OBJECTIVE: To characterize a glycosyltransferase (RpUGT1) from Rheum palmatum and investigate its specificity toward flavonoid compounds. METHODS: The RpUGT1 was expressed in Escherichia coli and screened for catalytic activity against a range of flavonoid substrates using a high-throughput HPLC assay method. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) were used to determine the structure of the product. Homology modeling, molecular docking analyses and site-directed mutagenesis studies were conducted to identify key residues responsible for its function. RESULTS: The recombinant RpUGT1 protein exhibited catalytic activity towards various flavonoids. Notably, RpUGT1 catalyzed the glycosylation of isorhamnetin to form 3-O-glucoside and kaempferol to form 7-O-glucoside, utilizing uridine diphosphate (UDP) glucose as the sugar donor. The homology modeling and molecular docking analyses identified key residues responsible for its activity. Subsequent site-directed mutagenesis studies highlighted the crucial role of K307 in catalysis. CONCLUSION These discoveries offer valuable perspectives on the role of the UGT family and establish a groundwork for forthcoming research on the synthesis of flavonoids in plants.

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.

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.

italic>Polygonatum franchetii Hua is a medicinal plant endemic to China from Polygonatum Mill. The chloroplast genomes of two P. franchetii individuals sampled from two different habitats were sequenced by using the DNBSEQ-T7 high-throughput sequencing platform. After assembly and annotation, the two complete chloroplast genomes were characterized, and then comparative and phylogenetic analyses were performed with other published chloroplast genome sequences from Polygonatum. The whole chloroplast genomes of the two P. franchetii individuals were 155 942 and 155 962 bp in length, with a large single copy region (LSC, 84 670 and 84 722 bp), a small single copy region (SSC, 18 564 and 18 566 bp) and a pair of reverse repeats (IRa/IRb, 26 354 and 26 337 bp), respectively. Both of them contained 113 genes, including 79 protein-coding genes (PCGs), 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. Comparative analyses showed that the genome length, the guanine and cytosine (GC) content, genes content and order were highly conserved between the two P. franchetii individuals and among different Polygonatum species. The detected repeat sequences, including dispersed repeats, tandem repeats and simple sequence repeats (SSRs), were also relatively similar in types and positions, though showing a slightly difference in number. No significant expansion or contraction of the inverted repeat regions was found. Sequences variation between the two P. franchetii individuals was lower than that among different Polygonatum species. Besides, coding sequences (CDS) showed less divergence than noncoding sequences, and sequence divergence of IRs regions was lower than that of the LSC and SSC regions, both intraspecifically and interspecifically. Eight sequences with high nucleotide diversity among different species were screened, all of which were found located in the LSC and SSC regions. Phylogenetic inference showed that all Polygonatum species clustered into a monophyletic clade with a 100% bootstrap value, within which, species in section Verticillata formed a distinct group, section Sibirica and section Polygonatum were sister groups. The two P. franchetii individuals grouped together and showed the closest phylogenetic affinity to P. stenophyllum Maxim., belonging to the section Verticillata. The chloroplast genome of P. franchetii and its phylogenetic position in Polygonatum were comprehensively investigated and clearly elucidated in this study, the results may lay a foundation for the resource development and utilization of P. franchetii, as well as further molecular identification and phylogenetic studies of medicinal Polygonatum species.

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.

Objective:To investigate the effect of homogeneous management combined with staged teaching on physicians receiving standardized training of hepatobiliary surgery.Methods:A total of 46 physicians who received standardized training in Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, from January to March 2020 were selected as control group and were given conventional teaching, and 50 physicians who received standardized training from April to June 2020 were selected as observation group and were given homogeneous management combined with staged teaching. The two groups were compared in terms of professional level, clinical ability, and the degree of satisfaction with teaching before and after teaching. SPSS 24.0 was used to perform the independent samples t-test, the paired t-test, the chi-square test, and the rank sum test. Results:After teaching, both groups had significant increases in the scores of theoretical examination and operation skill examination, and compared with the control group, the observation group had significantly higher scores of theoretical examination (94.57±3.28 vs. 90.32±2.12) and operation skill examination (94.37±4.18 vs. 91.25±3.46). After teaching, both groups had significant increases in the scores of clinical consultation, physical examination, humanistic concern, clinical diagnosis, communication ability, organizational ability, and overall evaluation, and the observation group had significantly higher scores of the above seven aspects than the control group (6.98±0.94/6.45±0.14/6.95±0.88/6.65±0.93/6.53±0.26/6.84±0.92/6.58±0.35 vs. 6.13±0.31/6.21±0.76/6.21±0.42/6.18±0.35/6.32±0.61/6.33±0.24/6.25±0.71). The observation group had a significantly higher overall satisfaction rate than the control group [94.00% (47/50) vs. 78.26% (36/46)].Conclusion:In the standardized training and teaching of hepatobiliary surgery, homogeneous management combined with staged teaching can improve the professional level and clinical ability of physicians and enhance the degree of satisfaction with teaching.

OBJECTIVE: In order to distinguish the traditional Chinese medicine Bupleurum falcatum and its adulterants effectively and develop a better understanding of the factors affecting synonymous codon usage, codon usage patterns of chloroplast genome, we determine the complete chloroplast (cp) genome of B. falcatum and clarify the main factors that influence codon usage patterns of 78 genes in B. falcatum chloroplast genome. METHODS: The total genomic DNA of fresh leaves from a single individual of B. falcatum was extracted with EASYspin plus Total DNA Isolation Kit and 2 μg genome DNA was sequenced using Illumina Hiseq 2500 Sequencing Platform. The cp genome of B. falcatum was reconstructed with MITObim v1.8 and annotated in the program CPGAVAS2 with default parameters. Python script and Codon W were used to calculate the codon usage bias parameters. RESULTS: The full length of B. falcatum cp genome was 155 851 bp, 132 different genes were annotated in this cp genome containing 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. The codon usage models tended to use A/T-ending codons. The neutrality plot, ENC plot, PR2-Bias plot and correspondence analysis showed that both compositional constraint under selection and mutation could affect the codon usage models in B. falcatum cp genome. Furthermore, three optimal codons were identified and most of these three optimal codons ended with G/U. CONCLUSION The cp genome of B. falcatum has been characterized and the codon usage bias in B. falcatum cp genome is influenced by natural selection, mutation pressure and nucleotide composition. The results will provide much more barcode information for species discrimination and lay a foundation for future research on codon optimization of exogenous genes, genetic engineering and molecular evolution in B. falcatum.

The whole chloroplast genome ofthe medicinal plant Paeonia mairei H. Lév. was sequenced using the Illumina HiSeq X Ten platform and then assembled, annotated, and characterized by bioinformatic methods in this study. The complete chloroplast genome of P. mairei is 152 731 bp in length with the typical quadripartite structure, which consists of a large single copy-region (LSC, 84 402 bp), a small single copy-region (SSC, 16 969 bp), and a pair of inverted repeat regions (IRa and IRb, 25 680 bp), with an overall GC content of 38.4%. A total of 136 predicted genes, including 90 protein-coding genes, 38 tRNA genes and eight rRNA genes were identified. Among these, seven protein-coding genes, seven tRNA genes and four rRNA genes were found duplicated in the IR regions. In addition, 28 dispersed repeats, 10 tandem repeats, and 64 simple sequence repeats were detected within the whole chloroplast genome of P. mairei. Comparative analyses between 12 Peaonia species showed that the chloroplast genomes are highly conserved in length, gene content, gene order, and GC content. Meanwhile, the noncoding sequences (intergenic regions and introns) show a higher variation than the protein coding sequences, and sequences from the LSC region and SSC region are more variable than those from the IR regions. P. mairei was inferred forming in a distinct clade with P. lactiflora, P. obovate, and P. anomala subsp. veitchii with a 100% bootstrap value and is phylogenetically closest to P. lactiflora. These results may provide a basis for further genetic studies and the development and utilization of medicinal P. mairei.

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.

Objective: To identifiy a receptor-like kinase (RLK) encoding gene named as DoRLK (GenBank accession No. ANC68272.1) from Dendrobium officinale. Methods: RT-PCR and RACE technologies were used to isolate the full length cDNA of DoRLK. Characteristics of physiochemical properties, conserved domains, and subcellular localization of the deduced DoRLK protein were determined by a series of bioinformatics tools. The analyses of multiple alignment and phylogenetic tree were performed using DNASTAR 6.0 and MEGA 7.0 softwares, respectively. Quantitative PCR was used for gene expression analysis. Results: The results showed that the full length cDNA of DoRLK was 1 715 bp in length and encoded a 423 aa protein with a molecular weight of 47 800.88 and an isoelectric point (pI) of 9.47. The deduced DoRLK protein, like other RLK proteins, constituted one conserved domains (85—370) and one transmembrane motifs (250—270). Multiple sequence alignment and phylogenetic analyses demonstrated that DoRLK had high identity (43.62%—63.35%) to a number of RLK genes from various plants and was closely related to Phalaenopsis equestris, Phoenix dactylifera and Asparagus officinalis. Real time quantitative PCR (qPCR) analysis revealed that DoRLK was expressed in the three included organs. The transcripts were the most abundant in the roots with 2.22 fold over that in the leaves,followed by that in the stems with 2.75 fold. Conclusion: Molecular characterization of DoRLK will be useful for further functional elucidation of the gene involving in D. officinale responses to environmental factors.