Integrated analysis of transcriptomics and metabolomics of garden asparagus (Asparagus officinalis L.) under drought stress.

BACKGROUND: Drought is a leading environmental factor affecting plant growth. To explore the drought tolerance mechanism of asparagus, this study analyzed the responses of two asparagus varieties, namely, 'Jilv3' (drought tolerant) and 'Pacific Early' (drought sensitive), to drought stress using metabolomics and transcriptomics. RESULTS: In total, 2,567 and 7,187 differentially expressed genes (DEGs) were identified in 'Pacific Early' and 'Jilv3', respectively, by comparing the transcriptome expression patterns between the normal watering treatment and the drought stress treatment. These DEGs were significantly enriched in the amino acid biosynthesis, carbon metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction pathways. In 'Jilv3', DEGs were also enriched in the following energy metabolism-related pathways: citrate cycle (TCA cycle), glycolysis/gluconeogenesis, and pyruvate metabolism. This study also identified 112 and 254 differentially accumulated metabolites (DAMs) in 'Pacific Early' and 'Jilv3' under drought stress compared with normal watering, respectively. The amino acid, flavonoid, organic acid, and soluble sugar contents were more significantly enhanced in 'Jilv3' than in 'Pacific Early'. According to the metabolome and transcriptome analysis, in 'Jilv3', the energy supply of the TCA cycle was improved, and flavonoid biosynthesis increased. As a result, its adaptability to drought stress improved. CONCLUSIONS: These findings help to better reveal the molecular mechanism underlying how asparagus responds to drought stress and improve researchers' ability to screen drought-tolerant asparagus varieties as well as breed new varieties.

Physiological and transcriptome analysis of changes in endogenous hormone and sugar content during the formation of tender asparagus stems.

Asparagus is a nutritionally dense stem vegetable whose growth and development are correlated with its quality and yield. To investigate the dynamic changes and underlying mechanisms during the elongation and growth process of asparagus stems, we documented the growth pattern of asparagus and selected stem segments from four consecutive elongation stages using physiological and transcriptome analyses. Notably, the growth rate of asparagus accelerated at a length of 25 cm. A significant decrease in the concentration of sucrose, fructose, glucose, and additional sugars was observed in the elongation region of tender stems. Conversely, the levels of auxin and gibberellins(GAs) were elevated along with increased activity of enzymes involved in sucrose degradation. A significant positive correlation existed between auxin, GAs, and enzymes involved in sucrose degradation. The ABA content gradually increased with stem elongation. The tissue section showed that cell elongation is an inherent manifestation of stem elongation. The differential genes screened by transcriptome analysis were enriched in pathways such as starch and sucrose metabolism, phytohormone synthesis metabolism, and signal transduction. The expression levels of genes such as ARF, GA20ox, NCED, PIF4, and otherswere upregulated during stem elongation, while DAO, GA2ox, and other genes were downregulated. The gene expression level was consistent with changes in hormone content and influenced the cell length elongation. Additionally, the expression results of RT-qPCR were consistent with RNA-seq. The observed variations in gene expression levels, endogenous hormones and sugar changes during the elongation and growth of asparagus tender stems offer valuable insights for future investigations into the molecular mechanisms of asparagus stem growth and development and provide a theoretical foundation for cultivation and production practices.

Screening and Preliminary Identification of Asparagus officinalis Varieties under Low-Temperature Stress.

To meet the large demand for Asparagus officinalis in the spring market and improve the economic benefits of cultivating asparagus, we explored the molecular mechanism underlying the response of A. officinalis to low temperature. First, "Fengdao No. 1" was screened out under low-temperature treatment. Then, the transcriptome sequencing and hormone detection of "Fengdao No. 1" and "Grande" (control) were performed. Transcriptome sequencing resulted in screening out key candidate genes, while hormone analysis indicated that ABA was important for the response to low temperature. The combined analysis indicated that the AoMYB56 gene may regulate ABA in A. officinalis under low temperature. And the phylogenetic tree was constructed, and subcellular localisation was performed. From these results, we speculated that the AoMYB56 gene may regulate ABA in A. officinalis. The results of this research provide a theoretical basis for the further exploration of low-temperature response in A. officinalis.

Structural identification and anti-neuroinflammatory effects of a pectin-arabinoglucuronogalactan complex, AOPB-1-1, isolated from Asparagus officinalis.

Asparagus officinalis L. is a horticultural crop that contains a variety of bioactive compounds with anti-inflammatory effects. Aqueous extracts of A. officinalis can noticeably improve the learning and memory function of model mice. Herein, a pectin-arabinoglucuronogalactan complex (AOPB-1-1) with a relative molecular weight of 90.8 kDa was isolated from A. officinalis. The repeating structural unit of AOPB-1-1 was identified through monosaccharide composition, methylation analysis, uronic acid reduction, partial acid hydrolysis, and nuclear magnetic resonance spectroscopy. AOPB-1-1 contains the rhamnogalacturonan-I (RG-I) domain of pectin polysaccharides (PPs) and arabinoglucuronogalactan (AGG) regions. The backbone of the AGG region is composed of →3,6)-ß-D-Galp-(1→ and →4)-ß-D-Glcp-(1→ residues substituted at the 4-position to the →4)-α-D-GalAp-(1→ residues of the RG-I main chain. The anti-neuroinflammatory activity of AOPB-1-1 suggests that it can significantly reduce the content of inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) and inhibit the expression of inflammatory genes including cyclooxygenase-2 (COX2), nitric oxide synthase (iNOS), TNF-α, IL-6, and interleukin-1ß (IL-1ß) in LPS-stimulated BV2 cells. Furthermore, its inhibitory effects on TNF-α and IL-6 levels were even better than those of minocycline. The significant anti-neuroinflammatory activity of AOPB-1-1 suggests its applicability as a therapeutic option for the treatment of Alzheimer's disease.

Molecular mechanisms of Asparagus racemosus willd. and Withania somnifera (L.) Dunal as chemotherapeutic adjuvants for breast cancer treatment.

ETHNOPHARMACOLOGICAL RELEVANCE: Despite various treatment modalities, the progression and metastasis of breast cancer (BC) are grave concerns due to the alarming disease-free survival rate (DFS) and overall survival rate (OS) of affected patients. Over the years, many antibiotics, synthetic compounds, medicinal plant isolates and polyherbal combinations have been used as adjuvants in therapy for the management of primary and secondary tumors. Paclitaxel (PTX)-based chemotherapy for breast cancer causes multiple adverse side effects in patients. Withania somnifera (L.) Dunal (WS) and Asparagus racemosus Willd. (AR) as Ayurveda-inspired plant-based adjuvants were investigated for their anticancer effects on MDA-MB-231 and 4T1 cells in mouse model systems. AIM OF THE STUDY: This study focused on evaluating the adjuvant properties of WS and AR plant extracts with PTX and their effectiveness over PTX alone in terms of tumor inhibition. MATERIALS AND METHODS: The effects of WS and AR on DNA double-strand breaks (DSBs), senescence induction and mitochondrial functions were evaluated in BC cells in vitro. The potential for cancer stem cell (CSC) inhibition was evaluated via mammosphere formation assays and CD44/CD24 immunostaining. In vivo tumor growth studies were conducted in athymic BALB/c mice for MDA-MB-231 cells and in BALB/c mice for 4T1 cells. RESULTS: Induction of senescence was evident due to DSBs induced by the WS and AR extracts. Mammosphere formation and CD44/CD24 CSC markers were reduced after treatment with WS, AR or the combination of both in MCF-7 cells. WS or AR inhibited epithelial-to-mesenchymal transition (EMT). In vivo studies demonstrated that tumor growth inhibition was more pronounced in the treated group than in the PTX alone group and the untreated control group. CONCLUSION: Our study showed that the use of WS or AR plant hydroalcoholic extracts in combination with paclitaxel (PTX) has better effects on sensitivity and efficacy than PTX alone, as demonstrated in in vitro BC cells and mouse models with BC cell grafts. Hence, scheduling adjuvant therapy with WS or AR alone or combined with PTX can be advantageous for the management of triple-negative BC (TNBC). Further studies are warranted in human clinical conditions to ascertain the efficacy of these treatments.

Quality Evaluation of Asparagus officinalis by Profile of Amino Acids and Mineral Elements in Different Parts Combined with Chemometrics Methods.

Asparagus officinalis has a homologous value in medicine and vegetables. Its immature stem, commonly called asparagus, is a central edible part. Asparagus skin and leaf also contain rich nutrients. However, these parts are often discarded. This study investigated amino acid and mineral elements in immature stem, skinless asparagus, asparagus skin, and leaf. Their quality was further evaluated by chemometrics methods such as principal component analysis and neural network analysis. The results showed amino acid content was high in immature stem and skinless asparagus and low in leaf, whereas the mineral elements were in four parts. Quality evaluation results showed four parts were divided into three grades. Immature stem and skinless asparagus were grouped into cluster 1 with the best quality as high-quality raw materials in food and health-care products. Meanwhile, three AA (Cys, His, Arg) and two mineral elements (Na, Cr) were identified as quality evaluation iconic substances.

Yarrowia lipolytica increased the activities of disease defense related enzymes and anti-fungal compounds in asparagus (Asparagus officinalis).

Fungal diseases pose significant threats to the production of asparagus, resulting in economic losses and decreased crop quality. The potential of the yeast Yarrowia lipolytica as a biocontrol agent against Fusarium proliferatum, a common pathogen of asparagus, was investigated in this study. The effects of Y. lipolytica treatment on decay incidence, disease index, and activities of major disease defense-related enzymes were investigated. In addition, we examined the levels of antifungal compounds such as total phenols, flavonoids, and lignin in asparagus plants exposed to Y. lipolytica. The results showed that Y. lipolytica treatment significantly reduced decay incidence and disease index caused by F. proliferatum when compared to the control group. Furthermore, Y. lipolytica-treated plants showed increased activity of disease defense-related enzymes, indicating that defense responses were activated. The activities of all evaluated enzymes were significantly higher in Y. lipolytica-treated asparagus, indicating an improved ability to combat fungal pathogens. Furthermore, Y. lipolytica treatment increased the content of antifungal compounds such as total phenols, flavonoids, and lignin, which are known to possess antimicrobial properties. These findings highlight the potential of Y. lipolytica as a biocontrol agent for fungal diseases in asparagus crops. The ability of Y. lipolytica to reduce disease incidence, boost disease defense-related enzymes, and increase antifungal compound content provides valuable insights into its efficacy as a natural and sustainable approach to disease management. However, further investigations are needed to optimize application methods and determine its efficacy under field conditions.

Renal-protective effect of Asparagus officinalis aqueous extract against lead-induced nephrotoxicity mouse model.

Lead is one of the cursed substances that threaten all human life. Lead poisoning can occur through food or water contaminations and it is hard to be detected. This incognito metal accumulates over time and resides in the liver, kidneys, and brain tissues leading to serious medical conditions, affecting organ functions, causing failure, kidney tubule degeneration, and destroying neuronal development. However, known metal chelators have bad negative effects. Asparagus officinalis (AO) is a promising herb; its root extract exhibited antioxidant, antiapoptotic, protective, and immunomodulatory activities. Inspired by those reasons, this study investigated to which extent Asparagus extract affected male mice's renal toxicity caused by lead acetate (LA) and antioxidant defense system. This work screened for its nephroprotective activity in four mouse groups: negative and positive control, LA group with renal injury, and diseased but pretreated mice with AO extract (AOE). Kidney index and kidney function biomarkers were evaluated. Antioxidant activities, lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), nitric oxide (NO), and reduced glutathione (GSH) were also tested. Furthermore, inflammatory cytokine (tumor necrosis factor-α (TNF-α), interleukin-1 ß (IL-1ß), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)), inducible nitric oxide synthase (iNOS), renal pro-apoptotic protein (Bax), antiapoptotic protein (Bcl-2), and caspase-3 levels were evaluated. The results showed that LA administration induced oxidative stress, renal inflammation, apoptosis, and renal histopathological alteration. However, due to its antioxidant activities, AOE was found to restrain oxidative stress, therefore preventing inflammation and apoptosis. Collectively, AOE perfectly clogged lead poisoning sneaking, stopped the bad deterioration, and succeeded to protect kidney tissues from toxicity, inflammation, and apoptosis.

Genome-wide identification and comprehensive analysis heat shock transcription factor (Hsf) members in asparagus (Asparagus officinalis) at the seeding stage under abiotic stresses.

Heat shock transcription factors (Hsf) are pivotal as essential transcription factors. They function as direct transcriptional activators of genes regulated by thermal stress and are closely associated with various abiotic stresses. Asparagus (Asparagus officinalis) is a vegetable of considerable economic and nutritional significance, abundant in essential vitamins, minerals, and dietary fiber. Nevertheless, asparagus is sensitive to environmental stresses, and specific abiotic stresses harm its yield and quality. In this context, Hsf members have been discerned through the reference genome, and a comprehensive analysis encompassing physical and chemical attributes, evolutionary aspects, motifs, gene structure, cis-acting elements, collinearity, and expression patterns under abiotic stresses has been conducted. The findings identified 18 members, categorized into five distinct subgroups. Members within each subgroup exhibited analogous motifs, gene structures, and cis-acting elements. Collinearity analysis unveiled a noteworthy pattern, revealing that Hsf members within asparagus shared one, two, and three pairs with counterparts in Arabidopsis, Oryza sativa, and Glycine max, respectively.Furthermore, members displayed tissue-specific expression during the seedling stage, with roots emerging as viable target tissue. Notably, the expression levels of certain members underwent modification under the influence of abiotic stresses. This study establishes a foundational framework for understanding Hsf members and offers valuable insights into the potential application of molecular breeding in the context of asparagus cultivation.

Aspacochioside C from Asparagus cochinchinensis attenuates eumelanin synthesis via inhibition of TRP2 expression.

Aspacochioside C (ACC) is a steroidal saponin isolated from Asparagus cochinchinensis. Steroidal saponins, such as pseudoprotodioscin and dioscin, are known to inhibit melanogenesis, but the role of ACC in melanogenesis remains unknown. Due to the toxic effect of the commonly used skin whitening agents like arbutin, kojic acid and α-lipoic acid alternative plant products are recentlybeen studied for their anti-hypergmentation effect. This study explores the role of ACC in melanogenesis in both in vivo and in vitro models. Here, we for the first time demonstrate that ACC attenuated α-MSH- and UVB-induced eumelanin production by inhibiting tyrosinase-related protein (TRP)-2 protein expression in both murine B16F10 and human melanoma MNT1 cells. However, ACC had no significant effect on pheomelanin concentration. ACC also decreased the pigmentation density in zebrafish embryos, which indicates that ACC targets TRP2 and inhibits eumelanin synthesis. Our results demonstrate that ACC inhibits TRP2, thereby attenuating eumelanin synthesis both in in vitro and in vivo zebrafish model. Therefore, ACC can potentially be used as an anti-melanogenic agent for both aesthetic and pharmaceutical purposes.

Comparative and phylogenetic analysis of Asparagus meioclados Levl. and Asparagus munitus Wang et S. C. Chen plastomes and utility of plastomes mutational hotspots.

Tiandong is a vital traditional Chinese herbal medicine. It is derived from the tuber root of the Asparagus cochinchinensis according to the Pharmacopoeia of the people's republic of China (2020 Edition). On account of the similar morphology, Asparagus meioclados and Asparagus munitus were used as Tian-Dong in southwest China. Chloroplast (cp) genomes are highly active genetic components of plants and play an extremely important role in improving the efficiency of the identification of plant species. To differentiate the medicinal plants belonging to the genus Asparagus, we sequenced and analyzed the complete plastomes (plastid genomes) of A. meioclados and A. munitus and obtained two plastomes whose length changed to 156,515 bp and 156,381 bp, respectively. A total of 111 unique genes have been detected in plastome, which included 78 protein-coding genes, 29 tRNA genes and 4 rRNA genes. In plastomes of A. meioclados and A. munitus, 14,685 and 14,987 codons were detected, among which 9942 and 10,207 had the relative synonymous codon usage (RSCU) values higher than 1, respectively. A. meioclados and A. munitus have 26 SSRs patterns, among which A. meioclados was 25 and A. munitus 21. The average Ka/Ks value was 0.36, and positive selection was detected in genes of the photosynthetic system (ndhF and rbcL) in Asparagus species. To perform the comparative analysis of plastomes, the two newly sequenced plastomes of the A. meioclados and A. munitus species were compared with that of A. cochinchinensis, and 12 hotspots, including 5 coding regions and 7 inter-genomic regions, were identified. Based on the whole plastome of Asparagus, 2 divergent hotspots (accD and rpl32-trnL-UAG) and 1 international barcode fragment (rbcL) were screened, which may be used as particular molecular markers for the identification of Asparagus species. In addition, we determined the phylogenetic relationship between A. meioclados and A. munitus in the genus Asparagus. This study enriches our knowledge of the molecular evolutionary relationships of the Asparagus genus and provides treasured data records for species identification, molecular breeding, and evolutionary analysis of this genus.

Nutritional Composition Profiles and Quality Evaluation of Different Cultivars of Asparagus Officinalis with Potential as Functional Foods and Health-Care Products.

Asparagus officinalis is a health-care vegetable with homology value of medicine and food. The quality of A. officinalis is greatly different from various cultivars. It is essential to reveal the relationship between the variety and quality. This study investigated six nutritional compositions in ten A. officinalis cultivars, including amino acid, mineral substance, carbohydrate, vitamin C, protein and total sugar. Five chemometrics methods were further employed to evaluate their quality. The results consistently showed that ten varieties were divided into three grades as nutritional composition differences. HuaMiaoF1, JinGuan and FeiCuiMingZhu were grouped into cluster3 with the best quality, and Atlas and Jersey Giant were grouped into cluster1 with the lowest quality. Therefore, HuaMiaoF1, JinGuan and FeiCuiMingZhu can be suggested as good raw materials for medicine, food and health-care products industries. Meanwhile, the comprehensive application of five chemometrics methods was confirmed as a reliable methodology for quality evaluation of A. officinalis.

Comparison of the inedible parts of white and green asparagus based on metabolomics and network pharmacology.

Asparagus is a perennial herb and is widely used as food and medicine in China. In this study, untargeted metabolomics analysis was applied to compare the chemical differences between the edible and inedible parts of asparagus, as well as the inedible parts of white and green asparagus. A total of 342 compounds were identified in the asparagus extracts, and 24 steroid saponins, 31 oxylipins and 36 LysoGPLs were identified for the first time in asparagus. Metabolomics analysis showed that the inedible part of white asparagus is rich in steroidal saponins, oxylipins and alkaloids, while the inedible part of green asparagus is rich in flavonoids, phenolic acids, LysoGPLs and amino acids. The inedible part of white asparagus showed significantly higher inhibitory effects on breast cancer 4T-1 cells than that of green asparagus. Network pharmacology analysis and molecular docking showed that the biological difference is related to higher levels of steroidal saponins and oxylipins in the inedible part of white asparagus. This study is useful for the wasted resource utilization of inedible parts of asparagus.

Steroidal saponin profiles and their key genes for synthesis and regulation in Asparagus officinalis L. by joint analysis of metabolomics and transcriptomics.

BACKGROUND: Asparagus officinalis L. is a worldwide cultivated vegetable enrichened in both nutrient and steroidal saponins with multiple pharmacological activities. The upstream biosynthetic pathway of steroidal saponins (USSP) for cholesterol (CHOL) synthesis has been studied, while the downstream pathway of steroidal saponins (DSSP) starting from cholesterol and its regulation in asparagus remains unknown. RESULTS: Metabolomics, Illumina RNAseq, and PacBio IsoSeq strategies were applied to different organs of both cultivated green and purple asparagus to detect the steroidal metabolite profiles & contents and to screen their key genes for biosynthesis and regulation. The results showed that there is a total of 427 compounds, among which 18 steroids were detected with fluctuated concentrations in roots, spears and flowering twigs of two garden asparagus cultivars. The key genes of DSSP include; steroid-16-hydroxylase (S16H), steroid-22-hydroxylase (S22H) and steroid-22-oxidase-16-hydroxylase (S22O-16H), steroid-26-hydroxylase (S26H), steroid-3-ß-glycosyltransferase (S3ßGT) and furostanol glycoside 26-O-beta-glucosidases (F26GHs) which were correlated with the contents of major steroidal saponins were screened, and the transcriptional factors (TFs) co-expressing with the resulted from synthetic key genes, including zinc fingers (ZFs), MYBs and WRKYs family genes were also screened. CONCLUSIONS: Based on the detected steroidal chemical structures, profiles and contents which correlated to the expressions of screened synthetic and TFs genes, the full steroidal saponin synthetic pathway (SSP) of asparagus, including its key regulation networks was proposed for the first time.

Enzyme Inhibition and Antioxidant Activities of Asparagus officinalis L. and Analysis of Its Phytochemical Content by LC/MS/MS.

In the study, water, ethanol, methanol, dichloromethane, and acetone extracts of Asparagus officinalis L. were obtained by maceration. DPPH⋅, ABTS⋅+ , FRAP, and CUPRAC methods determined the antioxidant capacities of all extracts. Moreover, the in vitro effects of extracts on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase (CA)-I, CA-II and α-Glycosidase were investigated. At a 10 µg/ml concentration, the extract with the highest Fe3+ reduction capacity was ethanol (AE), and the extract with the highest Cu2+ reduction capacity was acetone (AA). AE for AChE (IC50 =21.19 µg/ml) and α-Glycosidase (IC50 : 70.00 µg/ml), methanol (AM) for BChE (IC50 =17.33 µg/ml), CA-I and II (IC50 =79.65 and 36.09 µg/ml, respectively) showed the most potent inhibition effect. The content analysis of acetone extract was performed with LC/MS-MS, the first three phytochemicals found most were p-Coumaric acid, rutin, and 4-hydroxybenzoic acid (284.29±3.97, 135.39±8.19, and 102.06±5.51 µg analyte/g extract, respectively).

Protocols for extraction and purification of rutin from leafy by-products of asparagus (Asparagus officinalis) and characterization of the purified product.

Valorization of asparagus leafy by-products as a potential source of rutin through selected extraction and purification protocols was investigated. Protocol resulting in the highest extraction yield was first selected. Crude extract was subject to purification via multiple liquid-liquid back extraction using ethanol, methanol or water as a solvent; selection of the most appropriate purification solvent was made based on rutin solubility. The proposed purification protocol yielded yellow-color crystals, which were characterized by fluorescence microscopy, Fourier-transform infrared spectroscopy and liquid chromatography-mass spectrometry to confirm them as rutin. Purity of rutin was confirmed by ultra-performance liquid chromatography at 97.6%; yield of the purified rutin was determined to be 78.2%. The remaining rutin (21.8%) was found in the liquids collected at various stages of purification; such liquids could be recycled using the same purification process. The proposed protocols are simple, yet effective for rutin extraction and purification from asparagus leafy by-products.

AoSAP8-P encoding A20 and/or AN1 type zinc finger protein in asparagus officinalis L. Improving stress tolerance in transgenic Nicotiana sylvestris.

The full length CDS of an A20 and AN1 type zinc finger gene (named AoSAP8-P), located nearby the male specific Y chromosome (MSY) region of Asparagus officinalis (garden asparagus) was amplified by RT-PCR from purple passion. This gene, predicted as the stress associated protein (SAPs) gene families, encodes 172 amino acids with multiple cis elements including light, stress response box, MYB and ERF binding sites on its promoter. To analyze its function, the gene expression of different organs in different asparagus gender were analyzed and the overexpressed transgenic Nicotiana sylvestris lines were generated. The results showed the gene was highly expressed in both flower and root of male garden asparagus; the germination rate of seeds of the T2 transgenic lines (T2-5-4 and T2-7-1) under the stress conditions of 125 mM NaCl and 150 mM mannitol were significantly higher than the wild type (WT) respectively. When the potted T2-5-4, T2-7-1 lines and WT were subjected to drought stress for 24 days and the leaf discs immerged into 20 % PEG6000 and 300 mM NaCl solution for 48 h respectively, the T2-5-4 and T2-7-1 with AoSAP8-P expression showed stronger drought, salt and osmotic stress tolerance. When compared, the effects of AoSAP8-P overexpression on productive development showed that the flowering time of transgenic lines, were âˆ¼ 9 day earlier with larger but fewer pollens than its WT counterparts. However, there were no significant differences in anthers, stigmas and pollen viability between the transgenic lines and WT. Our results suggested that, the AoSAP8-P gene plays a role in improving the stress resistance and shortening seeds generation time for perianal survival during the growth and development of garden asparagus.

A Joint Transcriptomic and Metabolomic Analysis Reveals the Regulation of Shading on Lignin Biosynthesis in Asparagus.

Asparagus belongs to the Liliaceae family and has important economic and pharmacological value. Lignin plays a crucial role in cell wall structural integrity, stem strength, water transport, mechanical support and plant resistance to pathogens. In this study, various biological methods were used to study the mechanism of shading on the asparagus lignin accumulation pathway. The physiological results showed that shading significantly reduced stem diameter and cell wall lignin content. Microstructure observation showed that shading reduced the number of vascular bundles and xylem area, resulting in decreased lignin content, and thus reducing the lignification of asparagus. Cinnamic acid, caffeic acid, ferulic acid and sinapyl alcohol are crucial intermediate metabolites in the process of lignin synthesis. Metabolomic profiling showed that shading significantly reduced the contents of cinnamic acid, caffeic acid, ferulic acid and sinapyl alcohol. Transcriptome profiling identified 37 differentially expressed genes related to lignin, including PAL, C4H, 4CL, CAD, CCR, POD, CCoAOMT, and F5H related enzyme activity regulation genes. The expression levels of POD, CCoAOMT, and CCR genes were significantly decreased under shading treatment, while the expression levels of CAD and F5H genes exhibited no significant difference with increased shading. The downregulation of POD, CCoAOMT genes and the decrease in CCR gene expression levels inhibited the activities of the corresponding enzymes under shading treatment, resulting in decreased downstream content of caffeic acid, ferulic acid, sinaperol, chlorogenic acid and coniferin. A significant decrease in upstream cinnamic acid content was observed with shading, which also led to decreased downstream metabolites and reduced asparagus lignin content. In this study, transcriptomic and metabolomic analysis revealed the key regulatory genes and metabolites of asparagus lignin under shading treatment. This study provides a reference for further understanding the mechanism of lignin biosynthesis and the interaction of related genes.

Nutritional composition of green asparagus (Asparagus officinalis L.), edible part and by-products, and assessment of their effect on the growth of human gut-associated bacteria.

Asparagus is considered a healthy food with a high content of bioactive compounds. In this study, the proximate and mineral composition, non-digestible carbohydrates and bioactive compounds of edible spear, spear by-product and root have been evaluated. Their activity on the growth of human gut-associated bacteria has been studied. The results support the high nutritional and functional value of the asparagus, including its by-products, highlighting the potential of the non-edible parts to be used as prebiotics. A remarkable content in xylose, inulin, flavonoids and saponins has been found. It has been shown that the spear by-product can be selectively used to promote the growth of commensal or probiotic lactobacilli and bifidobacteria strains. It has been confirmed that any part of the asparagus has a potential future as a healthy food or as health-promoting ingredients, however more work is required to identify the compounds able to modulate the human gut microbiota.

Evaluation of immunological adjuvant activities of saponin rich fraction from the fruits of Asparagus adscendens Roxb. with less adverse reactions.

The hemolytic activity, in vitro as well as in vivo toxicity, and immunomodulatory potential of saponins-rich fraction of Asparagus adscendens Roxb. fruit (AA-SRF) have been assessed in this study in order to explore AA-SRF as an alternative safer adjuvant to standard Quil-A saponin. The AA-SRF showed lower hemolytic activity (HD50 = 301.01 ± 1.63 µg/ml) than Quil-A (HD50 = 17.15 ± 2.12 µg/ml). The sulforhodamine B assay also revealed that AA-SRF was less toxic to VERO cells (IC50≥200 ± 4.32 µg/ml) than Quil-A (IC50 = 60 ± 2.78 µg/ml). The AA-SRF did not lead to mortality in mice up to 1.6 mg and was much safer than Quil-A for in vivo use. Conversely, mice were subcutaneously immunized with OVA 100 µg alone or along with Alum (200 µg) or Quil-A (10 µg) or AA-SRF (50 µg/100 µg/200 µg) on days 0 and 14. The AA-SRF at 100 µg dose best supported the LPS/Con A primed splenocyte proliferation activity, elevated the serum OVA-specific total IgG antibody, IL-12, CD4 titer and upsurged CD3/CD19 expression in spleen as well as lymph node sections which in turn advocated its adjuvant potential. Thus, AA-SRF can be further studied for use as a safe alternative adjuvant in vaccines.