MYB transcription factors play many important regulatory roles in plant growth and development, secondary metabolism, and stress adaptation processes. In this work, an MYB gene containing a complete open reading frame (ORF) was selected from the transcriptome database of R. palmatum L. RpMYB4 ORF and cloned, encoding a polypeptide of 245 amino acids with a molecular weight of 26.99 kDa. RpMYB4 lacks a signal peptide or transmembrane domain but contains two conserved DNA binding domains (HTH-MYB) of the R2R3-MYB subfamily at the N-terminus. Multiple-sequence alignment demonstrated that RpMYB4 shared as high as 61% identity with many MYB proteins from other species. Phylogenetic analysis showed that RpMYB4 had the closest relationship with FtMYB8 and was clustered in the S4 subfamily. Subcellular localization by confocal microscopy showed that an RpMYB4-GFP-fusion protein localized to the nucleus in tobacco. Real-time fluorescence quantitative PCR analyses revealed that RpMYB4 was differentially expressed in various tissues, with the highest expression in leaves, followed by petioles, rhizome, and roots, and with the lowest level in mature seeds. After treatment of R. palmatum L. seedlings with 200 μmol·L^-1 MeJA, the expression of RpMYB4 in leaves was down-regulated within 24 h, and significantly up-regulated after 200 μmol·L^-1 SA treatment at 12 h and 24 h. However, gene expression did not change with 200 μmol·L^-1 ABA treatment. The transcripts of RpMYB4 under drought, high temperature, and mechanical injury stresses reached a peak at 24 h, 24 h, and at 3 h, respectively, while RpMYB4 expression was inhibited by low temperature stress, reaching its lowest value at 6 h. The gene showed no significant response to salt stress. Overall, RpMYB4 was cloned from R. palmatum L. for the first time, showed high expression in leaves, and was responsive to SA and various abiotic stress treatments including drought, high temperature, and mechanical injury. The results will be useful for further analysis of secondary metabolism and stress adaptations in R. palmatum L.

OBJECTIVE To improve the quality evaluation method of Platycodonis Radix, to study the differences in the quality of three-years-old Platycodonis Radix under different harvesting periods, and to determine the optimal harvesting period of Platycodonis Radix. METHODS The leachate, ash, moisture, refractive index and the content of six saponins were used as the quality evaluation indexes. The differences between the herbs of Platycodonis Radix at different harvesting periods were characterized with the help of mathematical and statistical methods. And link the entropy weight method, gray correlation analysis and TOPSIS method were combined to obtain the statistical analysis of the relevant indexes and the quality ranking information of the herbs in different harvesting periods. RESULTS There were significant differences between the quality evaluation indexes of three-years-old Platycodonis Radix at different harvesting periods. The added multi-indicator testing had improved the quality evaluation system of Platycodonis Radix and enhanced the "Drug properties-Effectiveness" linkage of the herbs. And the results of the comprehensive quality evaluation model showed that the herbs harvested around October 21 (Frost’s Descent) were ranked best in terms of comprehensive index. CONCLUSION In order to ensure the quality of Platycodonis Radix, the best harvesting period for three-years-old Platycodonis Radix is determined around the "Frost’s Descent" season, taking into account the characteristics of the herbs' appearance and the material basis of herbs.

In this study, the molecular mechanism of Cinnamomi Cortex-Rehmanniae Radix (CR) in the prevention and treatment of osteoporosis (OP) was investigated by integrating compatibility analysis of compound, bioinformatics and metabolomics. The rat OP models were established, and the Micro-CT indexes and pathological sections were comprehensively evaluated. The results showed that compared with the model group, the indexes such as bone mineral density (BMD) and bone volume/tissue volume (BV/TV) were significantly increased after CR treatment (P < 0.05), and the bone trabeculae were arranged into mesh. The results of UHPLC-Q-TOF/MS mainly involved amino acid metabolism, lipid metabolism and estrogen metabolism pathways. Integrating bioinformatics and metabolomics analysis, it was finally found that: ① cinnamic acid and ethylcinnamate inhibit inflammatory factors such as TNF, IL-1β, and IL-13, thereby preventing and treating OP; ② multiple active ingredients of CR target ESR2, PPARG, and CYP19A1, GABRA1 and other targets, regulate cAMP synthesis, AMPK signaling pathway and lipid metabolism, thereby regulating estrogen levels to prevent and treat OP; ③ oleic acid, arachic acid, etc. act on AR, VDR and other targets, and regulate HIF-1 signaling pathway and AGE-RAGE signaling pathway, thereby regulating osteoblasts and osteoclasts, and affecting calcium and phosphorus absorption to maintain bone homeostasis. This study clarified the molecular mechanism of CR in preventing and treating OP from the perspective of multi-directional regulation of inflammatory factors, estrogen and bone homeostasis, and provided theoretical basis for the clinical application of CR and the development of compound. This experiment complied with the ethical standards of animal experiments and was approved by the Animal Ethics Committee of Shaanxi University of Chinese Medicine (No. SUCMDL20210309002).

In order to explore the use of DNA barcode in the identification of wild Phytolacca resources in the Shaanxi Guanzhong area, 29 DNA samples were amplified and sequenced by using the universal primers ITS2 and psbA-trnH. The sequences were spliced and proof-read by Codon CodeA aligner V3.0, followed by blast comparison and identification analysis; mega 6.0 was used to analyze sequence characteristics, Kimura 2-Parameter (K2P) was used to analyze distance and intraspecific or interspecific variation, and Neighbor-Joining trees were established to evaluate the ability of two pairs of candidate sequences to distinguish Phytolaccae Radix from its adulterants. The results showed that the success rate of PCR amplification and sequencing of ITS2 and psbA-trnH was 100%; the NJ tree showed that both ITS2 and psbA-trnH sequences could separate P. acinosa, P. americana, other species of the same genus like P. japonica, P. exiensis and two adulterant species into a single clade; primer ITS2 had an advantage over psbA-trnH in determining interspecific genetic distances. Therefore, both ITS2 and psbA-trnH sequences can be used for identification of Phytolacca and their adulterants, which provides a theoretical basis for the distribution of wild Phytolacca resources and their rational development and utilization.

As one kind of v-myb avian myeloblastosis viral oncogene homolog (MYB) transcription factors, R1-MYB (MYB-related) family plays an important role in plant growth and development, as well as environmental stress and hormone signal transduction. In this study, R1-MYB family genes in Rheum palmatum L. were systematically screened based on full-length transcriptome sequencing analysis. Firstly, the physicochemical, protein domain and molecular evolution characteristics of the coding proteins were analyzed. Furthermore, the tissue expression levels of R1-MYB genes were analyzed by RNA-seq. We also investigated the expression pattern of RpMYB24 in response to various hormones and abiotic stresses. The results showed that a total of 49 R1-MYB genes were identified, which mainly encoded thermally stable hydrophilic proteins. Most of the deduced proteins were predicted to locate in nucleus. Each protein had a large proportion of random curl and α helix, and also had the W-type conserved amino acids which were the signature of MYB. R1-MYB family members were distributed in five subgroups, including circadian clock associated 1 (CCA1)-like, I-box (GATAAG)-like, CAPRICE (CPC)-like, telomere repeat binding factor (TRF)-like and TATA binding protein (TBP)-like, and the number of CCA1-like was the majority. RNA-seq revealed that 49 R1-MYB genes were differentially expressed in roots, rhizomes and leaves of R. palmatum, and the expression levels of 15 and 23 genes in roots and rhizomes were higher than those in leaves, respectively. RpMYB24 transcript was induced by abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA) treatment, and could also significantly respond to injury, low temperature and high temperature stresses except drought stress. This study systematically identified the R1-MYB family genes and their molecular characteristics, better for further gene functional validation, and then provide a scientific basis for the transcriptional regulation mechanism research into rhubarb quality formation.

italic>Tussilago farfara L. is a perennial herb of Tussilago genus in the Compositae family. Its dried buds and leaves have good biological activities and have a long history of medicinal use in China and Europe. In this paper, we investigated the whole chloroplast genome characteristics, sequence duplication, structural variation and phylogeny of the Tussilago farfara L. After sequencing the Tussilago farfara L. chloroplast genome using Illumination technology, the complete Tussilago farfara L. chloroplast genome was further obtained by assembly and annotation, followed by a series of inverted repeat-large single copy/small single copy region contraction and expansion analysis, genome sequence variation, etc. The sequences of 13 homologous plants downloaded from NCBI were used to construct a neighbor-joining phylogenetic tree. The results showed that the total GC content of the chloroplast genome was 37.4% and the length was 150 300 bp; 125 genes were annotated, including 82 protein-coding genes, 35 tRNAs and 8 rRNAs; 148 (simple sequence repeats, SSR) loci were detected, and the relative synonymous codon usage showed that 31 codons out of 64 codons had a usage of >1. In the phylogenetic analysis, the chloroplast genomes of the seven species of Asteraceae, including the Yulin Tussilago farfara L., were highly conserved, and the sequence variation of the (large single-copy, LSC) and (small single-copy, SSC) regions was higher than that of the (inverted repeat, IR) region. This is in general agreement with the reported phylogeny of Yulin Tussilago farfara L. In this study, we obtained a high quality chloroplast genome and analyzed its genome characteristics, codon preference, SSR characteristics, SC/IR boundary, sequence variation and phylogeny, which can provide a basis for species identification, genetic diversity analysis and resource development of this medicinal plant.