AUTHOR=Guo Lirong , Zhao Wei , Wang Yan , Yang Yu , Wei Cuimei , Guo Jian , Dai Jianye , Hirai Masami Yokota , Bao Aike , Yang Zhigang , Chen Haijuan , Li Yimeng 

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

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1034625

DOI=10.3389/fpls.2022.1034625

ISSN=1664-462X

ABSTRACT=<p>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 (<italic>Nicotiana tabacum</italic>). Four previously reported prenyltransferases, including <italic>GuILDT</italic> from <italic>Glycyrrhiza uralensis</italic>, <italic>HlPT1</italic> from <italic>Humulus lupulus</italic>, and <italic>SfILDT</italic> and <italic>SfFPT</italic> from <italic>Sophora flavescens</italic>, were subjected to an <italic>in planta</italic> 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 <italic>GmCHS8</italic> and <italic>GmCHR5</italic> from <italic>Glycine max</italic>, endogenous isoliquiritigenin was generated in tobacco leaves (21.0 μg/g dry weight). After transformation with a multigene vector carrying <italic>GmCHS8</italic>, <italic>GmCHR5</italic>, and <italic>SfFPT</italic>, <italic>de novo</italic> biosynthesis of IBC was achieved in transgenic tobacco T<sub>0</sub> lines, in which the highest amount of IBC was 0.56 μg/g dry weight. The yield of IBC in transgenic plants was nearly equal to that in <italic>SfFPT</italic> transient expression experiments, in which substrate supplement was sufficient, indicating that low IBC yield was not attributed to the substrate supplement. Our research provided a prospect to produce valuable prenylflavonoids using plant-based metabolic engineering.</p>