Ethylene production cytokinin stimulation

Cytokinins stimulate ethylene production in wheat leaves (Loveys and Wareing 1971), pea stems (Fuchs and Liebermann 1968) and mungbean hypo-cotyls (Lau and Yang 1976, Imaseki etal. 1975). Since cytokinins increase the levels of free lAA, it is possible that the cytokinin effect on ethylene production is mediated by lAA. 

Brassinosteroids are reported to stimulate overall plant growth and development, especially under stress conditions, to enhance auxin-induced growth as well as auxin-induced ethylene production (5, 6). Brassinosteroids interact with most of the phytohormones, such as cytokinins and gibberellins, and in particular with auxin. 

Chloro-3-methyl-4-nitro-lH-pyrazole (Release) has no auxin-, gib-berellin-, or cytokinin-like activity, yet it is an ejffective abscission agent. At the present, there is no evidence to indicate that Release retards auxin, gibberellin, or cytokinin activity. It does stimulate and enhance the tissue production of ethylene (105). Release is fairly stable, and there is no indication that it is degraded by the tissue to ethylene per se (106). 

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