Dynamic changes of polyphenols and related enzyme activities during tobacco growth.

The changes of polyphenols and related enzyme activities in the leaf of tobacco variety Jiyan No.9 during its growth and development in different districts of Yanbian were studied.The results showed that the chlorogenic acid content in tobacco leaf arrived to peak value when the leaf age was 60 days,then it had a slight decrease,and reached the maximum at 90 days leaf-age.The contents of rutin and scopoletin all reached the maximum at 60 days leaf-age;after that,the content of rutin first increased slightly and then decreased,while the content of scopoletin continued to decline.The activities of polyphenol oxidase and peroxidase(POD) reached the maximum at 60 days leaf-age,and then declined gradually;POD still had a higher activity at 90 days leaf-age.For the content of polyphenols in tobacco leaf,Dunhua,Wangqing and Longjing decreased in succession.