| Title: | Isolation and functional analysis of squalene synthase gene in tea plant Camellia sinensis |
| Author(s): | Fu J; Liu G; Yang M; Wang X; Chen X; Chen F; Yang Y; |
| Address: | "Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China; Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, Hangzhou, 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China. Electronic address: mybatigoal@tricaas.com. Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China; Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, Hangzhou, 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China. Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China; National Center for Tea Plant Improvement, Hangzhou, 310008, China. Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA. Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China; National Center for Tea Plant Improvement, Hangzhou, 310008, China. Electronic address: yjyang@tricaas.com" |
| DOI: | 10.1016/j.plaphy.2019.06.030 |
| ISSN/ISBN: | 1873-2690 (Electronic) 0981-9428 (Linking) |
| Abstract: | "Tea contains high quantities and diverse types of triterpenoids, particularly in the form of saponins. However, little is yet known about the molecular basis of triterpenoid biosynthesis in tea plant. Here we report on isolation and functional analysis of squalene synthase (SQS) gene from tea plant (Camellia sinensis var. sinensis), which controls the biosynthesis of triterpenoids precursor. First, a full-length cDNA of squalene synthase, designated CsSQS, was isolated from tea plant. The protein is highly homologous to SQSs from other plants. Using CsSQS-reporter assays, CsSQS was demonstrated to be endoplasmic reticulum membrane-bound. The coding region of CsSQS excluding transmemberane sequence was expressed in Escherichia coli. Recombinant CsSQS catalyzed the formation of squalene using farnesyl-pyrophosphate (FPP) as substrate with NADPH and Mg(2+). In tea plant leaves, CsSQS expression was significantly induced by both herbivore and mechanical damages. Consistent with the stronger induction of CsSQS expression by mechanical damage than herbivory, tea plants injured mechanically released squalene as a volatile compound, which however was not detected from herbivore-damaged tea plants. Furthermore, it was found that the flowers of another tea plant cultivar Camellia sinensis var. assamica contain higher concentrations of squalene than the cultivar sinensis, indicating variations among tea plant varieties. With the identification and molecular characterization of squalene synthase in tea plant, next, we can ask the questions about the roles of squalene as a volatile product as well as a precursor for triterpenoids, which may promote product development from diverse tea materials and mining of excellent tea germplasm resources" |
| Keywords: | "Camellia sinensis/*enzymology/genetics/physiology Cloning, Molecular Endoplasmic Reticulum/metabolism Farnesyl-Diphosphate Farnesyltransferase/chemistry/*genetics/*metabolism Flowers/metabolism Gene Expression Regulation, Plant Herbivory Phylogeny Plant P;" |
| Notes: | "MedlineFu, Jianyu Liu, Guanhua Yang, Mei Wang, Xinchao Chen, Xinlu Chen, Feng Yang, Yajun eng France 2019/07/05 Plant Physiol Biochem. 2019 Sep; 142:53-58. doi: 10.1016/j.plaphy.2019.06.030. Epub 2019 Jun 24" |
