Dendrobium officinale , an important medicinal plant of the genus Dendrobium in Orchidaceae family, has been used as traditional Chinese medicine (TCM) for nearly thousands of years. Here, we report the first chromosome-level reference genome of D . officinale , based on PacBio long-reads, Illumina short-reads and Hi-C data. The high-quality assembled genome is 1.23 Gb long, with contig N50 of 1.44 Mb. A total of 93.53% genome sequences were assembled into 19 pseudochromosomes with a super scaffold N50 of 63.07 Mb. Through comparative genomic analysis, we explored the expanded gene families of D . officinale , and also their impact on environmental adaptation and biosynthesis of secondary metabolites. We further performed detailed transcriptional analysis of D. officinale , and identified the candidate genes involved in the biosynthesis of three main active ingredients, including polysaccharides, alkaloids and flavonoids. In addition, the MODIFYING WALL LIGNIN-1 ( MWL1 ) gene, which inferred from Genome-Wide Association Studies (GWAS) based on the resequencing date from D. officinale and five related species and their morphologic features, may contribute to the plant production (yield of stems) of D. officinale . Therefore, the high-quality reference genome reported in this study could benefits functional genomics research and molecular breeding of D. officinale .

Background: A large right subcostal incision performed by open hepatectomy is associated with significant post-operative pain and distress. However, post-operative analgesia solutions still need to be devised. We investigated the effects of intra- and post-operative infusion of dexmedetomidine (Dex) combined with oxycodone during open hepatectomy.Methods: In this prospective, randomized and double-blind investigation, 52 patients undergoing selective open hepatectomy were divided into Dex group (DEX infusion at an initial loading dose of 0.5 μg⋅kg-1 over 10 min before intubation then adjusted to a maintenance dose of 0.3 μg⋅kg-1⋅h-1 until incision suturing) or control (Con) group (0.9% sodium chloride was administered). Patient-controlled analgesia was administered for 48 h after surgery (Dex group: 60 mg oxycodone and 360 μg DEX diluted to 120 ml and administered at a bolus dose of 2 ml, with 5 min lockout interval and a 1 h limit of 20 ml. Con group: 60 mg oxycodone alone with the same regimen). The primary outcome was post-operative oxycodone consumption. The secondary outcomes included requirement of narcotic and vasoactive drugs, hemodynamics, incidence of adverse effects, satisfaction, first exhaust time, pain intensity, and the Ramsay Sedation Scale.Results: Post-operative oxycodone consumption was significantly reduced in Dex group from 4 to 48 h after surgery (P < 0.05). Heart rate in Dex group was statistically decreased from T1 (just before intubation) to T6 (20 min after arriving at the post-anesthesia care unit), while mean arterial pressure was significantly decreased from T1 to T3 (during surgical incision; P < 0.05). The consumption of propofol and remifentanil were significantly decreased in Dex group (P < 0.05). The VAS scores at rest at 1, 4, and 8 h and with cough at 24, and 48 h after surgery were lower, the first exhaust time were shorter, satisfaction with pain control was statistically higher and the incidence of nausea and vomiting was less in Dex group than in Con group (all P < 0.05).Conclusion: The combination of DEX and oxycodone could reduce oxycodone consumption and the incidence of nausea and vomiting, enhance the analgesic effect, improves patient satisfaction and shorten the first exhaust time.

No abstract

No abstract

Background Dendrobium nobile Lindl. is an important pharmacopeial plant with medicinal and ornamental value. This study sought to provide a technical means for the large-scale production of total alkaloid in D. nobile. Seedlings were cultured in vitro using a temporary immersion bioreactor system (TIBS). The four tested immersion frequencies (min/h; 5/2, 5/4, 5/6, and 5/8) influenced the production of biomass and total alkaloid content. In addition, to compare the effects of different concentrations of the phytohormone methyl jasmonate (MeJA) and treatment time on biomass and total alkaloid accumulation, MeJA was added to the TIBS medium after 50 days. Finally, total alkaloid production in semi-solid system (SSS), TIBS, and TIBS combined with the MeJA system (TIBS-MeJA) were compared. Results The best immersion frequency was found to be 5/6 (5 min every 6 h), which ensured appropriate levels of biomass and total alkaloid content in plantlets. The alkaloid content and production level of seedlings were the highest after treatment with 10 μM MeJA separately for 20 and 30 days using TIBS. The maximum content (7.41 mg/g DW) and production level (361.24 mg/L) of total alkaloid on use of TIBS-MeJA were 2.32- and 4.69-fold, respectively, higher in terms of content, and 2.07- and 10.49-fold, respectively, higher in terms of production level than those on using of TIBS (3.20 mg/g DW, 174.34 mg/L) and SSS (1.58 mg/g DW, 34.44 mg/L). Conclusions Our results show TIBS-MeJA is suitable for large-scale production of total alkaloid in in vitro seedlings. Therefore, this study provides a technical means for the large-scale production of total alkaloid in D. nobile.