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 × 10-5 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 × 10-4 and 2.22 × 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 (14C) benzyladenine to the petals, a small degree of transport of the 14C 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.