ABSTRACT
Isopentenyl diphosphate isomerase (IDI) is a key enzyme in the regulation of triterpenes biosynthesis and plays an important role in ginsenoside biosynthesis. In this study, two IDI genes, PvfIDI1 (GenBank No. MZ736417) and PvfIDI2 (GenBank No. MZ736418) were cloned from Panax vietnamensis var. fuscidiscus. The open reading frame of both PvfIDI1 and PvfIDI2 was 924 bp encoding 307 amino acids. The molecular weights of PvfIDI1 and PvfIDI2 were 34.84 kDa and 34.66 kDa, respectively, with theoretical pIs of 6.01 and 5.66. Bioinformatic analysis indicated that PvfIDI1 and PvfIDI2 contained two conserved sequences: TNTCCSHPL and WGEHELDY. Phylogenetic analysis showed that PvfIDI1 and PvfIDI2 were closely related to Panax notoginseng IDI. Expression analysis showed that both PvfIDI1 and PvfIDI2 genes are expressed in root, rhizome, stem and leaf of P. vietnamensis var. fuscidiscus. However, PvfIDI1 is highly expressed in the rhizome and PvfIDI2 is highly expressed in the stem. PvfIDI1 and PvfIDI2 recombinant proteins were expressed in E. coli; a functional coloration experiment showed that PvfIDI1 and PvfIDI2 could promote the accumulation of lycopene, indicating that both PvfIDI1 and PvfIDI2 encode functional IDI enzymes. The cloning and functional studies on PvfIDI1 and PvfIDI2 provide a foundation for the further study of IDI and the regulation of ginsenoside biosynthesis in P. vietnamensis var. fuscidiscus.
ABSTRACT
Objective:To investigate the relationship between the single nucleotide polymorphism（SNP）of function genes and effective components of <italic>Salvia miltiorrhiza</italic> and the molecular mechanism of specific quality formation of <italic>S. miltiorrhiza</italic>. Method:The fingerprints of components in <italic>S. miltiorrhiza</italic> from eight different habitats and varieties were obtained by high-performance liquid chromatography （HPLC）. The full-length cDNA of three functional genes<italic> </italic>acetyl-CoA C-acetyltransferase（<italic>SmAACT</italic>），4-diphosphocytidyl-2-C-methyl-<italic>D</italic>-erythritol kinase（<italic>SmCMK</italic>） and isopentenyl diphosphate isomerase（<italic>SmIPPI</italic>） in tanshinone metabolic pathway were amplified by polymerase chain reaction（PCR），cloned， and sequenced，followed by bioinformatics analysis. Result:The full-length cDNA sequences of three functional genes <italic>SmAACT</italic>，<italic>SmCMK</italic>， and <italic>SmIPPI</italic> in tanshinone metabolic pathway were obtained from 23 strains of <italic>S. miltiorrhiza</italic> from eight different habitats and varieties. As revealed by the analysis of SNP and amino acid polymorphisms of three functional genes，18，16， and 14 SNP sites were found respectively. HPLC results showed the samples from Beijing，Hubei，Shandong （No. SDB），Shanxi，Henan， and Shandong （No. SDZ） were clustered into one branch，and those from Hebei and Inner Mongolia were clustered into another branch， which suggested that the variation trend of <italic>S. miltiorrhiza</italic> components had little correlation with geographical distance，but the variety was a critical factor for the quality. Conclusion:There was an obvious genetic differentiation trend in <italic>S. miltiorrhiza</italic> from different habitats，and different origin-specific genotypes were formed. The molecular mechanism of the formation of the specific quality of <italic>S. miltiorrhiza</italic> from different habitats was discussed，which laid a foundation for the stability and effectiveness of clinical medication，and guided the breeding of excellent varieties of <italic>S. miltiorrhiza</italic>.