Organ-specific, integrated omics data-based study on the metabolic pathways of the medicinal plant Bletilla striata (Orchidaceae)

Abstract

Background Bletilla striata is one of the important species belonging to the Bletilla genus of Orchidaceae. Since its extracts have an astringent effect on human tissues, B. striata is widely used for hemostasis and healing. Recently, some other beneficial effects have also been uncovered, such as antioxidation, antiinflammation, antifibrotic, and immunomodulatory activities. As a key step towards a thorough understanding on the medicinal ingredient production in B. striata, deciphering the regulatory codes of the metabolic pathways becomes a major task. Results In this study, three organs (roots, tubers and leaves) of B. striata were analyzed by integrating transcriptome sequencing and untargeted metabolic profiling data. Five different metabolic pathways, involved in polysaccharide, sterol, flavonoid, terpenoid and alkaloid biosynthesis, were investigated respectively. For each pathway, the expression patterns of the enzyme-coding genes and the accumulation levels of the metabolic intermediates were presented in an organ-specific way. Furthermore, the relationships between enzyme activities and the levels of the related metabolites were partially inferred. Within the biosynthetic pathways of polysaccharides and flavonoids, long-range phytochemical transportation was proposed for certain metabolic intermediates and/or the enzymes. Conclusions The data presented by this work could strengthen the molecular basis for further studies on breeding and medicinal uses of B. striata.

An organ‐specific transcriptomic atlas of the medicinal plant Bletilla striata: Protein‐coding genes, microRNAs, and regulatory networks

“…In our previous study, >69 gigabyte of RNA‐seq data from three organs (leaf, root, and tuber with three biological replicates for each organ) of B. striata was combinatorially used for de novo transcriptome assembly (Ma et al., 2021). A total of 42,974 genes were annotated (see section 2.5).…”

“…The de novo assembled transcriptome of B. striata was recently reported by our group (Ma et al., 2021). Briefly, the transcriptome was annotated by using the public databases including NCBI nonredundant sequence database (http://www.ncbi.nlm.nih.gov/RefSeq/) (Pruitt et al., 2007), gene ontology (http://geneontology.org/) (Ashburner et al., 2000), Kyoto Encyclopedia of Genes and Genomes (https://www.kegg.jp/) (Ogata et al., 1999), Pfam (http://pfam.xfam.org/) (Mistry et al., 2021), UniProtKB/Swiss‐Prot (https://www.uniprot.org/) (The UniProt Consortium, 2021), and eggNOG (http://eggnog5.embl.de/#/app/home) (Huerta‐Cepas et al., 2019).…”

“…The de novo assembled transcriptome of B. striata was recently reported by our group (Ma et al, 2021). Briefly, the transcriptome was annotated by using the public databases including NCBI nonredundant sequence database (http:// www.ncbi.nlm.nih.gov/RefSeq/) (Pruitt et al, 2007), gene ontology (http://geneontology.org/) (Ashburner et al, 2000), Kyoto Encyclopedia of Genes and Genomes (https://www.…”

Haplotype‐resolved genome assembly of Bletilla striata (Thunb.) Reichb.f. to elucidate medicinal value

“…The polysaccharide synthesis pathway has been studied to some extent in some medicinal plants, such as D. officinale , G. elata and Polygonatum cyrtonema (Niu et al., 2021; Shan et al., 2021; Wang et al., 2019). Polysaccharides are mainly produced by enzymes encoded by a series of structural genes, such as GMMP , sacA and UGP2 (Ma et al., 2021; Meng et al., 2009; Niu et al., 2021). For each of the nine key families, we investigated relative and absolute expression patterns, and then identified 10 core BSP‐related genes that may be involved in B. striata polysaccharide synthesis.…”

“…To date, various constituents have been isolated and extracted from B. striata , mainly including anthocyanins, astragalus, benzyl, ethers, phenanthrax, polysaccharides and terpenes (He et al., 2017; Kong et al., 2015). However, polysaccharides are the main components of B. striata (Ma et al., 2021; Niu et al., 2020; Wang & Meng, 2015) and have various medicinal functions. Bletilla striata polysaccharides (BSPs) are common immune immunomodulators that not only prevent gastric ulcers but also promote coagulation (Luo et al., 2018; Xiang et al., 2022; Zhang et al., 2019).…”