Metabolic engineering of the phenylpropanoid pathway enhances the antioxidant capacity of Saussurea involucrata

PLoS One. 2013 Aug 14;8(8):e70665. doi: 10.1371/journal.pone.0070665. eCollection 2013.

Abstract

The rare wild species of snow lotus Saussurea involucrata is a commonly used medicinal herb with great pharmacological value for human health, resulting from its uniquely high level of phenylpropanoid compound production. To gain information on the phenylpropanid biosynthetic pathway genes in this critically important medicinal plant, global transcriptome sequencing was performed. It revealed that the phenylpropanoid pathway genes were well represented in S. involucrata. In addition, we introduced two key phenylpropanoid pathway inducing transcription factors (PAP1 and Lc) into this medicinal plant. Transgenic S. involucrata co-expressing PAP1 and Lc exhibited purple pigments due to a massive accumulation of anthocyanins. The over-expression of PAP1 and Lc largely activated most of the phenylpropanoid pathway genes, and increased accumulation of several phenylpropanoid compounds significantly, including chlorogenic acid, syringin, cyanrine and rutin. Both ABTS (2,2'-azinobis-3-ethylbenzotiazo-line-6-sulfonic acid) and FRAP (ferric reducing anti-oxidant power) assays revealed that the antioxidant capacity of transgenic S. involucrata lines was greatly enhanced over controls. In addition to providing a deeper understanding of the molecular basis of phenylpropanoid metabolism, our results potentially enable an alternation of bioactive compound production in S. involucrata through metabolic engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthocyanins / biosynthesis*
  • Antioxidants / metabolism*
  • Benzothiazoles
  • Chlorogenic Acid / metabolism
  • Chromatography, Liquid
  • Color
  • Gene Expression Regulation, Plant*
  • Glucosides / biosynthesis
  • Mass Spectrometry
  • Metabolic Engineering
  • Metabolic Networks and Pathways
  • Pancreatitis-Associated Proteins
  • Phenylpropionates
  • Plants, Medicinal / genetics*
  • Plants, Medicinal / metabolism
  • Rutin / biosynthesis
  • Saussurea / genetics*
  • Saussurea / metabolism
  • Sulfonic Acids
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transgenes

Substances

  • Anthocyanins
  • Antioxidants
  • Benzothiazoles
  • Glucosides
  • Pancreatitis-Associated Proteins
  • Phenylpropionates
  • REG3A protein, human
  • Sulfonic Acids
  • Transcription Factors
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
  • Chlorogenic Acid
  • Rutin
  • syringin

Grants and funding

This work was supported by the National Science Foundation of China (Grant No. 30873452 and 31200228). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.