ABSTRACT
OBJECTIVE@#The population density and diversity of Sinomenium acutum (Menispermaceae) have been greatly reduced recently by overharvesting for medicinal purposes in China. Therefore, it is urgent that the remaining populations are investigated, and that strategies for the utilization and conservation of this species are developed. This study aimed to find the possible glacial refugia and define the genetic diversity of S. acutum for its proper utilization and conservation.@*METHODS@#A total of 77 S. acutum samples were collected from four locations, Qinling Mountains, Daba Mountains, Dalou Mountains, and Xuefeng Mountains, in subtropical China. Genetic diversity among and between these populations were phylogenetically analyzed using four chloroplast DNA molecular markers (atpI-atpH, trnQ-5'rps16, trnH-psbA and trnL-trnF).@*RESULTS@#A total of 14 haplotypes (C1 to C14) were found in collected samples. Haplotypes C1 and C3 were shared among all populations, with C3 as the ancestral haplotype. Haplotypes C11 and C12 diverged the most from C3 and other haplotypes. No obvious phylogeographic structure was found in four locations using the GST/NST test. There is no evidence of rapid demographic expansion in S. acutum based on the mismatch distribution, and the results of Tajima's D test, and Fu's FS test. Our analyses of molecular variance revealed a high level of genetic variation within populations. In contrast, the genetic differentiation among S. acutum populations was low, indicating frequent gene flow.@*CONCLUSION@#Xuefeng, Dalou, and Daba Mountains were possible glacial refugia for the populations of S. acutum. C1, C3, C11 and C12 haplotypes of S. acutum should be carefully preserved and managed for their genetic value.
ABSTRACT
Objective: In order to explore the expression of sinomenine content control genes, synthetic control sites and expression pathway. Methods: In this study, high performance liquid chromatography (HPLC) was used to determine the content of sinomenine in the roots and stems of 49 Sinomenii Caulis in six populations. Two populations with large multiple differences in sinomenine content were selected, namely Shanxi Baoji and Guizhou Zunyi. The most representative of them were selected, and their roots and stems were taken for transcriptome sequencing and named as HR/LR and HS/LS. Results: Sequencing results showed that 355 201 transcripts were obtained by splicing clean reads, including 275 491 Unigene transcripts. There were 23 562 and 37 143 differentially expressed genes in HR/LR and HS/LS, respectively. GO database analysis showed that the functions of these differentially expressed genes were significantly enriched in aspartic-type endopeptidase activity and aspartic-type peptidase activity, it is speculated that these two enzymes might be encoded. The results of KEGG enrichment explained that the differentially expressed genes were involved in carbohydrate metabolism, protein binding to cell membrane and vitamin C synthesis. The results of qRT-PCR verified the expression of upstream key genes of the isoquinoline alkaloid synthesis pathway and found that it was positively correlated with the accumulation of sinomenine. Conclusion: This study provided a preliminary understanding of the molecular mechanism that caused the difference in sinomenine content, and provided a reference for further understanding of the accumulation rules and synthesis pathways of sinomenine.