Rapid identification of cytokinins by an immunological method

Abstract

A method for rapid identification of bacterial cytokinins has been developed in which cultures are fed [3H]adenine, the cytokinins (including 3H-labeled cytokinins) are isolated by immunoaffinity chromatography, and analyzed by HPLC with on-line scintillation counting. Analysis of Agrobaclerium tumefaciens strains showed that some produced primarily frans-zeatin, whereas others produced primarily frans-zeatin riboside. Pseudomonas syringae pv savastanoi produced mixtures of trans-zeatin, dihydrozeatin, 1″-methyl-frans-zeatin riboside, and other unknown cytokinin-like substances. Corynebacterium fascians, produced cis-zeatin, isopentenyladenine and isopentenyladenosine. The technique is designed for qualitative rather than quantitative studies and allows ready identification of bacterial cytokinins. It may also have utility in the study of plant cytokinins if adequate incorporation of label into cytokinin precursor pools can be achieved.