Genome-Wide Identification and Expression Analysis of TPS Gene Family in Liriodendron chinense

Abstract

Terpenoids play a key role in plant growth and development, supporting resistance regulation and terpene synthase (TPS), which is the last link in the synthesis process of terpenoids. <i>Liriodendron chinense,</i> commonly called the Chinese tulip tree, is a rare and endangered tree species of the family Magnoliaceae. However, the genome-wide identification of the <i>TPS</i> gene family and its transcriptional responses to development and abiotic stress are still unclear. In the present study, we identified a total of 58 <i>TPS</i> genes throughout the <i>L. chinense</i> genome. A phylogenetic tree analysis showed that they were clustered into five subfamilies and unevenly distributed across six chromosomes. A cis-acting element analysis indicated that <i>LcTPSs</i> were assumed to be highly responsive to stress hormones, such as methyl jasmonate (MeJA) and abscisic acid (ABA). Consistent with this, transcriptome data showed that most <i>LcTPS</i> genes responded to abiotic stress, such as cold, drought, and hot stress, at the transcriptional level. Further analysis showed that <i>LcTPS</i> genes were expressed in a tissue-dependent manner, especially in buds, leaves, and bark. Quantitative reverse transcription PCR (qRT-PCR) analysis confirmed that <i>LcTPS</i> expression was significantly higher in mature leaves compared to young leaves. These results provide a reference for understanding the function and role of the <i>TPS</i> family, laying a foundation for further study of the regulation of <i>TPS</i> in terpenoid biosynthesis in <i>L. chinense</i>.