Transcriptome analysis of Cinnamomum longepaniculatum by high-throughput sequencing

Background: Cinnamomum longepaniculatum is an important commercial crop and the main source of volatile terpenoids. The biosynthesis of key bioactive metabolites of C. longepaniculatum is not well understood because of the lack of available genomic and transcriptomic information. To address this issue, we performed transcriptome sequencing of C. longepaniculatum leaves to identify factors involved in terpenoid metabolite biosynthesis. Results: Transcriptome sequencing of C. longepaniculatum leaves generated over 56 million raw reads. The transcriptome was assembled using the Trinity software and yielded 82,061 unigenes with an average length of 879.43 bp and N50 value of 1387 bp. Furthermore, Benchmarking Universal Single-Copy Orthologs analysis indicated that our assembly is 91% complete. The unigenes were used to query the nonredundant database depending on sequence similarity; 42,809 unigenes were homologous to known genes in different species, with an annotation rate of 42.87%. The transcript abundance and Gene Ontology analyses revealed that numerous unigenes were associated with metabolism, while others were annotated in functional categories including transcription, signal transduction, and secondary metabolism. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that 19,260 unigenes were involved in 385 metabolic pathways, with 233 unigenes found to be involved in terpenoid metabolism. Moreover, 23,463 simple sequence repeats were identified using the microsatellite identification tool. Conclusion: This is the first detailed transcriptome analysis of C. longepaniculatum. The findings provide insights into the molecular basis of terpenoid biosynthesis and a reference for future studies on the genetics and breeding of C. longepaniculatum.

Methyl Jasmonate Affects Metabolism and Gene Transcription of Volatile Terpenoids from Amomum villosum Lour / 世界科学技术-中医药现代化

This study was aimed to reveal the effects and molecular regulation mechanism of methyl jasmonate (Me-JA) on volatile terpenoids from Amomum villosum Lour. After the leaves and fruits of A momum villosum Lour. were treated with different concentrations of MeJA, the volatile terpenoids of fresh fruits from A . villosum Lour. were ex-tracted with microwave method and analyzed by GC-MS. Then, leaves and fruits treated with MeJA were sequenced by Illumina. The transcriptome data was analyzed by bioinformatic methods. The results showed that there were 20 and 33 volatile terpenoids detected in peels and seed groups, respectively. Contents of volatile terpenoids in peels and seed groups were both improved after 600 μmol·L-1 MeJA treating fruits for 24 h, such as bornyl acetate, cam-phor, borneol, and etc. While 200 μmol·L-1 MeJA treating different parts for 24 h can regulate the biosynthesis of some volatile terpenoids in peels differently. And 200 μmol·L-1 MeJA treating fruits can improve the content of ma-jor volatile terpenoids in seed groups. A total of 68 168 unigenes were obtained with de novo assembly, and 48 627 unigenes were annotated after comparison with public protein databases. Analysis of functional annotation against KEGG database showed that there were 208 unigenes closely related with metabolism of volatile terpenoids and 22 u-nigenes related with MYC2 transcription factors. It was concluded that MeJA can effectively regulate the metabolism of volatile terpenoids from A . villosum Lour. There were a lot of candidate genes related with the biosynthesis of volatile terpenoids obtained by analyzing the transcriptome data which also provided a large amount of data for the discovery and regulation of functional genes related with the biosynthesis of volatile terpenoids from A . villosum Lour.