| Panax quinquefolium is a perennial herb of the Panax,which is a precious medicinal herb with using roots in traditional and Chinese medicine.It has the effect of tonifying qi and nourishing yin,clearing heat and rejuvenating.Panax quinquefolium is native in Canada and USA after being introduced to China.It has formed the main production areas in Northeast,North and Central of China.However,there are few reports on the introduction and planting of Panax quinquefolium in Yunnan province,and the growth and development of Panax quinquefolium under the forest and the changes of ginsenoside content are not clear.In this study,the experiment were observed of phenological rhythm,agronomic traits and the content of G-Rg1、G-Re、G-Rb1、G-Rc、G-Rb2、G-Rb3 and G-Rd in the main roots by using the annual to quadrennial Panax quinquefolium planted under the P.armandi forest in Luquan in Kunming as materials.Then,this study was used to analyze the expression of key genes in the ginsenoside biosynthesis pathway in P.quinquefolium by transcriptome sequencing technology.The results are as follows:1.The experiment were observed the growth phenological rhythm and agronomic traits of P.quinquefolium under the P.armandi forest in Luquan.The results showed that P.quinquefolium is suitable for the introduction and cultivation and able to complete the entire life cycle of early leaf stage,opened leaf stage,flowering stage,fruiting stage,yellow leaf stage,and dormancy stage in Luquan location.The early leaf stage of P.quinquefolium began to emerge in late March,entered the flowering stage in mid-May,entered the fruiting stage in mid-June,the stems and leaves on the ground withered in September,and the dormant stage was from mid-October to March of the following year.From April to October,the fresh weight roots of P.quinquefolium increased month by month.The fresh root weight of a single plant in October,reaching 4.03±0.49 g,9.04±0.57 g and 9.96±0.66 g.2.The contents of seven ginsenosides(G-Rg1,G-Re,G-Rb1,G-Rb1,G-Rc,G-Rb2,G-Rb3 and G-Rd)in the main roots of two-year-old to four-year-old P.quinquefolium were analyzed by high performance liquid chromatography.The results showed that the total content of seven ginsenosides was the highest in the three-year-old and four-year-old taproots in April,6.46±0.12 % and 3.70±0.25 %,respectively.Followed by the higher contents in August,4.23±0.17 % and3.19±0.31 %,respectively.The total content of seven ginsenosides in August in the two-year-old taproot was the highest 2.80±0.29 %,followed by 2.08±0.03 % in April.Therefore,under the premise of ensuring the yield of panax quinquefolium under the forest,the quality of P.quinquefolium can be duly harvested for three years or more before the end of the red fruit period in August and the wilting period in september.3.The gene expression profiles of P.quinquefolium were analyzed by in the main roots of April and August in different years.The expression profiles of key genes in ginsenoside synthesis were obtained,and the relative expression of key genes(FPS,DS,CYP716A47 and CYP6H)of the ginsenoside biosynthesis pathway in different growth stages of P.quinquefolium was analyzed by real-time PCR.The results showed that the key genes for ginsenoside biosynthesis in the main root of ginseng from the year old to the fourth year old were mainly expressed in August,which was higher than that in April.Phylogenetic analysis and gene correlation analysis of UGT71,UGT74 and UGT94 family UGT94 families were carried out,and the results showed that UGT74 family PQOG045250 was found.UGT71 families PQOG000460 and PQOG247570;The UGT94 family PQOG391980 is speculated to be involved in ginsenoside biosynthesis. |
