Identification and characterization of a novel gene involved in glandular trichome development in Nepeta tenuifolia.

Nepeta tenuifolia is a medicinal plant rich in terpenoids and flavonoids with antiviral, immunoregulatory, and anti-inflammatory activities. The peltate glandular trichome (PGT) is a multicellular structure considered to be the primary storage organ for monoterpenes; it may serve as an ideal model for studying cell differentiation and the development of glandular trichomes (GTs). The genes that regulate the development of GTs have not yet been well studied. In this study, we identified NtMIXTA1, a GT development-associated gene from the R2R3 MYB SBG9 family. NtMIXTA1 overexpression in tobacco resulted in the production of longer and denser GTs. Virus-induced gene silencing of NtMIXTA1 resulted in lower PGT density, a significant reduction in monoterpene concentration, and the decreased expression of genes related to monoterpene biosynthesis. Comparative transcriptome and widely targeted metabolic analyses revealed that silencing NtMIXTA1 significantly influenced the expression of genes, and the production of metabolites involved in the biosynthesis of terpenoids, flavonoids, and lipids. This study provides a solid foundation describing a mechanism underlying the regulation of GT development. In addition, this study further deepens our understanding of the regulatory networks involved in GT development and GT development-associated metabolite flux, as well as provides valuable reference data for studying plants with a high medicinal value without genetic transformation.

Quality analysis of Euryales Semen from different origins and varieties based on untargeted metabolomics.

Euryales Semen (ES) is sought-after for thousand years due to its multiple properties, mainly from the two cultivars (i.e. South Gordon Euryale (SE) and North Gordon Euryale (wild type, WT)). Currently, no effective way was established to recognize the two valuable and analogous kernels. We found high analogies of macroscopical traits and discovered WT seed was affected by ambient temperature, showing ostensible significant relationships with latitude and sea-level pressure. LC-MS based untargeted metabolomics helped us identified 177 putative metabolites. Pathway analysis revealed the underlying and vital roles of flavonoids during seeds development. Our results strongly suggested a strong level of similarity of WT from various regions on the strength of metabolic data. A multivariable model containing 51 chemical markers satisfactorily categorized WT and SE. This study obtained could be used to guide the varietal discrimination of ES.

Integrating RNA-seq with functional expression to analyze the regulation and characterization of genes involved in monoterpenoid biosynthesis in Nepeta tenuifolia Briq.

Nepeta tenuifolia Briq. (Lamiaceae) is a medicinal plant historically used in the East Asia region to treat cold and fever, and it is currently used as a clinically effective treatment for respiratory diseases. We previously found that monoterpenoids are the dominant volatile secondary metabolites in N. tenuifolia and their biosynthesis occurs in peltate glandular trichomes. To gain an insight into the molecular mechanisms underlying monoterpenoid biosynthesis in N. tenuifolia, we conducted transcriptome sequencing and examined the expression differences in monoterpene molecular pathway-related genes in different tissues and growth stages by qRT-RCR. In total, six p-menthane monoterpene biosynthetic genes in the (+)-menthone pathway were identified and cloned successfully based on transcriptome data. Moreover, the major constituents, including (+)-limonene, (-)-pulegone and (+)-menthone showed greater accumulation in the spikes than in other organs, such as the expression levels of related key enzyme genes. Additionally, the relative expression of pulegone reductase was the highest at 84 days, showing an inverse trend from (-)-pulegone relative content and leading to (+)-menthone accumulation in peltate glandular trichomes. Finished cloning of the gene for limonene 3-hydroxylase in N. tenuifolia (NtL3OH), heterologous expression in yeast, and in vitro assays were performed for functional characterization. Our study provides an important resource for further research of secondary metabolism of monoterpenes in peltate glandular trichomes of N. tenuifolia and other homologous species.

Multi-omics analysis of the bioactive constituents biosynthesis of glandular trichome in Perilla frutescens.

BACKGROUND: Perilla frutescens (L.) Britt is a medicinal and edible plant widely cultivated in Asia. Terpenoids, flavonoids and phenolic acids are the primary source of medicinal ingredients. Glandular trichomes with multicellular structures are known as biochemical cell factories which synthesized specialized metabolites. However, there is currently limited information regarding the site and mechanism of biosynthesis of these constituents in P. frutescens. Herein, we studied morphological features of glandular trichomes, metabolic profiling and transcriptomes through different tissues. RESULTS: Observation of light microscopy and scanning electron microscopy indicated the presence of three distinct glandular trichome types based on their morphological features: peltate, capitate, and digitiform glandular trichomes. The oil of peltate glandular trichomes, collected by custom-made micropipettes and analyzed by LC-MS and GC-MS, contained perillaketone, isoegomaketone, and egomaketone as the major constituents which are consistent with the components of leaves. Metabolomics and transcriptomics were applied to explore the bioactive constituent biosynthesis in the leaves, stem, and root of P. frutescens. Transcriptome sequencing profiles revealed differential regulation of genes related to terpenoids, flavonoids, and phenylpropanoid biosynthesis, respectively with most genes expressed highly in leaves. The genes affecting the development of trichomes were preliminarily predicted and discussed. CONCLUSIONS: The current study established the morphological and chemical characteristics of glandular trichome types of P. frutescens implying the bioactive constituents were mainly synthesized in peltate glandular trichomes. The genes related to bioactive constituents biosynthesis were explored via transcriptomes, which provided the basis for unraveling the biosynthesis of bioactive constituents in this popular medicinal plant.

[Study on Sparganium stoloniferum from different regions in China based on appearance characters and ISSR markers].

Based on the characteristics and ISSR molecular marker technology, the study is aimed to compare and perform genetic diversity analysis on Sparganium stoloniferum from 7 regions. Molecular identification method was established for S. stoloniferum from Hunan province. Differences among Sparganii Rhizoma samples from seven habitats were analyzed via measuring weight, length, width and thickness of them. Genetic diversity of S. stoloniferum from 7 regions was analyzed by screening out primers amplifying clear band and showing rich polymorphism, then a cultivars dendrogram was built. The target primer was screened out, and the specific band was sequenced. Nine ISSR primers were selected to amplified clear band, rich polymorphism. A total of 73 bands were amplified by nine ISSR primers selected from 27 ISSR primers. On average, each primer produced 8.0 bands. A total of 38 bands were polymorphic, which occupied 52.8% of all bands. The cultivars dendrogram showed the genetic similarity was 0.54-0.94. Genetic similarity coefficient of S. stoloniferum from Jiangsu province, Anhui province and Jiangxi province was big, indicating the differences among them were slight on genetic level. S. stoloniferum from Hunan province is quite different from samples from the other six habitats on appea-rance and genetic level. A specific band(327 bp) in S. stoloniferum from Hunan province was obtained via ISSR-857 primer, and was sequenced. According BLASTn database, there were few sequences similar to the gene fragment and had little correlation with the growth process of plant. ISSR molecular marker technology provides a new idea for the identification of S. stoloniferum. This result confirmed the particularity of S. stoloniferum from ancient Jingzhou.

Cyanidin-related antidepressant-like efficacy requires PI3K/AKT/FoxG1/FGF-2 pathway modulated enhancement of neuronal differentiation and dendritic maturation.

BACKGROUND: Cyanidin (CY) is one of the most abundant anthocyanidins found in red-purple diet sources such as grapes, blueberries and purple corns. CY has been proven to exhibit a wide range of biological functions including antioxidant, antiviral, anticarcinogenic and anti-inflammatory properties. PURPOSE: This study investigated the anti-depressive activity of CY and its related mechanism. METHODS: In the behavioral tests, CY-related effects on depressive symptoms were evaluated. Then the changes in PI3K/AKT/FOXG1/FGF-2 signaling and adult neurogenesis including doublecortin (DCX+) cell number, dendritic length, secondary and third dendrites number in the hippocampus were investigated by Immunofluorescence and Western blot analyses. PI3K antagonist LY 294,002 was used to verify the unique impact of PI3K/AKT/FoxG1/FGF-2 signaling on CY-related antidepressant efficacy. RESULTS: CY grossly reversed CUMS-induced behavioral defects, The DCX+ cell number and protein levels increased in CUMS mice receiving CY administration. LY 294,002 successfully blocked CY-induced improvements in depressive behaviors, neurogenesis, and protein levels in CUMS mice. CONCLUSION: The findings demonstrated that CY was efficacious in alleviating depression-like symptoms, which was dependent on PI3K/AKT/FoxG1/FGF-2 signaling-modulated neurogenesis enhancement.

Ultrasound-assisted extraction of geniposide from Gardenia jasminoides.

Fructus gardeniae (Zhizi), one of commonly-used traditional Chinese medicines, is derived from the ripe fruit of the evergreen shrub, Gardenia jasminoides Ellis, and is an ingredient of many traditional Chinese preparations, and has numerous pharmacological actions. Geniposide is the important bioactive element derived from F. gardeniae. This study established optimum conditions and method of ultrasound-assisted extraction for geniposide from F. gardeniae by exploring the different experimental parameters, such as type of solvent, ratio of solid/liquid, extraction temperature and extraction time. The data gained from this study is important to further extract and apply the geniposide and is also a significant reference to extract the bioactive compounds from plant materials by the ultrasound-assisted method.