Application of transport engineering to promote catharanthine production in Catharanthus roseus hairy roots

Abstract

Low accumulation levels of valuable plant secondary metabolites lead to high costs for these compounds production. In order to promote accumulation levels of these molecules, many efforts have been carried out during the past decades, such as elicitation, precursor feeding, tissue cultures and overexpression of pathway genes. However, these engineering strategies could only slightly increase the amounts of target metabolites, since biosynthesis pathways of these compounds are very complex and involving several different organelles and cell types. In this work, we used Catharanthus roseus hairy roots as research material to investigate the effect of transport engineering on monoterpenoid indole alkaloids (MIAs) production. Results showed that overexpresssion of catharanthine transporter, CrTPT2, in C. roseus hairy roots could dramatically increase the accumulation level of catharanthine to fivefold higher than that in control hairy roots, while other MIAs accumulation levels are not affected. Since the expression of pathway genes are at similar level, timely removal of catharanthine from where it is synthesized could be critical for promoting catharanthine production, which exemplifies the application of transport engineering to effective manipulation of plant secondary metabolites biosynthesis. Overexpression of catharanthine transporter, CrTPT2, in Catharanthus roseus hairy roots specifically promotes catharanthine production, which exemplifies an effective manipulation strategy for plant secondary metabolites biosynthesis.