RESUMO
Tropane alkaloids (TAs) are a class of anticholinergic drugs widely used in clinical practice and mainly extracted from plant, among which Atopa belladonna is the main commercial drug source. It is of great industrial value to obtain TAs in large quantities by plant metabolic engineering. In TAs pathway, cytochrome oxidase CYP82M3 catalyze the synthesis of tropinone and then tropinone reductase I (TRI) compete with TRII for tropinone to form tropine leading to the TAs synthesis (drainage). In this study, based on the "increasing flow and drainage" metabolic engineering strategy, two genes, namely HnCYP82M3 and DsTRI from Hyoscyamus niger and Datura stramonium, respectively, were overexpressed in the hair roots of A. belladonna, with a view to promote the TAs accumulation. The HnCYP82M3 gene was cloned from the root of H. niger, and it encoded amino acid with 91.7% sequence identity with AbCYP82M3 from A. belladonna. Overexpression of HnCYP82M3 alone did not affect the content of TAs in hair roots of A. belladonna, indicating that CYP82M3 was not a key enzyme in TAs biosynthesis. Simultaneous overexpression of HnCYP82M3 and DsTRI greatly promoted the accumulation of the three TAs, and the contents of hyoscyamine, anisodamine and scopolamine were 4.97 times, 2.83 times and 2.19 times that of the control, respectively, and the increase amplitude was greater than that of single overexpression of DsTRI. This study showed that the "increasing flow and drainage" strategy of enzyme genes co-expression at branch points was a promising metabolic engineering method to effectively improve the biosynthesis of TAs in A. belladonna, and laid a theoretical and technical foundation for the large-scale industrial acquisition of TAs.
RESUMO
Objective:To understand the research hotspots and development trends of oncology nurses at home and abroad from 2011 to 2020, so as to provide reference for related research.Methods:The articles related to oncology nurses at home and abroad from 2011 to 2020 were retrieved through China National Knowledge Infrastructure database, Web of Science database and PUBMED database, and the included literatures′ published journals, institutions and keywords were analyzed by using the online analysis of Statistical Analysis Toolkit for Informetrics3.2 and the software CiteSpace5.7.R1.Results:A total of 588 domestic and 738 foreign articles were included. Keywords analysis showed that domestic oncology nurse related research hotspots were occupational evaluation, hospice care, psychology and occupational protection. Oncology nurse at home and abroad research hotspots had both similarities and differences, different in fertility preservation, communication and so on.Conclusions:The domestic core journal forums of oncology nurse research are still too scattered, and there is a certain gap in the number of articles published between our country and other countries. China still needs to increase the research efforts in this field.