title: Comparative analysis of the terpenoid biosynthesis pathway in Azadirachta indica and Melia azedarach by RNA-seq.
abstract: Azadirachta indica (neem) is the only source of azadirachtin, which is known for its insecticide activity. Melia azedarach is a related species of A. indica, widely distributed in the south of China. In this study, the leaf transcriptomes of these two Meliaceae plants were sequenced. More than 40 million clean reads were generated from each library. About 80 % of A. indica reads were mapped to the neem genome, while 93 % of M. azedarach reads were mapped to its assembled transcripts and unigenes dateset. After mapping and assembly, 225,972 transcripts and 91,607 unigenes of M. azedarach were obtained and 1179 new genes of A. indica were detected. Comparative analysis of the annotated differentially expressed genes (DEG) showed that all six DEGs involved in terpenoid backbone biosynthesis were up-regulated in A. indica. Chemical analysis of the two plants revealed A. indica leaves contained 2.45 % total terpenoid and nearly 20-50 µg azadirachtin per gram, whereas azadirachtin was not detected in M. azedarach and total terpenoid content was reached 1.67 %. These results give us a better insight into the transcriptomes differences between A. indica and M. azedarach, and help us to understand the terpenoid biosynthesis pathway in vivo.
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Hang
authors.initials: H
authors.lastname: Xun
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory of Bamboo and Rattan Science and Technology of State Forestry Administration, International Center for Bamboo and Rattan, No. 8, Futong East Street, Wangjing Area, Chaoyang District, Beijing, 100102 People's Republic of China.
authors.forename: Feng
authors.identifier: 0000-0003-1111-8277
authors.initials: F
authors.lastname: Tang
keywords: Azadirachta indica; Azadirachtin; Melia azedarach; RNA-seq; Terpenoid biosynthesis