ISHS Acta Horticulturae 179: V International Symposium on Growth Regulators in Fruit Production
CYTOKININS AND FRUIT PRODUCTION |
| Authors: | J. Van Staden, E.L. Cook |
| Abstract:
Fruit production can be regarded as the ultimate expression of the efficiency, or the sum total, of all the physiological processes which occur within the plant. Thus when considering the role of cytokinins in this regard it is essential to realize that cytokinins act in concert with other plant hormones in many different physiological phenomena. For reasons of clarity and ease of discussion they are however, frequently considered in isolation. Of the five major classes of natural hormones the cytokinins appear to have been the least successful in the manipulation of fruit production. This, despite the fact that they are considered to play an important role in growth phenomena such as cell division, rooting, bud dormancy, the orderly partitioning of energy resources and sensecence, all of which feature prominently with respect to potential fruit production. There are many reasons why cytokinin involvement in plant growth and development is not well understood. As is the case for other hormones, nothing is known about the mode of action cytokinins nor have any hormone receptors been isolated. In additon, plant physiologists are plagued by the dilemna that the same hormone may bring about a different response in the same cell at different stages of development. These and may other factors, such as the interrelationships between different physiological processes, require clarification if advances are to be made in the control aof vegetative growth and ultimately, fruit production. To date hormone physiologists have concentrated almost exclusively on date relating to the biosynthesis, transport and metabolism of endegenous hormones in an attepmt to elucidate the primary action of these substances. Little progress, if any, has been made with respect to the mode of action and specific involvement of plant hormones in growth phenomena. In order to obtain an understanding of hormone action the time may well have come to move away from the accepted norms and to concentrate more at the molecular level. The use of modern biotechnology, mutants, and the development oif more accurate techniques will undoubtedly lead to a better identification of "target sites" for the manipulation of fruit production in its broadest sense. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
