Search Results (10)

Global climate change has led to an increased frequency of extreme weather events, with flooding caused by heavy rainfall posing a significant threat to plant growth and survival. Styrax japonicus, a species of ecological and economic importance, exhibits stronger flooding tolerance compared to its congener Styrax tonkinensis. Endogenous hormonal systems in plants are indispensable for integrating growth dynamics, developmental transitions, and ecological stress perception-transduction pathways. To investigate the response of S. japonicus to flooding stress at both hormonal and molecular levels, this study utilized annual seedlings of S. japonicus as experimental material. Two levels of flooding stress, waterlogging and submergence, were applied to examine the variations in endogenous hormone levels in S. japonicus roots under different stress conditions and durations. Combined with transcriptome sequencing, critical genes associated with hormone-mediated signaling and biosynthetic processes were identified. The results showed that the content of the ethylene precursor ACC exhibited a trend of “increase–decrease–increase”, with an earlier decline under submergence compared to waterlogging stress by approximately 10 days. Abscisic acid content sharply decreased at 5 d, followed by an initial increase and subsequent decrease, with higher ABA levels observed under waterlogging stress than under submergence. GA content significantly decreased after 10 d in both stress conditions. KEGG enrichment analysis revealed that the most prominently enriched pathway for DEGs was plant hormone signal transduction under both waterlogging and submergence stress, with 314 and 370 DEGs identified, respectively. Analysis of common genes indicated their association with ethylene, ABA, auxin, and BRs. After further investigation of DEGs in the ethylene and ABA biosynthesis process, we identified key enzyme genes encoding ACS, ACO, and NCED, which are critical for their biosynthesis. Full article

Approximately 12% of China’s papermaking raw materials are derived from wood, while the majority are sourced from branches. Styrax tonkinensis is a more desirable species for pulpwood in subtropical ultra-short rotations, whose branches are prone to breakage. Lignin has a significant impact on wood quality and pulping yield, and the growth process influences lignin biosynthesis. To explore the lignin biosynthesis pathway in S. tonkinensis, we determined the lignin content in the current-year and biennial branches on 20 July, 20 September, and 20 October and analyzed the transcriptome sequencing results. It was concluded that the lignin content showed an increasing trend in the current-year branches (182.26, 206.17, and 213.47 mg/g, respectively), while that in the biennial branches showed a decrease in the samples taken in October, without significant difference (221.77, 264.43, and 261.83 mg/g, respectively). The transcriptome sequencing results showed that 91,513 unigenes were spliced with a total length of 92,961,618 bp. KEGG pathway analysis indicated that the upregulated DEGs were mainly enriched in the phenylpropanoid biosynthesis pathway. Our study suggested that CCoAOMT, COMT, peroxidase, and F5H may serve as key enzymes regulating lignin synthesis in branches of S. tonkinensis, thereby influencing the lignin content. Full article

Plants from the genus Styrax have been extensively used in folk medicines to treat diseases such as skin diseases and peptic ulcers and as an antiseptic and analgesic. Most Styrax species, especially Styrax tonkinensis, which is used as an expectorant, antiseptic, and analgesic in Chinese traditional medicine, could screen resin after external injury. Styrax is also used in folk medicines in Korea to treat sore throat, bronchitis, cough, expectoration, paralysis, laryngitis, and inflammation. Different parts of various Styrax species can be widely employed for ethnopharmacological applications. Moreover, for ethnopharmacological use, these parts of Styrax species can be applied in combination with other folk medicines. Styrax species consist of versatile natural compounds, with some of them exhibiting particularly excellent pharmacological activities, such as cytotoxic, acetylcholinesterase inhibitory, antioxidant, and antifungal activities. Altogether, these exciting results indicate that a comprehensive review of plants belonging to this genus is essential for helping researchers to continuously conduct an in-depth investigation. In this review, the traditional uses, phytochemistry, corresponding pharmacological activities, and structure–activity relationships of different Styrax species are clarified and critically discussed. More insights into potential opportunities for future research are carefully assessed. Full article

As global climate change worsens, trees will have difficulties adapting to abiotic pressures, particularly in the field, where environmental characteristics are difficult to control. A prospective commercial and ornamental tree species, Styrax tonkinensis, has its seed oil output and quality reduced as a result, which lowers the economic benefits. This necessitates growers to implement efficient strategies to increase the seeds of woody biofuel species’ tolerance to abiotic stress. Numerous studies have shown that ZnO nanoparticles (NPs), a new material, and BRs assist plants to increase their resilience to abiotic stress and subsequently adapt to it. However, there have not been many investigations into S. tonkinensis seed resistance. In this study, we examined the changes in antioxidant enzyme activities and transcriptomic results of S. tonkinensis seeds throughout the seed development period to investigate the effects of 24-epibrassinolide (EBL), one of the BRs, and ZnO NPs treatments alone or together on the stress resistance of S. tonkinensis seeds. On 70, 100, and 130 days after flowering (DAF), spraying EBL or ZnO NPs increased the activity of antioxidant enzymes (POD, SOD, and CAT) in S. tonkinensis seeds. Moreover, when the EBL and ZnO NPs were sprayed together, the activities of antioxidant enzymes were the strongest, which suggests that the positive effects of the two can be superimposed. On 70 and 100 DAF, the EBL and ZnO NPs treatments improved seed stress resistance, mostly through complex plant hormone crosstalk signaling, which includes IAA, JA, BR, and ABA signaling. Additionally, ABA played an essential role in hormone crosstalk, while, on 130 DAF, due to the physiological characteristics of seeds themselves in the late stage of maturity, the improvement in seed stress resistance by EBL and ZnO NPs was related to protein synthesis, especially late embryogenesis-abundant protein (LEA), and other nutrient storage in seeds. Spraying EBL and ZnO NPs during the seed growth of S. tonkinensis could significantly increase seed stress resistance. Our findings provide fresh perspectives on how cultural practices can increase abiotic stress tolerance in woody seedlings. Full article

Styrax tonkinensis, whose seeds are rich in unsaturated fatty acids (UFAs), is a high oil value tree species, and the seed oil has perfect biodiesel properties. Therefore, the elucidation of the effect of 24-epibrassinolide (EBL) on fatty acid (FA) concentration and the expression of FA biosynthesis-related genes is critical for deeply studying the seed oil in S. tonkinensis. In this study, we aimed to investigate the changing trend of FA concentration and composition and identify candidate genes involved in FA biosynthesis under EBL treatment using transcriptome sequencing and GC-MS. The results showed that 5 μmol/L of EBL (EBL5) boosted the accumulation of FA and had the hugest effect on FA concentration at 70 days after flowering (DAF). A total of 20 FAs were identified; among them, palmitic acid, oleic acid, linoleic acid, and linolenic acid were the main components. In total, 117,904 unigenes were detected, and the average length was 1120 bp. Among them, 1205 unigenes were assigned to ‘lipid translations and metabolism’ in COG categories, while 290 unigenes were assigned to ‘biosynthesis of unsaturated fatty acid’ in KEGG categories. Twelve important genes related to FA biosynthesis were identified, and their expression levels were confirmed by quantitative real-time PCR. KAR, KASIII, and accA, encoding FA biosynthesis-related enzymes, all expressed the highest at 70 DAF, which was coincident with a rapid rise in FA concentration during seed development. FAD2 and FATB conduced to UFA and saturated fatty acids (SFA) accumulation, respectively. EBL5 induced the expression of FA biosynthesis-related genes. The concentration of FA was increased after EBL5 application, and EBL5 also enhanced the enzyme activity by promoting the expression of genes related to FA biosynthesis. Our research could provide a reference for understanding the FA biosynthesis of S. tonkinensis seeds at physiological and molecular levels. Full article

As the germ of a highly productive oil tree species, Styrax tonkinensis seeds have great potential to produce biodiesel and they have marvelous fatty acid (FA) composition. In order to explore the molecular regulatory mechanism of FA biosynthesis in S. tonkinensis seeds after methyl jasmonate (MJ) application, transcriptomic and metabolomic techniques were adopted so as to dissect the genes that are related to FA biosynthesis and their expression levels, as well as to discover the major FA concentration and composition. The results revealed that 200 μmol/L of MJ (MJ200) increased the crude fat (CF) mass fraction and generated the greatest impact on CF accumulation at 70 days after flowering. Twenty FAs were identified, among which palmitic acid, oleic acid, linoleic acid and linolenic acid were the major FAs, and the presence of MJ200 affected their concentrations variously. MJ200 could enhance FA accumulation through elevating the activity of enzymes that are related to FA synthesis. The number of differentially expressed genes increased with the seeds’ development in general. Fatty acid biosynthesis, the biosynthesis of unsaturated fatty acid, fatty acid elongation and glycerolipid metabolism were the main lipid metabolism pathways that were found to be involved. The changes in the expression levels of EAR, KAR, accA, accB and SAD2 were consistent with the changes in the CF mass fraction, indicating that they are important genes in the FA biosynthesis of S. tonkinensis seeds and that MJ200 promoted their expression levels. In addition, bZIP (which was screened by weighted correlation network analysis) also created significant impacts on FA biosynthesis. Our research has provided a basis for further studies on FA biosynthesis that is regulated by MJ200 at the molecular level and has helped to clarify the functions of key genes in the FA metabolic pathway in S. tonkinensis seeds. Full article

Background: Styrax tonkinensis is an economic tree species with high timber, medicine, oil, and ornamental value. Its seed, containing a particularly high oil content, are widely studied for their biodiesel properties by nutritional components and oil body ultrastructure. However, their comprehensive biochemical compositions have not been studied. Methods: During S. tonkinensis kernel development, we collected samples from four time points for metabolite profiling and classification through gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Results: A total of 187 and 1556 metabolites were obtained, respectively. All of the metabolites were grouped into 19 and 21 classes by their chemical properties and into 8 clusters based on their change trends, respectively. Among all the metabolites, carboxylic acids and derivatives, flavonoids, fatty acyls, glycerophospholipids, organooxygen compounds, prenol lipids, and steroids and steroid derivatives were the main components. Alanine, glutamine, tryptophan, tyrosine and valine were the five most abundant amino acids. Palmitic acid, stearic acid, oleic acid and linoleic acid were the four major free fatty acids. Flavans, flavonoid glycosides and o-methylated flavonoids were the three major flavonoids. The differential metabolites distributions between different time points were identified. A pathway enrichment was performed, which was mainly focused on three groups, amino acids metabolism, carbon flow from sucrose to lipid and secondary metabolites biosynthesis. Conclusions: It’s the first time to analyze the metabolite fingerprinting for developing S. tonkinensis kernels and identify varied kinds of flavonoids. We performed metabolite profiling, classification and pathway enrichment to assess the comprehensive biochemical compositions. Our results described the change in major metabolites and main metabolic processes during S. tonkinensis kernel development and provided a variety of bases for seed applications as biofuel or medicine. Full article

Inflammation is a key mediator in the progression of atherosclerosis (AS). Benzoinum, a resin secreted from the bark of Styrax tonkinensis, has been widely used as a form of traditional Chinese medicine in clinical settings to enhance cardiovascular function, but the active components of the resin responsible for those pharmaceutical effects remain unclear. To better clarify these components, a new phenylpropane derivative termed stybenpropol A was isolated from benzoinum and characterized via comprehensive spectra a nalysis. We further assessed how this phenylpropane derivative affected treatment of human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor-α (TNF-α). Our results revealed that stybenpropol A reduced soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-8 (IL-8), and interleukin-1β (IL-1β) expression by ELISA, inhibited apoptosis, and accelerated nitric oxide (NO) release in TNF-α-treated HUVECs. We further found that stybenpropol A decreased VCAM-1, ICAM-1, Bax, and caspase-9 protein levels, and increased the protein levels of Bcl-2, IKK-β, and IκB-α. This study identified a new, natural phenylpropane derivative of benzoinum, and is the first to reveal its cytoprotective effects in the context of TNF-α-treated HUVECs via regulation of the NF-κB and caspase-9 signaling pathways. Full article

The hydrophobicity and color stability of wood are important properties that can be easily changed when wood is used as a raw material for outdoor products, reducing the service life of wood. Herein, an epoxy@ZnO coating was applied by a two-step simple spray coating method to improve the hydrophobicity and color stability of Styrax tonkinensis wood. The hydrophobicity, robustness of coating, as well as the color stability of uncoated wood samples and epoxy@ZnO coated wood samples were evaluated. The microstructure morphology and crystal structures of the coating were also characterized by a field-emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) analysis, respectively. Results showed that the obtained epoxy@ZnO coating was not only superhydrophobic with an average water contact angle of 154.1°, but also maintained superhydrophobicity with an average water contact angle of 149.6° after five water jetting tests. The color stability of the coated wood samples was improved by around 50% compared to that of uncoated wood samples. Additionally, a continuous epoxy@ZnO coating with hierarchical micro/nanoscale structures constructed by the wurtzite hexagonal structure of ZnO micro/nanoparticles on wood surfaces was confirmed. Full article

Seed oil content is an important characteristic for the potential biofuel feedstock benzoin (Styrax tonkinensis). With the aim of further understanding benzoin lipid biosynthesis, the endosperm and embryo cell ultrastructures were acquired through transmission electron microscopy (TEM); the relative oil body area per cell (ROA) and oil body diameter (OBD) were then calculated by analyzing TEM images via computer software. The endosperm ROA peaked at 99 days after flowering (DAF) (79.04%), and the embryo ROA dynamic fitted the “S” curve. Significant linear relations (p < 0.01) were only observed between endosperm ROAs and the contents of whole-kernel crude lipid and fatty acids. The endosperm OBD (1.18–2.43 μm) was larger than that of embryo OBD (0.38–0.77 μm). M-shaped dynamics of acetyl coenzyme carboxylase (ACC) and diglyceride acyltransferase (DGAT) activities resembled the dynamic of endosperm OBD, as two peaks were observed at 78 and 113 DAF; the big oil body (≥1.8 μm) fraction in endosperm increased as kernel ACC and DGAT activities also increased, and vice-versa. Embryo OBD gradually increased, with the big oil body (≥0.5 μm) proportion increasing and the small oil body (<0.5 μm) proportion decreasing in general. Our results collectively suggested the distinct lipid accumulation patterns in the two benzoin kernel tissues, and revealed that the endosperm may determine the whole kernel oil biosynthetic process. Full article