Study On The Correlation Among Accumulation Of Main Components And Key Enzyme Activities And Gene Expression In Different Parts Of Polygala Tenuifolia Willd.

There are obvious differences in functions and compositions among the underground parts(such as root bark and xylem)and the aerial part(such as rhizome,stem and leaf)of Polygala tenuifolia Willd..Onjisaponins and sugar esters are the main chemical constituents in the root,xanthones are the main chemical constituents in the aerial part of P.tenuifolia.The study was conducted to investigate the distribution and dynamic changes of chemical composition,antioxidant enzymes/key enzymes and related enzyme genes in different parts of P.tenuifolia,as well as the relationships among component content,enzyme activity and gene expression.It will provide basis for the development of non-medicinal parts and directional regulation of effective components of P.tenuifolia.The main findings are as follows:1.The characteristic chromatograms of different parts and developmental stages of P.tenuifolia were established,compared to the characteristic chromatograms,the similarity of the aerial part(stem,leaf,flower and fruit)of P.tenuifolia was over 0.95,the similarity of rhizomewas less than 0.90,the similarity of the underground parts(root bark,core and root tip)was less than 0.65.Phenols,xanthones and mangiferin were mainly distributed in the tender leaves of P.tenuifolia,of which the content decreased along with the growth,and the content peaked at the end of May.The onjisaponins were mainly distributed in the root bark.During the whole development periods,the contents increased first and then decreased,and reached the peak during full blooming stage(mid-July).3,6’-disinapoylsucrose was mainly distributed in the root bark.The content was on the increase throughout the developmental stages and reached the peak at wither period(early October).2.SOD activity was the highest in the old leaves in leaf-expansion stage(end of May),which was positively correlated with the content of xanthones.CAT activity was the highest in young leaves at late fruit stage(early September),which were positively correlated with phenylpropanoid content.As key enzymes of phenylpropanoid biosynthesis pathway,the activities of PAL and C4 H were the highest in root tips at fruit stage(mid August),and they were negatively correlated with the contents of total phenols,kaempferol and quercetin.SQE and β-AS,two key enzymes of onjisaponins biosynthesis pathway,exhibited the highest activity in young leaves and middle leaves of late fruit stage(early September),which were positively correlated with content of phenylpropanoid in P.tenuifolia..CHS and CHI,the key enzymes for flavonoid biosynthesis,exhibited the strongest activity in the shoot pex in late fruit stage(early September)and early wilting stage(mid September).CHS activity was positively correlated with content of kaempferol.CHI activity was negatively correlated with content of mangiferin.3.Peak value of nitrogen enzyme activity accumulation obviously lagged behind the peak of gene expression level in P.tenuifolia.PtSQE and Ptβ-AS genes were highly expressed in root tip,which were expressed to the highest level in late fruit stage(early September)and budding stage(late June)respectively.PtSQE and Ptβ-AS genes were positively correlated with the contents of onjisaponins in P.tenuifolia.PtCHS gene was highly expressed in stem tip,and the highest expression was in late fruit stage(early September),which was negatively correlated with content of mangiferin.