# Diversity and Functional Evolution of Terpene Synthases in Rosaceae
); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (Y.X. ); [EMAIL_ADDRESS] (J.F. ); [EMAIL_ADDRESS] (Y.X.J. ); [EMAIL_ADDRESS] (T.W. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (Y.X. ); [EMAIL_ADDRESS] (J.F. ); [EMAIL_ADDRESS] (Y.X.J. ); [EMAIL_ADDRESS] (T.W. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (Y.X. ); [EMAIL_ADDRESS] (J.F. ); [EMAIL_ADDRESS] (Y.X. ); [EMAIL_ADDRESS] (Y.X.J. ); [EMAIL_ADDRESS] (T.W. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P. ); [EMAIL_ADDRESS] (H.P.) Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China  
[EMAIL_ADDRESS] (H.P. );Terpenoid compounds have been characterized in almond, apple, and peach [2; 3; 4; 5]. Volatile compounds in almond (plum subfamily) mainly consist of fatty acid-derived volatiles, several monoterpenes, sesquiterpenes, and phenylpropanoids, and significant differences in volatile composition were observed between different tissues and various varieties [3]. Apple (apple subfamily) fruit produce more than 300 volatile organic compounds (VOCs), including alcohols, aldehyde esters, and ketones; the specific VOC composition in apple depends on several factors, including cultivar, climacter ethylene production levels, maturity, and environmental conditions [4; 5]. More than 100 volatile chemicals have been identified in peach (plum subfamily) fruit, in which linalool is a key odorant that affects fruit aroma and consumer preference; over-expression of _terpene synthase gene 3_ led to linalool accumulation [2]. Thus, small changes in volatile content have the potential to affect fruit flavor quality, there is an emphasized interest to regulate fruit flavor related volatiles, and epigenetic regulation of terpenoids is also a control strategy during fruit ripening [6; 7]. To facilitate the breeding of Rosaceae species with desirable sensory qualities and improve their qualities under stress conditions, a better understanding of the genetic determinants of aroma and flavor in general and terpenes in particular is required. Terpenoids represent the largest group of natural products and make up diverse secondary metabolites. Terpenoid composition not only represents a critical attribute in determining the quality of horticultural food products, such as taste and aroma, but also functions widely in plant development and defense, such as attracting pollinators, defending against herbivores, and acting as anti-bacterial agents [8; 9; 10]. Plant terpenoids (isoprene-C5, monoterpenes-C10, sesquiterpenes-C15, diterpenes-C20, and polyterpenoids-C5 xn) are some compounds derived from isomeric 5-carbon building blocks isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) [11; 12]. About 50,000 terpenoid metabolites including monoterpenes, sesquiterpenes, anditerpenes have been identified in higher plants, liverworts, and fungi [11; 12]. In general, for a better adaptation to a local ecological niche, each species typically synthesizes only a small fraction of terpenoid metabolites [9; 13].