Comprehensive analysis of metabolome and transcriptome reveals the mechanism of color formation in different leave of Loropetalum Chinense var. Rubrum.

BACKGROUND: Loropetalum chinense var. rubrum (L. chinense var. rubrum) is a precious, coloured-leaf native ornamental plant in the Hunan Province. We found an L. chinense var. rubrum tree with three different leaf colours: GL (green leaf), ML (mosaic leaf), and PL (purple leaf). The mechanism of leaf coloration in this plant is still unclear. Therefore, this study aimed to identify the metabolites and genes involved in determining the colour composition of L. chinense var. rubrum leaves, using phenotypic/anatomic observations, pigment content detection, and comparative metabolomics and transcriptomics. RESULTS: We observed that the mesophyll cells in PL were purple, while those in GL were green and those in ML were a mix of purple-green. The contents of chlorophyll a, b, carotenoids, and total chlorophyll in PL and ML were significantly lower than those in GL. While the anthocyanin content in PL and ML was significantly higher than that in GL. The metabolomics results showed the differences in the content of cyanidin 3-O-glucoside, delphinidin 3-O-glucoside, cyanidin 3,5-O-diglucoside, pelargonidin, and petunidin 3,5-diglucoside in ML, GL, and PL were significant. Considering that the change trend of anthocyanin content change was consistent with the leaf colour difference, we speculated that these compounds might influence the colour of L. chinense var. rubrum leaves. Using transcriptomics, we finally identified nine differentially expressed structural genes (one ANR (ANR1217); four CYP75As (CYP75A1815, CYP75A2846, CYP75A2909, and CYP75A1716); four UFGTs (UFGT1876, UFGT1649, UFGT1839, and UFGT3273) and nine transcription factors (two MYBs (MYB1057 and MYB1211), one MADS-box (MADS1235), two AP2-likes (AP2-like1779 and AP2-like2234), one bZIP (bZIP3720), two WD40s (WD2173 and WD1867) and one bHLH (bHLH1631) that might be related to flavonoid biosynthesis and then impacted the appearance of colour in L. chinense var. rubrum leaves. CONCLUSION: This study revealed potential molecular mechanisms associated with leaf coloration in L. chinense var. rubrum by analyzing differential metabolites and genes related to the anthocyanin biosynthesis pathway. It also provided a reference for research on leaf colour variation in other ornamental plants.

Stage-specific feed intake restriction differentially regulates placental traits and proteome of goats.

A total of twenty-four healthy twin-bearing Liuyang black goats were allocated to two trials. In Trial 1, twelve goats received either the control diet (CG, n 6, 100 % feed) or restricted diet (RG, n 6, 60 % feed of CG) from gestation days 26 to 65 after synchronisation. In Trial 2, the remaining goats were randomly and equally divided into two treatments: CG and RG from days 95 to 125 of gestation. Placental traits, fetal weight, serum parameters, nitric oxide (NO), angiogenesis gene expression and cotyledon proteome were measured at the end of each trial. In early pregnancy, the total and relative weights of placenta, uterine caruncle and cotyledon, as well as fetus, were increased (P<0·05) in RG. The NO content in maternal serum was also increased (P<0·05) in RG. In all, fifty differentially expressed proteins were identified in cotyledon. The up-regulated proteins are related to proliferation and fission of trophoblast cell and the placenta angiogenesis. During the late pregnancy trial, placental weight was increased (P<0·05) in RG, but weight of the fetus was decreased (P<0·05). The capillary density in the cotyledon was also decreased (P<0·01). A total of fifty-eight proteins were differentially expressed in cotyledon. The up-regulated proteins in RG are related to placenta formation, blood flow regulation and embryonic development. These results indicated that feed intake restriction during gestation influenced the placental and fetal development in a stage-dependent manner. These findings have important implications for developing novel nutrient management strategies in goat production.

Widely Targeted Metabolomics and Network Pharmacology Reveal the Nutritional Potential of Yellowhorn (Xanthoceras sorbifolium Bunge) Leaves and Flowers.

Yellowhorn (Xanthoceras sorbifolium Bunge) is a unique oilseed tree in China with high edible and medicinal value. However, the application potential of yellowhorn has not been adequately explored. In this study, widely targeted metabolomics (HPLC-MS/MS and GC-MS) and network pharmacology were applied to investigate the nutritional potential of yellowhorn leaves and flowers. The widely targeted metabolomics results suggested that the yellowhorn leaf contains 948 non-volatile metabolites and 638 volatile metabolites, while the yellowhorn flower contains 976 and 636, respectively. A non-volatile metabolite analysis revealed that yellowhorn leaves and flowers contain a variety of functional components beneficial to the human body, such as terpenoids, flavonoids, alkaloids, lignans and coumarins, phenolic acids, amino acids, and nucleotides. An analysis of volatile metabolites indicated that the combined action of various volatile compounds, such as 2-furanmethanol, ß-icon, and 2-methyl-3-furanthiol, provides the special flavor of yellowhorn leaves and flowers. A network pharmacology analysis showed that various components in the flowers and leaves of yellowhorn have a wide range of biological activities. This study deepens our understanding of the non-volatile and volatile metabolites in yellowhorn and provides a theoretical basis and data support for the whole resource application of yellowhorn.

Effects of a steam explosion pretreatment on sugar production by enzymatic hydrolysis and structural properties of reed straw.

Reed lignocellulose was subjected to a steam explosion pretreatment to obtain a high conversion rate of sugar after subsequent enzymatic hydrolysis using a commercial cellulase mixture. Under conditions of differing temperature (200 °C, 220 °C and 240 °C) and residence time (2, 5, and 8 min), the effect of the pretreatment on the sugar yield from enzymatic hydrolysis was studied. The highest respective reducing sugar and glucose yields were 36.14% and 15.35% after 60-h enzymatic hydrolysis of reed straw that had been pretreated with a steam explosion at 220 °C for 5 min. Fourier transform infrared spectrophotometry (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used in this study to comprehensively investigate the steam explosion-induced changes in the organizational structure and morphological properties of reed straw to analyze the reason for the increased sugar yield from enzymatic hydrolysis after the steam explosion.

Comprehensive improvement of nutrients and volatile compounds of black/purple rice by extrusion-puffing technology.

Introduction: Black/purple rice is a pigmented rice variety that contains high levels of anthocyanins, flavonoids, and other valuable bioactive compounds. Owing to its robust anti-inflammatory and antioxidant properties, black/purple rice exerts a beneficial effect on human health. Extrusion puffing technology has emerged as a promising means of improving rice flavor with lesser effect on nutrient content. In this study, metabolomics approach was used to conduct comprehensive metabolomics analyses aimed at examining the impact of extrusion puffing on black/purple rice nutritional value and flavor. Methods: Firstly, the basic nutrient composition contents and extrudate characteristics of black/purple rice and Extrusion puffed black/purple rice were conducted. Then metabolomics profiling analyses of black/purple rice samples were performed to explore the impact of the extrusion puffing process on nutrient content and bioactive properties, in which we quantitatively determined the flavonoids and evaluated relative contents of volatile compounds. Results: These analyses revealed that following extrusion puffing, black/purple rice exhibited significant improvements in the content of nutrients including flavonoids, minerals, and proteins together. Extrusion puffing additionally increased the diversity of volatile compounds within black/purple rice. Discussion: These results suggest that extrusion puffing represents an effective means of substantially improving the functional and nutritional properties of black/purple rice, offering beneficial effects on consumer health. Overall, these data provide novel insights into the quality of extrusion puffed black/purple rice that will guide future efforts to establish how extrusion puffing can alter the nutrient content in a range of foods, thereby supporting the further development of a range of healthy food products.

Protective effect of resveratrol against pseudorabies virus-induced reproductive failure in a mouse model.

Resveratrol (RES), a natural polyphenol that is abundant in grapes, exerts anti-inflammatory, anti-oxidative, and antiviral bioactive effects. Protective effects of RES against pseudorabies virus (PrV)- induced reproductive failure were investigated in a mice model. Injection of PrV partially induced stillbirth and abortion, and caused poor growth of progeny. Treatment with RES attenuated the reproductive failure induced by the virus with recovery of the serum progesterone level. RES improved the growth performance of newborn mice. RES can attenuate the reproductive failure induced by PrV in mice.

Serum amino acids profile and the beneficial effects of L-arginine or L-glutamine supplementation in dextran sulfate sodium colitis.

This study was conducted to investigate serum amino acids profile in dextran sulfate sodium (DSS)-induced colitis, and impacts of graded dose of arginine or glutamine supplementation on the colitis. Using DSS-induced colitis model, which is similar to human ulcerative colitis, we determined serum profile of amino acids at day 3, 7, 10 and 12 (5 days post DSS treatment). Meanwhile, effects of graded dose of arginine (0.4%, 0.8%, and 1.5%) or glutamine (0.5%, 1.0% and 2.0%) supplementation on clinical parameters, serum amino acids, colonic tight junction proteins, colonic anti-oxidative indicators [catalase, total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px)], colonic pro-inflammatory cytokines [interleukin-1 beta (IL-1ß), IL-6, IL-17 and tumor necrosis factor alpha (TNF-α)] in DSS-induced colitis were fully analyzed at day 7 and 12. Additionally, the activation of signal transduction pathways, including nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPK), phosphoinositide-3-kinases (PI3K)/PI3K-protein kinase B (Akt), and myosin light chain kinase (MLCK)-myosin light chain (MLC20), were analyzed using immunoblotting. Serum amino acids analysis showed that DSS treatment changed the serum contents of amino acids, such as Trp, Glu, and Gln (P<0.05). Dietary arginine or glutamine supplementation had significant (P<0.05) influence on the clinical and biochemical parameters (T-SOD, IL-17 and TNF-α) in colitis model. These results were associated with colonic NF-κB, PI3K-Akt and MLCK signaling pathways. In conclusion, arginine or glutamine could be a potential therapy for intestinal inflammatory diseases.

Immune responses of mice immunized by DNA plasmids encoding PCV2 ORF 2 gene, porcine IL-15 or the both.

Porcine circovirus type 2 (PCV2) is associated with many kinds of diseases including postweaning multisystemic wasting syndrome (PMWS). It affects the immune system of swine and causes huge epidemic losses every year. In our previous study, we provided evidence that DNA plasmid bearing porcine IL-15 (pVAX-pIL-15) might serve as an immune enhancer for DNA plasmid encoding porcine reproductive and respiratory syndrome virus GP5 gene. In this study, PCV2 open reading frame (ORF)2 gene was cloned into the eukaryotic expression vector pVAX, resulting in the plasmid pVAX-PCV2-ORF2. Transient expression of the plasmid in BHK-21 cells could be detected using immunofluorescence assay. Experimental mice were divided into 5 groups and immunized with PBS, pVAX, pVAX-pIL-15, pVAX-PCV2-ORF2 or pVAX-pIL-15 plus pVAX-PCV2-ORF2. The results showed that the mice co-inoculated with pVAX-PCV2-ORF2 plus pVAX-pIL-15 had higher humoral and cellular immune responses than the others. In addition, DNA plasmid bearing PCV2 ORF2 gene had a protective effect against challenge with PCV2 in mice which could be promoted with the utilization of pIL-15.

Development and evaluation of a novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of type II porcine reproductive and respiratory syndrome virus.

The objective of this study was to develop a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of type II porcine reproductive and respiratory syndrome virus (PRRSV). Based on sequence alignment, four primers were designed amplifying the M gene of type II PRRSV and were subsequently utilized in an RT-LAMP assay. The RT-LAMP product had a ladder-like pattern of bands and the optimal reaction condition for this assay was determined to be 40 min at 63°C. Comparative analysis indicated that the RT-LAMP method was more sensitive than a conventional RT-PCR assay and comparable to a real-time PCR assay. In addition, the RT-LAMP assay was capable of detecting type II PRRSV in field samples and differentiating type II PRRSV from seven other porcine viruses which are all associated frequently with similar clinical symptoms.

Immune responses induced by DNA vaccines bearing Spike gene of PEDV combined with porcine IL-18.

Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea, a highly contagious enteric disease of swine. The Spike (S) protein is one of the main structural proteins of PEDV capable of inducing neutralizing antibodies in vivo. Herein, we generated three distinct DNA constructs in the eukaryotic expression plasmid pVAX1; one encoding the S protein [pVAX1-(PEDV-S)], the second encoding the N-terminal fragment (S1) [pVAX1-(PEDV-S1)] containing potent antigenic sites, and the third expressing the porcine interleukin-18 (pIL-18) [pVAX1-(IL-18)]. Immunofluorescence assays in BHK-21 cells demonstrated successful protein expression from all 3 constructs. Kunming mice were injected separately with each of these constructs or with a pVAX1-(PEDV-S1)/pVAX1-(IL-18) combination, an attenuated PEDV vaccine, or vector only control. Animals were examined for T lymphocyte proliferation, anti-PEDV antibodies, IFN-γ and IL-4 protein levels, and cytotoxic T cell function in mouse peripheral blood and spleen. In all cases, results showed that pVAX1-(PEDV-S) and the combination of pVAX1-(PEDV-S1) with pVAX1-(IL-18) induced the strongest responses; however, pIL-18 had no adjuvant effects when given in combination with pVAX1-(PEDV-S1).