Molecular Cloning and Characterization of DXS and DXR Genes in the Terpenoid Biosynthetic Pathway of Tripterygium wilfordii

Abstract

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) genes are the key enzyme genes of terpenoid biosynthesis but still unknown in Tripterygium wilfordii Hook. f. Here, three full-length cDNA encoding DXS1, DXS2 and DXR were cloned from suspension cells of T. wilfordii with ORF sizes of 2154 bp (TwDXS1, GenBank accession no.KM879187), 2148 bp (TwDXS2, GenBank accession no.KM879186), 1410 bp (TwDXR, GenBank accession no.KM879185). And, the TwDXS1, TwDXS2 and TwDXR were characterized by color complementation in lycopene accumulating strains of Escherichia coli, which indicated that they encoded functional proteins and promoted lycopene pathway flux. TwDXS1 and TwDXS2 are constitutively expressed in the roots, stems and leaves and the expression level showed an order of roots > stems > leaves. After the suspension cells were induced by methyl jasmonate, the mRNA expression level of TwDXS1, TwDXS2, and TwDXR increased, and triptophenolide was rapidly accumulated to 149.52 µg·g−1, a 5.88-fold increase compared with the control. So the TwDXS1, TwDXS2, and TwDXR could be important genes involved in terpenoid biosynthesis in Tripterygium wilfordii Hook. f.

Phytochemical and comparative transcriptome analyses reveal different regulatory mechanisms in the terpenoid biosynthesis pathways between Matricaria recutita L. and Chamaemelum nobile L.

“…There are at least two ways in which the biosynthesis of terpenoids can be regulated: (1) at the level of terpenoid backbone biosynthesis and (2) at the level of substrates for TPSs. Previous studies have suggested that in the terpenoid backbone biosynthesis pathway, the rate of metabolic flux through the MEP pathway is controlled by DXS and DXR [29]. Furthermore, DXS and HDR are encoded by small gene families; there are three functional DXS genes in maize [31] and two different HDR genes in Pinus taeda [32].…”

“…In the MEP pathway, one DXS (1-deoxy-D-xylulose-5-phosphate synthase) and two DXR (1-deoxy-D-xylulose-5-phosphate reductoisomerase) genes were down regulated in MC-DF vs MC-RF. Also, DXS and DXR may play rate-limiting roles in controlling metabolic flux through the MEP pathway [29]. A previous study reports that DXS and HDR are both encoded by small gene families in higher plants, and influence the accumulation of downstream isoprenoids [30].…”

Transcriptome Assembly and Gene Expression Analysis of Leaf and Rhizome tissues of Dioscorea opposita

“…Based on previous reports [55,56], we speculate the expression levels of dioscin in different tissues of D. opposita may be different and are related to key enzymes of the biosynthetic pathway. Therefore, to explore the dioscin accumulation and translocation in leaf and rhizome tissues, we compared the differentially expressed genes (DEGs) and elementary identi ed terpene biosynthetic genes through the RNA-seq, which would lay a foundation to study the terpenoids biosynthesis pathway.…”

Cloning and Expression Analysis of MEP Pathway Enzyme-encoding Genes in Osmanthus fragrans

“…For instance, there are three DXS genes encoding functional enzymes in maize ( Zea mays ), and two different genes encoding HDR have been identified in loblolly pine ( Pinus taeda ) [34,35]. Furthermore, previous studies have suggested that DXS and DXR have rate-limiting roles when controlling the metabolic flux through the MEP pathway [36]. Recently, the genetic transformation of Artemisia annua enhanced the biosynthesis of artemisinin by overexpressing DXR gene [37].…”