Molecular cloning and expression analysis of a novel tea terpene synthase
Journal
Acta Horticulturae
Journal Volume
1297
Pages
659-666
Date Issued
2020
Author(s)
Abstract
Semi-fermented oolong tea is an important feature of teas in Taiwan with characteristic aroma that affects tea quality, and volatile terpenes account for more than 50% of the aroma compounds. During semi-fermented tea manufacturing process, relative content of floral and fruity aroma compounds, including some volatile terpenes, increase in a fluctuating profile; however, the associated molecular mechanism and enzymatic reactions remain unclear. In order to identify key enzyme involved in the biosynthesis of tea volatile terpenes, one novel unigene annotated to Arabidopsis thaliana terpene synthase 4 (AT1G61120), a geranyllinalool synthase, was singled out for further investigation based on the transcriptome database established in former study. This unigene was designated as Camellia sinensis terpene synthase 4 (CsTPS4). CsTPS4 contained a 2,517 bp open reading frame, which can be translated to protein sequence with 839 amino acids, and the predicted molecular weight was 97 kDa. With the use of primer sets designed according to CsTPS4 unigene sequence, the cloning of this gene had been completed. In the process of semi-fermented tea manufacturing, the expression level of CsTPS4 was upregulated during solar withering and fluctuated during indoor withering and shaking procedure. The maximum expression level of CsTPS4 appeared in late stages of fermentation, corresponding to high volatile terpene contents and suggesting the potential role of this gene to participate in volatile terpene biosynthesis. Further research on CsTPS4 characterization will provide clearer evidence on the function of this gene in the formation of tea terpenes, especially during manufacturing process. ? 2020 International Society for Horticultural Science. All rights reserved.
Type
conference paper