ABSTRACT
Objective:To study the effect of different hormone ratios on the callus induction of roots,stems and leaves of Polygala tenuifolia,and determine and analyze the amount of flavonoids in roots,stems and leaves of P. tenuifolia. Method:With MS as the basic medium and roots,stems and leaves of P. tenuifolia sterile seedings as explants,the effects of 2,4-D,NAA and 6-BA on callus induction and flavonoid accumulation in different parts of roots,stems and leaves of P. tenuifolia were determined by orthogonal test. Result:2,4-D,NAA and 6-BA had significant effects on the callus induction rate of roots,stems and leaves of P. tenuifolia. The optimal callus induction combination of leaves was MS+3.0 mg·L-1 2,4-D+1.0 mg·L-1 NAA+1.5 mg·L-1 6-BA,the optimal callus induction combination of stems was MS+1.0 mg·L-1 2,4-D+3.0 mg·L-1 NAA+1.5 mg·L-1 6-BA,the optimal callus induction combination for roots was MS+1.0 mg·L-1 2,4-D+1.0 mg·L-1 NAA+1.0 mg·L-1 6-BA. And 2,4-D,NAA and 6-BA had significant effects on flavonoid accumulation in the stem callus of P. tenuifolia,and MS+3.0 mg·L-1 2,4-D+1.0 mg·L-1 NAA+0.5 mg·L-1 6-BA was the best flavonoid accumulation combination.NAA,6-BA had significant effects on flavonoid accumulation in the leave callus of P. tenuifolia,while 2,4-D had no significant effect,and MS+3.0 mg·L-1 2,4-D+2.0 mg·L-1 NAA+1.0 mg·L-1 6-BA was the optimal flavonoid accumulation combination,the three hormones had no significant effect on the accumulation of flavonoids in the root callus of P. tenuifolia,and MS+2.0 mg·L-1 2,4-D+1.0 mg·L-1 NAA+1.5 mg·L-1 6-BA was the best flavonoid accumulation combination. Conclusion:Under the conditions,the callus induction rate of roots,stems and leaves of P. tenuifolia is 100%, especially, the callus of P. tenuifolia leaves was the optimal,which is followed by P. tenuifolia stems and P. tenuifolia roots. Under the conditions,the amount of flavonoids in roots,stems and leaves of P. tenuifolia reach 21.31,24.56,23.61 mg·g-1,respectively.
ABSTRACT
Objective:To study the changes in total phenolic and flavonoid content and antioxidant enzyme activity of Polygala tenuifolia callus in MS medium with different concentrations of H2O2,in order to explore the physiological mechanism of Polygala tenuifolia callus in adapting to H2O2 environmental stress at the cellular level. Method:Five gradients of 0,5,10,15,20 mmol·L-1 were set for H2O2 concentration and added to MS medium, with P. tenuifolia callus as the experimental material. Total phenols,total flavonoids and antioxidant enzyme activities of callus were determined after 5,10,15,20,25 d of culture,respectively. Result:The contents of total phenols and flavonoids were the highest when the concentration of H2O2 was 5 mmol·L-1 for 15 d. The SOD activity was the highest when the callus was cultured for 5 d and the exogenous H2O2 concentration was 5 mmol·L-1. POD activity was the highest at 25 d and 5 mmol·L-1 concentration of exogenous H2O2.CAT activity was the highest at 25 d and 15 mmol·L-1 concentration of exogenous H2O2. Conclusion:P. tenuifolia callus has the ability to adapt to the environmental stress of H2O2 at a certain concentration. When it is subjected to the environmental stress of H2O2,P. tenuifolia callus can alleviate the damage by regulating its secondary metabolites and protecting enzyme system. It can significantly promote the content of total phenols and flavonoids in secondary metabolites at 5-10 mmol·L-1. SOD activity was significantly increased at 5 d and the concentration of exogenous H2O2 of 5 mmol·L-1. POD activity was significantly increased at 25 d and the concentration of exogenous H2O2 of 5 mmol·L-1. CAT activity was significantly increased at 25 d and concentration of exogenous H2O2 of 15 mmol·L-1.