Research Article

Analysis of Polygala tenuifolia Transcriptome and Description of Secondary Metabolite Biosynthetic Pathways by Illumina Sequencing

Figure 5

Schematic of the putative biosynthetic pathways of two major classes of active compounds in P. tenuifolia. Saponin biosynthesis pathway (a) and phenylpropanoid biosynthesis pathway (b). Enzyme abbreviations: AACT, acetyl CoA C-acetyltransferase or acetoacetyl-CoA thiolase; HMGS, 3-hydroxy-3-methylglutaryl CoA synthase; HMGR, 3-hydroxy-3-methylglutaryl CoA reductase; MVK, mevalonate kinase; PMK, phosphomevalonate kinase; PMD, mevalonate pyrophosphate decarboxylase; DXS, 1-deoxy-D-xylulose-5-phosphate synthase; DXR, 1-deoxy-D-xylulose-5-phosphate reductoisomerase; MCT, 2-C-methyl-erythritol 4-phosphate cytidylytransferase; CMK, 4-(Cytidine 5′-diphospho)-2-C-methyl-D-erythritol kinase; MDS, 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase; HDS, 1-hydroxy-2-methyl-butenyl-4-diphosphatesynthase; HDR, isopentenyl pyrophosphate (IPP)/3, 3-dimethylallyl pyrophosphate (DMAPP) synthase; IPPI, isopentenyl pyrophosphate isomerase; GPPS, geranyl diphosphate synthase; FPPS, farnesyl diphosphate synthase; SQS, squalene synthase; SE, squalene epoxidase; CAS, cycloartenol synthase; β-AS, β-amyrin synthase; DS, dammarenediol synthase; PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-coumarate CoA ligase; CHS, chalcone synthase; CHI, chalcone isomerase; F3′5′H, flavonoid 3′,5′-hydroxylase; F3H, flavanone 3-hydroxylase; FLS, flavonol synthase; HCT, hydroxycinnamoyl-transferase; C3′H, p-coumaroyl shikimate 3′ hydroxylase; CCoAoMT, caffeoyl CoA 3-O-methyltransferase; CCR, cinnanoyl-CoA reductase; CAD, cinnamyl alcohol dehydrogenase; CYPs, cytochrome P450s; UGTs, glycosyltransferases.
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