Modification of the cytokinin promotion of deoxyisoflavone synthesis in soybean tissue.

Soybean tissue incubated in liquid media formed daidzin in response to cytokinin when the media contained 0.1 m sucrose but formed another, unidentified compound when the media contained 0.6 m sucrose or mannitol. The cytokinin effect in either setup was detectable only after a lag period of several hours. Addition of possible precursors of the compounds being synthesized or of related compounds did not alter the lag period to any great extent. Trans-cinnamic acid did perhaps shorten it a little as did preincubation of the tissue in the basal medium before the addition of kinetin. Several inhibitors of RNA synthesis substantially reduced the production of daidzin and the other compound. Protein synthesis inhibitors were also effective except that cycloheximide and puromycin actually promoted synthesis of the unknown compound while inhibiting that of daidzin. The results do not give a clear impression as to how the cytokinins are involved in the synthesis of the compounds, but are at least suggestive that cytokinin is involved in RNA or protein synthesis.