Overexpression of the Liriodendron tulipifera TPS32 gene in tobacco enhances terpenoid compounds synthesis

<i>Liriodendron</i>, a relic genus from the Magnoliaceae family, comprises two species, <i>L. tulipifera</i> and <i>L. chinense</i>. <i>L. tulipifera</i> is distinguished by its extensive natural distribution in Eastern North America. Conversely, <i>L. chinense</i> is nearing endangerment due to its low regeneration rate. A pivotal aspect in the difference of these species involves terpenoids, which play crucial roles in plant growth and attracting pollinators. However, the complex molecular mechanisms underlying terpenoid roles in <i>Liriodendron</i> are not well understood. Terpene Synthases (TPS) genes are widely reported to play a role in terpenoid biosynthesis, hence, this study centers on <i>TPS</i> genes in <i>Liriodendron</i> spp. Employing multiple bioinformatics methods, a differential expression gene in <i>L. tulipifera</i>, <i>LtuTPS32</i>, was discerned for further functional analysis. Subcellular localization results reveal the involvement of <i>LtuTPS32</i> in chloroplast-associated processes, hence participate in terpenoid biosynthesis within chloroplasts. Heterologous transformation of the <i>LtuTPS32</i> gene into tobacco significantly elevates the levels of common terpenoid compounds, including chlorophyll, gibberellin, and carotenoids. Collectively, these findings not only underscore the role of the <i>LtuTPS32</i> gene in the biosynthesis of terpenoids but also lay a foundation for future research on interspecific differences in <i>Liriodendron</i>.