###### Abstract
Since there are no significant morphological differences among these three species, they have been classified based on their geographical distributions [26; 27]. _C. keiskei_ is also called 'the Asian Lilly of the Valley' and is only distributed in Korea, Japan and China [28]. _Convallaria_ possesses potent cardioactive glycosides and functions as a geophyte, rendering it toxic to herbivores [29]. These geophytic toxins represent a promising reservoir of bioactive metabolites with substantial potential for both health-related and agronomic applications [30]. In addition, _Convallaria_ is a bell-shaped flower with a sweet aroma and is extensively used in fragrances and other cosmetic products owing to the presence of volatile compounds [31; 32]. Notably, as early as 1765, a French florist employed _Convallaria_ as a perfumed floral product, suggesting the existence of multiple volatile organic compounds (VOCs) in all parts of the plant [33]. [PERSON] et al. [34] analyzed the presence of volatile constituents present in the _C. keiskei_ flower using a GC-MS approach. They identified four terpene alcohols, accounting for 47.91% of the volatile composition, followed by ten saturated hydrocarbons (24.41%), three monoterpenes (5.8%), thirteen unsaturated hydrocarbons (9.16%), and an additional twenty-two compounds, including acids, alcohols, aldehydes, esters, ketones and terpene esters, comprising 12.4% of the total composition. Among these compounds, the primary volatile terpene constituents found in _C. keiskei_ flowers were dihydromyrcenol (17.85%), _trans_-geraniol (17.14%), nerol (12.78%) and pentadecane (11.91%). These compounds are known to contribute significantly to the floral scents associated with _C. keiskei_. In contrast, thus far, no molecular studies have been conducted to comprehensively investigate the genes associated with volatile biosynthesis in _C. keiskei_. More recently, several genomic studies have focused on unraveling the genome structure and evolutionary aspects of _Convallaria_[26; 27]. Notably, _Convallaria_ is the first genus to provide evidence of mitochondrial DNA transfer to the chloroplast genome in the Asparagales order, making it an excellent model plant for studying genome evolution [26; 27]. However, despite these advances, to the best of our knowledge, no transcriptomic studies have been conducted to elucidate the genes involved in essential oil synthesis in _C. keiskei_. Additionally, recent transcriptome analysis has been widely used to identify the genes involved in floral scent metabolites in some plant species [35; 36; 37; 38; 39]. Therefore, in the present study, we conducted a comparative analysis of the leaf, flower and root of _C. keiskei_ using transcriptomic analyses to understand the genes involved in essential oil biosynthesis. In addition, we performed an analysis of _TPS_ genes in _C. keiskei_ to discover and gain knowledge of their contribution in a tissue-specific manner. Our findings reveal distinct patterns of _TPS_ genes in the leaf, flower and root, with tissue-specific expression patterns. This indicates that one _TPS_ gene may be involved in synthesizing multiple mono- and sesquiterpenes in _C. keiskei_. This study is the first comprehensive transcriptomic analysis of _C. keiskei_, providing transcriptomic data on which may further enrich the understanding of the molecular regulation and biosynthesis of terpenoid-related genes, which are the primary component of _C. keiskei_ essential oil in the genus.