Unusual ethylene-related behavior in senescing flowers of the carnation Sandrosa |
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Authors: | Shimon Mayak Tsipora Tirosh |
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Affiliation: | The Kennedy-Leigh Centre for Horticultural Research, Faculty of Agriculture. The Hebrew Univ. of Jerusalem, P. O. Box 12, Rehovot 76–100. Israel. |
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Abstract: | The time course of ethylene production by senescing carnation ( Dianthus caryophyllus L. cv. Sandrosa) flowers was studied. These flowers are unusual in that they do not exhibit an autocatalytic increase in ethylene production nor do they develop petal in-rolling. Exposure of the flowers to exogenous ethylene resulted in a rise in their ethylene-forming enzyme (EFE) activity and ethylene production, and at the same time a marked decline in their fresh weight. Natural senescence was also accompanied by a rise in EFE activity, but with no concomitant rise in 1-amino cyclopropane carboxylic acid synthase activity nor in ethylene production. A shift in responsiveness to ethylene was observed, with young flowers more responsive to exogenous ethylene than older flowers. The results are discussed in terms of a proposed mechanism allowing for the decline in competence of this cultivar to respond to ethylene during senescence. |
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Keywords: | Carnations Dianthus caryophyllus ethylene flower responsiveness to ethylene senescence |
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