Next Article in Journal
Conflicting Roles of 20-HETE in Hypertension and Stroke
Previous Article in Journal
Genome-Wide Expression Profiling of Genes Associated with the Lr47-Mediated Wheat Resistance to Leaf Rust (Puccinia triticina)
Open AccessArticle

Molecular Cloning and Functional Identification of a Squalene Synthase Encoding Gene from Alfalfa (Medicago sativa L.)

Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
*
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Int. J. Mol. Sci. 2019, 20(18), 4499; https://doi.org/10.3390/ijms20184499
Received: 24 August 2019 / Revised: 9 September 2019 / Accepted: 10 September 2019 / Published: 11 September 2019
The quality of alfalfa, a main forage legume worldwide, is of great importance for the dairy industry and is affected by the content of triterpene saponins. These natural terpenoid products of triterpene aglycones are catalyzed by squalene synthase (SQS), a highly conserved enzyme present in eukaryotes. However, there is scare information on alfalfa SQS. Here, an open reading frame (ORF) of SQS was cloned from alfalfa. Sequence analysis showed MsSQS had the same exon/intron composition and shared high homology with its orthologs. Bioinformatic analysis revealed the deduced MsSQS had two transmembrane domains. When transiently expressed, GFP-MsSQS fusion protein was localized on the plasma membrane of onion epidermal cells. Removal of the C-terminal transmembrane domain of MsSQS improved solubility in Escherichia coli. MsSQS was preferably expressed in roots, followed by leaves and stems. MeJA treatment induced MsSQS expression and increased the content of total saponins. Overexpression of MsSQS in alfalfa led to the accumulation of total saponins, suggesting a correlation between MsSQS expression level with saponins content. Therefore, MsSQS is a canonical squalene synthase and contributes to saponin synthesis in alfalfa. This study provides a key candidate gene for genetic manipulation of the synthesis of triterpene saponins, which impact both plant and animal health.
Keywords: alfalfa; saponins; squalene synthase; transgenic alfalfa alfalfa; saponins; squalene synthase; transgenic alfalfa
MDPI and ACS Style

Kang, J.; Zhang, Q.; Jiang, X.; Zhang, T.; Long, R.; Yang, Q.; Wang, Z. Molecular Cloning and Functional Identification of a Squalene Synthase Encoding Gene from Alfalfa (Medicago sativa L.). Int. J. Mol. Sci. 2019, 20, 4499.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

1
Back to TopTop