Mechanisms of exogenous chemicals regulating nicotine biosynthesis I. Effects of exogenous chemicals on the intermediate products in nicotine biosynthesis

Experiments were carried out to study the effects of exogenous chemicals on nicotine contents and intermediate products in nicotine biosythesis in flue-cured tobacco.The results showed that effects of those on the nicotine biosynthesis intermediate products were also different.The main pathway included:(1) by regulating nicotinic acid and polyamine contents,nicotine content was changed at last;(2) by affecting polyamine metabolism,that in turn affected the nicotine content in tobacco leaves.