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Seven undescribed phenylpropanoid constituents, including three new bibenzyl derivatives (

Cucumber is a warm climate vegetable that is sensitive to chilling reactions. Chilling can occur at any period of cucumber growth and development and seriously affects the yield and quality of cucumber. Hydrogen (H2) is a type of antioxidant that plays a critical role in plant development and the response to stress. Hydrogen-rich water (HRW) is the main way to use exogenous hydrogen. This study explored the role and mechanism of HRW in the cucumber defense response to chilling stress. The research results showed that applying 50% saturated HRW to the roots of cucumber seedlings relieved the damage caused by chilling stress. The growth and development indicators, such as plant height, stem diameter, leaf area, dry weight, fresh weight, and root length, increased under the HRW treatment. Photosynthetic efficiency, chlorophyll content, and Fv/Fm also improved and reduced energy dissipation. In addition, after HRW treatment, the REC and MDA content were decreased, and membrane lipid damage was reduced. NBT and DAB staining results showed that the color was lighter, and the area was smaller under HRW treatment. Additionally, the contents of O2− and H2O2 also decreased. Under chilling stress, the application of HRW increased the activity of the antioxidases SOD, CAT, POD, GR, and APX and improved the expression of the SOD, CAT, POD, GR, and APX antioxidase genes. The GSSG content was reduced, and the GSH content was increased. In addition, the ASA content also increased. Therefore, exogenous HRW is an effective measure for cucumber to respond to chilling stress.

Hepatocellular carcinoma (HCC) is the most common type of primary liver malignancy, with increased mortality and morbidity. Accumulating evidence suggested that 40S ribosomal protein S24 (RPS24) is related to malignant outcomes and progression. However, the role of RPS24 remains unclear in HCC. The mRNA and protein expression pattern of RPS24 in HCC was explored and confirmed based on the bioinformatics analysis and histological examination. The correlation between RPS24 expression and clinicopathological features, diagnostic value, prognosis, methylation status, and survival were evaluated. Then, we divided the HCC cohort into two groups based on the expression of RPS24, and performed the functional enrichment and immune cells infiltration analysis of RPS24. Furthermore, in vivo and in vitro experiments were performed to investigate the effect of RPS24 on HCC cells. RPS24 was observed to be elevated in HCC samples. RPS24 overexpression or RPS24 promoter methylation contributed to an unfavorable prognosis for HCC patients. The genes in the high RPS24 expression group were mainly enriched in DNA replication, cell cycle E2F targets, and the G2M checkpoint pathway. Moreover, the expression level of RPS24 was significantly related to immune infiltration and immunotherapy response. Our experiments also demonstrated that RPS24 knockdown suppressed the growth of HCC cells and tumor proliferation of the xenograft model. Therefore, RPS24 can be a potential adverse biomarker of HCC prognosis acting through facilitating cell proliferation and the formation of an immunosuppressive microenvironment in HCC. Targeting RPS24 may offer a promising therapeutic option for HCC management.

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Traditional bone defect treatments are limited by an insufficient supply of autologous bone, the immune rejection of allogeneic bone grafts, and high medical costs. To address this medical need, bone tissue engineering has emerged as a promising option. Among the existing tissue engineering materials, the use of electroactive scaffolds has become a common strategy in bone repair. However, single-function electroactive scaffolds are not sufficient for scientific research or clinical application. On the other hand, multifunctional electroactive scaffolds are often complicated and expensive to prepare. Therefore, we propose a new tissue engineering strategy that optimizes the electrical properties and biocompatibility of carbon-based materials. Here, a hydroxyapatite/carbon nanofiber (HAp/CNF) scaffold with optimal electrical activity was prepared by electrospinning HAp nanoparticle-incorporated polyvinylidene fluoride (PVDF) and then carbonizing the fibers. Biochemical assessments of the markers of osteogenesis in human adipose-derived stem cells (h-ADSCs) cultured on HAp/CNF scaffolds demonstrate that the material promoted the osteogenic differentiation of h-ADSCs in the absence of an osteogenic factor. The results of this study show that electroactive carbon materials with a fibrous structure can promote the osteogenic differentiation of h-ADSCs, providing a new strategy for the preparation and application of carbon-based materials in bone tissue engineering.

Although previous studies continuously report an increased risk of hearing loss in diabetes patients, the impact of the disease on the inner ear remains unexplored. Herein, we examine the pathophysiology of diabetes-associated hearing impairment and cochlear synaptopathy in a mouse model of diabetes. Male B6.BKS(D)-Leprdb/J (db/db, diabetes) and heterozygote (db/+, control) mice were assigned into each experimental group (control vs. diabetes) based on the genotype and tested for hearing sensitivity every week from 6 weeks of age. Each cochlea was collected for histological and biological assays at 14 weeks of age. The diabetic mice exerted impaired hearing and a reduction in cochlear blood flow and C-terminal-binding protein 2 (CtBP2, a presynaptic ribbon marker) expression. Ultrastructural images revealed severely damaged mitochondria from diabetic cochlea accompanied by a reduction in Cytochrome c oxidase subunit 4 (COX4) and CR6-interacting factor 1 (CRIF1). The diabetic mice presented significantly decreased levels of platelet endothelial cell adhesion molecule (PECAM-1), B-cell lymphoma 2 (BCL-2), and procaspase-9, but not procaspase-8. Importantly, significant changes were not found in necroptotic programmed cell death markers (receptor-interacting serine/threonine-protein kinase 1, RIPK1, RIPK3, and mixed lineage kinase domain-like pseudokinase, MLKL) between the groups. Taken together, diabetic hearing loss is accompanied by synaptopathy, microangiopathy, damage to the mitochondrial structure/function, and activation of the intrinsic apoptosis pathway. Our results imply that mitochondrial dysfunction is deeply involved in diabetic hearing loss, and further suggests the potential benefits of therapeutic strategies targeting mitochondria.

Cucumber powdery mildew caused by Sphaerotheca fuliginea is a leaf disease that seriously affects cucumber’s yield and quality. This study aimed to report two nucleotide-binding site-leucine-rich repeats (NBS-LRR) genes CsRSF1 and CsRSF2, which participated in regulating the resistance of cucumber to S. fuliginea. The subcellular localization showed that the CsRSF1 protein was localized in the nucleus, cytoplasm, and cell membrane, while the CsRSF2 protein was localized in the cell membrane and cytoplasm. In addition, the transcript levels of CsRSF1 and CsRSF2 were different between resistant and susceptible cultivars after treatment with exogenous substances, such as abscisic acid (ABA), methyl jasmonate (MeJA), salicylic acid (SA), ethephon (ETH), gibberellin (GA) and hydrogen peroxide (H2O2). The expression analysis showed that the transcript levels of CsRSF1 and CsRSF2 were correlated with plant defense response against S. fuliginea. Moreover, the silencing of CsRSF1 and CsRSF2 impaired host resistance to S. fuliginea, but CsRSF1 and CsRSF2 overexpression improved resistance to S. fuliginea in cucumber. These results showed that CsRSF1 and CsRSF2 genes positively contributed to the resistance of cucumber to S. fuliginea. At the same time, CsRSF1 and CsRSF2 genes could also regulate the expression of defense-related genes. The findings of this study might help enhance the resistance of cucumber to S. fuliginea.

Crop domestication, which gives rise to a number of desirable agronomic traits, represents a typical model system of plant evolution. Numerous genomic evidence has proven that noncoding RNAs such as microRNAs and phasiRNAs, as well as protein-coding genes, are selected during crop domestication. However, limited data shows plant long noncoding RNAs (lncRNAs) are also involved in this biological process. In this study, we performed strand-specific RNA sequencing of cultivated rice Oryza sativa ssp. japonica and O. sativa ssp. indica, and their wild progenitor O. rufipogon. We identified a total of 8528 lncRNAs, including 4072 lncRNAs in O. rufipogon, 2091 lncRNAs in japonica rice, and 2365 lncRNAs in indica rice. The lncRNAs expressed in wild rice were revealed to be shorter in length and had fewer exon numbers when compared with lncRNAs from cultivated rice. We also identified a number of conserved lncRNAs in the wild and cultivated rice. The functional study demonstrated that several of these conserved lncRNAs are associated with domestication-related traits in rice. Our findings revealed the feature and conservation of lncRNAs during rice domestication and will further promote functional studies of lncRNAs in rice.

Flowering time is one of the most important agronomic traits in wheat production. A proper flowering time might contribute to the reduction or avoidance of biotic and abiotic stresses, adjust plant architecture, and affect the yield and quality of grain. In this study, TaTOE1-B1 in wheat produced three transcripts (TaTOE1-B1-1, TaTOE1-B1-2, and TaTOE1-B1-3) by alternative splicing. Compared to the longest transcript, TaTOE1-B1-1, TaTOE1-B1-3 has a deletion in the sixth exon (1219–1264 bp). Under long-day conditions, the heterologous overexpression of the TaTOE1-B1-3 gene delayed flowering, prolonged the vegetative growth time, and enlarged the vegetative body of Arabidopsis, but that of TaTOE1-B1-1 did not. As typical AP2 family members, TaTOE1-B1-1 and TaTOE1-B1-3 are mainly located in the nucleus and have transcriptional activation activities; the transcriptional activation region of TaTOE1-B1-3 is located in the C-terminal. In TaTOE1-B1-3 overexpression lines, the expression of flowering-related AtFT and AtSOC1 genes is significantly downregulated. In addition, this study confirms the protein–protein interaction between TaTOE1-B1-3 and TaPIFI, which may play an important role in flowering inhibition. These results provide a theoretical basis for the precise regulation of wheat flowering time.

Delivery of substances into the inner ear via local routes is increasingly being used in clinical treatment. Studies have focused on methods to increase permeability through the round window membrane (RWM) and enhance drug diffusion into the inner ear. However, the clinical applications of those methods have been unclear and few studies have investigated the efficacy of methods in an inner ear injury model. Here, we employed the medium chain fatty acid caprate, a biologically safe, clinically applicable substance, to modulate tight junctions of the RWM. Intratympanic treatment of sodium caprate (SC) induced transient, but wider, gaps in intercellular spaces of the RWM epithelial layer and enhanced the perilymph and cochlear concentrations/uptake of dexamethasone. Importantly, dexamethasone co–administered with SC led to significantly more rapid recovery from noise-induced hearing loss at 4 and 8 kHz, compared with the dexamethasone-only group. Taken together, our data indicate that junctional modulation of the RWM by SC enhances dexamethasone uptake into the inner ear, thereby hastening the recovery of hearing sensitivity after noise trauma.

Pathogen-induced cell death is closely related to plant disease susceptibility and resistance. The cucumber (Cucumis sativus L.) mildew resistance locus O (CsMLO1) and calmodulin (CsCaM3) genes, as molecular components, are linked to nonhost resistance and hypersensitive cell death. In this study, we demonstrate that CsMLO1 interacts with CsCaM3 via yeast two-hybrid, firefly luciferase (LUC) complementation and bimolecular fluorescence complementation (BiFC) experiments. A subcellular localization analysis of green fluorescent protein (GFP) fusion reveals that CsCaM3 is transferred from the cytoplasm to the plasma membrane in Nicotiana benthamiana, and CsCaM3 green fluorescence is significantly attenuated via the coexpression of CsMLO1 and CsCaM3. CsMLO1 negatively regulates CsCaM3 expression in transiently transformed cucumbers, and hypersensitive cell death is disrupted by CsCaM3 and/or CsMLO1 expression under Corynespora cassiicola infection. Additionally, CsMLO1 silencing significantly enhances the expression of reactive oxygen species (ROS)-related genes (CsPO1, CsRbohD, and CsRbohF), defense marker genes (CsPR1 and CsPR3) and callose deposition-related gene (CsGSL) in infected cucumbers. These results suggest that the interaction of CsMLO1 with CsCaM3 may act as a cell death regulator associated with plant immunity and disease.

Amyloid fibrillation by hen egg white lysozyme under the influence of tannic acid was investigated by atomic force microscopy and fluorescence spectroscopy. Tannic acid was found to be able to induce the formation of amyloid fibrils with an interesting mixed morphology. Such morphology features with the existence of areas of thickening alternating with areas of normal height. This novel modulation effect of tannic acid on amyloid fibrillation was interpreted by the established surface-catalyzed secondary nucleation theory. We further performed a fluorescence quenching study to investigate the intermolecular interaction between tannic acid and lysozyme. The results support that lysozyme and tannic acid interact with each other mainly through hydrophobic interactions. We also discussed why hydrogen-bonding interaction is not a dominant factor in the interaction between tannic acid and lysozyme though tannic acid contains a significant amount of hydroxyl groups. Our work provides new insight into the effect of tannic acid, a well-known amyloid inhibitor, on amyloid fibrillation.

The anther cuticle, which is mainly composed of lipid polymers, functions as physical barriers to protect genetic material intact, however, the mechanism of lipid biosynthesis in maize (Zea mays. L.) anther remains unclear. Herein, we report a male sterile mutant, male sterile 305 (ms305), in maize. It was shown that the mutant displayed a defective anther tapetum development and premature microspore degradation. Three pathways that are associated with the development of male sterile, including phenylpropanoid biosynthesis, biosynthesis of secondary metabolites, as well as cutin, suberine, and wax biosynthesis, were identified by transcriptome analysis. Gas chromatography-mass spectrometry disclosed that the content of cutin in ms305 anther was significantly lower than that of fertile siblings during the abortion stage, so did the total fatty acids, which indicated that ms305 mutation might lead to blocked synthesis of cutin and fatty acids in anther. Lipidome analysis uncovered that the content of phosphatidylcholine, phosphatidylserine, diacylglycerol, monogalactosyldiacylglycerol, and digalactosyldiacylglycerol in ms305 anther was significantly lower when compared with its fertile siblings, which suggested that ms305 mutation disrupted lipid synthesis. In conclusion, our findings indicated that ms305 might affect anther cuticle and microspore development by regulating the temporal progression of the lipidome in maize.

Bioelectrochemical systems (BES) are groups of bioelectrochemical technologies and platforms that could facilitate versatile environmental and biological applications. The performance of BES is mainly determined by the key process of electron transfer at the bacteria and electrode interface, which is known as extracellular electron transfer (EET). Thus, developing novel electrodes to encourage bacteria attachment and enhance EET efficiency is of great significance. Recently, three-dimensional (3D) electrodes, which provide large specific area for bacteria attachment and macroporous structures for substrate diffusion, have emerged as a promising electrode for high-performance BES. Herein, a comprehensive review of versatile methodology developed for 3D electrode fabrication is presented. This review article is organized based on the categorization of 3D electrode fabrication strategy and BES performance comparison. In particular, the advantages and shortcomings of these 3D electrodes are presented and their future development is discussed.

Corynespora leaf spot caused by Corynespora cassiicola is one of the major diseases in cucumber (Cucumis sativus L.). However, the resistance mechanisms and signals of cucumber to C. cassiicola are unclear. Here, we report that the mildew resistance locus O (MLO) genes, CsMLO1 and CsMLO2, are both negative modulators of the cucumber defense response to C. cassiicola. Subcellular localization analysis showed that CsMLO1 and CsMLO2 are localized in the plasma membrane. Expression analysis indicated that the transcript levels of CsMLO1 and CsMLO2 are linked to the defense response to C. cassiicola. Transient overexpression of either CsMLO1 or CsMLO2 in cucumber cotyledons reduced resistance to C. cassiicola, whereas silencing of either CsMLO1 or CsMLO2 enhanced resistance to C. cassiicola. The relationships of pathogenesis-related proteins, reactive oxygen species (ROS)-associated genes, and abscisic acid (ABA)-related genes to the overexpression and silencing of CsMLO1/CsMLO2 in non-infested cucumber plants were investigated. The results indicated that CsMLO1 mediated resistance against C. cassiicola by regulating the expression of pathogenesis-related proteins and ROS-associated genes, as well as through ABA signaling pathway-associated genes. The CsMLO2-mediated resistance against C. cassiicola primarily involves regulation of the expression of pathogenesis-related proteins. Our findings will guide strategies to enhance the resistance of cucumber to corynespora leaf spot.

Biodiesel, a non-toxic and biodegradable fuel, has recently become a major source of renewable alternative fuels. Utilization of lipase as a biocatalyst to produce biodiesel has advantages over common alkaline catalysts such as mild reaction conditions, easy product separation, and use of waste cooking oil as raw material. In this study, Pseudomonas cepacia lipase immobilized onto magnetic nanoparticles (MNP) was used for biodiesel production from waste cooking oil. The optimal dosage of lipase-bound MNP was 40% (w/w of oil) and there was little difference between stepwise addition of methanol at 12 h- and 24 h-intervals. Reaction temperature, substrate molar ratio (methanol/oil), and water content (w/w of oil) were optimized using response surface methodology (RSM). The optimal reaction conditions were 44.2 °C, substrate molar ratio of 5.2, and water content of 12.5%. The predicted and experimental molar conversions of fatty acid methyl esters (FAME) were 80% and 79%, respectively.