Physiology and transcriptome of Eucommia ulmoides seeds at different germination stages

E. ulmoides (Eucommia ulmoides) has significant industrial and medicinal value and high market demand. E. ulmoides grows seedlings through sowing. According to previous studies, plant hormones have been shown to regulate seed germination. To understand the relationship between hormones and E. ulmoides seed germination, we focused on examining the changes in various indicators during the germination stage of E. ulmoides seeds. We measured the levels of physiological and hormone indicators in E. ulmoides seeds at different germination stages and found that the levels of abscisic acid (ABA), gibberellin (GA), and indole acetic acid (IAA) significantly varied as the seeds germinated. Furthermore, we confirmed that ABA, GA, and IAA are essential hormones in the germination of E. ulmoides seeds using Gene Ontology and Kyoto Encyclopedia of Genes and Genomics enrichment analyses of the transcriptome. The discovery of hormone-related synthesis pathways in the control group of Eucommia seeds at different germination stages further confirmed this conclusion. This study provides a basis for further research into the regulatory mechanisms of E. ulmoides seeds at different germination stages and the relationship between other seed germination and plant hormones.

EuTGA1, a bZIP transcription factor, positively regulates EuFPS1 expression in Eucommia ulmoides

Eucommia ulmoides (E. ulmoides) is widely cultivated and exhibits remarkable adaptability in China. It is the most promising rubber source plant in the temperate zone. E. ulmoides gum (EUG) is a trans-polyisoprene with a unique "rubber-plastic duality", and is widely used in advanced materials and biomedical fields. The transcription of Farnesyl pyrophosphate synthase (FPS), the rate-limiting enzyme of EUG biosynthesis, is controlled by regulatory mechanisms that remain poorly elucidated. In this research, 12 TGA transcription factors (TFs) in E. ulmoides were identified. Promoter prediction results revealed that the EuFPS1 promoter had binding sites for EuTGAs. Subsequently, the EuTGA1 was obtained by screening the E. ulmoides cDNA library using the EuFPS1 promoter as a bait. The individual yeast one‑hybrid and dual-luciferase assays confirmed that in the tobacco plant, EuTGA1 interacted with the EuFPS1 promoter, resulting in a more than threefold increase in the activity of the EuFPS1. Subcellular localization study further revealed that EuTGA1 is localized in the nucleus and acts as a TF to regulate EuFPS1 expression. In addition, qRT-PCR analysis demonstrated that the expression trend of EuFPS1 and EuTGA1 was the same at different time of the year. Notably, low temperature and MeJA treatments down-regulated EuTGA1 expression. Additionally, the transient transformation of EuTGA1 enhanced NtFPS1 expression in tobacco plants. Overall, this study identified a TF that interacted with EuFPS1 promoter to positively regulate EuFPS1 expression. The findings of this study provide a theoretical basis for further research on the expression regulation of EuFPS1.

Dietary supplementation of water extract of Eucommia ulmoides bark improved caecal microbiota and parameters of health in white-feathered broilers

Eucommia ulmoides has been used as a food and medicine homologue for a long time in China. We hypothesize that Eucommia ulmoides achieves its health-promoting effects via altering gut microbiota. Here, we investigated the effects of water extract of Eucommia ulmoides bark on caecal microbiota and growth performance, antioxidant activity, and immunity in white-feathered broilers treated for 42 days. A total of 108 one-day-old Cobb white-feathered broilers were randomly assigned to three treatment groups: control diet, 0.75% Eucommia ulmoides diet (EU Ⅰ) and 1.5% Eucommia ulmoides diet (EU Ⅱ). The results showed that EU Ⅱ treatment improved average body weight (ABW), thigh muscle quality and total length of intestines, and decreased the serum total triglycerides and total cholesterol (TC) (p < 0.05). Eucommia ulmoides supplementation increased serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant activities and content of immunoglobulins, and reduced levels of malondialdehyde and tumour necrosis factor-α (TNF-α) (p < 0.05). Moreover, the supplementation increased the diversity of caecal microbiota and reduced the pathogenic genera Escherichia Shigella and Helicobacter. The genera Ochrobactrum, Odoribater, Klebsiella, Enterobacter, Georgenia and Bifidobacterium were positively associated with the ABW, total intestinal length, serum levels of GSH-Px, SOD and immunoglobulins (p < 0.001) and negatively associated with the TC and TNF-α (p < 0.01), suggesting an association of the changes of gut microbiota and improvement of broiler health. Meanwhile, Eucommia ulmoides supplementation enriched the Kyoto Encyclopedia of Genes and Genomes pathway of exocrine secretion from the pancreas, circadian entrainment and inhibited lipopolysaccharide biosynthesis. In conclusion, Eucommia ulmoides water extract can be used as a feed additive to improve poultry industry production.

Positive regulation of the Eucommia rubber biosynthesis-related gene EuFPS1 by EuWRKY30 in Eucommia ulmoides

Eucommia rubber is a secondary metabolite from Eucommia ulmoides that has attracted much attention because of its unique properties and enormous potential for application. However, the transcriptional mechanism regulating its biosynthesis has not yet been determined. Farnesyl pyrophosphate synthase is a key enzyme in the Eucommia rubber biosynthesis. In this study, the promoter of EuFPS1 was used as bait, EuWRKY30 was screened from the cDNA library of EuFPS1 via a yeast one-hybrid system. EuWRKY30 belongs to the WRKY IIa subfamily and contains a WRKY domain and a C2H2 zinc finger motif, and the expressed protein is located in the nucleus. EuWRKY30 and EuFPS1 exhibited similar tissue expression patterns, and yeast one-hybrid and dual-luciferase experiments confirmed that EuWRKY30 directly binds to the W-box element in the EuFPS1 promoter and activates its expression. Moreover, the overexpression of EuWRKY30 significantly upregulated the expression level of EuFPS1, further increasing the density of the rubber particles and Eucommia rubber content. The results of this study indicated that EuWRKY30 positively regulates EuFPS1, which plays a critical role in the synthesis of Eucommia rubber, provided a basis for further analysis of the underlying transcriptional regulatory mechanisms.

Genome-Wide Identification and Expression Analysis of Growth-Regulating Factors in Eucommia ulmoides Oliver (Du-Zhong)

The roots, stems, leaves, and seeds of Eucommia ulmoides contain a large amount of trans-polyisoprene (also known as Eu-rubber), which is considered to be an important laticiferous plant with valuable industrial applications. Eu-rubber used in industry is mainly extracted from leaves. Therefore, it is of great significance to identify genes related to regulating the leaf size of E. ulmoides. Plant growth-regulating factors (GRFs) play important roles in regulating leaf size, and their functions are highly conserved across different plant species. However, there have been very limited reports on EuGRFs until now. In this study, eight canonical EuGRFs with both QLQ and WRC domains and two putative eul-miR396s were identified in the chromosome-level genome of E. ulmoides. It is found that, unlike AtGRFs, all EuGRFs contain the miR396s binding site in the terminal of WRC domains. These EuGRFs were distributed on six chromosomes in the genome of E. ulmoides. Collinearity analysis of the E. ulmoides genome revealed that EuGRF1 and EuGRF3 exhibit collinear relationships with EuGRF2, suggesting that those three genes may have emerged via gene replication events. The collinear relationship between EuGRFs, AtGRFs, and OsGRFs showed that EuGRF5 and EuGRF8 had no collinear members in Arabidopsis and rice. Almost all EuGRFs show a higher expression level in growing and developing tissues, and most EuGRF promoters process phytohormone-response and stress-induced cis-elements. Moreover, we found the expression of EuGRFs was significantly induced by gibberellins (GA3) in three hours, and the height of E. ulmoides seedlings was significantly increased one week after GA3 treatment. The findings in this study provide potential candidate genes for further research and lay the foundation for further exploring the molecular mechanism underlying E. ulmoides development in response to GA3.

Eucommia ulmoides Leaves Alleviate Cognitive Dysfunction in Dextran Sulfate Sodium (DSS)-Induced Colitis Mice through Regulating JNK/TLR4 Signaling Pathway

Ulcerative colitis (UC) is one of the inflammatory bowel diseases (IBD) that is characterized by systemic immune system activation. This study was performed to assess the alleviative effect of administering an aqueous extract of Eucommia ulmoides leaves (AEEL) on cognitive dysfunction in mice with dextran sulfate sodium (DSS)-induced colitis. The major bioactive compounds of AEEL were identified as a quinic acid derivative, caffeic acid-O-hexoside, and 3-O-caffeoylquinic acid using UPLC Q-TOF/MSE. AEEL administration alleviated colitis symptoms, which are bodyweight change and colon shortening. Moreover, AEEL administration protected intestinal barrier integrity by increasing the tight junction protein expression levels in colon tissues. Likewise, AEEL improved behavioral dysfunction in the Y-maze, passive avoidance, and Morris water maze tests. Additionally, AEEL improved short-chain fatty acid (SCFA) content in the feces of DSS-induced mice. In addition, AEEL improved damaged cholinergic systems in brain tissue and damaged mitochondrial and antioxidant functions in colon and brain tissues caused by DSS. Also, AEEL protected against DSS-induced cytotoxicity and inflammation in colon and brain tissues by c-Jun N-terminal kinase (JNK) and the toll-like receptor 4 (TLR4) signaling pathway. Therefore, these results suggest that AEEL is a natural material that alleviates DSS-induced cognitive dysfunction with the modulation of gut-brain interaction.

Dietary supplementation of Eucommia leaf extract to growing-finishing pigs alters muscle metabolism and improves meat quality

OBJECTIVE

The objective of this study was to investigate the influence of dietary supplementation of Eucommia ulmoides leaf extract (ELE) on muscle metabolism and meat quality of pigs with and without pre-slaughter transportation.

METHODS

In a 43-day feeding experiment, a total of 160 pigs with an initial body weight 60.00±2.00 kg were randomly assigned into four groups in a completely randomized design with 10 replicates. Pigs in groups A and C were fed a basal diet and pigs in groups B and D were fed a basal diet supplemented with 0.5% ELE. Pigs were slaughtered with (group B and D) or without (group A and C) pre-slaughter transport. Muscle chemical composition, postmortem glycolysis, meat quality and muscle metabolome were analyzed.

RESULTS

Dietary ELE supplementation had no effect on the proximate composition of porcine muscle, but increased free phenylalanine, proline, citruline, norvaline, and the total free amino acids in muscle. In addition, dietary ELE increased decanoic acid and eicosapentaenoic acid, but decreased heptadecanoic acid, oleic acid, trans-oleic acid, and monounsaturated fatty acids in muscle. Meat quality measurement demonstrated that ELE improved meat water holding capacity and eliminated the negative effects of pre-slaughter transport on meat cooking yield and tenderness. Dietary ELE reduced muscle glycolytic potential, inhibited glycolysis and muscle pH decline in the postmortem conversion of muscle to meat and increased the activity of citrate synthase in muscle. Metabolomics analysis by liquid chromatographic tandem mass spectrometric showed that ELE enhanced muscle energy level, regulated AMP-activated protein kinase (AMPK) signaling, modulated glycogenolysis/glycolysis, and altered the metabolism of carbohydrate, fatty acids, ketone bodies, amino acids, purine, and pyrimidine.

CONCLUSION

Dietary ELE improved meat quality and alleviated the negative effect of preslaughter transport on meat quality by enhancing muscle oxidative metabolism capacity and inhibiting glycolysis in postmortem muscle, which is probably involved its regulation of AMPK.

Pinoresinol diglucoside mitigates dexamethasone-induced osteoporosis and chondrodysplasia in zebrafish

BACKGROUND

The global increase in the aging population has led to a higher incidence of osteoporosis among the elderly.

OBJECTIVE

This study aimed to evaluate the protective properties of pinoresinol diglucoside (PDG), an active constituent of Eucommia ulmoides, against dexamethasone-induced osteoporosis and chondrodysplasia.

METHODS

A zebrafish model of osteoporosis was established by exposing larval zebrafish to dexamethasone. The impact of PDG on bone mineralization was assessed through alizarin red and calcein staining. Alkaline phosphatase activity was quantified to evaluate osteoblast function. The influence of PDG on chondrogenesis was estimated using alcian blue staining. Fluorescence imaging and motor behavior analysis were employed to assess the protective effect of PDG on the structure and function of dexamethasone-induced skeletal teratogenesis. qPCR determined the expression of osteogenesis and Wnt signaling-related genes. Molecular docking was used to assess the potential interactions between PDG and Wnt receptors.

RESULTS

PDG significantly increased bone mineralization and corrected spinal curvature and cartilage malformations in the zebrafish model. Furthermore, PDG enhanced swimming abilities compared to the model group. PDG mitigated dexamethasone-induced skeletal abnormalities in zebrafish by upregulating Wnt signaling, showing potential interaction with Wnt receptors FZD2 and FZD5.

CONCLUSION

PDG mitigates dexamethasone-induced osteoporosis and chondrodysplasia by promoting bone formation and activating Wnt signaling.

Smartphone-based electrochemical sensor for cost-effective, rapid and on site detection of chlorogenic acid in herbs using biomass-derived hierarchically porous carbon synthesized by a soft-hard dual template method

To achieve excellent germplasm resource screening and ensure the quality control of herbal tea raw material, it is important to establish a cost-effective, rapid, and on site quantitative detection method for their bioactive constituents. We developed a smartphone-operated sensor for electrochemical detection of chlorogenic acid (CGA) using hierarchically porous carbon (DSiFPC), synthesized through a soft-hard dual template strategy with tannin acid as a carbon source, silica colloid as a hard template, and Pluronic F127 as a soft template. The DSiFPC modified glassy carbon electrode sensor showed excellent electrocatalytic ability towards CGA, with a wide linear range of 0.03-1 μM and a low limit of detection of 6.2 nM. It was successfully applied for detecting CGA in dried flowers of Lonicera japonica. Furthermore, a portable sensor utilizing a DSiFPC modified screen-printed electrode was employed for on site detection of CGA in fresh Eucommia ulmoides leaves, yielding satisfactory recoveries.

Effects of lactic acid bacteria on antioxidant activity in vitro and aroma component of Eucommia ulmoides tea

Eucommia ulmoides tea is a popular functional health drink in Asian countries, but its unique herbal aroma is difficult for consumers to accept. The effects of four lactic acid bacteria strains (Lactobacillus plantarium, Lactobacillus bulgaricus, Lactobacillus acidophilus and Streptococcus thermophilus) fermentation on the physicochemical property, antioxidant activity in vitro and aroma component of E. ulmoides leaves were studied. Within the four strains, the sample by L. bulgaricus fermentation showed the higher concentrations of chlorogenic acid, geniposidic acid and stronger antioxidant activity in vitro. Moreover, the sample by L. bulgaricus fermentation produced a stronger fruity and floral flavor. These results suggested that L. bulgaricus was the best strain for fermentation E. ulmoides tea. The differences between different strains should be considered when selecting lactic acid bacteria for raw material fermentation of fruits and vegetables.

Leaf phenotypic variation and its response to environmental factors in natural populations of Eucommia ulmoides

BACKGROUND

Eucommia ulmoides leaves have high medicinal and economic value as a dual-purpose substance for medicine and food. Employing leaves from 13 natural populations of Eucommia ulmoides as research objects, this study reveals the variation patterns of intra-specific and inter-specific trait variation and explores the response of leaf characteristics to geographical and climatic changes, aiming to provide a scientific basis for the efficient utilization of leaf resources and the breeding of superior varieties.

RESULTS

Descriptive statistical analysis and nested analysis of variance showed significant differences in 11 leaf traits of Eucommia ulmoides inter-populations and intra-populations, with an average coefficient of variation of 17.45%. The coefficient of variation for average leaf phenotypic traits is 20.77%, and the leaf phenotypic variation is mainly from the variation intra-populations. Principal component analysis reveals that the cumulative contribution rate of the top three principal components which mainly contributed to the phenotypic variation of Eucommia ulmoides leaves reached 74.98%, which could be sorted into size traits (34.57%), color traits (25.82%) and shape traits (14.58%). In addition, correlation analysis expresses there is a specific co-variation pattern among leaf traits, with a strong connection between shape, size, and color traits. Geographic and climatic distances are significantly correlated, and mantel test and correlation analysis indicate that leaf traits of Eucommia ulmoides are mainly influenced by altitude. With the increase of altitude, the leaves become smaller. Partial correlation analysis shows that after controlling climate factors, the correlation between some characters and geographical factors disappears significantly. Temperature and precipitation have a great influence on the variation of leaf phenotypic traits, and the larger the leaves are in areas with high temperature and heavy rainfall.

CONCLUSIONS

These findings contribute to a further understanding of the leaf morphological characteristics of Eucommia ulmoides and the extent to which the environment influences leaf trait variation. They can provide a scientific basis for the protection and application of Eucommia ulmoides leaf resources in the future.

Comprehensive genomic characterisation of the NAC transcription factor family and its response to drought stress in Eucommia ulmoides

The NAC transcription factor family enhances plant adaptation to environmental challenges by participating in signalling pathways triggered by abiotic stressors and hormonal cues. We identified 69 NAC genes in the Eucommia ulmoides genome and renamed them according to their chromosomal distribution. These EuNAC proteins were clustered into 13 sub-families and distributed on 16 chromosomes and 2 scaffolds. The gene structures suggested that the number of exons varied from two to eight among these EuNACs, with a multitude of them containing three exons. Duplicated events resulted in a large gene family; 12 and four pairs of EuNACs were the result of segmental and tandem duplicates, respectively. The drought-stress response pattern of 12 putative EuNACs was observed under drought treatment, revealing that these EuNACs could play crucial roles in mitigating the effects of drought stress responses and serve as promising candidate genes for genetic engineering aimed at enhancing the drought stress tolerance of E. ulmoides. This study provides insight into the evolution, diversity, and characterisation of NAC genes in E. ulmoides and will be helpful for future characterisation of putative EuNACs associated with water deficit.

Quantitative Detection of Natural Rubber Content in Eucommia ulmoides by Portable Pyrolysis-Membrane Inlet Mass Spectrometry

Eucommia ulmoides gum (EUG) is a natural polymer predominantly consisting of trans-1,4-polyisoprene. Due to its excellent crystallization efficiency and rubber-plastic duality, EUG finds applications in various fields, including medical equipment, national defense, and civil industry. Here, we devised a portable pyrolysis-membrane inlet mass spectrometry (PY-MIMS) approach to rapidly, accurately, and quantitatively identify rubber content in Eucommia ulmoides (EU). EUG is first introduced into the pyrolyzer and pyrolyzed into tiny molecules, which are then dissolved and diffusively transported via the polydimethylsiloxane (PDMS) membrane before entering the quadrupole mass spectrometer for quantitative analysis. The results indicate that the limit of detection (LOD) for EUG is 1.36 μg/mg, and the recovery rate ranges from 95.04% to 104.96%. Compared to the result of pyrolysis-gas chromatography (PY-GC), the average relative error is 1.153%, and the detection time was reduced to less than 5 min, demonstrating that the procedure was reliable, accurate, and efficient. The method has the potential to be employed to precisely identify the rubber content of natural rubber-producing plants such as Eucommia ulmoides, Taraxacum kok-saghyz (TKS), Guayule, and Thorn lettuce.

The NAC transcription factor family in Eucommia ulmoides: Genome-wide identification, characterization, and network analysis in relation to the rubber biosynthetic genes

The NAC transcription factor family is a large plant gene family, participating in plant growth and development, secondary metabolite synthesis, biotic and abiotic stresses responses, and hormone signaling. Eucommia ulmoides is a widely planted economic tree species in China that can produce trans-polyisoprene: Eucommia rubber (Eu-rubber). However, genome-wide identification of the NAC gene family has not been reported in E. ulmoides. In this study, 71 NAC proteins were identified based on genomic database of E. ulmoides. Phylogenetic analysis showed that the EuNAC proteins were distributed in 17 subgroups based on homology with NAC proteins in Arabidopsis, including the E. ulmoides-specific subgroup Eu_NAC. Gene structure analysis suggested that the number of exons varied from 1 to 7, and multitudinous EuNAC genes contained two or three exons. Chromosomal location analysis revealed that the EuNAC genes were unevenly distributed on 16 chromosomes. Three pairs of genes of tandem duplicates genes and 12 segmental duplications were detected, which indicated that segmental duplications may provide the primary driving force of expansion of EuNAC. Prediction of cis-regulatory elements indicated that the EuNAC genes were involved in development, light response, stress response and hormone response. For the gene expression analysis, the expression levels of EuNAC genes in various tissues were quite different. To explore the effect of EuNAC genes on Eu-rubber biosynthesis, a co-expression regulatory network between Eu-rubber biosynthesis genes and EuNAC genes was constructed, which indicated that six EuNAC genes may play an important role in the regulation of Eu-rubber biosynthesis. In addition, this six EuNAC genes expression profiles in E. ulmoides different tissues were consistent with the trend in Eu-rubber content. Quantitative real-time PCR analysis showed that EuNAC genes were responsive to different hormone treatment. These results will provide a useful reference for further studies addressing the functional characteristics of the NAC genes and its potential role in Eu-rubber biosynthesis.

Genome-wide identification and expression analysis of MADS-box transcription factors reveal their involvement in sex determination of hardy rubber tree (Eucommia ulmoides oliv.)

Eucommia ulmoides is a famous rubber-producing and medicinal tree species that produces unisexual flowers on separate individuals from the earliest stage of stamen/pistil primordium formation. To explore the genetic regulation pathway of sex in E. ulmoides, comprehensive genome-wide analyses and tissue-/sex-specific transcriptome comparisons of MADS-box transcription factors were performed for the first time in this work. Quantitative real-time PCR technique was employed to further validate the expression of genes that are assigned to floral organ ABCDE model. A total of 66 non-redundant E. ulmoides MADS-box (EuMADS) genes were identified, they were classified into Type I (M-type, 17 genes) and Type II (MIKC, 49 genes). Complex protein-motif composition, exon-intron structure and phytohormone-response cis-elements were detected in MIKC-EuMADS genes. Furthermore, 24 differentially-expressed EuMADS genes (DEGs) between male and female flowers, and two DEGs between male and female leaves were revealed. Amongst the 14 floral organ ABCDE model-related genes, there were 6 (A/B/C/E-class) and 5 (A/D/E-class) genes displayed male- and female-biased expression respectively. In particular, one B-class gene EuMADS39 and one A-class gene EuMADS65 were almost exclusively expressed in male trees, no matter in flower or leaf tissues. Collectively, these results suggested a critical role of MADS-box transcription factors in sex determination of E. ulmoides, which is conducive to decoding the molecular regulation mechanism of sex in E. ulmoides.

Identification of a Hydroxygallic Acid Derivative, Zingibroside R1 and a Sterol Lipid as Potential Active Ingredients of Cuscuta chinensis Extract That Has Neuroprotective and Antioxidant Effects in Aged Caenorhabditis elegans

We examined the effects of the extracts from two traditional Chinese medicine plants, Cuscuta chinensis and Eucommia ulmoides, on the healthspan of the model organism Caenorhabditis elegans. C. chinensis increased the short-term memory and the mechanosensory response of aged C. elegans. Furthermore, both extracts improved the resistance towards oxidative stress, and decreased the intracellular level of reactive oxygen species. Chemical analyses of the extracts revealed the presence of several bioactive compounds such as chlorogenic acid, cinnamic acid, and quercetin. A fraction from the C. chinensis extract enriched in zingibroside R1 improved the lifespan, the survival after heat stress, and the locomotion in a manner similar to the full C. chinensis extract. Thus, zingibroside R1 could be (partly) responsible for the observed health benefits of C. chinensis. Furthermore, a hydroxygallic acid derivative and the sterol lipid 4-alpha-formyl-stigmasta-7,24(241)-dien-3-beta-ol are abundantly present in the C. chinensis extract and its most bioactive fraction, but hardly in E. ulmoides, making them good candidates to explain the overall healthspan benefits of C. chinensis compared to the specific positive effects on stress resistance by E. ulmoides. Our findings highlight the overall anti-aging effects of C. chinensis in C. elegans and provide first hints about the components responsible for these effects.

Rapid identification of the geographical origin of Eucommia ulmoides by using excitation-emission matrix fluorescence combined with chemometric methods

Eucommia ulmoides is an important and valuable traditional Chinese medicine with various medical functions, and has been widely used as health food in China, Japan, South Korea and other Asian countries for many years. The efficacy and quality of E. ulmoides are closely associated with the geographical origin. In this work, the potential of excitation-emission matrix (EEMs) fluorescence coupled with chemometric methods was investigated for simple, rapid and accurate for identification E. ulmoides from different geographical origins. Parallel factor analysis (PARAFAC) was applied for characterizing the fluorescence fingerprints of E. ulmoides samples. Moreover, k-nearest neighbor (kNN), principal component analysis-linear discriminant analysis (PCA-LDA) and partial least squares discriminant analysis (PLS-DA) models were used for the classification of E. ulmoides samples according to their geographical origins. The results showed that kNN model was more suitable for identification of E. ulmoides samples from different provinces. The kNN model could identify E. ulmoides samples from eight different geographical origins with 100% accuracy on the training and test sets. Therefore, the proposed method was available for conveniently and accurately determining the geographical origin of E. ulmoides, which can expect to be an attractive alternative method for identifying the geographic origin of other traditional Chinese medicines.

Determination of multiple pesticides in Eucommia ulmoides followed by gas chromatography mass spectrometry based on a solid-phase extraction method

Eucommia ulmoides, a precious Chinese herbal medicine, lack of studies on the detection of its pesticide residues. A simple sample preparation based on the solid-phase extraction (SPE) procedure was established for the analysis of 16 kinds of pesticides in Eucommia ulmoides by gas chromatography mass spectrometry (GC-MS) with selective ion monitoring mode. Here, the type and volume of extraction solvent and eluent, the kinds of sorbents in SPE Cleanert column, were optimized. Under the optimal conditions, a good linear relationship was obtained in the range of 0.005 to 5.0 mg/L with correlation coefficient (r) higher than 0.9990, and the average recoveries (AR) of 16 pesticides ranged from 79.6 to 109.2% at the spiking levels of 0.01, 0.1, and 0.5 mg/kg. The relative standard deviations (RSD) were 0.78 to 9.56% (n = 6). The results show that the established method can not only fully meet the analytical requirements of various pesticides in Eucommia ulmoides, but also have the potential to be applied in the detection of pesticide residues in others Chinese herbal medicine.

Central and Enteric Neuroprotective Effects by Eucommia ulmoides Extracts on Neurodegeneration in Rotenone-induced Parkinsonian Mouse

Parkinson's disease (PD) is a progressive neurodegenerative disease of both the central and peripheral / enteric nervous systems. Oxidative stress and neuroinflammation are associated with the pathogenesis of PD, suggesting that anti-oxidative and anti-inflammatory compounds could be neuroprotective agents for PD. Eucommia ulmoides (EU) is a traditional herbal medicine which exerts neuroprotective effects by anti-inflammatory and anti-oxidative properties. Our previous study showed that treatment with chlorogenic acid, a component of EU, protected against neurodegeneration in the central and enteric nervous systems in a PD model. In this study, we examined the effects of EU extract (EUE) administration on dopaminergic neurodegeneration, glial response and α-synuclein expression in the substantia nigra pars compacta (SNpc), and intestinal enteric neurodegeneration in low-dose rotenone-induced PD model mice. Daily oral administration of EUE ameliorated dopaminergic neurodegeneration and α-synuclein accumulation in the SNpc. EUE treatment inhibited rotenone-induced decreases in the number of total astrocytes and in those expressing the antioxidant molecule metallothionein. EUE also prevented rotenone-induced microglial activation. Furthermore, EUE treatment exerted protective effects against intestinal neuronal loss in the PD model. These results suggest that EU exerts neuroprotective effects in the central and enteric nervous systems of rotenone-induced parkinsonism mice, in part by glial modification.

Inactivation of Salmonella typhimurium SL1344 by Chlorogenic Acid and the Impairment of Cellular Integrity

Chlorogenic acid (CGA) is an antibacterial agent that can be isolated from Eucommia ulmoides Oliver, a Chinese medicinal and edible plant food. The inhibitory effect of CGA on bacterial growth and stiffness of the outer membrane (OM) had been reported, while more evidence were required to elucidate its impairment of cell wall. In this study, the morphological and physiochemical changes of Salmonella cells under CGA treatment were investigated. Firstly, the minimum inhibitory concentration (MIC) of CGA against Salmonella was assayed. Later, the permeability of OM and activity of the proteins released were measured and observed to reveal the alteration of OM characteristic and cellular morphology. Finally, reactive oxygen species and cell membrane fluidity were analyzed, respectively, to elucidate how CGA damaged cell surface. The results showed that MIC of CGA against Salmonella was 6.25 mg/L. Under sub-lethal doses of CGA, the OM permeability and the release of soluble proteins were enhanced evidently, and Salmonella cells showed more deformed and shrunken, confirming the impairment of cellular integrity under CGA. Finally, the possible cause of cell surface damage was investigated. the fluidity of the membrane was increased upon CGA treatment, which may the possible cause of OM by CGA.

Whole genome re-sequencing reveals the genetic diversity and evolutionary patterns of Eucommia ulmoides

Eucommia ulmoides (E. ulmoides) is a deciduous perennial tree belonging to the order Garryales, and is known as "living fossil" plant, along with ginkgo (Ginkgo biloba), metaspaca (Metasequoia glyptostroboides) and dove tree (Davidia involucrata Baill). However, the genetic diversity and population structure of E. ulmoides are still  ambiguous nowdays. In this study, we re-sequenced the genomes of 12 E. ulmoides accessions from different major climatic geography regions in China to elucidate the genetic diversity, population structure and evolutionary pattern. By integration of phylogenetic analysis, principal component analysis and population structure analysis based on a number of high-quality SNPs, a total of 12 E. ulmoides accessions were clustered into four different groups. This result is consistent with their geographical location except for group samples from Shanghai and Hunan province. E. ulmoides accessions from Hunan province exhibited a closer genetic relationship with E. ulmoides accessions from Shanghai in China compared with other regions, which is also supported by the result of population structure analyses. Genetic diversity analysis further revealed that E. ulmoides samples in Shanghai and Hunan province were with higher genetic diversity than those in other regions in this study. In addition, we treated the E. ulmoides materials from Shanghai and Hunan province as group A, and the other materials from other places as group B, and then analyzed the evolutionary pattern of E. ulmoides. The result showed the significant differentiation (Fst = 0.1545) between group A and group B. Some candidate highly divergent genome regions were identified in group A by selective sweep analyses, and the function analysis of candidate genes in these regions showed that biological regulation processes could be correlated with the Eu-rubber biosynthesis. Notably, nine genes were identified from selective sweep regions. They were involved in the Eu-rubber biosynthesis and expressed in rubber containing tissues. The genetic diversity research and evolution model of E. ulmoides were preliminarily explored in this study, which laid the foundation for the protection of germplasm resources and the development and utilization of multipurpose germplasm resources in the future.

Ulmoidol, an unusual nortriterpenoid from Eucommia ulmoides Oliv. Leaves prevents neuroinflammation by targeting the PU.1 transcriptional signaling pathway

Chronic neuroinflammation is closely associated with the development of neurodegenerative diseases, including Alzheimer's disease (AD). In the current study, 13 anti-neuroinflammatory compounds were isolated from Eucommia ulmoides Oliv. leaves. Among these compounds, trans-sinapaldehyde (6), 3',4',5,7-tetrahydroxy-3-methylflavone (7), and amarusine A (13) were isolated from E. ulmoides leaves for the first time. The ursane-type C₂₉-triterpenoid, ulmoidol (ULM, 9), significantly inhibited the production of proinflammatory mediators and reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, ULM inhibited the cluster of differentiation 14 (CD14)/Toll-like receptor 4 (TLR4) signaling pathway and consequently limited the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Notably, electrophoretic mobility shift assay (EMSA) and molecular docking analyses indicated that ULM could prevent PU box binding-1 (PU.1) from binding to DNA, suggesting that PU.1 might be a potential ULM target. In conclusion, ULM alleviates neuroinflammatory responses in microglia, which could be partly explained by its targeting of PU.1 and the resulting suppression of the TLR4/MAPK/NF-κB signaling pathways. These results suggested that ULM may have therapeutic potential as an agent for treating neuroinflammation-related neurodegenerative diseases.

Identification, evolution and expression analysis of WRKY gene family in Eucommia ulmoides

The WRKY transcription factors is one of the largest families of transcription factors (TFs) in plants and involved in multiple biological processes. However, the role of the WRKY family had not been reported in Eucommia ulmoides. In this study, 45 WRKY genes (EuWRKY1-45) with conserved WRKY domain were identified in E. ulmoides and classified into three groups. The group II was further divided into five subgroups based on phylogenetic analysis, and each clade was well supported by the conserved motifs. All the genes were located on 34 different scaffolds respectively. A number of development-, light-, hormone-, and stress-related elements were randomly distributed in the promoter sequences of EuWRKYs. Expression profiles indicated that EuWRKY genes were involved in leaf development, and majority of EuWRKYs genes were highly expressed in leaf buds. Co-expression analysis of WRKYs suggested an intricate interplay of growth-related responses. EuWRKY4 was involved in a complex proteins interaction network. Collectively, our results provide extensive insights into the WRKY gene family, thereby contributing to the screening of additional candidate genes in E. ulmoides.

Illicium verum and Eucommia ulmoides leaf extracts promote nutrient availability and antioxidant capacity in piglets by upregulating duodenal and jejunal Nrf2/TNF-α

The effect of Illicium verum extracts (IVE) or Eucommia ulmoides leaf extracts (ELE) on nutrient availability, duodenal and jejunal antioxidant ability of Duroc ×Landrace × Yorkshire (DLY) and Chinese native Licha-black (LCB) piglets was investigated. Ninety-six piglets (48 DLY and 48 LCB respectively) without significant difference in body weight (11.22 ± 0.32 kg) were used in a 2 × 4 factorial design. Animals were randomly allocated to four treatments, and each had four replicates with three DLY and three LCB piglets. Treatments were basal diet (CON) and basal diet with 500 mg/kg IVE, 250 mg/kg ELE and 50 mg/kg chlortetracycline (CHL) respectively. Animals were placed individually for 7-days adaptation following 42-days test. Results showed the significant interaction (p < 0.05) between dietary treatments and pig species in activity of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px), content of malondialdehyde (MDA), and α-tumour necrosis factor (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2/TNF-α at mRNA and protein level in duodenum and jejunum of DLY and LCB piglets. The IVE and ELE increased (p < 0.05) activity of GSH-Px and T-SOD, and the Nrf2/TNF-α at mRNA and protein level, however, the decreased (p < 0.05) MDA content, and TNF-α at mRNA and protein level in duodenum and jejunum were observed. The CHL decreased (p < 0.05) activity of GSH-Px and T-SOD, TNF-α and Nrf2 at mRNA and protein level in duodenum, but increased (p < 0.05) MDA content and Nrf2/TNF-α in jejunum. DLY piglets had higher (p < 0.05) nutrient digestibility (organic matter, crude protein and gross energy), availability (biological value and net protein utilization), MDA content, and TNF-α at mRNA and protein level in jejunum, and had lower (p < 0.05) activity of GSH-Px and T-SOD, and Nrf2 and Nrf2/TNF-α at mRNA and protein level in duodenum and jejunum than LCB. In conclusion, the 500 mg/kg IVE and 250 mg/kg ELE improved the nutrient availability, and the improvement of antioxidant capacity is realized by activating the Nrf2/TNF-α of duodenum and jejunum. The CHL had adverse effects on antioxidant ability of DLY and LCB piglets. The results showed that the nutrient digestion and absorption capacity of DLY were stronger than that of LCB piglets, but the antioxidant capacity was lower than that of LCB piglets. Therefore, the IVE and ELE are recommended as a new potential alternative to antibiotics in piglets' diets.

p-Terphenyls From Aspergillus sp. GZWMJZ-055: Identification, Derivation, Antioxidant and α-Glycosidase Inhibitory Activities

One new (1) and fifteen known (2–16) p-terphenyls were isolated from a solid culture of the endophytic fungus Aspergillus sp. GZWMJZ-055 by adding the leaves of its host Eucommia ulmoides. Furthermore, nine p-terphenyls (17–25) were synthesized from the main compounds (5–7), among which derivatives 18, 19, 21, 22, and 25 are new p-terphenyls. Compounds 15 and 16 were also, respectively, synthesized from compounds 6 and 7 by oxidative cyclization of air in the presence of silica gel. These p-terphenyls especially those with 4,2′,4″-trihydroxy (4–7, 20, 21) or 4, 4″-dihydroxy-1,2,1′,2′-furan (15, 16) substituted nucleus, exhibited significant antioxidant and α-glucosidase inhibitory activities and lower cytotoxicity to caco-2 cells. The results indicated their potential use as lead compounds or dietary supplements for treating or preventing the diabetes.

Enhanced Healthspan in Caenorhabditis elegans Treated With Extracts From the Traditional Chinese Medicine Plants Cuscuta chinensis Lam. and Eucommia ulmoides Oliv

To uncover potential anti-aging capacities of Traditional Chinese Medicine (TCM), the nematode Caenorhabditis elegans was used to investigate the effects of Eucommia ulmoides and Cuscuta chinensis extracts, selected by screening seven TCM extracts, on different healthspan parameters. Nematodes exposed to E. ulmoides and C. chinensis extracts, starting at the young adult stage, exhibited prolonged lifespan and increased survival after heat stress as well as upon exposure to the pathogenic bacterium Photorhabdus luminescens, whereby the survival benefits were monitored after stress initiation at different adult stages. However, only C. chinensis had the ability to enhance physical fitness: the swimming behavior and the pharyngeal pumping rate of C. elegans were improved at day 7 and especially at day 12 of adulthood. Finally, monitoring the red fluorescence of aged worms revealed that only C. chinensis extracts caused suppression of intestinal autofluorescence, a known marker of aging. The results underline the different modes of action of the tested plants extracts. E. ulmoides improved specifically the physiological fitness by increasing the survival probability of C. elegans after stress, while C. chinensis seems to be an overall healthspan enhancer, reflected in the suppressed autofluorescence, with beneficial effects on physical as well as physiological fitness. The C. chinensis effects may be hormetic: this is supported by increased gene expression of hsp-16.1 and by trend, also of hsp-12.6.

Orthodontic Aligner Incorporating Eucommia ulmoides Exerts Low Continuous Force: In Vitro Study

The aim of this study was to investigate the orthodontic force exerted by thermoplastic orthodontic appliances incorporating Eucommiaulmoides in terms of usefulness as the aligner-type orthodontic device. Erkodur, Essix C+^®, Eucommia elastomer, and edgewise brackets were used (n = 3, each; thickness = 1.0 mm, each). The orthodontic force on the upper right incisor was measured every 24 h for two weeks using a custom-made measuring device. The force of the Eucommia elastomer (4.25 ± 0.274 N) and multi bracket system (5.32 ± 0.338 N) did not change from the beginning to the end (p > 0.01). The orthodontic force exerted by the Eucommia elastomer was lower than that of the multi-bracket orthodontic appliance from the beginning to the end. The force of Erkodur significantly decreased from the beginning to 24 h (6.47 ± 1.40 N) and 48 h (3.30 ± 0.536 N) (p < 0.01). The force of Essix C+^® significantly decreased from the beginning (13.2 ± 0.845 N) to 24 h (8.77 ± 0.231 N) (p < 0.01). The thermoplastic orthodontic appliance made of Eucommia elastomer continuously exerted a constant orthodontic force for two weeks under water immersion conditions. The orthodontic force of Eucommia elastomer was found to be similar to the orthodontic force exerted by the multi-bracket orthodontic appliance with 0.019 × 0.025 in nickel–titanium wire. These results suggest that the Eucommia elastomer has possibly become one of the more useful materials to form thermoplastic orthodontic appliance exerting low continues orthodontic force.

Application of network pharmacology and molecular docking to elucidate the potential mechanism of Eucommia ulmoides-Radix Achyranthis Bidentatae against osteoarthritis

BACKGROUND

Osteoarthritis is a disabling disease, which seriously affects the quality of life of patients. Increasing evidence has indicated that Chinese herbal medicine including Eucommia ulmoides (EU) and Radix Achyranthis Bidentatae (RAB) have potential in the treatment of osteoarthritis, and this is associated with their multi-target and multi-link action characteristics. Although their potential anti-arthritic activity has been reported, the exact mechanism of EU-RAB action in osteoarthritis remains unexplored. Therefore, this study explores the mechanism of EU-RAB against osteoarthritis using network pharmacology and molecular docking technology.

METHODS

Public databases including TCMSP、BATMAN-TCM、OMIM and Genecards were used to predict the bioactive ingredients and putative targets of EU-RAB against osteoarthritis. Enrichment analysis was performed to expound the biological functions and associated pathways of the hub targets. Cytoscape software was used to construct a "compounds-targets-pathways" network for elucidating the comprehensive molecular mechanism of EU-RAB against osteoarthritis. Molecular docking was used to verify the correlation between the main active ingredients and hub targets.

RESULTS

Network pharmacological analysis of EU-RAB in the treatment of osteoarthritis, identified 50 active ingredients including quercetin, kaempferol, wogonin, and baicalein with important biological effect. A total of 68 key targets were screened, including IL-6, EGFR, MAPK8, etc., and they were found to be enriched in a series of signaling pathways, such as apoptosis, TNF, MAPK, PI3K/AKT, and IL-17 signaling pathways. Moreover, molecular docking analysis showed that the main ingredients were tightly bound to the core targets, further confirming the anti-arthritic effects.

CONCLUSION

Based on network pharmacology and molecular docking analysis, the present study provides insights into the potential mechanism of EU-RAB in osteoarthritis after successfully screening for associated key target genes and signaling pathways. These findings further provide a theoretical basis for further pharmacological research into the potential mechanism of EU-RAB in osteoarthritis.

[Research advances in chemical constituents and pharmacological activities of different parts of Eucommia ulmoides]

To date, 205 compounds have been identified from different medicinal parts of Eucommia ulmoides, including lignans, iridoid terpenoids, phenols, flavonoids, terpenoids and steroids, polysaccharides and others. Their pharmacological effects include blood pressure-lowering, blood sugar-lowering, blood lipids-regulating, prevention of osteoporosis, anti-inflammation, liver protection, anti-cancer and so on. Their efficacy and mechanism from different parts are slightly different. In this paper, the chemical composition, pharmacological action and mechanism of different parts of E. ulmoides were systematically summarized, as well as its quality control and processing research, to provide theoretical basis for further rational development and utilization of E. ulmoides.

Transcriptome analysis of terpenoid biosynthetic genes and simple sequence repeat marker screening in Eucommia ulmoides

Trans-polyisoprene rubber is produced in the tissues of leaves, bark, and fruit of Eucommia ulmoides and is considered an important energy source. Transcript profiles of two tissues from E. ulmoides cv. Qinzhong No. 3, leaf and fruit, were analysed using the Illumina HiSeq 2000 system. In total, 104 million clean reads were obtained and assembled into 58,863 unigenes. Through gene functional classification, 28,091 unigenes (47.72%) were annotated and 65 unigenes have been hypothesized to encode proteins involved in terpenoid biosynthesis. In addition, 10,041 unigenes were detected as differentially expressed unigenes, and 29 of them were putatively related to terpenoid biosynthesis. The synthesis of trans-polyisoprene rubbers in E. ulmoides was hypothesised to be dominated by the mevalonate pathway. Farnesyl diphosphate synthase 2 (FPPS2) was considered a key component in the biosynthesis of trans-polyprenyl diphosphate. Rubber elongation factor 3 (REF3) might be involved in stabilising the membrane of rubber particles in E. ulmoides. To date, 351 simple sequence repeats (SSRs) were validated as polymorphisms from eight E. ulmoides plants (two parent plants and six F₁ individuals), and these could act as molecular markers for genetic map density increase and breeding improvement of E. ulmoides.

Flavonoids from Eucommia ulmoides and their in vitro hepatoprotective activities

A phytochemical investigation of the barks of Eucommia ulmoides Oliv. resulted in the isolation of 18 flavonoids (1-18). The new compound, eucommiaflavone (1) was structurally elucidated by various spectroscopic analyses. In particular, Mo₂(OAc)₄-induced circular dichroism (ICD) analysis was applied to determine the absolute configuration of 1. Furthermore, five flavonoids (4, 9, 11, 13, and 15) revealed significant in vitro hepatoprotective activity against D-galactosamine-induced cytotoxicity in human hepatoma HepG2 cells.

Engineering a microcarrier based on a polysaccharide-growth factor complex for enhancing the proliferation of mesenchymal stem cells

Mesenchymal stem cell (MSC) delivery has been broadly investigated as a cell-based therapy strategy towards various diseases and tissue injury. In these applications, the cell-delivery vehicle plays a crucial role in determining the therapeutic performance of MSCs and their fate post-implantation. We report here the development of a microcarrier system combining platelet-derived growth factor-BB (PDGF-BB) and a PDGF-BB-binding polysaccharide - Eucommia ulmoides (EUP3) - for MSC cultivation. First, we investigated the optimal conditions to prepare the EUP3-PDGF-BB complex, by comparing its i) diameter, ii) morphology, and iii) bioactivity to promote MSC proliferation and fibroblast migration in vitro, under different PDGF-BB/EUP3 ratios. Then, we fabricated microspheres using gelatin and EUP3 as the matrix while stabilizing PDGF-BB at the optimal ratio for MSC adhesion and growth. Live staining and SEM observation indicated that the prepared microspheric carrier supported MSC growth and maintained cell stemness. We suggest that the EUP3/PDGF-gelatin microcarriers can potentially serve as a cell-delivery vehicle for tissue engineering.

Effect of Illicium verum or Eucommia ulmoides leaf extracts on the anti-stress ability, and mRNA and protein expression of Nrf2 and TNF-α in Duroc × Landrace × Yorkshire and Chinese native Licha-black nursery piglets

Plant extracts are considered to be an effective alternative to antibiotics in response to weaning stress in piglets. This study evaluated the effect of Illicium verum extracts (IVE) or Eucommia ulmoides leaf extracts (ELE) on growth performance, serum and liver antioxidant ability of nursery piglets, as well as the difference of IVE and ELE on Duroc × Landrace × Yorkshire (DLY) and Chinese native Licha-black (LCB) piglets. A total of 96 nursery piglets (48 DLY and 48 LCB piglets) with an average body weight of 11.22 ± 0.32 kg were randomly divided into four treatments in a 2 × 4 factorial design. Each treatment had four replicates with 3 DLY and 3 LCB piglets per replicate respectively. Treatments included: basal diet, basal diet + 500 mg/kg IVE, basal diet + 250 mg/kg ELE and basal diet + 50 mg/kg chlortetracycline (CHL). All piglets were housed individually for the 42 days trial period after 7 days adaptation. Results showed that there were significant interactions (p < .05) between piglets species and dietary treatments in average daily gain (ADG) and feed efficiency, serum and hepatic glutathione peroxidase (GSH-Px) and malondialdehyde (MDA), hepatic integral optical density (IOD) of α-tumour necrosis factor (TNF-α), hepatic relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2)/TNF-α and protein expression of TNF-α. Regardless of piglets species, supplementation with IVE and ELE increased (p < .05) ADG and feed efficiency, T-SOD and GSH-Px in serum and liver, hepatic IOD of Nrf2, hepatic mRNA and protein expression of Nrf2/TNF-α. However, CHL treatment resulted in lower (p < .05) serum GSH-Px and hepatic mRNA and protein expression of Nrf2/TNF-α, and higher hepatic MDA and IOD of TNF-α. Compared to LCB, DLY piglets had higher (p < .05) ADG and feed efficiency, serum and hepatic MDA, and protein expression of TNF-α, but lower (p < .05) ADFI, liver index, serum and hepatic GSH-Px, hepatic IOD of TNF-α, mRNA expressions of Nrf2/TNF-α were observed. In conclusion, Illicium verum (500 mg/kg) and Eucommia ulmoides leaf (250 mg/kg) extracts can increase the growth performance and antioxidant ability of DLY and LCB piglets, while chlortetracycline produces undesirable side-effects on the antioxidant ability of DLY and LCB piglets. Illicium verum and Eucommia ulmoides leaf extracts produced different antioxidant effects in DLY and LCB piglets with the Chinese native Licha-black pig responding better than Duroc × Landrace × Yorkshire.

Integration of Transcriptomes, Small RNAs, and Degradome Sequencing to Identify Putative miRNAs and Their Targets Related to Eu-Rubber Biosynthesis in Eucommia ulmoides

Eucommia ulmoides has attracted much attention as a valuable natural rubber (Eu-rubber) production tree. As a strategic material, Eu-rubber plays a vital role in general and defence industries. However, the study of Eu-rubber biosynthesis at a molecular level is scarce, and the regulatory network between microRNAs (miRNAs) and messenger RNAs (mRNAs) in Eu-rubber biosynthesis has not been assessed. In this study, we comprehensively analyzed the transcriptomes, small RNAs (sRNAs) and degradome to reveal the regulatory network of Eu-rubber biosynthesis in E. ulmoides. A total of 82,065 unigenes and 221 miRNAs were identified using high-throughput sequencing; 20,815 targets were predicted using psRNATarget software. Of these targets, 779 miRNA-target pairs were identified via degradome sequencing. Thirty-one miRNAs were differentially expressed; 22 targets of 34 miRNAs were annotated in the terpenoid backbone biosynthesis pathway (ko00900) based on the Kyoto Encyclopedia of Genes and Genomes (KEGG). These miRNAs were putatively related to Eu-rubber biosynthesis. A regulatory network was constructed according to the expression profiles of miRNAs and their targets. These results provide a comprehensive analysis of transcriptomics, sRNAs and degradome to reveal the Eu-rubber accumulation, and provide new insights into genetic engineering techniques which may improve the content of Eu-rubber in E. ulmoides.

Dynamic Changes in Metabolite Accumulation and the Transcriptome during Leaf Growth and Development in Eucommia ulmoides

Eucommia ulmoides Oliver is widely distributed in China. This species has been used mainly in medicine due to the high concentration of chlorogenic acid (CGA), flavonoids, lignans, and other compounds in the leaves and barks. However, the categories of metabolites, dynamic changes in metabolite accumulation and overall molecular mechanisms involved in metabolite biosynthesis during E. ulmoides leaf growth and development remain unknown. Here, a total of 515 analytes, including 127 flavonoids, 46 organic acids, 44 amino acid derivatives, 9 phenolamides, and 16 vitamins, were identified from four E. ulmoides samples using ultraperformance liquid chromatography–mass spectrometry (UPLC-MS) (for widely targeted metabolites). The accumulation of most flavonoids peaked in growing leaves, followed by old leaves. UPLC-MS analysis indicated that CGA accumulation increased steadily to a high concentration during leaf growth and development, and rutin showed a high accumulation level in leaf buds and growing leaves. Based on single-molecule long-read sequencing technology, 69,020 transcripts and 2880 novel loci were identified in E. ulmoides. Expression analysis indicated that isoforms in the flavonoid biosynthetic pathway and flavonoid metabolic pathway were highly expressed in growing leaves and old leaves. Co-expression network analysis suggested a potential direct link between the flavonoid and phenylpropanoid biosynthetic pathways via the regulation of transcription factors, including MYB (v-myb avian myeloblastosis viral oncogene homolog) and bHLH (basic/helix-loop-helix). Our study predicts dynamic metabolic models during leaf growth and development and will support further molecular biological studies of metabolite biosynthesis in E. ulmoides. In addition, our results significantly improve the annotation of the E. ulmoides genome.

[Community composition and ecological functional structural analysis of endophytic fungi in bark of Eucommia ulmoides in different areas]

Based on high-throughput sequencing and metagenomic technology,the community composition and ecological functions of endophytic fungi in the bark of Eucommia ulmoides from three producing areas,Fengxiang town in Zunyi county of Guizhou province,Lingyang town of Cili county of Hunan province and Mumen town of Wangcang county of Sichuan province,were analyzed. A total of110 865 effective sequences of endophytic fungi were obtained in the study. The corresponding fungal group of OTUs after clustering belonged to 3 phyla( Ascomycota,Basidiomycota,Zygomycota),10 classes,25 orders,41 families,57 genera and 74 species. Among them,the dominant genera of Sichuan Wangcang Bark of E. ulmoides( EWP) was an unclassified genus in the Nectriaceae of the Crimsonaceae,with a relative abundance of 54. 79%; The dominant species of Hunan Cili Bark of E. ulmoides( ECP) was the unclassified genus of Ascomycota,with a relative abundance of 39. 97% and the dominant species of Guizhou Zunyi bark( EZP) was Lophiostoma,and its relative abundance was 47. 07%. The analysis of α diversity indicated that the shannon diversity index of endophytic fungi from different places was as follows: ECP: 1. 340 2>EZP: 1. 380 4 > EWP: 1. 168 3. The simpson diversity index was: EWP( 0. 427 3) >EZP( 0. 332 5) > ECP( 0. 313 6). FUNGuild software platform analysis displayed that endophytic fungi of E. ulmoides bark from three producing areas contained the following 14 functional groups: plant pathogen,animal pathogen and endophyte et al.,the number of functional groups in the 3 samples of E. ulmoides reached up 8 genera and exceeded one half of the total number. Correlation analysis of Canonical correspondence analysis( CCA) between endophytic fungal community diversity and four active compounds of E. ulmoides were analyzed,the results showed that the contents of pinoresinol diglucoside and chlorogenic acid,to a certain extend,had a positive correlation with an unclassified genus of Davidiellaceae,Mortierella,Chaetomium and Pestalotiopsis from the endophytic fungi in EWP sample.

The total flavonoid of Eucommia ulmoides sensitizes human glioblastoma cells to radiotherapy via HIF-α/MMP-2 pathway and activates intrinsic apoptosis pathway

Background: As one of the most common and lethal malignant primary brain tumors, glioblastomas (GBMs) are identified as grade IV neoplasms, the most severe grade, according to WHO classification systems. The outcome of surgery against GBMs is limited since its frequent relapse. Radiotherapy is a crucial and widely used treatment after surgery, while the strong radioresistance of GBM cells still becomes a severe problem of radiotherapy. Eucommia ulmoides Oliv. is used for the treatment of various diseases, such as lower blood pressure and inflammation. Purpose: To explore the anti-tumor effect of Eucommia ulmoides Oliv. against GBMs. Methods: Dose-viability assays were performed to examine the anti-tumor effect. Would-healing and transwell assays were carried out to evaluate the migration and invasion ability of GBMs. Cell apoptosis was detected by 33, 258 staining, and the expressions of key proteins were examined by western blot. Results: In this study, we confirmed that the inhibitory effect of the total flavonoid of Eucommia ulmoides on proliferation, migration and invasion of human GBM cells. Its favorable effects inspired us to explore the potential ability in enhancing radiosensitivity of GBM cells. The results demonstrated that it could further induce apoptosis during radiotherapy via intrinsic apoptosis pathway. Besides, it could significantly reduce the malondialdehyde level after radiotherapy, which suggested it inhibited tumor cell and protected normal neuronal cells. By examining the expression of important genes of radioresistant pathway, we found a significant decrease of HIF-α/MMP-2 when using the total flavonoid of Eucommia ulmoides during radiotherapy. Conclusion: This result suggests that the enhancement of radiotherapy may be mediated by modulating glucose metabolism of GBMs in HIF-α/MMP-2 pathway.

Prediction of Drug Positioning for Quan-Du-Zhong Capsules Against Hypertensive Nephropathy Based on the Robustness of Disease Network

Hypertensive nephropathy (HN) is a medical condition in which chronic high blood pressure causes different kidney damage, including vascular, glomerular and tubulointerstitial lesions. For HN patients, glomerular and tubulointerstitial lesions occur in different renal structure with distinct mechanisms in the progression of renal damage. As an extraction of Eucommia ulmoides, Quan-du-zhong capsule (QDZJN) has the potential to treat HN due to antihypertensive and renal protective activities. Complicated mechanism of HN underlying various renal lesions and the “multi-component and multi-target” characteristics of QDZJN make identifying drug positioning for various renal lesions of HN complex. Here, we proposed an approach based on drug perturbation of disease network robustness, that is used to assess QDZJN positioning for various HN lesions. Topological characteristics of drug-attacked nodes in disease network were used to evaluated nodes importance to network. To evaluate drug attack on the whole disease network of various HN lesions, the robustness of disease networks before/after drug attack were assessed and compared with null models generated from random networks. We found that potential targets of QDZJN were specifically expressed in the kidneys and tended to participate in the “inflammatory response,” “regulation of blood pressure,” and “response to LPS and hypoxia,” and they were also key factors of HN. Based on network robustness assessment, QDZJN may specifically target glomeruli account to the stronger influence on glomerular network after removal of its potential targets. This prediction strategy of drug positioning is suitable for multi-component drugs based on drug perturbation of disease network robustness for two renal compartments, glomeruli and tubules. A stronger influence on the disease network of glomeruli than of tubules indicated that QDZJN may specifically target glomerular lesion of HN patients and will provide more evidence for precise clinical application of QDZJN against HN. Drug positioning approach we proposed also provides a new strategy for predicting precise clinical use of multi-target drugs.

Enrichment and Purification of Aucubin from Eucommia ulmoides Ionic Liquid Extract Using Macroporous Resins

Aiming to address the shortcomings of high-concentration ethanol or methanol extraction solutions that need to be diluted and concentrated prior to use in conventional macroporous resin adsorption approaches, an efficient approach for enrichment and purification of aucubin from the ionic liquid extraction solution of samaras of Eucommia ulmoides was proposed. Among the nine kinds of macroporous resins investigated, the HPD850 resin was found to be the most suitable. Equilibrium adsorption tests were investigated and found to be better fitted by the Langmuir isotherm model. After the dynamic tests on a column packed with HPD850, the optimum operational conditions were as follows: for the absorption process, an initial aucubin concentration of 9.87 mg/L, a sample volume of 13 bed volumes (BV), and a flow rate of 2 BV/h; for the water washing process, 5 BV of deionized water and a flow rate of 3 BV/h; for the ethanol desorption process, a 10–80% ethanol volume fraction as the eluent, 2 BV for each ethanol volume fraction, and a flow rate of 3 BV/h. The 40–80% ethanol volume fraction eluent was collected and concentrated to produce the final products, resulting in an aucubin purity and recovery of 79.41% and 72.92%, respectively.

Whole-Genome Comparison Reveals Heterogeneous Divergence and Mutation Hotspots in Chloroplast Genome of Eucommia ulmoides Oliver

Eucommia ulmoides (E. ulmoides), the sole species of Eucommiaceae with high importance of medicinal and industrial values, is a Tertiary relic plant that is endemic to China. However, the population genetics study of E. ulmoides lags far behind largely due to the scarcity of genomic data. In this study, one complete chloroplast (cp) genome of E. ulmoides was generated via the genome skimming approach and compared to another available E. ulmoides cp genome comprehensively at the genome scale. We found that the structure of the cp genome in E. ulmoides was highly consistent with genome size variation which might result from DNA repeat variations in the two E. ulmoides cp genomes. Heterogeneous sequence divergence patterns were revealed in different regions of the E. ulmoides cp genomes, with most (59 out of 75) of the detected SNPs (single nucleotide polymorphisms) located in the gene regions, whereas most (50 out of 80) of the indels (insertions/deletions) were distributed in the intergenic spacers. In addition, we also found that all the 40 putative coding-region-located SNPs were synonymous mutations. A total of 71 polymorphic cpDNA fragments were further identified, among which 20 loci were selected as potential molecular markers for subsequent population genetics studies of E. ulmoides. Moreover, eight polymorphic cpSSR loci were also developed. The sister relationship between E. ulmoides and Aucuba japonica in Garryales was also confirmed based on the cp phylogenomic analyses. Overall, this study will shed new light on the conservation genomics of this endangered plant in the future.

Effects of polyphenolic extract from Eucommia ulmoides Oliver leaf on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs

To investigate the effects of polyphenolic extract from Eucommia ulmoides Oliver leaf (PEEU) on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs, 30 weaned male Huzhou lambs were equally divided into three treatments and fed the basal diet supplemented with 0 (CON), 5 (PEEU5) or 10 (PEEU10) g/kg PEEU. Dietary PEEU supplementation did not affect growth performance and apparent digestibility of nutrients. Compared with the CON group, lambs in the PEEU10 group had lower ammonia nitrogen concentration (p < .01) and acetic acid to propionic acid ratio (p < .05) and higher the molar proportion of propionate (p < .05) in rumen fluid. Ammonia nitrogen concentration (p < .01) and the molar proportion of propionate (p < .05) were affected by an interaction between PEEU and sampling day. Dietary PEEU supplementation at 10 g/kg increased total antioxidant capacity (p < .05), superoxide dismutase (p < .05) and glutathione peroxidase (p < .01) activities in serum and glutathione peroxidase activity (p < .05) in liver and decreased (p < .05) malondialdehyde content in serum and liver compared with the CON group. In conclusion, dietary PEEU supplementation affected rumen fermentation patterns and improved antioxidant status of fattening lambs.

Comparison of Multiple Bioactive Constituents in Different Parts of Eucommia ulmoides Based on UFLC-QTRAP-MS/MS Combined with PCA

Eucommia ulmoides Oilv. (EU), also called Du-zhong, is a classical traditional Chinese medicine. Its bark, leaf, and male flower are all used for medicinal purposes, called Eucommiae Cortex (EC), Eucommiae Folium (EF), and Eucommiae Flos Male (EFM). In order to study the difference in synthesis and the accumulation of metabolites in different parts of EU, a reliable method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was developed for the simultaneous determination of a total of 21 constituents, including two lignans, 6 iridoids, 6 penylpropanoids, 6 flavonoids, and one phenol in the samples (EC, EF, and EFM). Furthermore, principal component analysis (PCA) was performed to evaluate and classify the samples according to the contents of these 21 constituents. All of the results demonstrated that the chemical compositions in EC, EF, and EFM were significantly different and the differential constituents (i.e., aucubin, geniposidic acid, chlorogenic acid, pinoresinol-di-O-β-d-glucopyranoside, geniposide, cryptochlorogenic acid, rutin, and quercetin) were remarkably associated with sample classifications. The research will provide the basic information for revealing the laws of metabolite accumulation in EC, EF, and EFM from the same origin.

Complete genome sequence of Bacillus velezensis 157 isolated from Eucommia ulmoides with pathogenic bacteria inhibiting and lignocellulolytic enzymes production by SSF

Bacillus velezensis 157 was isolated from the bark of Eucommia ulmoides, and exhibited antagonistic activity against a broad spectrum of pathogenic bacteria and fungi. Moreover, B. velezensis 157 also showed various lignocellulolytic activities including cellulase, xylanase, α-amylase, and pectinase, which had the ability of using the agro-industrial waste (soybean meal, wheat bran, sugarcane bagasse, wheat straw, rice husk, maize flour and maize straw) under solid-state fermentation and obtained several industrially valuable enzymes. Soybean meal appeared to be the most efficient substrate for the single fermentation of B. velezensis 157. Highest yield of pectinase (19.15 ± 2.66 U g-1), cellulase (46.69 ± 1.19 U g-1) and amylase (2097.18 ± 15.28 U g-1) was achieved on untreated soybean meal. Highest yield of xylanase (22.35 ± 2.24 U g-1) was obtained on untreated wheat bran. Here, we report the complete genome sequence of the B. velezensis 157, composed of a circular 4,013,317 bp chromosome with 3789 coding genes and a G + C content of 46.41%, one circular 8439 bp plasmid and a G + C content of 40.32%. The genome contained a total of 8 candidate gene clusters (bacillaene, difficidin, macrolactin, butirosin, bacillibactin, bacilysin, fengycin and surfactin), and dedicates over 15.8% of the whole genome to synthesize secondary metabolite biosynthesis. In addition, the genes encoding enzymes involved in degradation of cellulose, xylan, lignin, starch, mannan, galactoside and arabinan were found in the B. velezensis 157 genome. Thus, the study of B. velezensis 157 broadened that B. velezensis can not only be used as biocontrol agents, but also has potentially a wide range of applications in lignocellulosic biomass conversion.

Ectopic expression of EuWRI1, encoding a transcription factor in E. ulmoides, changes the seeds oil content in transgenic tobacco

The WRINKLED1 (WRI1) gene is a well-established key transcriptional regulator involved in the regulation of fatty acid biosynthesis in developing seeds. In this study, a new WRI1 gene was isolated from seeds of Eucommia ulmoides and named EuWRI1. A close link between gibberellins signaling and EuWRI1 gene expression was suggested in this study. Functional characterization of EuWRI1 was elucidated through seed-specific expression in tobacco. In transgenic tobacco, the expression of EuWRI1 in eight independent transgenic lines was detected by semiquantitative RT-PCR. The relative mRNA accumulation of genes encoding enzymes involved in fatty acid biosynthesis (biotin carboxyl carrier protein and keto-ACP synthase 1) was also assayed in tobacco seeds. Analysis of the seeds oil content and starch content indicated that the transgenic lines showed a significant increase in seeds oil content, whereas starch content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (16:0), linoleic acid (18:2) and linolenic acid (18:3) increased significantly in seeds of transgenic tobacco lines, but stearic acid (18:0) levels significantly declined. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:337-346, 2018.

Identification of the Sex-Biased Gene Expression and Putative Sex-Associated Genes in Eucommia ulmoides Oliver Using Comparative Transcriptome Analyses

Eucommia ulmoides is a model representative of the dioecious plants with sex differentiation at initiation. Nevertheless, the genetic mechanisms of sexual dimorphism and sex determination in E. ulmoides remain poorly understood. In this study de novo transcriptome sequencing on Illumina platform generated >45 billion high-quality bases from fresh leaves of six male and female individuals of E. ulmoides. A total of 148,595 unigenes with an average length of 801 base-pairs (bp) were assembled. Through comparative transcriptome analyses, 116 differentially expressed genes (DEGs) between the males and the females were detected, including 73 male-biased genes and 43 female-biased genes. Of these DEGs, three female-biased genes were annotated to be related with the sexually dimorphic gutta content in E. ulmoides. One male-biased DEG was identified as putative MADS box gene APETALA3, a B class floral organ identity gene in the flowering plants. SNPs calling analyses further confirmed that the APETALA3-like gene was probably involved in the sex determination in E. ulmoides. Four other male-biased DEGs were potential sex-associated genes as well with segregated SNPs in accord with sex type. In addition, the SNPs density was 1.02 per kilobase (kb) in the expressed genes of E. ulmoides, implying a relatively high genetic diversity.

Overexpression of a New Chitinase Gene EuCHIT2 Enhances Resistance to Erysiphe cichoracearum DC in Tobacco Plants

In this study, we cloned a new chitinase gene, EuCHIT2, from Eucommia ulmoides Oliver (E. ulmoides) using rapid amplification of cDNA ends (RACE) technology and constructed an overexpression vector, pSH-35S-EuCHIT2, to introduce it into tobacco (Nicotiana tabacum cv. Xanthi). Resistance to Erysiphe cichoracearum de Candolle (E.cichoracearum DC) and molecular mechanisms in the transgenic tobacco were determined by drop inoculation, spore counting, determination of physicochemical indicators, and analysis of gene expression. The chitinase activity and resistance to E. cichoracearum DC were significantly higher in the transgenic tobacco than in wild-type tobacco (p < 0.05). The activities of peroxidase (POD) and catalase (CAT), after inoculation with E. cichoracearum DC, were higher in the transgenic tobacco than in the wild-type. Conversely, the malondialdehyde (MDA) content was significantly lower in the transgenic tobacco than the wild-type before and after inoculation. In addition, our study also indicated that the resistance to E. cichoracearum DC might involve the salicylic acid (SA) and jasmonic acid (JA) pathways, because the expression levels of pathogenesis-related gene 1 (PR-1a) and coronatine-insensitive 1 (COI1) were significantly increased and decreased, respectively, after inoculation with E. cichoracearum DC. The present study supports the notion that PR-1a and POD participate in resistance to E. cichoracearum DC in the transgenic tobacco plants.

Gene coexpression network for trans-1,4-polyisoprene biosynthesis involving mevalonate and methylerythritol phosphate pathways in Eucommia ulmoides Oliver

Eucommia ulmoides, a deciduous dioecious plant species, accumulates trans-1,4-polyisoprene (TPI) in its tissues such as pericarp and leaf. Probable TPI synthase (trans-isoprenyl diphosphate synthase (TIDS)) genes were identified by expressed sequence tags of this species; however, the metabolic pathway of TPI biosynthesis, including the role of TIDSs, is unknown. To understand the mechanism of TPI biosynthesis at the transcriptional level, comprehensive gene expression data from various organs were generated and TPI biosynthesis related genes were extracted by principal component analysis (PCA). The metabolic pathway was assessed by comparing the coexpression network of TPI genes with the isoprenoid gene coexpression network of model plants. By PCA, we dissected 27 genes assumed to be involved in polyisoprene biosynthesis, including TIDS genes, genes encoding enzymes of the mevalonate (MVA) pathway and the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, and genes related to rubber synthesis. The coexpression network revealed that 22 of the 27 TPI biosynthesis genes are coordinately expressed. The network was clustered into two modules, and this was also observed in model plants. The first module was mainly comprised of MEP pathway genes and TIDS1 gene, and the second module, of MVA pathway genes and TIDS5 gene. These results indicate that TPI is likely biosynthesized by both the MEP and MVA pathways and that TIDS gene expression is differentially controlled by these pathways.

Genome-Wide Identification of MicroRNAs and Their Targets in the Leaves and Fruits of Eucommia ulmoides Using High-Throughput Sequencing

MicroRNAs (miRNAs), a group of endogenous small non-coding RNAs, play important roles in plant growth, development, and stress response processes. Eucommia ulmoides Oliver (hardy rubber tree) is one of the few woody plants capable of producing trans-1, 4-polyisoprene (TPI), also known as Eu-rubber, which has been utilized as an industrial raw material and is extensively cultivated in China. However, the mechanism of TPI biosynthesis has not been identified in E. ulmoides. To characterize small RNAs and their targets with potential biological roles involved in the TPI biosynthesis in E. ulmoides, in the present study, eight small RNA libraries were constructed and sequenced from young and mature leaves and fruits of E. ulmoides. Further analysis identified 34 conserved miRNAs belonging to 20 families (two unclassified families), and 115 novel miRNAs seemed to be specific to E. ulmoides. Among these miRNAs, fourteen conserved miRNAs and 49 novel miRNAs were significantly differentially expressed and identified as Eu-rubber accumulation related miRNAs. Based on the E. ulmoides genomic data, 202 and 306 potential target genes were predicted for 33 conserved and 92 novel miRNAs, respectively; the predicted targets are mostly transcription factors and functional genes, which were enriched in metabolic pathways and biosynthesis of secondary metabolites. Noticeably, based on the expression patterns of miRNAs and their target genes in combination with the Eu-rubber accumulation, the negative correlation of expression of six miRNAs (Eu-miR14, Eu-miR91, miR162a, miR166a, miR172c, and miR396a) and their predicted targets serving as potential regulators in Eu-rubber accumulation. This study is the first to detect conserved and novel miRNAs and their potential targets in E. ulmoides and identify several candidate genes potentially controlling rubber accumulation, and thus provide molecular evidence for understanding the roles of miRNAs in regulating the TPI biosynthesis in E. ulmoides.

De novo sequencing of Eucommia ulmoides flower bud transcriptomes for identification of genes related to floral development

Eucommia ulmoides Oliver is a woody perennial dioecious species native to China and has great economic value. However, little is known about flower bud development in this species. In this study, the transcriptomes of female and male flower buds were sequenced using the Illumina platform, a next-generation sequencing technology that provides cost-effective, highly efficient transcriptome profiling. In total, 11,558,188,080 clean reads were assembled into 75,065 unigenes with an average length of 1011 bp by de novo assembly using Trinity software. Through similarity comparisons with known protein databases, 47,071 unigenes were annotated, 146 of which were putatively related to the floral development of E. ulmoides. Fifteen of the 146 unigenes had significantly different expression levels between the two samples. Additionally, 24,346 simple sequence repeats were identified in 18,565 unigenes with 12,793 sequences suitable for the designed primers. In total, 67,447 and 58,236 single nucleotide polymorphisms were identified in male and female buds, respectively. This study provides a valuable resource for further conservation genetics and functional genomics research on E. ulmoides.

Characterization of Glycolytic Pathway Genes Using RNA-Seq in Developing Kernels of Eucommia ulmoides

Eucommia ulmoides Oliver, the only member of the Eucommiaceae family, is a rare and valuable tree used to produce a highly valued traditional Chinese medicine and contains α-linolenic acid (ALA) up to 60% of the total fatty acids in the kernels (embryos). Glycolysis provides both cellular energy and the intermediates for other biosynthetic processes. However, nothing was known about the molecular basis of the glycolytic pathway in E. ulmoides kernels. The purposes of this study were to identify novel genes of E. ulmoides related to glycolytic metabolism and to analyze the expression patterns of selected genes in the kernels. Transcriptome sequencing based on the Illumina platform generated 96,469 unigenes in four cDNA libraries constructed using RNAs from 70 and 160 days after flowering kernels of both low- and high-ALA varieties. We identified and characterized the digital expression of 120 unigenes coding for 24 protein families involved in kernel glycolytic pathway. The expression levels of glycolytic genes were generally higher in younger kernels than in more mature kernels. Importantly, several unigenes from kernels of the high-ALA variety were expressed more than those from the low-ALA variety. The expression of 10 unigenes encoding key enzymes in the glycolytic pathway was validated by qPCR using RNAs from six kernel stages of each variety. The qPCR data were well consistent with their digital expression in transcriptomic analyses. This study identified a comprehensive set of genes for glycolytic metabolism and suggests that several glycolytic genes may play key roles in ALA accumulation in the kernels of E. ulmoides.