[Research progress on chemical constituents, pharmacological activities and clinical application of Bolbostemma paniculatum].

Bolbostemma paniculatum is a commonly used Chinese medicinal material effective in clearing heat, removing toxin, eliminating phlegm, and alleviating swelling. The anti-tumor activity it possesses makes it a research hotspot. At present, 76 compounds have been isolated from B. paniculatum, including triterpenoids, sterols, alkaloids, anthraquinones, organic acids, etc., with anti-tumor, antiviral, and immunosuppressive pharmacological activities. This study reviewed the research on the chemical constituents and pharmacological effects of B. paniculatum over the past 20 years, aiming to provide a scientific basis for the research on the pharmacodynamic material basis and promote the development and utilization of B. paniculatum.

Transcriptome-Wide Identification and Characterization of the JAZ Gene Family in Mentha canadensis L.

Jasmonate ZIM-domain (JAZ) proteins are the crucial transcriptional repressors in the jasmonic acid (JA) signaling process, and they play pervasive roles in plant development, defense, and plant specialized metabolism. Although numerous JAZ gene families have been discovered across several plants, our knowledge about the JAZ gene family remains limited in the economically and medicinally important Chinese herb Mentha canadensis L. Here, seven non-redundant JAZ genes named McJAZ1-McJAZ7 were identified from our reported M. canadensis transcriptome data. Structural, amino acid composition, and phylogenetic analysis showed that seven McJAZ proteins contained the typical zinc-finger inflorescence meristem (ZIM) domain and JA-associated (Jas) domain as conserved as those in other plants, and they were clustered into four groups (A-D) and distributed into five subgroups (A1, A2, B1, B2, and D). Quantitative real-time PCR (qRT-PCR) analysis showed that seven McJAZ genes displayed differential expression patterns in M. canadensis tissues, and preferentially expressed in flowers. Furthermore, the McJAZ genes expression was differentially induced after Methyl jasmonate (MeJA) treatment, and their transcripts were variable and up- or down-regulated under abscisic acid (ABA), drought, and salt treatments. Subcellular localization analysis revealed that McJAZ proteins are localized in the nucleus or cytoplasm. Yeast two-hybrid (Y2H) assays demonstrated that McJAZ1-5 interacted with McCOI1a, a homolog of Arabidopsis JA receptor AtCOI1, in a coronatine-dependent manner, and most of McJAZ proteins could also form homo- or heterodimers. This present study provides valuable basis for functional analysis and exploitation of the potential candidate McJAZ genes for developing efficient strategies for genetic improvement of M. canadensis.

Analysis of genetic variability and relationships among Mentha L. using the limonene synthase gene, LS.

The genus Mentha comprises a group of aromatic plants with worldwide distribution. Because of frequent interspecific hybridization, the genetic relationships within the genus are not clearly understood. Limonene synthase, which catalyses the first committed step in the essential oil monoterpene biosynthetic pathway, is considered to be a possible rate limiting enzyme. With the homology-based cloning method, primers were designed according to cDNA sequence to amplify full-length DNA sequences in 13 Mentha samples from five species, using Perilla as an outgroup. Analyses of gene structure, length variation, GC-content, Ts/Tv ratio and evolutionary diversity were carried out. Consensus phylogenetic trees were obtained using maximum likelihood, neighbor-joining, and maximum parsimony, respectively, based on the full-length genomic DNA sequences, complete ORF coding sequences and predicted amino acid sequences. The results presented here based on the sequence of MhLS provide the first credibly supported genetic relationships for Mentha, which enables a basis for further mint taxonomy, cultivation and breeding.