Transcriptional profile of Taxus chinensis cells in response to methyl jasmonate.

BACKGROUND: Methyl jasmonate (MeJA) has been successfully used as an effective elicitor to enhance production of taxol and other taxanes in cultured Taxus cells. However the mechanism of MeJA-mediated taxane biosynthesis remains unclear. Genomic information for species in the genus Taxus is currently unavailable. Therefore, information about the transcriptome of Taxus cells and specifically, description of changes in gene expression in response to MeJA, is needed for the better exploration of the biological mechanisms of MeJA-mediated taxane biosynthesis.

RESULTS: In this research, the transcriptome profiles of T. chinensis cells at 16 hours (T16) after MeJA treatment and of mock-treated cells (T0) were analyzed by "RNA-seq" to investigate the transcriptional alterations of Taxus cell in response to MeJA elicitation. More than 58 million reads (200 bp in length) of cDNA from both samples were generated, and 46,581 unigenes were found. There were 13,469 genes found to be expressed differentially between the two timepoints, including all of the known jasmonate (JA) biosynthesis/JA signaling pathway genes and taxol-related genes. The qRT-PCR results showed that the expression profiles of 12 randomly selected DEGs and 10 taxol biosynthesis genes were found to be consistent with the RNA-Seq data. MeJA appeared to stimulate a large number of genes involved in several relevant functional categories, such as plant hormone biosynthesis and phenylpropanoid biosynthesis. Additionally, many genes encoding transcription factors were shown to respond to MeJA elicitation.

CONCLUSIONS: The results of a transcriptome analysis suggest that exogenous application of MeJA could induce JA biosynthesis/JA signaling pathway/defence responses, activate a series of transcription factors, as well as increase expression of genes in the terpenoid biosynthesis pathway responsible for taxol synthesis. This comprehensive description of gene expression information could greatly facilitate our understanding of the molecular mechanisms of MeJA-mediated taxane biosynthesis in Taxus cells.