The Secondary Metarbolism Of Scutellaria Baicalensis Georgi Regulated By Reactive Oxygen Species

Scutellaria baicalensis Georgi is a common medicinal material in our country.It's quality is closely related to the environment.The aim of our study is to control the secondary metabolism of Scutellaria baicalensis though mimic stress,and to promote the accumulation of the major active components in the medicinal herbs.To establish a new method for improving the quality of cultivated Scutellaria baicalensis Georgi,the upper part of Scutellaria baicalensis was sprayed with 0.004?mol/L?0.4?mol/L?40?mol/L H2O2 and 0.004?mol/L?0.4?mol/L?40?mol/L Na2S2O4 solution,and investigate the active oxygen contents,antioxidant enzyme activities,activities of flavonoid biosynthesis enzymes,and related gene expression in Scutellaria baicalensis Georgi.After applying H2O2,the activities of antioxidant enzymes in the ground part of Scutellaria baicalensis Georgi were changed in different degrees.The activities of phenylalanine ammonia transaminase(PAL)increased.The SOD activity in the subterranean part of the Scutellaria baicalensis Georgi in 0.004?mol/L H2O2,0.4?mol/L H2O2 treatment group was consistently lower than that in the control group.The 40?mol/L H2O2 treatment group was elevated at third day.The activities of POD decreased rapidly from third day.Ingeneral,the ability of anti-oxidaseto eliminatereactive oxygen was decreased,and the reactive oxygen is accumulated in the form of H2O2.In the first day after treatment,the H2O2contents increased significantly.The expression and activities of PAL in the underground part also increased significantly,which promoted the accumulation of flavonoids,showing glycosides decreased slightly and the aglycons increased significantly.The concentration of 0.004?mol/L is the best.In the second day after treatment,the content of baicalein and wogonoside in the 0.004?mol/LH2O2 group was 5.11%and 0.90%,5.9%and 7.2%lower than that of control.The contents of baicalin and wogonin were 0.324%and 0.110%respectively,2.46 times and 0.83 times higher than that of the control.The SOD activities in the 0.004?mol/L,0.4?mol/L and40?mol/L Na2S2O4 treatment group was lower than the control group after Na2S2O4 administration.The activities of CAT significantly increased after treatment in the first day,then return to the original level.The activities of POD decreased slightly after different content of Na2S2O4 treatment in the first day.The activities of PPO increased in the first day,and then decreased gradually.In general,the ability of antioxidant enzymes removal reactive oxygen species was eliminated and reduced the accumulation of reactive oxygen species in the form of H2O2.In the first day after treatment,the H2O2 contents decreased significantly.The expression and activities of PAL in the underground part also increased significantly,which promoted the accumulation of flavonoids,showing glycosides decreased slightly and the aglycons increased significantly.The concentration of 0.004?mol/L is the best.In the second day after treatment,the contents of baicalein and wogonoside in the 0.004?mol/LH2O2 group was 5.31%and 0.99%2.2%and 2.1%lower than that of control.The contents of baicalin and wogonin were 0.266%and 0.094%respectively,2.27 times and 1.96 times higher than that of the control.With H2O2 and Na2S2O4,the flavonoid contents of secondary metabolites in Scutellaria baicalensis Georgi was significantly increased.Because the pharmacological activities of baicalein substances was strong,H2O2 and Na2S2O4significantly increased the contents of baicalein,which could improve the quality of Scutellaria baicalensis Georgi.