Cytokinin content and location in the leaves of the wild-type and transgenic tobacco plants

Cytokinin content was assayed in the leaves of tobacco (Nicotiana tabacum L .) plants, nontransformed (wild type) and transformed with agenetic constru ct containing the light-inducible ipt gene, using liquid chromatography fol lowed by mass spectrophotometry and by thin-layer chromatography combined w ith immunoenzyme assay. Immunocytological location of phytohormones was inv estigated after successively treating plant tissue sections with polyclonal antibodies against zeatin riboside, species-specific immunoglobulins label ed with colloid gold, and silver preparation. Cytokinin content in leaves o f the transformed plants was higher than in those of wild-type plants. The bottom leaves of the former accumulated zeatin nucleotide. The contents of zeatin and zeatin riboside in the upper leaves exceeded that in the lower l eaves both in transformed and wild-type plants. Staining agrees the content s of zeatin and zeatin riboside in the leaves were shown to correlate with the intensity of immunostaining of leaf sections. High zeatin content in th e bottom leaves of transgenic plants did not affect the level of immunostai ning.