Cloning and ectopic expression analysis of squalene epoxidase 1 gene from Pseudostellaria heterophylla
10.7501/j.issn.0253-2670.2017.13.023
- Author:
Guan-Shui CHEN
1
Author Information
1. College of Life Sciences, Fujian Agriculture and Forestry University
- Publication Type:Journal Article
- Keywords:
Ectopic expression;
Pseudostellaria heterophylla (Miq.) Pax;
Squalene epoxidase;
Transgenic tobacco;
Triterpenoid saponin
- From:
Chinese Traditional and Herbal Drugs
2017;48(13):2733-2739
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To clone the full-length cDNA encoding squalene epoxidase 1 (SQE1), a key enzyme of triterpenes biosynthesis, from Pseudostellaria heterophylla and to perform functional analysis. Methods: With the total RNA as template, the full-length cDNA of SQE1 in P. heterophylla was cloned via RT-PCR and rapid amplification of cDNA ends (RACE) techniques. The bioinformatics of the cloned SQE1 gene was performed. The target gene was transfered into tobacco by Agrobacterium-mediated transformation. Results: The full-length cDNA (2 038 bp) of SQE1 gene was obtained with an open reading frame of 1 554 bp, encoding 517 amino acid polypeptides, which had higher homology with the known SQEs in other medicinal species. The calculated relative molecular mass was 5.67 × 104, the isoelectric point was 8.8. The deduced protein sequence exhibited FAD-binding domains and four transmembrane regions. The content of total triterpenes was increased in transgenic tobacco plants. Conclusion: This is the first report that the full-length cDNA encoding SQE1 from P. heterophylla is cloned. The ectopic expression of SQE1 could promote to increase the content of total triterpenes in transgenic plant. This work provides a foundation for exploring the biosynthetic pathway of triterpenes in P.heterophylla and their applications in bioengineering.
