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

Abstract

Cytokinin content was assayed in the leaves of tobacco (Nicotiana tabacum L.) plants, nontransformed (wild type) and transformed with agenetic construct containing the light-inducible ipt gene, using liquid chromatography followed by mass spectrophotometry and by thin-layer chromatography combined with immunoenzyme assay. Immunocytological location of phytohormones was investigated after successively treating plant tissue sections with polyclonal antibodies against zeatin riboside, species-specific immunoglobulins labeled with colloid gold, and silver preparation. Cytokinin content in leaves of 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 leaves both in transformed and wild-type plants. Staining agrees the contents of zeatin and zeatin riboside in the leaves were shown to correlate with the intensity of immunostaining of leaf sections. High zeatin content in the bottom leaves of transgenic plants did not affect the level of immunostaining.