Functional Characterization of Sesquiterpene Synthase fromPolygonum minus

Abstract

Polygonum minus is an aromatic plant, which contains high abundance of terpenoids, especially the sesquiterpenes C15H24. Sesquiterpenes were believed to contribute to the many useful biological properties in plants. This study aimed to functionally characterize a full length sesquiterpene synthase gene from P. minus. P. minus sesquiterpene synthase (PmSTS) has a complete open reading frame (ORF) of 1689 base pairs encoding a 562 amino acid protein. Similar to other sesquiterpene synthases, PmSTS has two large domains: the N-terminal domain and the C-terminal metal-binding domain. It also consists of three conserved motifs: the DDXXD, NSE/DTE, and RXR. A three-dimensional protein model for PmSTS built clearly distinguished the two main domains, where conserved motifs were highlighted. We also constructed a phylogenetic tree, which showed that PmSTS belongs to the angiosperm sesquiterpene synthase subfamily Tps-a. To examine the function of PmSTS, we expressed this gene in Arabidopsis thaliana. Two transgenic lines, designated as OE3 and OE7, were further characterized, both molecularly and functionally. The transgenic plants demonstrated smaller basal rosette leaves, shorter and fewer flowering stems, and fewer seeds compared to wild type plants. Gas chromatography-mass spectrometry analysis of the transgenic plants showed that PmSTS was responsible for the production of β-sesquiphellandrene.

Annotation of the Corymbia terpene synthase gene family shows broad conservation but dynamic evolution of physical clusters relative to Eucalyptus

“…Given that increased gene copies often result in increased expression of the subsequent product, there may also be a maximum amount of TPS genes that eucalypts can support without experiencing specific deleterious gene dosage effects. For example, the overexpression of particular TPS-a genes has been shown to retard growth in tomato (Fray et al 1995), tobacco (Busch et al 2002) and A. thaliana (Aharoni et al 2003;Ee et al 2014) (though not without exception, see Schnee et al (2006)). This is thought to be the result of under-expression of primary metabolites, such as gibberellin and abscisic acid, due to terpenoid precursor reserves becoming exhausted by the over-synthesis of secondary metabolites.…”

Identification and characterization of a novel sesquiterpene synthase, 4-amorphen-11-ol synthase, from <i>Artemisia maritima</i>

“…The encoded protein of AmAOS contains all typical motifs of sesquiterpene synthase, i.e., R(R,P)(X) 8 W, RXR, DDXXD, and NSE/DTE motifs, and shows 86% amino acid sequence identity to AmBOS (Christianson 2006;Ee et al 2014;Tholl et al 2005; Figure 3, Supplemental Table S2). The RXR and DDXXD motifs of this enzyme and those of AmBOS are identical.…”

Sesquiterpene Production in Methyl Jasmonate-Induced Persicaria minor Cell Suspension Culture

“…Sesquiterpene analysis was carried out using HS-SPME following Ee et al (2014). Samples stored at -80°C were defrosted at room temperature for 30 min.…”

“…Analysis was carried out following Ee et al (2014) on Agilent 7890A gas chromatograph (Agilent Technologies, Wilmington, DE, USA) coupled with 5975C inert MSD triple-axis detector (Agilent) with Electron Ionization (EI) as ion source. After sampling, the SPME fiber was retracted from the vials and immediately injected into GC inlet.…”