Cytokinins in cut carnation flowers. IV effects of benzyladenine on flower longevity and the role of different longevity treatments on its transport following application to the petals

Abstract

A low concentration of benzyladenine (4 .44 x 10 -'M) accelerated the senescense of cut carnation flowers . This effect could be reversed by STS-treatment but not by keeping the flowers in a holding solution containing 4% ethanol . This appears to be the first report indicating that cytokinins at a specific level may actually enhance flower senescense . The higher levels tested (1 .11 x 10 -" and 2 .22 x 10 -4 M) retarded senescense, being in agreement with published results . The applied cytokynin was metabolized slowly in the petals to a compound(s) which co-chromatographed with ribosylbenzyladenine when separated by TLC and when fractionated by HPLC . In the experiments applying ( 14 C) benzyladenine to the petals, a small degree of transport of the 14 C was detected in naturally senescing (control) cut flowers and when treated with ethrel . The transported 14C was detected in both the ovaries and in the stems and co-chromatographed with benzyladenine . Where flower senescense was delayed (ethanol or STS) no movement from the petals was detected . This suggests that the cytokinin moved within the assimilate stream, along with sugars .

Effect of gibberellic acid on carnation flower senescence: evidence that the delay of carnation flower senescence by gibberellic acid depends on the stage of flower development

“…A supra-optimal response to dose was reported for the effect of GA, on the opening of statice buds [23] and on carnation flower longevity when buds were treated before dry storage [9]. Supra-optimal responses have also been demonstrated, for example, in the case of cytokinins on carnation flower longevity [24]. Collectively the above facts could explain the inconsistent effect of GA, on flower longevity reported hitherto [1 11.…”

“…The application of other senescence-delaying compounds such as ethanol [12] and silver ions [21] has resulted in similar petal shrivelling, but this did not occur in the case of cytokinins [24]. Likewise, the modification of ethylene climacteric following GA, treatments shows similarities and differences to other senescence-retarding factors [12, 211. Given that consistent results can now be obtained by using the approach developed in this study, the role of gibberellins in sustaining the pre-senescent carnation flower and their function in its hormonal balance during senescence can now be studied in greater detail.…”

Cytokinins in cut carnation flowers. IX. Transport and metabolism of iso-pentenyladenine and the effect of its derivatives on flower longevity

“…To date considerable attention has been given to the effect of both natural and synthetic cytokinins on the longevity of cut carnation flowers [1, 4,7,8,9,10] . While dihydrozeatin and some of its derivatives are effective in delaying carnation senescence zeatin is ineffective [11] .…”

Effect of Alcohols and Their Interaction with Ethylene on the Ripening of Epidermal Pericarp Discs of Tomato Fruit

“…Exogenous application of high levels of ethanol can retard the senescence of cut carnation flowers (12,13,33), excised oat leaves (31), and inhibit the sprouting of potato tubers (4). However, ethanol did not delay the senescence of cut lily and tulip flowers (13); flowers in which ethylene does not appear to control senescence.…”