Short - tenn effects of cytokinins on the lipid fatty acids of green leaves

Isolated shoots of Cotrur btumei and isolated leaves from this species and from Impaliens Jut/ani were fed zeatin for different periods. High doses of the bonnone (100 ~g/rnJ ) caused a measurable effect on lipid fatty acid composition after a two-hour feeding period in uolated leaves of <AInu. The maximum effects were at 20-30 }Jg zeatin taken up per g fresh weight. With the leaves of Impatimr, higher doses of the bonnonc were needed to obtain optimal effecu. In both species, the proportion of linolenic acid increased and that of palmitic acid decreased. For higher concentratiOIlS, the reverse was true. The effecu of the honnone on the fatty acids of glycolipids were more apparent than on those of ph~pholipids. The results are discussed in view of the general importance of dose-response curves for cytokinin dfecu and the possible effects on cell membranes. Key words; <Aleus blwnri Cytokinins Dose-re5ponse curve Fatty acids Impatims Juitani.