THE EFFECTS OF TEMPERATURE ON CYTOKININ LEVELS IN SHOOTS AND ROOTS OFWHEAT SEEDLINGS

The contents of the cytokinins in shoots and roots of eight-day-old wh eat (Triticum durum L., cv. Bezenchukskaya 139) seedlings were studied after lowering the temperatures of the air and nutrient medium from 2 5 and 22 degrees C, respectively, to 16 degrees C and after the subseq uent restoration of the initial temperature. Immunoenzymic assay follo wing cytokinin separation by TLC demonstrated that the contents of zea tin and its riboside were sharply reduced in chilled shoots. Chilling did not affect the content of zeatin nucleotide, which was higher in t he shoots than in the roots. With the subsequent temperature rise to t he initial level, the level of zeatin nucleotide in shoots rapidly dec reased, and the levels of zeatin and its riboside increased. This cyto kinin redistribution is related to the transpiration rate.