Comparative Transcriptome Analyses of Different Rheum officinale Tissues Reveal Differentially Expressed Genes Associated with Anthraquinone, Catechin, and Gallic Acid Biosynthesis.

Rheum officinale Baill. is an important traditional Chinese medicinal herb, its dried roots and rhizomes being widely utilized to cure diverse diseases. However, previous studies mainly focused on the active compounds and their pharmacological effects, and the molecular mechanism underlying the biosynthesis of these ingredients in R. officinale is still elusive. Here, we performed comparative transcriptome analyses to elucidate the differentially expressed genes (DEGs) in the root, stem, and leaf of R. officinale. A total of 236,031 unigenes with N50 of 769 bp was generated, 136,329 (57.76%) of which were annotated. A total of 5884 DEGs was identified after the comparative analyses of different tissues; 175 and 126 key enzyme genes with tissue-specific expression were found in the anthraquinone, catechin/gallic acid biosynthetic pathway, respectively, and some of these key enzyme genes were verified by qRT-PCR. The phylogeny of the PKS III family in Polygonaceae indicated that probably only PL_741 PKSIII1, PL_11549 PKSIII5, and PL_101745 PKSIII6 encoded PKSIII in the polyketide pathway. These results will shed light on the molecular basis of the tissue-specific accumulation and regulation of secondary metabolites in R. officinale, and lay a foundation for the future genetic diversity, molecular assisted breeding, and germplasm resource improvement of this essential medicinal plant.

Transcriptome profiles of yellowish-white and fuchsia colored flowers in the Rheum palmatum complex reveal genes related to color polymorphism.

Flower color variation is ubiquitous in many plant species, and several studies have been conducted to elucidate the underlying molecular mechanism. There are two flower color variants (yellowish-white and fuchsia) in the Rheum palmatum complex, however, few studies have investigated this phenomenon. Here, we used transcriptome sequencing of the two color variants to shed light on the molecular and biochemical basis for these color morphs. Comparison of the two transcriptomes identified 9641 differentially expressed unigenes (DEGs), including 6477 up-regulated and 3163 down-regulated genes. Functional analyses indicated that several DEGs were related to the anthocyanin biosynthesis pathway, and the expression profiles of these DEGs were coincident with the qRT-PCR validation results, indicating that expression levels of structural genes have a profound effect on the color variation in the R. palmatum complex. Our results suggested that the interaction of transcription factors (MYB, bHLH and WRKY) also regulated the anthocyanin biosynthesis in the R. palmatum complex. Estimation of selection pressures using the dN/dS ratio showed that 1106 pairs of orthologous genes have undergone positive selection. Of these positively selected genes, 21 were involved in the anthocyanin biosynthetic pathway, indicating that they may encode the proteins for structural alteration and affect flower color in the R. palmatum complex.

Tourism Competitiveness Evaluation: Evidence From Mountain Tourism in China.

The evaluation of tourism competitiveness is an important tool for analyzing the potential of tourism in a specific context. Enshi Autonomous Prefecture (EAP) in China is selected as a case through which to explore the potential of mountain tourism and its competitiveness in the tourism industry. This study develops EAP's mountain tourism competitiveness model focusing on three criteria: core competitiveness of mountain tourism, the economic environment's competitiveness, and infrastructure competitiveness. Context-specific customized evaluation index has been applied to data collected from EAP Statistical Yearbook for 2005-2014. The study reveals that the value of EAP's mountain tourism core competitiveness, economic and environmental competitiveness, and infrastructure competitiveness are 84.292, 13.4, and 2.308%, respectively. When tourism core competitiveness is increased by one unit, EAP's mountain tourism competitiveness will increase by 0.84292 units. Similarly, when economic environment competitiveness is increased by one unit, EAP's mountain tourism competitiveness will increase by 0.134 units. EAP's mountain tourism competitiveness increases by 0.02308 units when infrastructure competitiveness increases by one unit. The major reasons for low levels of competitiveness were lack of awareness of the county authority, a low level of cooperation, and weak infrastructure. The recommendations from the study's findings are as follows. Firstly, the county authority should appropriately improve the relationship between competition and cooperation, maintaining cooperation in competition, and competition in cooperation. Secondly, the county authority should strengthen communication by establishing an effective coordinated mechanism. Thirdly, the county authority should improve the sense of cooperation and jointly develop the mountain tourism market. Fourthly, the county authority should improve the construction of tourism infrastructure and break down the barriers to tourism cooperation. The study's findings help develop a "win-win" cooperation mechanism within the competition and support the sustainable development of the mountain tourism industry while reducing poverty and promoting the revitalization of the mountains of China.

Tissue-specific transcriptome for Rheum tanguticum reveals candidate genes related to the anthraquinones biosynthesis.

Rheum tanguticum (Maxim. ex Regel) Maxim. ex Balf. is a herbaceous perennial plant indigenous to China, and its root and rhizomes were usually used as an important traditional Chinese medicine. However, the genomic resources are still scarce for R. tanguticum and even for Rheum genus. Transcriptome datasets from different tissues of R. tanguticum were obtained to screen the genes related to anthraquinones biosynthesis, and five free anthraquinones were also determined. Nine cDNA libraries of roots, stems and leaves were generated, and a total of 272 million high-quality reads were assembled into 257,942 unigenes. Based on the functional annotation, A total of 227 candidate enzyme genes involved in the MVA, MEP, shikimate and polyketide pathways were identified, and several differentially expressed genes found functionally associated with anthraquinones biosynthesis showed distinct tissue-specific expression patterns. Especially, we found that the expression levels of PKS III genes might result in the content differences of free anthraquinones in different tissues of R. tanguticum. Besides, 137,400 SSR loci were identified, and 64,081 SSR primer pairs were successfully designed based on these loci. Our results not only provide cues for the genetic mechanism of anthraquinone content differences in different tissues of R. tanguticum, but also lay genomic foundation for the subsequent genetic engineering and breeding for Rheum species. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01099-8.

[Correlation of hepatitis B e antigen with hepatitis B virus DNA in the serum of chronic hepatitis B patients after treatment].

OBJECTIVE: To analyze the correlation of hepatitis B virus (HBV) DNA with the serological markers of HB in the serum of chronic HB patients after treatment PCR method and to analyze the status of these markers and the multiplication of virus. METHODS: Peripheral blood samples were collected from 480 chronic HB patients, aged 15 - 50, who had been treated by anti-nucleotide drugs or traditional Chinese herbs and showed normal ALT/AST. Both COBAS AMPLICOR HBV MONIORTM kit (internal-standard PCR method) and Light Cycler real time fluorescent quantitative PCR instrument (external-quantitative standard PCR method) were used to measure the HBV DNAS level. 42 of the 312 patients with the HBV DNA level lower than the minimum test limit measured by COBAS AMPLICOR HBV MONIORTM kit and HBeAg positive (>4 S/CO) underwent microparticle enzyme immunoassay (MEIA) to test the HBsAg, anti-HBs, HBeAg, anti-HBe, and HBcIgG. RESULTS: Seven of the 42 patients with HBV DNA negative measured by COBAS AMPLICOR HBV MONIORTM kit lower then the minimum test limit were shown as HBV DNA positive by Light Cycler real time fluorescent quantitative PCR. The 42 patients were HBsAg (+), anti-HBs (-), HBeAg (+), anti-HBe (-), and anti-HBcIgG (-), with an average HBeAg level of 42.26 S/CO and a positive HBeAg rate of 13.46%. CONCLUSION: HBeAg positivity does not necessarily means an active multiplication of HBV. The changes of the serological markers of HBV may be not consistent with that of HBV DNA. It is more objective to undergo both internal-standard and external-quantitative standard methods.