Integrative analysis of the pharmaceutical active ingredient and transcriptome of the aerial parts of Glycyrrhiza uralensis under salt stress reveals liquiritin accumulation via ABA-mediated signaling
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ABSTRACT: The aerial parts of Glycyrrhiza uralensis supply substantial raw material for the extraction of active pharmaceutical ingredients comprehensively utilized in many industries. Liquiritin is the unique and most abundant flavonoid active component in G. uralensis. It has a wide range of pharmacological activities and high economic value. Our previous study indicated that moderate salt stress increased the content of active ingredients. However, the regulatory mechanism remains unclear. In this study, RNA-sequencing (RNA-seq) of the aerial parts of G. uralensis treated with 150 mM NaCl for 0, 2, 6, and 12 h was performed to identify the key genes and metabolic pathways regulating pharmacological active component accumulation. The main active component detection showed that liquiritin was the major ingredient and exhibited more than a 10-fold significant increase in the 6-h NaCl treatment. Temporal expression analysis of the obtained 4245 differentially expressed genes (DEGs) obtained by RNA-seq revealed two screened profiles that included the significant up-regulated DEGs (UDEGs) at different treatment points. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these UDEGs identified phenylpropanoid metabolism and flavonoid biosynthesis as the most significantly enriched pathways in 2-h treated materials. Interestingly, the carotenoid biosynthesis pathway that is related to ABA synthesis was also discovered, and the ABA content was significantly promoted after 6-h NaCl treatment. Following ABA stimulation, the content of liquiritin demonstrated a significant and immediate increase after 2-h treatment, with the corresponding consistent expression of genes involved in the pathways of ABA signal transduction and flavonoid biosynthesis, but not in the pathway of glycyrrhizic acid biosynthesis. Therefore, salt stress might promote liquiritin accumulation through the ABA-mediated signaling pathway in G. uralensis. Our study provides candidate genes and pathways controlling liquiritin synthesis, and would drive progress in genetic improvement and promote the comprehensive utilization of the aerial part of G. uralensis.
Project description:Integrative analysis of the pharmaceutical active ingredient and transcriptome of the aerial parts of Glycyrrhiza uralensis under salt stress reveals liquiritin accumulation via ABA-mediated signaling
Project description:Scutellaria viscidula Bunge (Labiatae), a perennial herb, is an important medicinal plant that possesses broad pharmacological actions. S. viscidula contains flavonoids with good bioactivities (e.g. baicalin, wogonoside, baicalein and wogonin) mainly in its dry root, which is used as alternative to Scutellaria baicalensis in the north of China. Furthermore, S. viscidula also has flavones with interesting diverged structures such as panicolin, viscidulin I, viscidulin II and viscidulin III. Tracing the dynamic process of gene expression will help reveal the mechanism of flavonoid synthesis in S. viscidula, as well as the 4'-deoxyflavone biosynthesis in S. baicalensis. One way is to generate and analyze the expressed sequence tags (ESTs). However, little is known on the transcriptome information of S. viscidula, particularly the key genes involved in flavonoid biosynthesis. In this study, we conducted de novo transcriptome analysis of S. viscidula and obtained 42,310,834 reads and 40,052 unigenes, respectively. We revealed 177 genes relating to flavonoid biosynthesis, where 23 key enzyme encoding genes including CHS, CHI, F3H, PAL and 4CL were annotated. Furthermore, we investigated the dynamic expression of CHS, CHI, F3H, MYB2, and bHLH of stem, root and leaf of S. viscidula in May, July and September. Our results showed that these key genes had important regulatory function and exhibited positive correlation with total flavonoid content in different growth stages of S. viscidula. Collectively, this study provides high-quality transcriptome data of S. viscidula, and further gives significant information for understanding the molecular mechanism of gene expression and active ingredients in Scutellaria plants.
Project description:Our study demonstrated the fluctuation of flavonoid biosynthesis in the two pomelo cultivars and laid a theoretical foundation for pomelo breeding to generate fruits with high flavonoid content.
Project description:Flavonoid biosynthesis in grape berry skin is affected by environmental factors such as light and temperature. However, the components of the light-signaling and low-temperature-induced ABA signaling networks related to flavonoid accumulation in grape berry skin have not been fully elucidated. To clarify details of the possible light- and ABA-related signal transduction networks, we performed comprehensive transcriptome analysis using grape berries cultured under different light and temperature conditions. We identified 40 light-inducible genes, 55 low-temperature-inducible genes, and 34 genes induced by light plus low temperature.
Project description:High temperature and drought are the primary yield-limiting environmental constraints for staple food crops. Heat shock transcription factors (HSF) terminally regulate the plant abiotic stress responses to maintain growth and development under extreme environmental conditions. HSF genes of Subclass A2 predominantly express under heat stress (HS) and activate the transcriptional cascade of defense-related genes. In this study, a highly heat-inducible HSF, HvHSFA2e was constitutively expressed in barley (Hordeum vulgareL.) to investigate its role in abiotic stress response and plant development. Transgenic barley plants displayed enhanced heat and drought tolerance in terms of increased chlorophyll content, improved membrane stability, reduced lipid peroxidation, and less accumulation of ROS in comparison to wild-type (WT) plants. Transcriptome analysis revealed that HvHSFA2e positively regulates the expression of abiotic stress-related genes encoding HSFs, HSPs, and enzymatic antioxidants, contributing to improved stress tolerance in transgenic plants. The major genes of ABA biosynthesis pathway, flavonoid, and terpene metabolism were also upregulated in transgenics. Our findings show that HvHSFA2e mediated upregulation of heat-responsive genes, modulation in ABA and flavonoid biosynthesis pathways enhance drought and heat stress tolerance.
Project description:we performed a genome-wide analysis of AS events in G. uralensis at different time points under drought stress using a high-throughput RNA sequencing approach. We detected 2479 and 2764 AS events in the aerial part (AP) and underground part (UP), respectively, of drought-stressed G. uralensis. Of these, last exon variable shear and exon skipping were the main types of AS. Overall, 2653 genes undergoing significant AS regulation were identified from the AP and UP of G. uralensis exposed to drought for 2, 6, 12, and 24 h. Gene Ontology analyses indicated that AS plays an important role in the regulation of nitrogen and protein metabolism in the drought response of G. uralensis. Notably, the spliceosomal pathway and basal transcription factor pathway were significantly enriched with differentially spliced genes (DSGs) under drought stress. Genes related to splicing regulators in the AP and UP of G. uralensis responded to drought stress and themselves underwent AS under drought conditions. In summary, our data suggest that drought-responsive AS directly and indirectly regulates the drought response of G. uralensis. Further in-depth studies on the functions and mechanisms of AS during abiotic stresses will provide new strategies for improving plant stress resistance.
Project description:To understand how CTS-12 the ABA-dependent multi-levels of regulation, the integration of transcriptomic and metabolomic profiling using the two-way orthogonal projections to latent structures (O2PLS) and OPLS discriminant analysis (OPLS-DA) modeling was performed to investigate the mechanisms underlying chilling tolerance. Our results revealed that metabolic flux shifts, including the activation of stachyose biosynthesis, amino acid metabolism pathways, phenylpropanoid/flavonoid biosynthesis, and ABA biosynthesis, and inhibition of glycolysis, occurred under chilling treatment, and in the recovery period, the differentially expressed genes/metabolites (DEGs/DEMs) that mapped to glutamate-related pathways, β-alanine biosynthesis and degradation, and serotonin biosynthesis pathways were differentiated between 9311 and DC90. Particularly, the differential alterations of the DEMs/DEGs, including galactinol, β-alanine, glutamate, naringenin, serotonin, abscisic acid (ABA), and LOC_Os03g44380 (OsNCED3), might be involved in the chilling stress phenotype variation of 9311 and DC90. The involvement of ABA pathway was validated by CRISPR/Cas9-edited of discriminatory DEGs OsNCED3 which impaired chilling tolerance of japonica rice. In addition, chilling tolerance of rice was associated with the balance of water uptake and loss that was modulated by stomatal movement under chilling stress. Therefore, we speculated that the CTS-12-mediated ABA signaling pathway leads to transcriptional regulation of chilling-responsive genes and, in turn, triggers metabolic shifts to coordinately regulate the stomatal movement of guard cells. The results of this study improve our understanding of the multilevel regulation of wild rice in response to chilling stress.
Project description:To investigate the relationships between hormones and critical components in tea leaves during withering process, we detected the alterations of abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA), catechins, theanine, and caffeine in tea leaves withered at different time points from 0 to 24 hours. The content of ABA increased from 0h to 9h and decreased thereafter and JA content continuous increased, however, SA content was no significantly changes during withering process. Except for gallocatechin (GC) and epicatechin (EC), the contents of other critical components were significantly reduced at 24h. Transcriptome analysis shown that compared with 0h, a total of 2,256, 3,654, and 1,275 differentially expressed genes (DEGs) were identified at 9h, 15h, and 24h, respectively. The pathways of“Phenylalanine, tyrosine and tryptophan biosynthesis”, and “Phenylalanine metabolism” involved in biosynthesis of catechins were enriched significantly with DEGs of all comparisons. Weighted correlation network analysis (WGCNA) of co-expression genes indicated that many of modules were correlated with a specific trait only, however, the darkolivegreen module were correlated with two traits ABA and theanine during withering process. Our study indicates that withering induced dramatic alteration of the gene transcription, hormones (ABA, JA, and SA) and important components, and ABA may regulate theanine matebolism during this process.
Project description:Intervention group:High flavonoid content fruit and vegetable diet guidance;Control group:No
Primary outcome(s): Flavonoid markers;Salivary cortisol;Blood cortisol;Gut microbiota;Mental Health Assessment Questionnaire;Fecal short chain fatty acids;Changes in defecation habits and traits
Study Design: Parallel
Project description:A double cropping system has been commercially adopted in subtropical regions in southern China, where there is abundant sunshine and heat resources. In this viticulture system, the first growing season normally starts as a summer cropping cycle; then, the vine is pruned and forced by hydrogen cyanamide, resulting in a second crop in January of the next year. Due to climate differences between the two growing seasons, flavonoid content and composition varies greatly. In this study, changes in the transcriptome of flavonoid-associated pathways were compared in berries grown under the double cropping system; in addition, the accumulation of flavonoid compounds was compared. Specific alterations in MYB transcription factors occurred in winter cropping berries around veraison. Then, the winter cropping cycle distinctly induced the flavonoid metabolic pathways while triggering the ripening-associated pathways. Notably, the climate conditions in winter cropping positively affected flavonoid biosynthesis, while the summer season took a major toll on anthocyanin accumulation. In addition, the three classes of flavonoid compounds responded differently to the changing climate; the anthocyanins and flavonols were promoted several fold, whereas no consistent increase was found for flavan-3-ols. Conclusively, flavonoid biosynthesis in grapes grown under a double cropping system showed seasonal or climatic-specific accumulation patterns.