Preliminary Study On The Function Of ?-AS Gene Of Aralia Elata And SS Gene Of Panax Notoginseng

Aralia elata and Panax notoginseng belong to the medicine plants of Araliaceae.The ?-AS gene(Ae?-AS)of A.elata and the SS gene(PnSS)of P.notoginseng are the key enzyme genes during the biosynthesis of triterpenoids.In this paper,the Ae?-AS gene and the PnSS gene were transferred into Nicotiana tabacum and A.elata,respectively.The the relative expression of 4 key enzymes(FPS,SS,SE and ?-AS)in transgenic N.bacum and A.elata were analyzied with the q-PCR method.The relative expression of PnSS in A.elata was determined with the q-PCR method,and the content of squalene and oleanolic acid in callus and somatic stalk of transgenic A.elata with the high-performance liquid phase.Also,the relative expressions of 4 key enzymes and the contents of squalene and oleanolic acid,were analyzed,in the transgenic somatic lines.The specific results are as follows:1.After the plant expression vector of ?-AS gene of A.elata was contructed,12 transgenic lines were obtained.The relative expression of FPS,SS,SE and ?-AS genes in transgenic tobacco was significantly higher than that of wild type.The relative expression of above genes in lines 16 and 17 was significantly higher than that of other lines;the relative expression of FPS and SS genes was the highest in line 16;the expression of SE and ?-AS in line 17 was the highest.2.The PnSS gene was transferred into the A.elata,and the embryogenic callus and the somatic embryo genes were obtained.The relative expression of PnSS in transgenic callus 7 and 21 was significantly higher than that of other strains,the relative expression of FPS gene in transgenic callus 2 and 11 was significantly higher than that of wild type,The relative expression of SE gene in transgenic callus 7 was significantly higher than that in wild type,and the relative expression of SE gene in transgenic callus 12 was significantly higher than other strains.The relative expression of PnSS in transgenic somatic embryos strains 7 and 21 was significantly higher than that of the other strains,the relative expression of the SE gene in the transgenic somatic embryo line 7 was significantly higher than that of the wild type,The relative expression levels of ?-AS genes were significantly higher than those of the wild type,and the relative expression levels of the lines 7 and 25 were significantly higher than those of the other lines.3.The content of squalene in all transgenic callus lines and somatic germ lines was significantly higher than that of wild type.The oleanolic acid content in all transgenic callus lines and somatic germ lines was significantly lower than that in the wild type,and the squalene and oleanolic acid were higher in all transgenic somatic lines than in the transgenic callus line.4.The transgenic somatic lines were treated with 200 ?mol/L MeJA for 1,3,and 5 d.The results showed that all the treated somatic embryos grew.After treatment for 1 d,all transgenic and wild-type growth increased significantly.With the increase of treatment time,the growth of somatic embryos of all lines gradually decreased,and the dry weight of all transgenic lines was higher than that of wild type.At 1 day,the growth of transgenic lines 21 and 25 was significantly higher than that of other lines.5.The somatic embryos obtained by the above treatment were used to detect the expression of key enzyme genes(FPS,SE,?-AS,ASS,PnSS genes).The results showed that the relative expression of The FPS in transgenic lines 2 and 21 and 25 increased significantly after treatment for 1 d,and decreased significantly after 3 d treatment,and increased at 5 d.All transgenic lines were treated for 1 d.The relative expression level increased significantly,and the relative expression levels of SE and SS genes in transgenic line 21 were significantly higher than those in other lines.6.The content of squalene and oleanolic acid in the transgenic somatic embryos was detected.The results showed that the content of squalene in transgenic lines 7 and 21 was higher than that in other lines and control.The oleanolic acid content of transgenic line 21 was higher than other lines and controls at 1 d.