Abstract

In the methyl-D-erythritol-4-phosphate (MEP) pathway, 1-deoxy-D-xylose-5-phosphate synthase (DXS) is considered the key enzyme for the biosynthesis of terpenoids. In this study,PmDXS(MK970590) was isolated fromPinus massoniana. Bioinformatics analysis revealed homology of MK970590 with DXS proteins from other species. Relative expression analysis suggested thatPmDXSexpression was higher in roots than in other plant parts, and the treatment ofP. massonianaseedlings with mechanical injury via 15% polyethylene glycol 6000, 10 mM H2O2, 50 μM ethephon (ETH), 10 mM methyl jasmonate (MeJA), and 1 mM salicylic acid (SA) resulted in an increased expression ofPmDXS. pET28a-PmDXSwas expressed inEscherichia coliTransB (DE3) cells, and stress analysis showed that the recombinant protein was involved in resistance to NaCl and drought stresses. The subcellular localization ofPmDXSwas in the chloroplast. We also cloned a full-length 1024 bpPmDXSpromoter.GUSexpression was observed inNicotiana benthamianaroots, stems, and leaves.PmDXSoverexpression significantly increased carotenoid, chlorophyll a, and chlorophyll b contents and DXS enzyme activity, suggesting thatDXSis important in isoprenoid biosynthesis. This study provides a theoretical basis for molecular breeding for terpene synthesis regulation and resistance.Keywords:Pinus massoniana;DXS;expression pattern;terpenoid;prokaryotic expression;chlorophyll