| Scutellaria baicalensis Georgi is a perennial herb of Scutellaria in lamiaceae.S.baicalensis Georgi is mainly distributed in Heilongjiang,Jilin,Liaoning,Inner Mongolia,Hebei,Henan,Gansu,Shaanxi,Shanxi,Shandong,Sichuan and other places.Traditional Chinese Medicine's S.baicalensis Georgi is the dried root of S.baicalensis Georgi.It has the functions of clearing heat and drying dampness,purging fire and detoxifying,hemostasis and protecting placenta and so on.With the rapid development of traditional Chinese medicine industry,the demand for plant medicinal materials is also increasing.The rapid growth of market demand for S.baicalensis Georgi accelerates the continuous expansion of its cultivation area and the continuous improvement of its quality requirements.The main medicinal ingredients of medicinal plants are secondary metabolites,and the factors affecting their synthesis and accumulation are not only closely related to the external environmental conditions,but also the internal gene expression is an important factor causing the differences in the active ingredients of medicinal plants.Therefore,it is of great significance to elucidate the accumulative regularity of the active ingredients of S.baicalensis Georgi for the high quality and yield of S.baicalensis Georgi.In this study,the root tissues of annual S.baicalensis Georgi and biennial S.baicalensis Georgi were taken as the objects,and the synthesis and accumulation of main medicinal ingredients of S.baicalensis Georgi were taken as evaluation indexes.On the basis of previous research work,the dynamic changes of synthesis and accumulation of main active ingredients in S.baicalensis Georgi at different growth stages were systematically studied.Combined with the ecological factors and gene expression of key enzymes in flavonoids synthesis pathway,the relationship between the expression of key enzymes and ecological factors on the accumulation of active ingredients in S.baicalensis Georgi was discussed.The main research results are as follows:1.The yield and the content of main medicinal ingredients of S.baicalensis Georgi in different growth stages were determined by using the root tissues of S.baicalensis Georgi in the first and second years as experimental materials.The results showed that the yield of annual S.baicalensis Georgi from September to October,which accounted for 89%of the total yield of annual S.baicalensis Georgi.Biennial S.baicalensis Georgi had the highest yield in early October and the dry weight was 6.30g per plant at that stage.The content of baicalin in annual autumn was the highest in early September?11.72%?and then decreased gradually.The content of baicalein increased slowly at first,reached the highest in mid-late September and then decreased.The content of baicalin in biennial S.baicalensis Georgi showed a"M"type change,with the highest at the end of May?13.22%?.Compared with annual S.baicalensis Georgi,baicalin content increased by 1.49%at the highest level.The second peak appeared at the end of August.While the content of baicalein showed a"W"type change,and the highest at the beginning of July?1.34%?.Combining with the yield and content of active ingredients of S.baicalensis Georgi,the total yield of main active ingredients of annual S.baicalensis Georgi in autumn increased rapidly in September,reached the highest in mid-October,and the content of baicalin reached 50.56g·m-2.The total yield of main active ingredients of biennial S.baicalensis Georgi increased rapidly from mid-late July to late August,accounting for 46%of the total yield of the second year of growth of S.baicalensis Georgi,and reached the highest in mid-late September,reaching 0.68 g per plant.Therefore,the best harvest time of biennial S.baicalensis Georgi in Changchun area is mid-late September.2.The relationship between the expression levels of key enzyme genes?PAL,C4H,4CL,CHS,CHI,FNS,F6H,UBGAT,GUS?and the content of main medicinal ingredients in S.baicalensis Georgi was studied by using the roots of S.baicalensis Georgi as experimental materials.The results showed that the expression of key enzymes genes has different effects on the quality synthesis of S.baicalensis Georgi in different growth stages of S.baicalensis Georgi.For annual S.baicalensis Georgi in autumn,baicalein was positively correlated with CHS,4CL and CHI genes,and the correlation coefficient was 0.69,0.67 and 0.57,respectively.Therefore,CHS,4CL and CHI genes played an important role in the accumulation of baicalein content.Baicalin,wogonoside and total flavonoids were positively correlated with PAL gene,and the correlation coefficient was 0.57,0.57 and 0.60,respectively.Total flavonoids were positively correlated with CHS,F6H and 4CL genes,and the correlation coefficient was 0.61,0.59 and0.57,respectively.Therefore,PAL,CHS,F6H and 4CL genes had a great influence on the synthesis and accumulation of annual S.baicalensis Georgi's quality.There was a significant positive correlation between C4H gene and baicalein in biennial S.baicalensis Georgi,with a correlation coefficient of 0.52,indicating that C4H gene can effectively promote the accumulation of baicalein in biennial S.baicalensis Georgi'root.In conclusion,the expression of key enzymes has different effects on the quality synthesis of S.baicalensis Georgi at different growth and development stages.The formation of quality of S.baicalensis Georgi in autumn is greatly affected by the expression of key enzymes.3.The relationship between ecological factors and accumulation of major medicinal ingredients,the expression of key enzyme genes in root tissues of S.baicalensis Georgi was studied at different growth stages.In terms of quality formation,there were significant correlations between photosynthetic active radiation and baicalin,baicalein and total flavonoids in annual autumn.The correlation coefficient was 0.74,0.68 and 0.74,respectively.Soil water content and soil temperature were significantly correlated with baicalin,wogonoside,baicalein and total flavonoids,among which the correlation coefficient with baicalin were 0.85 and 0.82,respectively,and with total baicalin was 0.87 and 0.90,respectively.The correlation between air temperature and baicalin,baicalein and total flavonoids was significant,and the correlation coefficient was 0.77,0.78 and 0.82,respectively.In conclusion,photosynthetic active radiation,soil water content,soil temperature and air temperature are important ecological factors,which have great influence on the quality synthesis and accumulation of annual S.baicalensis Georgi in autumn.The soil water content of biennial S.baicalensis Georgi at different growth stages was negatively correlated with baicalein and wogonin,and the correlation coefficient were-0.56 and-0.58,respectively.Baicalin is the storage form of baicalein.It is speculated that the moderate increase of water content in soil will help to promote the transformation of baicalein into baicalin.In terms of gene expression,photosynthetic active radiation were significantly positively correlated with PAL,CHI,FNS and GUS genes for annual S.baicalensis Georgi in autumn,and the correlation coefficient with PAL gene was 0.69;soil moisture content was significantly correlated with PAL,FNS and GUS genes,and the correlation coefficient was 0.76,0.71 and0.71,respectively;soil temperature and air temperature were significantly correlated with 4CL,CHS,CHI and F6H genes.The correlation coefficient with 4CL gene was 0.76 and 0.78respectively,and with CHS gene was 0.73 and 0.75 respectively.Therefore,photosynthetic active radiation,soil water content,soil temperature and air temperature also play an important role in promoting the expression of key enzymes genes in annual S.baicalensis Georgi.Only4CL gene in biennial S.baicalensis Georgi showed a significant correlation with air temperature,the correlation coefficient was 0.55,indicating that the increase of air temperature was conducive to the expression of 4CL gene in biennial S.baicalensis Georgi.In conclusion,compared with biennial S.baicalensis Georgi,the quality of annual S.baicalensis Georgi in autumn is more strongly correlated with the ecological factors and expression of key enzymes.The quality synthesis of annual S.baicalensis Georgi in autumn is more susceptible to external environment.The sensitivity of biennial S.baicalensis Georgi is weaker.The management of soil water content should be strengthened during the cultivation of annual S.baicalensis Georgi. |
PDF Full Text Request