibit DNA reduplication in the shoot meristem, which appears to be necessary for successful induction of flowers. Here again a parallel with vernalization is revealed, since successful vernalization also appears to be associated with cells that are capable of dividing (page 301). The ability to divide also implies the ability to... 

The sections on the induction of flowering will have appeared to some readers as rather too hypothetical inspite of all the facts that we know. This is because there are considerably more data which we don t know. It is just in this connection with photoperiodism that we cannot help mentioning one more subject, the central relationships of which are unknown inspite of a wealth of pieces of data. We intend to discuss briefly circadian rhythms. 

Evans, L. T. The Induction of Flowering. Macmillan of Australia, North Melbourne 1969. 

Lumsden, P.J., Saji, H., and Furuya, M., Action spectra confirm two separate actions of phytochrome in the induction of flowering in Lemna paucicostata 441, Plant Cell Physiol, 28, 1237,1987. 

Is the list of interacting plant growth hormones complete Almost certainly it is not. Only very recently abscisic acid (Fig. 9.8), which is involved in leaf and fruit abscission and in bud dormancy in woody plants, was discovered. There is considerable evidence for the involvement of a flowering hormone (florigen) in the induction of flower initiation and for the involvement of additional hormones in the functioning of vascular cambia. 

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