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Red ginseng is a steamed and dried processing product of the cultivating root and rhizome of Panax ginseng C. A. Mey., which is one of the most widely used in ginseng products. The main active ingredient of red ginseng is ginsenoside, which is different from the content of ginseng caused by thermal process, such as chemical transformation by hydrolysis reaction and hydrated reaction. In recent years, the treatment of type 2 diabetes mellitus (T2DM) by red ginseng has attracted extensive attention. Ginsenoside has the effect of treating T2DM, but it is not easy to be absorbed directly by oral administration, and the bioavailability is low. Therefore, the metabolism of ginsenoside of red ginseng was studied in this research. The influence of intestinal flora on diseases has been paid more and more attention. Studies have shown that drug molecules can interact with intestinal microorganisms to produce metabolites of intestinal flora and active components of traditional Chinese medicine transformed by intestinal flora, which may be a new way to reveal the potential mechanism of action of red ginseng. Therefore, it is necessary to identify and elucidate ginsenosides in feces. A method of ultra performance liquid chromatography mass spectrometry (UPLC-MS) was established for qualitative and quantitative analysis of ginsenosides in red ginseng, and the content changes of ginsenosides in feces and serum of rats after intragastric administration of total ginsenosides were analyzed. Thermo Syncronis C18 column (100 mm×2.1 mm×1.7 μm) was used, mobile phase A was 0.1% formic acid in water, mobile phase B was acetonitrile, and flow rate was 0.2 mL/min, injection volume was 5 μL, UPLC was equipped with binary linear gradient pump, mass spectrometry was adopted electrospray negative ion mode. Ginsenosides were identified by the information of the retention times, molecular mass, and specific MS/MS fragments. The developed UPLC-MS method for quantitative analysis of ginsenosides was validated with respect to linearity, precision, repeatability, stability, and recovery. The result showed that the detection method of ginsenoside is speedy and accurate. Ginsenosides NotoR1, Rg1, Re, Rf, Rg2, Rh1, Rb1, Rc, Ro, Rb2, Rb3, Rd, Rg3, Rk1 in feces and serum of rats are detected, which show that the intestinal flora did not completely transform ginsenoside, and a part of ginsenosides are absorbed into the blood as prototype components playing a role in the treatment of T2DM. The changes of metabolites of ginsenoside in feces were studied with the prolongation of intervention time, which provided a certain basis for the pharmacodynamics of ginsenosides in red ginseng.

Weighted gene co-expression network analysis (WGCNA) is a method for analysing gene expression patterns across multiple samples, clustering genes with similar expression patterns and identifying key genes associated with specific traits or phenotypes. In this study, we investigated the effects of fucoxanthin accumulation in Phaeodactylum tricornutum in response to abiotic stresses of phosphorus deficiency, red light, and yellow light using transcriptome sequencing and weighted gene co-expression network analysis. The results showed that compared to the control, the fucoxanthin content of P. tricornutum was significantly increased after phosphorus deficiency and red light treatment ( P <0.05), but significantly decreased after yellow light treatment ( P <0.05). A weighted gene co-expression network was constructed using 10,392 genes obtained from transcriptome sequencing, and β=18 (R 2 >0.8) was chosen as a soft threshold in order to ensure a scale-free network. A total of 10 co-expression modules were identified by correlation analysis of fucoxanthin content, with the purple module positively correlated with fucoxanthin content ( r =0.9, P =1E-200), and 9 key genes were identified, including five genes in the fucoxanthin biosynthesis pathway ( DXR , PSY , PDS1 , ZEP2 , VDL2 ) and 4 transcription factors ( bHLH5 , HOX2 , CCHH13 , HSF1b ). Further qRT-PCR confirmed that key genes were more highly expressed in the phosphorus deficiency treatment and linear regression analysis showed that the relative gene expressions were all highly correlated with the transcriptome data. The results of this study provide a basis for further investigation of the complex regulatory mechanisms of fucoxanthin in P. tricornutum.

β-carotenoid hydroxylase (CHYB) is an important rate-limiting enzyme in the biosynthesis of plant carotenoid. In this study, chyb1 and chyb2, two gene families in Dunaliella viridis were obtained by RNA-seq. The fragment of promoters of CHYB family genes, 1 080 bp for chyb1 (GenBank No. KY012338) and 1 155 bp for chyb2 (GenBank No. KY012339) were cloned by the Genome Walking Technology, respectively. Cis-acting elements of two promoters were analyzed by Plantcare soft. The results show that the chyb1 gene promoter contains more cis-acting elements in responses to abiotic stresses, such as methyl jasmonate, arachidonic acid, acetylsalicylic acid, and so on. On the other hand, the chyb2 promoter contains more cis-acting elements in response to light stress. qRT-PCR results show that the mRNA expression levels of CHYBs are modulated by their promoters, and different CHYB gene families response to distinct stresses.

In order to understand the gene information, function, haloduric pathway (glycerolipid metabolism) and related key genes for Dunaliella viridis, we used Illumina HiSeqTM 2000 high-throughput sequencing technology to sequence its transcriptome. Trinity soft was used to assemble the data to form transcripts. Based on the Clusters of Orthologous Groups (COG), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG ) databases, we carried out functional annotation and classification, pathway annotation, and the opening reading fragment (ORF) sequence prediction of transcripts. The key genes in the glycerolipid metabolism were analyzed. The results suggested that 81,593 transcripts were found, and 77,117 ORF sequences were predicted, accounting for 94.50% of all transcripts. COG classification results showed that 16,569 transcripts were assigned to 24 categories. GO classification annotated 76,436 transcripts. The number of transcripts for biologcial processes was 30,678, accounting for 40.14% of all transcripts. KEGG pathway analysis showed that 26,428 transcripts were annotated to 317 pathways, and 131 pathways were related to metabolism, accounting for 41.32% of all annotated pathways. Only one transcript was annotated as coding the key enzyme dihydroxyacetone kinase involved in the glycerolipid pathway. This enzyme could be related to glycerol biosynthesis under salt stress. This study further improved the gene information and laid the foundation of metabolic pathway research for Dunaliella viridis.