## 1 Introduction  
Plants produce a flower aroma that plays a significant role in their economic value and aesthetic properties [1]. Each plant has its own unique floral aroma, consisting of volatile organic compounds, which are mainly derivatives of fatty acids, terpenoids, and phenylpropanoids or benzoids. Thus,an understanding of the mechanism associated with the formation of these floral aromas is necessary to create new breeds, mainly in plants that produce less volatile compounds [2; 3]. Two independent and separate pathways, methyleryththird phosphate (MEP) and mevalonic acid (MVA), are responsible for the synthesis of terpenoids [3]. The MVA pathway is involved in the biosynthesis of sesquiterpenes, which accounts for 28% of all floral terpenoids. In contrast, the MEP pathway is mainly involved in the biosynthesis of monoterpene and diterpene, producing approximately 53% and 1% of the total floral terpenoids, respectively [4]. To date, many flower-specific terpene syntheses have been isolated and characterized, such aslinaloid in _Arabidopsis thaliana_, _Osmanthus fragrans_, _Antitrhinun majus_, _Clarkia breweri_, and _Hedychium coronarium_[4; 5; 6; 7]; myxene in _Alstroemeria peruviana_ and _A. majus_[8]; 1,8-cineole in _Nicotiana suaveolens_, _Citrus unshiu_, and _H. coronarium_[9; 10]; \(E\)-(\(\beta\))-ccimine in _A. majus_ and _H. coronarium_[11; 12; 13]; sesquiterpene \(\alpha\)-farnesene in _Actiidia delicosa_ and _H. coronarium_[14; 15]; germacrene D in _Rosa hybrid_, _A. delicosa_, and _Vitus vinifera_[13; 16]; rerolidol in _A. chinensis_ and _A. majus_[17]; valence in _V. vinifera_[16]; \(\beta\)-ylangene, \(\beta\)-copaene, \(\beta\)-cubenen, and \(\alpha\)-bergamotene in _Cunagaodorata_ var. _fruticose_[18], and \(\beta\)-caryophyllene in _A. thaliana_, _Ocimum kilimandscharicum_, and _Daucus carota_[19; 20; 21]. However, the regulatory mechanisms and the biosynthesis of the floral aroma, especially in woody ornamental plants, are mostly undiscovered. Jasmonates (JAs), biologically active intermediates involved in the production pathways of jasmonic acid, are associated with a series of biological processes [22] including the ripening of fruits, the production of viable pollen, the growth of roots, tendril coiling, plant responses against the abiotic stress, wounds, and defense against insect pests [23; 24; 25; 26; 27; 28; 29]. JAs are also released as volatile organic compounds (VOCs) and help as a communicator between plants in response to mutual dangers [30]. JAs induce the expression of terpene synthase genes, which results in the release of more terpenides [31]. The upregulation of terpene synthase (TPS) genes is also related to the development of flowers in plants [32]. In this content, methyl jasmonic acid (MeJA) treatment increases the production of monoterpene (E)-\(\beta\)-ocimine and linaloid in tobacco [33]. JAs treatment upregulates the transcription of TPS03 (At4g16740), encoding (E)-\(\beta\)-ocimine synthase in arabidopsis [34]. The MYC family members are basic transcription factors of helix-loop-helix (bHLH) that have numerous functions and are very important in the regulation mechanisms of plants. One of the members of this family, MYC2, has been found to show a significant role in various plant developmental mechanisms including cold stress, insect pest attack, salt stress, salinity, drought, response to light conditions, anthocyanin production, terpene synthesis, and different signaling pathways such as jasmonic acid (JA), gibberellins (GAs), abscisic aid (ABA), auxin (IAA), and salicylic acid (SA) [2; 20; 21; 26; 27; 35]. MYC2 has also been reported as one of the major players in the crosstalk between JA and GA signaling. It also plays a role as a signal integrator of the JA and GA pathways and was shown to be a positive important regulator of the induction of JA and GA and the expression of terpene synthase genes in _Arabidopsis_[20].