AUTHOR=Wang Qian-Qian , Zhu Meng-Jia , Yu Xia , Bi Yuan-Yang , Zhou Zhuang , Chen Ming-Kun , Chen Jiating , Zhang Diyang , Ai Ye , Liu Zhong-Jian , Lan Siren 

TITLE=Genome-Wide Identification and Expression Analysis of Terpene Synthase Genes in Cymbidium faberi

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.751853

DOI=10.3389/fpls.2021.751853

ISSN=1664-462X

ABSTRACT=<p>Terpene synthases (TPSs) are essential for forming terpenes, which play numerous functional roles in attracting pollinators, defending plants, and moderating the interaction between plants. TPSs have been reported in some orchids, but genome-wide identification of terpenes in <italic>Cymbidium faberi</italic> is still lacking. In this study, 32 putative TPS genes were classified in <italic>C. faberi</italic> and divided into three subfamilies (TPS-a, TPS-b, and TPS-e/f). Motif and gene structure analysis revealed that most <italic>CfTPS</italic> genes had the conserved aspartate-rich DDxxD motif. TPS genes in the TPS-a and TPS-b subfamilies had variations in the RRX<sub>8</sub>W motif. Most <italic>cis</italic>-elements of <italic>CfTPS</italic> genes were found in the phytohormone responsiveness category, and MYC contained most of the numbers associated with MeJA responsiveness. The <italic>K</italic>a/<italic>K</italic>s ratios of 12/13 <italic>CfTPS</italic> gene pairs were less than one, indicated that most <italic>CfTPS</italic> genes have undergone negative selection. The tissue-specific expression patterns showed that 28 genes were expressed in at least one tissue in <italic>C. faberi</italic>, and TPS genes were most highly expressed in flowers, followed by leaves and pseudobulbs. In addition, four <italic>CfTPS</italic> genes were selected for the real-time reverse transcription quantitative PCR (RT-qPCR) experiment. The results revealed that <italic>CfTPS12</italic>, <italic>CfTPS18</italic>, <italic>CfTPS23</italic>, and <italic>CfTPS28</italic> were mainly expressed in the full flowering stage. <italic>CfTPS18</italic> could convert GPP to β-myrcene, geraniol, and α-pinene <italic>in vitro</italic>. These findings of <italic>CfTPS</italic> genes of <italic>C. faberi</italic> may provide valuable information for further studies on TPSs in orchids.</p>