Original Research ARTICLE
The biosynthesis of heterophyllin B in Pseudostellaria heterophylla from prePhHB-encoded precursor
- 1Guiyang College of Traditional Chinese Medicine, China
- 2Graduate School of Tianjin University of Traditional Chinese Medicine, China
- 3School of Pharmacy, Guiyang University of Chinese Medicine, China
Plant cyclopeptides are a large group of small molecule metabolites found in a wide variety of plants, including traditional Chinese medicinal plants. However, the majority of the cyclopeptides have not been studied for their biosynthetic mechanisms, including heterophyllin B (HB), which is one of the active compounds existing in the tuberous roots of Pseudostellaria heterophylla. Here, we screened the precursor genes (prePhHB) of HB in P. heterophylla and identified its validity in vivo and in vitro. First, we developed a new method to screen the precursors of HB from 16 candidate linear peptides. According to transcriptome sequencing data, we identified the genes that encoded the HB precursors and confirmed that the prePhHB-coded linear peptide could enzymatically synthesize HB. Next, we generated the transgenic tobacco that expressed prePhHB, and the results showed that HB was detected in transgenic tobacco. Moreover, we revealed the prePhHB differential expression as the result of the difference in the content of HB in P. heterophylla. The mutation of prePhHB in P. heterophylla influences the synthesis of HB. These results suggest that the prePhHB-encoded linear peptide (IFGGLPPP) is a precursor of HB in P. heterophylla. These findings provide new ideas for the study of the linear structure of CPs and lay a foundation for the biosynthesis of HB.
Keywords: Cyclic peptide, Heterophyllin B, gene, prePhHB, Pseudostellaria heterophylla
Received: 24 Aug 2018;
Accepted: 10 Sep 2019.
Copyright: © 2019 Zheng, Zhou, Jiang, Zhang, Li, Xiao, Wei, Yang, Xu, Gong, Zhang and Bi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Prof. Tao Zhou, Guiyang College of Traditional Chinese Medicine, Guiyang, Guizhou Province, China, firstname.lastname@example.org
Prof. Weike Jiang, School of Pharmacy, Guiyang University of Chinese Medicine, Guiyang, Guizhou Province, China, Jwk_88@163.com