Transcriptional activation of a geranylgeranyl diphosphate synthase gene, GGPPS2, isolated from Scoparia dulcis by treatment with methyl jasmonate and yeast extract

Abstract

A cDNA clone, designated SdGGPPS2, was isolated from young seedlings of Scoparia dulcis. The putative amino acid sequence of the translate of the gene showed high homology with geranylgeranyl diphosphate synthase (GGPPS) from various plant sources, and the N-terminal residues exhibited the characteristics of chloroplast targeting sequence. An appreciable increase in the transcriptional level of SdGGPPS2 was observed by exposure of the leaf tissues of S. dulcis to methyl jasmonate, yeast extract or Ca(2+) ionophore A23187. In contrast, SdGGPPS1, a homologous GGPPS gene of the plant, showed no or only negligible change in the expression level upon treatment with these stimuli. The truncated protein heterologously expressed in Escherichia coli in which the putative targeting domain was deleted catalyzed the condensation of farnesyl diphosphate and isopentenyl diphosphate to liberate geranylgeranyl diphosphate. These results suggested that SdGGPPS2 plays physiological roles in methyl jasmonate and yeast extract-induced metabolism in the chloroplast of S. dulcis cells.

Elucidation of terpenoid metabolism in Scoparia dulcis by RNA-seq analysis

“…On the other hand, GGPPSs were abundantly expressed in leaves when compared with expression in roots. In addition, the present result is consistent with previous data that GGPPSs might be composed of several homologous genes22.…”

“…In the second stage, two GGPP synthases (GGPPSs) from S. dulcis have been cloned and functionally characterized2021. In addition, our previous study revealed that SdGGPS1 and SdGGPS2 were expressed as constitutive and inducible homologous genes, respectively22. However, the enzymes involved in cyclization and modification to produce SDB at the third and fourth stages described above are still unknown, whereas ent -copalyl diphosphate synthase (SdCPS1) has been cloned and functionally characterized23.…”

Functional characterization of NADPH-cytochrome P450 reductase and cinnamic acid 4-hydroxylase encoding genes from Scoparia dulcis L.

“…Plant P450s play an important role in the biosynthesis of secondary metabolites and are often induced by various stresses. In previous reports, it was demonstrated that the biosynthesis of SDB, a tetracyclic diterpene in S. dulcis, is markedly activated by the MJ and yeast extract treatments (Nkembo et al 2005;Yamamura et al 2014). It is clear that a large number of P450s are responsible for not only SDB biosynthesis but also in the other biosynthetic reactions of secondary metabolites in S. dulcis (Yamamura et al 2017).…”