Transcriptome Analysis of Secondary Metabolism Pathway, Transcription Factors, and Transporters in Response to Methyl Jasmonate in Lycoris aurea

Abstract

Lycoris aurea, a medicinal species of the Amaryllidaceae family, is used in the practice of traditional Chinese medicine (TCM) because of its broad pharmacological activities of Amaryllidaceae alkaloids. Despite the officinal and economic importance of Lycoris species, the secondary mechanism for this species is relatively deficient. In this study, we attempted to characterize the transcriptome profiling of L. aurea seedlings with the methyl jasmonate (MeJA) treatment to uncover the molecular mechanisms regulating plant secondary metabolite pathway. By using short reads sequencing technology (Illumina), two sequencing cDNA libraries prepared from control (Con) and 100 μM MeJA-treated (MJ100) samples were sequenced. A total of 26,809,842 and 25,874,478 clean reads in the Con and MJ100 libraries, respectively, were obtained and assembled into 59,643 unigenes. Among them, 41,585 (69.72%) unigenes were annotated by basic local alignment search tool similarity searches against public sequence databases. These included 55 Gene Ontology (GO) terms, 128 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and 25 Clusters of Orthologous Groups (COG) families. Additionally, 4,175 differentially expressed genes (DEGs; false discovery rate ≤ 0.001 and |log2 Ratio| ≥ 1) with 2,291 up-regulated and 1,884 down-regulated, were found to be affected significantly under MeJA treatment. Subsequently, the DEGs encoding key enzymes involving in the secondary metabolite biosynthetic pathways, transcription factors, and transporter proteins were also analyzed and summarized. Meanwhile, we confirmed the altered expression levels of the unigenes that encode transporters and transcription factors using quantitative real-time PCR (qRT-PCR). With this transcriptome sequencing, future genetic and genomics studies related to the molecular mechanisms associated with the chemical composition of L. aurea may be improved. Additionally, the genes involved in the enrichment of secondary metabolite biosynthesis-related pathways could enhance the potential applications of L. aurea.

Identification, molecular characterization and expression of JAZ genes in Lycoris aurea

“…Besides, although the induction effects of exogenous methyl jasmonate (MeJA) treatments on Amaryllidaceae alkaloids accumulation has been reported [37,38], little is known about the possible transcriptional or post-transcriptional regulation mechanism of this biological process in L. aurea. Recently, the transcriptome and small RNA sequencing under MeJA-treated L. aurea have been performed [39,40], which provided us a basic database to identify the key genes potentially involved in regulating the biological processes (especially Amaryllidaceae alkaloids biosynthesis) of L. aurea. Hence, in this study, based on our previous transcriptome data of L. aurea treated with MeJA [39], seven JAZ genes (LaJAZ1-LaJAZ7) were isolated and cloned.…”

“…Recently, the transcriptome and small RNA sequencing under MeJA-treated L. aurea have been performed [39,40], which provided us a basic database to identify the key genes potentially involved in regulating the biological processes (especially Amaryllidaceae alkaloids biosynthesis) of L. aurea. Hence, in this study, based on our previous transcriptome data of L. aurea treated with MeJA [39], seven JAZ genes (LaJAZ1-LaJAZ7) were isolated and cloned. Also, the expression profiles of these genes in different tissues and their response to MeJA were analyzed.…”

Increased antioxidant activity and polyphenol metabolites in methyl jasmonate treated mung bean (Vigna radiata) sprouts

“…The detection of exogenous MeJA can stimulate the production of phytochemicals in a number of different plants, such as sweet basil, raspberries, and radish sprouts, thereby improving their antioxidant activity shelf life (Kim et al, 2011;Tang et al, 2014b). Plants cope with the vital stress conditions including biotic and abiotic (elicitor exposure) through a variety of defense responses, which are mediated by production of different secondary metabolites for instance phenolics, flavonoids, and alkaloids, etc (Saeed et al, 2017;Wang et al, 2017).…”

Transcriptome and small RNA combined sequencing analysis of cold tolerance response in non-heading Chinese cabbage

“…The clean reads of each sample, which were sequence aligned with the designated reference genome. Gene expression analysis, which was performed, based on the comparison results; differentially expressed genes, which were identified, based on their expression levels in different samples, and their functional annotation and enrichment analysis were aslo performed [67].…”