Heterologous biosynthesis of isobavachalcone in tobacco based on in planta screening of prenyltransferases

Abstract

Isobavachalcone (IBC) is a prenylated chalcone mainly distributed in some Fabaceae and Moraceae species. IBC exhibits a wide range of pharmacological properties, including anti-bacterial, anti-viral, anti-inflammatory, and anti-cancer activities. In this study, we attempted to construct the heterologous biosynthesis pathway of IBC in tobacco ( Nicotiana tabacum ). Four previously reported prenyltransferases, including GuILDT from Glycyrrhiza uralensis , HlPT1 from Humulus lupulus , and SfILDT and SfFPT from Sophora flavescens , were subjected to an in planta screening to verify their activities for the biosynthesis of IBC, by using tobacco transient expression with exogenous isoliquiritigenin as the substrate. Only SfFPT and HlPT1 could convert isoliquiritigenin to IBC, and the activity of SfFPT was higher than that of HlPT1. By co-expression of GmCHS8 and GmCHR5 from Glycine max, endogenous isoliquiritigenin was generated in tobacco leaves (21.0 mg/g dry weight). After transformation with a multigene vector carrying GmCHS8 , GmCHR5 , and SfFPT , de novo biosynthesis of IBC was achieved in tobacco calluses (0.46 mg/g dry weight). The yield of IBC in calluses was nearly equal to that in SfFPT transient expression experiments, in which substrate supplement was sufficient, indicating that low IBC yield was caused by the low activity of SfFPT. Our research provided a prospect to produce valuable prenylflavonoids using plant-based metabolic engineering.

Recent advances in reactive oxygen species scavenging nanomaterials for wound healing

“…[58,59] In Figure 5A, the reversible switching between Fe 2+ and Fe 3+ oxidation states has been illustrated which results in ROS production and scavenging through the oxidation-reduction cycles. The antioxidant activities of IONzymes benefits the therapeutic effects during wound healing process [34,60,61] (Figure 5B,C). Prussian blue ) is an iron-based coordination compound and PB-based nanoparticles show great enzyme mimetic properties and anti-inflammatory activities.…”

“…This electrospun hybrid nanofibrous wound dressing possesses high catalase-like enzymatic activity to quickly convert H 2 O 2 into O 2, as well as excellent wettability, water permeability, and cell proliferation in wounds. Guo et al [60] synthesized IONPs to promote peroxide-like catalytic activity for bacteria-infected wound therapy. They found that IONPs induced conversion of H 2 O 2 to hydroxyl radicals to prevent bacterial infection and biofilm formation, leading to efficiently enhanced wound healing in mouse models.…”