Abstract:
Gardenia jasminoides flowers are white in color and smell pleasant, which have high ornamental value and are an important source of natural spices in daily life. Terpenes are the main components of the unique aroma of
G. jasminoides, but the key terpene synthase (TPS) for the biosynthesis of such volatile products has not been identified. Here, based on the high-quality genome of
G. jasminoides, the analyses of transcriptome data, phylogenetic tree and conserved domain were used to fully explore
TPS genes related to the floral scent biosynthesis. The results showed that 44
TPSs were identified in
G. jasminoides, which were unevenly distributed on 11 chromosomes. All
GjTPSs were clustered into five subfamilies, and 27
GjTPSs belonged to the angiosperm-specific clades, including TPS-a, TPS-b and TPS-g. Combined with the transcriptome data and quantitative real-time PCR (qRT-PCR) analyses of five organs, five candidate
GjTPS genes with high expression in blooming flower were screened, and all of them contained the active motif DDXXD and NSE/DTE necessary for TPS to perform catalytic functions. Among them, GjTPS1, GjTPS2, GjTPS3 and GjTPS27 were grouped in TPS-b clade, which were presumed to be TPS for biosynthesizing the main floral scent components in
G. jasminoides such as linalool and ocimene, while GjTPS18 from clade TPS-a may be farnesene synthase. The results provide support for the functional characterization of
TPS genes catalyzed the terpene products in flowers and promote the research on the regulation of floral scent biosynthesis in
G. jasminoides.