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Effect of Regenerated Roots and Shoots on Nicotine Production in Tobacco Tissue Culture

The accumulation of nicotine in regenerated shoot and root tissues of Nicotiana tabacum L. cv MD 872 grown from callus culture has been examined by high pressure liquid chromatography (HPLC) procedures. The presence of roots on callus tissue dramatically increased the accumulation of nicotine in both callus without shoots and in callus which had regenerated shoots. When shoots were regenerated, the concentration of nicotine that accumulated in callus decreased whether roots were present or not. When varying concentrations of the nicotine precursors ornithine and putrescine were fed to callus derived tissue with and without regenerated roots, the rooted tissue was able to take up the precursors and accumulate nicotine in the shoots in amounts greater than controls. The half-life turnover rate for 3H-nicotine absorbed by the roots and transported into shoots was approximately 48 hours. These experiments indicate that although the root is the major site of synthesis of nicotine in tobacco, the accumulation of nicotine in various parts of the plant is regulated by the interaction of both root and shoot tissue.