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Histone and non-histone methylations are important post-translational modifications in plants. Histone methylation plays a crucial role in regulating chromatin structure and gene expression. However, the involvement of non-histone methylation in plant biological processes remains largely unknown.The methylated substrates and methylation sites during tomato fruit ripening were identified by LC-MS/MS. Bioinformatics of lysine methylated proteins was conducted to analyze the possible role of methylated proteins. The effects of methylation modification on protein functions were preliminarily investigated by site-directed mutation simulation.A total of 241 lysine methylation (mono-, di- and trimethylation) sites in 176 proteins were identified with two conserved methylation motifs: xxxxxxExxx_K_xxxExxxxxx and xxxxxxExxx_K_xxxxxxxxxx. These methylated proteins were mainly related to fruit ripening and senescence, oxidation reduction process, signal transduction, stimulus and stress responses, and energy metabolism. Three representative proteins, thioredoxin (Trx), glutathione S-transferase T1 (GST T1), and NADH dehydrogenase (NOX), were selected to investigate the effect of methylation modifications on protein activity. Mimicking demethylation led to decreased Trx activity but increased GST T1 and NOX activities. In addition, RT-qPCR exhibited that the expression of many genes that encode proteins subjected to methylation was upregulated during fruit ripening.Our study suggests that tomato fruit ripening undergo non-histone lysine methylation, which may participate in the regulation of fruit ripening. It is the first report of methyl proteome profiling of non-histone lysine in horticultural crops.

Contaminants on architectural ceramics have become a major problem in people's lives. Interestingly, superhydrophobic surfaces offer a new avenue for anti-fouling applications. In this work, a UV-laser process for constructing groove-like microstructures on architectural ceramics and subsequent fluoridation treatment were used to create superhydrophobic surfaces. After laser processing, nanoporous structures were generated inside the grooves, while the cracked layer was deposited on the non-irradiated area, building up a micro/nanoscale morphology on the ceramic surface. Moreover, the effects of groove pitch and laser scanning cycle on surface morphology and wettability were investigated. Results indicate that the fluoridated groove-like microstructured surface showed good superhydrophobicity based on the Cassie-Baxter model. Dynamic behavior of water droplets impacting on the as-prepared superhydrophobic surface was studied to verify its low adhesion. Additionally, the superhydrophobic surface exhibited remarkable repellency to various stain liquids and outstanding self-cleaning properties. These findings may contribute to developing anti-fouling applications for the architectural ceramics industry.

This study aims to investigate the potential clinical function of long non-coding RNA CERS6-AS1 (lncRNA CERS6-AS1) integrated miR-567 in gastric cancer. The expression of CERS6-AS1 in gastric cancer tissues was detected through RT-qPCR in contrast to the normal tissues. The correlation between the expression of lncRNA CERS6-AS1 and the characteristics of clinical data was analyzed. Kaplan-Meier curve was used to assess the survival analysis, while Cox proportional hazards model multivariate analysis was performed to evaluate the prognostic risk factors of gastric cancer to verify the prognostic possibility of CERS6-AS1. The expression of CERS6-AS1 in different gastric cancer cells was detected, being the development of gastric cancer cells after knockdown CERS6-AS1 studied using CCK-8, Transwell migration, and invasion detection methods. The targeting effect and interaction between CERS6-AS1 and miR-567 through biological analysis and luciferase activity detection. The expression of lncRNA CERS6-AS1 was elevated in gastric cancer tissues and cells. The results of this study demonstrate that the condition of gastric cancer patients was related to the expression of CERS6-AS1, and therefore CERS6-AS1 might be a prognostic factor for the progression of gastric cancer. In addition, the ability of gastric cancer cells to proliferate, migrate and invade could be reduced by knockdown CERS6-AS1. After CERS6-AS1 knockdown, the expression level of miR-567 in gastric cancer tissues decreased, while the expression level of miR-567 increased. In conclusion, lncRNA CERS6-AS1 might promote the progression of gastric cancer and had the potential as a prognostic marker of gastric cancer.

The ripening of fleshy fruits is a unique developmental process that Arabidopsis and rice lack. This process is driven by hormones and transcription factors. However, the critical and early regulators of fruit ripening are still poorly understood. Here, we revealed that SlJMJ7, an H3K4 demethylase, is a critical negative regulator of fruit ripening in tomato. Combined genome-wide transcription, binding sites, histone H3K4me3 and DNA methylation analyses demonstrated that SlJMJ7 regulates a key group of ripening-related genes, including ethylene biosynthesis (ACS2, ACS4 and ACO6), transcriptional regulation (RIN and NOR) and DNA demethylation (DML2) genes, by H3K4me3 demethylation. Moreover, loss of SlJMJ7 function leads to increased H3K4me3 levels, which directly activates ripening-related genes, and to global DML2-mediated DNA hypomethylation in fruit, which indirectly prompts expression of ripening-related genes. Together, these effects lead to accelerated fruit ripening in sljmj7 mutant. Our findings demonstrate that SlJMJ7 acts as a master negative regulator of fruit ripening not only through direct removal of H3K4me3 from multiple key ripening-related factors, but also through crosstalk between histone and DNA demethylation. These findings reveal a novel crosstalk between histone methylation and DNA methylation to regulate gene expression in plant developmental processes.

Histone methylation plays important roles in plant development. However, the role of histone methylation in fruit ripening remains unclear. Here, a total of 16 Jumonji domain-containing proteins (JMJs) were identified from banana genome. During fruit ripening, expression of MaJMJ15 was significantly upregulated. Exogenous ethylene accelerated the upregulation whereas 1-methylcyclopropene delayed the process, suggesting that MaJMJ15 positively regulates banana fruit ripening. MaJMJ15 is an H3K27me3 site-specific demethylase. Transient overexpression of MaJMJ15 promoted banana fruit ripening. Moreover, the global H3K27me3 was decreased by MaJMJ15. Furthermore, MaJMJ15 directly targeted several key ripening-related genes (RRGs) in banana including NAC transcription factor 1/2 (MaNAC1/2), 1-aminocyclopropane-1-carboxylate synthase 1 (MaACS1), 1-aminocyclopropane-1-carboxylate oxidase 1 (MaACO1) and expansin 2 (MaEXP2), removed H3K27me3 from their chromatin, and activated their expression. Our data suggest that MaJMJ15 is an H3K27me3 demethylase, which is involved in the regulation of banana fruit ripening by activating expression of key RRGs via removal of H3K27me3.

SnO2-based ceramics (Sn1−xSbxO2, 0 ≤ x ≤ 0.06, denoted as xATO; Sn0.95−ySb0.05MnyO2, 0 ≤ y ≤ 0.05, denoted as yMATO) were prepared by solid-state reaction method. XRD analysis revealed that all ceramics contain rutile-type crystalline structure and no impurity was detected. The effect of Sb and Mn doping on temperature sensitivity and electrical stability of the ceramics were investigated. yMATO ceramics show typical NTC behavior contributed from both grain and grain boundary effect. The room-temperature resistivities from 3.88 Ω cm to 38.5 kΩ cm and temperature sensitivity constants (B25/85) from 288 to 5808 K can be adjusted by altering the content of Mn ions. Mn doping can enhance the electrical stability of the ceramics, the aging-induced resistivity change rate is 0.6% of 0.04MATO ceramic after being aged at 150 °C for 500 h, while 0.05ATO ceramic without Mn doping has resistance change rate of − 14.29%.

CuO-based materials have broad scope of practical applications. Improving its conductivity might be important for enhancing the performance of CuO-based materials. Here, Cu1−xSrxO ceramics with various concentration of isovalent Sr-ion were prepared via a traditional solid reaction method. X-ray diffraction revealed that Sr14Cu24O41 phase formed when Sr-ion was doped. Sr14Cu24O41 phase has an incommensurately modulated structure with high conductivity. The quantity of Sr14Cu24O41 phase increases with Sr-ion content and its distribution is almost homogenous in Cu1−xSrxO ceramics. The room-temperature resistivity ρ25 of Cu1−xSrxO ceramics shows significantly decrease even if with a very small amount of Sr-ion, such as the ρ25 of CuO is 114.18 kΩ cm and the one of Cu0.99Sr0.01O ceramic is 32.69 Ω cm. The co-existing of Cu2+, Cu+ ions, and existence of high conductive Sr14Cu24O41 phase in the Cu1−xSrxO ceramics are responsible for their high conductivities.

The alternative splicing of select genes is an important mechanism to regulate responses to endogenous and environmental signals in plants. However, the role of alternative splicing in regulating fruit ripening remains unclear. Here, we discovered that MaMYB16L, an R1-type MYB transcription factor, undergoes alternative splicing and generates two transcripts, the full-length isoform MaMYB16L and a truncated form MaMYB16S, in banana fruit. During banana fruit ripening, the alternative splicing process intensifies with downregulated MaMYB16L and upregulated MaMYB16S. Moreover, MaMYB16L is a transcriptional repressor that directly binds with the promoters of many genes associated with starch degradation and MaDREB2, a positive ripening regulator, and represses their expression. In contrast, MaMBY16S lacks a DNA-binding domain but competitively combines and forms non-functional heterodimers with functional MaMYB16L. MaMYB16L-MaMYB16S heterodimers decrease the binding capacity and transrepression activity of MaMYB16L. The downregulation of MaMYB16L and the upregulation of MaMYB16S, that is, a decreased ratio of active to non-active isoforms, facilitates the activation of ripening-related genes and thereby promotes fruit ripening. Furthermore, the transient overexpression of MaMYB16S promotes banana fruit ripening, whereas the overexpression of MaMYB16L delays this process. Therefore, the alternative splicing of MaMYB16L might generate a self-controlled regulatory loop to regulate banana fruit ripening.

Biobased materials such as cellulose, chitin, silk, soy, and keratin are attractive alternatives to conventional synthetic materials for filtration applications. They are cheap, naturally abundant, and easily fabricated with tunable surface chemistry and functionality. With the planet’s increasing crisis due to pollution, the need for proper filtration of air and water is undeniably urgent. Additionally, fibers that are antibacterial and antiviral are critical for public health and in medical environments. The current COVID-19 pandemic has highlighted the necessity for cheap, easily mass-produced antiviral fiber materials. Biopolymers can fill these roles very well by utilizing their intrinsic material properties, surface chemistry, and hierarchical fiber morphologies for efficient and eco-friendly filtration of physical, chemical, and biological pollutants. Further, they are biodegradable, making them attractive as sustainable, biocompatible green filters. This review presents various biopolymeric materials generated from proteins and polysaccharides, their synthesis and fabrication methods, and notable uses in filtration applications.

Both cytokinin and NAC transcription factors were reported to involve in leaf senescence. However, the mechanism of NAC transcription factors how to regulate cytokinin-delayed leaf senescence is still unknown. In this study, application of N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU), a cytokinin analogue, significantly delayed leaf senescence and maintained cytokinin content of Chinese flowering cabbage during storage. Meanwhile, the expression of an NAC transcriptional activator (BrNAC029) was increased but suppressed by CPPU treatment. Furthermore, BrNAC029 activated the expressions of chlorophyll catabolic genes BrPAO and BrSGR2, cytokinin oxidase gene BrCKX1 and senescence maker gene BrSAG113 by binding to their promoters. Additionally, overexpressions of BrNAC029 in tobacco and Arabidopsis accelerated leaf senescence and up-expressed the related genes. Taken together, it was suggested that BrNAC029 may serve as a transcriptional activator to activate the transcriptions of these related genes to eventually accelerate leaf senescence of Chinese flowering cabbage by promoting chlorophyll degradation and reducing endogenous cytokinin level.

Fruit chilling injury is the result of physiological dysfunction due to membrane lipid phase change, oxidative damage of biomacromolecules and respiratory metabolism abnormality. However, the involvement of transcription factors in response to fruits chilling tolerance remains largely unclear. Here, MaMYB13 was identified to participate in banana fruit response to chilling stress. MaMYB13 has transcriptional activation activity. When exposed to low temperature, expression of MaMYB13 was enormously induced. Moreover, MaMYB13 promoter was activated by chilling stress. MaMYB13 bound to the promoters of several important very-long-chain fatty acids (VLCFAs) and phenylpropanoids biosynthesis-related genes, including MaKCS11, Ma4CL6 and MaAAE1, and activated their transcription. Furthermore, MaKIN10 X1/3 interacted with MaMYB13 and enhanced MaMYB13-mediated transcriptional activation possibly via phosphorylation. Altogether, our results unravel the mechanism of MaMYB13-MaKIN10 X1/3 interaction regulating banana fruit chilling tolerance through activating the expression of MaKCS11, Ma4CL6 and MaAAE1, providing new insights into the regulatory network of MYB transcription factor.

To develop a new kind of thermistor with the negative temperature coefficient (NTC) behaviour, the Cu/Mo co-doped YFeO3 based ceramics were prepared by wet-chemical synthesis and sintering at 1300?C. The orthorhombic perovskite structure was identified in all ceramics by XRD analysis. The possible valence states of Fe, Cu and Mo in the doped YFeO3 compounds were examined by X-ray photoelectron spectroscopy. By adjusting the concentration of Cu- and Mo-ions, the room temperature resistivity (?25) and temperature-sensitive constant (B25/85) can be modified from 1.13?103 to 3.09?105 ??cm and 3000 to 7000K, respectively. The complex impedances at various temperatures (from 25 to 150?C) are tested and analysed. The results show that both grain and grain boundary exhibit the NTC characteristics. The electrical conduction mechanisms composing of polaron hopping conduction and band conduction were proposed in the YFeO3 based ceramics.

Redox modification of functional or regulatory proteins has emerged as an important mechanism of post-translational modification. However, the role of redox modifications of transcription factors mediated by methionine sulfoxide reductase (Msr) in regulating physiological processes in plants remains unclear, especially in fruit ripening. In this study, we determined that MaNAC42, a transcriptional activator, is involved in the regulation of fruit ripening in banana under oxidative stress. Integrated analysis of ChIP-qPCR and EMSA data showed that MaNAC42 directly binds to promoters of genes related to oxidative stress and ripening. Ectopic overexpression of MaNAC42 in Arabidopsis delays dark-induced senescence in leaves, indicating that MaNAC42 plays a negative role in senescence. Furthermore, we found that MaNAC42 is a target of MaMsrB2, a methionine sulfoxide reductase B. Methionine oxidation in MaNAC42 (i.e. sulfoxidation) or mimicking sulfoxidation by mutating methionine to glutamine both lead to decreased DNA-binding capacity and transcriptional activity. On the other hand, MaMsrB2 can partially repair oxidized MaNAC42 and restore its DNA-binding capacity. Thus, our results suggest a novel regulatory mechanism of fruit ripening in banana involving MaMsrB2-mediated redox regulation of the ripening-related transcription factor MaNAC42.

The present study aimed to explore the role of the long noncoding RNA cytoskeleton regulator (CYTOR) in non-small cell lung cancer (NSCLC) radiosensitivity by manipulating the microRNA (miR)-206/prothymosin α (PTMA) axis. First, 58 pairs of NSCLC and paracancerous tissues, normal human lung epithelial cells and NSCLC cells were collected to analyze CYTOR expression and the relation- ship between CYTOR and NSCLC prognosis. Subsequently, CYTOR expression in radioresistant cells was assessed. Radioresistant cells with low CYTOR expression and parental cells with high CYTOR expression were established. Functional assays were then performed to assess changes in cell radiosensitivity after irradiation treatment. Subsequently, the downstream mechanism of CYTOR was explored. The binding interactions between CYTOR and miR-206 and between miR-206 and PTMA were predicted and certified. Xenograft transplantation was applied to confirm the role of CYTOR in the radiosensitivity of NSCLC. CYTOR was overexpressed in NSCLC and was associated with poor prognosis. CYTOR was further upregulated in NSCLC cells with radioresistance. CYTOR knockdown enhanced the radiosensitivity of NSCLC cells, while overexpression of CYTOR led to the opposite result. Mechanistically, CYTOR specifically bound to miR-206 and silencing CYTOR promoted miR-206 to enhance the radiosensitivity of NSCLC cells. PTMA is a target of miR-206 and silencing CYTOR inhibited PTMA expression via miR-206, thus promoting radiosensitivity of NSCLC cells. CYTOR knockdown also enhanced NSCLC cell radiosensitivity in vivo. CYTOR was highly expressed in NSCLC, while silencing CYTOR potentiated NSCLC cell radiosensitivity by upregulating miR-206 and suppressing PTMA. The present study preliminarily revealed the role of CYTOR in radiotherapy sensitivity of NSCLC and provided a novel potential target for the clinical treatment of NSCLC.

Negative temperature coefficient (NTC) ceramics based on simple ZnO were prepared and investigated in present work, where slight amount of Al- and La- ions were added as semiconductor dopants, and Cu-ions were selected as the sintering agent and property modificator. All the prepared ZnO-based ceramics have a wurtzite structure and show typical NTC characteristic. For various contents of Al-, La- and Cu- ions in ZnO-based ceramics, ρ25 can be adjusted from 0.65 kΩ cm to 3.28 MΩ cm, and B values were obtained in range of 2500 K to 5850 K. The ageing treatment at 125 °C for 600 h in air revealed that the ZnO-based ceramics have high thermal stability with the resistance shift

Nuclear factor Y (NF-Y) is a heterotrimeric transcription factor, which plays important roles in plant growth, development and stress responses. Yet little information regarding the role of NF-Y in regulating fruit ripening is available. In this study, a total of 44 NF-Y genes (14 MaNF-YAs, 16 MaNF-YBs, and 14 MaNF-YCs) were isolated and confirmed from the banana genome. Their distribution on chromosomes, gene structures, phylogenetic relationship with other species, cis-acting elements, genome synteny and tissue-specific expression were characterized. Furthermore, it was found that expression of six MaNF-Ys, i.e. MaNF-YA5/B1/B2/C9/C11/C14, were up-regulated as harvested fruit ripened, and their expression were accelerated by ethylene, but delayed by 1-MCP. In contrast, harvested banana fruit ripening was accompanied by down-regulation of MaNF-YA1/A3/A6/B3/B6/C2/C5. Ethylene accelerated their down-regulation while 1-MCP delayed the process. These results indicated that MaNF-YA5/B1/B2/C9/C11/C14 and MaNF-YA1/A3/A6/B3/B6/C2/C5 were implicated in the regulation of harvested banana fruit ripening, functioning as transcriptional activators and repressors, respectively.

Ascorbate peroxidase (APX) is a key antioxidant enzyme that is involved in diverse developmental and physiological process and stress responses by scavenging H2O2 in plants. APX itself is also subjected to multiple posttranslational modifications (PTMs). However, redox-mediated PTM of APX in plants remains poorly understood. Here, we identified and confirmed that MaAPX1 interacts with methionine sulfoxide reductase B2 (MsrB2) in bananas. Ectopic overexpression of MaAPX1 delays the detached leaf senescence induced by darkness in Arabidopsis. Sulfoxidation of MaAPX1, i.e., methionine oxidation, leads to loss of the activity, which is repaired partially by MaMsrB2. Moreover, mimicking sulfoxidation by mutating Met36 to Gln also decreases its activity in vitro and in vivo, whereas substitution of Met36 with Val36 to mimic the blocking of sulfoxidation has little effect on APX activity. Spectral analysis showed that mimicking sulfoxidation of Met36 hinders the formation of compound I, the first intermediate between APX and H2O2. Our findings demonstrate that the redox state of methionine in MaAPX1 is critical to its activity, and MaMsrB2 can regulate the redox state and activity of MaAPX1. Our results revealed a novel post-translational redox modification of APX.

Colon cancer is one of most common cancers. The progression of various cancers is driven by miRNA-570. The role of miRNA-570 in the progression of colon cancer remains unclear. We aimed to investigate the clinical function of miR-570 and its impact on colon cancer cells. We evaluated the expression of miR-570 in colon cancer cells and analyzed its influence on the various clinical parameters. The Kaplan-Meier curve was plotted to understand the clinical role of miR-570. Cox regression analysis was performed to predict the prognostic factors in colon cancer. The Cell Counting Kit-8 was used to investigate the effect of miR-570 on cell proliferation. The transwell migration assay was performed to quantify cell migration and invasion. The quantitative real-time polymerase chain reaction technique was used to analyze the sample system. The results revealed that the level of miR-570 expression in colon cancer tissues and cell lines was low. The abnormal expression of miR-570 was associated with tumor size, extent of differentiation, lymph node metastasis, and tumor-node-metastasis stages. Downregulation of miR-570 indicated poor overall survival (OS), poor relapse-free survival, and unfavorable cancer-specific survival (CSS) rates in patients with colon cancer. The results from Cox regression analysis revealed that miR-570 expression could be used as an independent prognostic biomarker for OS and CSS in colon cancer. Overexpression of miR-570 can potentially result in the inhibition of cell proliferation, migration, and invasion. The results proved that miR-570 could potentially function as a tumor suppressor and a potential prognostic factor in patients with colon cancer.

Fruit ripening is governed by a complex regulatory network. Reversible histone methylation and demethylation regulate chromatin structure and gene expression. However, little is known about the involvement of histone demethylases in regulating fruit ripening. Here, we found that the tomato (Solanum lycopersicum) SlJMJ6 encodes a histone lysine demethylase that specifically demethylates H3K27 methylation. Overexpression of SlJMJ6 accelerates tomato fruit ripening, which is associated with the upregulated expression of a large number of ripening-related genes. Integrated analysis of RNA-seq and chromatin immunoprecipitation followed by sequencing identified 32 genes directly targeted by SlJMJ6 and transcriptionally upregulated with decreased H3K27m3 in SlJMJ6-overexpressed fruit. Numerous SlJMJ6-regulated genes are involved in transcription regulation, ethylene biosynthesis, cell wall degradation and hormone signaling. Eleven ripening-related genes including RIPENING INHIBITOR (RIN), 1-aminocyclopropane 1-carboxylate synthase-4 (ACS4), 1-aminocyclopropane-1-carboxylate oxidase 1 (ACO1), pectate lyase (PL) and beta-galactosidase 4 (TBG4), and a DNA demethylase DML2, were confirmed to be regulated directly by SlJMJ6 through removing H3K27me3. Our results demonstrate that SlJMJ6 is a ripening-prompting H3K27me3 demethylase that activates the expression of the ripening-related genes by modulating H3K27me3, thereby facilitating tomato fruit ripening. Our work also reveals a novel link between histone demethylation and DNA demethylation in regulating fruit ripening. To our knowledge, this is the first report of the involvement of a histone lysine demethylase in the regulation of fruit ripening.

Thioredoxins (Trxs) are important redox regulators in organisms. However, their involvement in fruit senescence and quality deterioration remains unclear. In this study, one Trx (DlTrx1) and one NADPH-dependent Trx reductase (DlNRT1) cDNAs, were cloned from longan fruit. The DlTrx1 could be effectively reduced by the DlNTR1. Expression of DlTrx1 and DlNTR1 were up-regulated during fruit senescence and quality deterioration. We further identified 33 potential Trx target proteins in longan, including one glutathione peroxidase (DlGpx). DlTrx1 could physically interact with DlGpx. DlTrx1 in combination with DlNTR1 effectively activated DlGpx activity by regulating its redox state. Cys90 in DlGPx could form a disulfide bond with either Cys42 or Cys71, which were the sites of redox modulation. Furthermore, DlGpx exhibited a higher ratio of disulfide bonds to sulfhydryl groups in senescent or deteriorative fruit. We propose that Trx-mediated redox regulation of DlGpx is involved in senescence or quality deterioration of harvested longan fruit.

Transcription factors (TFs) are important regulators of plant growth and development and responses to stresses. TFs themselves are also prone to multiple posttranslational modifications (PTMs). However, redox-mediated PTM of TFs in plants remains poorly understood. Here, we established that NON-RIPENING (NOR), a master TF regulating tomato (Solanum lycopersicum) fruit ripening, is a target of the Met sulfoxide reductases A and B, namely E4 and SlMsrB2, respectively, in tomato. Met oxidation in NOR, i.e. sulfoxidation, or mimicking sulfoxidation by mutating Met-138 to Gln, reduces its DNA-binding capacity and transcriptional regulatory activity in vitro. E4 and SlMsrB2 partially repair oxidized NOR and restore its DNA-binding capacity. Transgenic complementation of the nor mutant with NOR partially rescues the ripening defects. However, transformation of nor with NOR-M138Q, containing mimicked Met sulfoxidation, inhibits restoration of the fruit ripening phenotype, and this is associated with the decreased DNA-binding and transcriptional activation of a number of ripening-related genes. Taken together, these observations reveal a PTM mechanism by which Msr-mediated redox modification of NOR regulates the expression of ripening-related genes, thereby influencing tomato fruit ripening. Our report describes how sulfoxidation of TFs regulates developmental processes in plants.

Squalene and β-sitosterol are health-benefit compounds due to their nutritional and medicinal properties. It has been reported that the content of these bioactive compounds is relatively high in Torreya grandis nuts. However, it is not yet known what changes in squalene and β-sitosterol accumulation occur during the special post-ripening process of T. grandis nuts and the effect of the well-known ripening hormone ethylene on the regulatory mechanism of their biosynthetic pathways. Thus, we performed transcriptome and metabolite analyses. The results showed that ethylene not only promoted the post-ripening process but also enhanced the accumulation of squalene by inducing gene expression in the mevalonate pathway. At the same time, ethylene treatment also promoted the accumulation of other sterols but inhibited gene expression in the β-sitosterol biosynthesis pathway. In addition, co-expression and correlation analysis suggested a framework for the transcriptional regulation of squalene and β-sitosterol biosynthesis genes under ethylene treatment.

6-Benzylaminopurine (BAP), a synthetic cytokinin, can elicit plant growth and development by stimulating cell division. In this study, the effects of BAP on decay and pericarp browning of harvested litchi fruit in relation to phenolics and ROS metabolism were investigated. Application of BAP significantly inhibited decay incidence of harvested litchi, associated with a direct inhibition on Peronophythora litchii, the major pathogenic fungi. In addition, BAP-treated fruit showed significantly lower pericarp browning, accompanied by reduced PPO activity, increased PAL activity and higher contents of anthocyanin and total phenolic compounds. Moreover, BAP reduced H2O2 accumulation and lipid peroxidation, which may account for browning inhibition to an extent. Furthermore, higher activities of SOD, CAT and APX and DPPH radical scavenging capacity in BAP-treated fruit possibly benefited reducing ROS accumulation and lipid peroxidation. Overall, application of BAP showed great potential to control decay and browning and extend shelf life of harvested litchi.

Nb-doped cathode materials with the formula Li(Ni0.7Mn0.3)1−xNbxO2 (x = 0, 0.01, 0.02, 0.03, 0.04) have been prepared successfully by calcining the mixtures of LiOH·H2O, Nb2O5, and Ni0.7Mn0.3(OH)2 precursor formed through a simple continuous co-precipitation method. The effects of Nb substitution on the crystal structure and electrochemical properties of LiNi0.7Mn0.3O2 were studied systematically by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and various electrochemical measurements. The results show that the lattice parameters of the Nb substitution LiNi0.7Mn0.3O2 samples are slightly larger than that of pure LiNi0.7Mn0.3O2, and the basic α-NaFeO2 layered structure does not change with the Nb doping. What’s more, better morphology, lower resistance, and good cycle stability were obtained after Nb substitution. In addition, CV test exhibits that Nb doping results in lower electrode polarization and XPS results indicate that the valence of Mn kept constant but the component of Ni3+ decreased after doping. All the results indicate that Nb doping in LiNi0.7Mn0.3O2 is a promising method to improve the properties of Ni-rich lithium-ion batteries positive-electrode materials.

Four types of sustainable sodium carboxylate-derived materials are investigated as novel electrodes with high performance for lithium-ion batteries. Benefiting from the porous morphology provided by their intermolecular interactions, increasing capacity, excellent cycle stability and superior rate performance are observed for the sodium carboxylate- derived materials. The sodium oxalate (SO) electrodes displayed an increasing discharging capacity at a current density of 50 mA g−1 with with maximum values of 242.9 mA h g−1 for SO-631 and 373.9 mA h g−1 for SO-541 during the 100th cycle. In addition, the SO-541, SC-541 (sodium citrate), ST- 541 (sodium tartrate) and SP-541 (sodium pyromellitate) electrode materials displayed high initial capacities of 619.6, 392.3, 403.7 and 278.1 mA h g−1, respectively, with capacity retentions of 179%, 148%, 173% and 108%, respectively, after 200 cycles at 50 mA g−1 with. Even at a high current density of 2,000 mA g−1 with, the capacities remain 157.6, 131.3, 146.6 and 137.0 mA h g−1, respectively. With these superior electrochemical properties, the sodium carboxylate-derived materials could be considered as promising organic electrode materials for large-scale sustainable lithium-ion batteries.

The potent role of endogenous melatonin (MEL) in affecting chilling injury (CI) and related chilling tolerance regulatory mechanisms in harvested litchi fruit during refrigeration at 4 °C were investigated in this study. In the first experiment, exogenous MEL exposure exerted an inhibitory impact on the development of CI severity in refrigerated litchi fruit, as indicated by the lower CI index and delayed red color loss of pericarp, whereas treatment with p-chlorophenylalanine (p-CPA), an inhibitor of MEL biosynthesis, aggravated the degree of CI. The suppression of CI afforded by exogenous MEL was abated under the combined application of exogenous MEL and p-CPA. In the second experiment, the effects of p-CPA alone treatment on changes in biochemical parameters during refrigeration were analyzed. The results showed that p-CPA down-regulated the expressions of MEL biosynthesis genes, including LcTDC, LcT5H and LcSNAT, contributing to reduced generation of endogenous serotonin and MEL. p-CPA treatment accelerated oxidative stress-triggered membrane deterioration, as reflected by increases in relative leakage rate (RLR), reactive oxygen species (ROS) production, lipoxygenase (LOX) activity and malondialdehyde (MDA) accumulation. The membrane damage caused by p-CPA further resulted in loss of subcellular compartmentalization and enzymatic oxidation, as demonstrated by increased activities of polyphenol oxidase (PPO) and peroxidase (POD) in parallel with reduced contents of total phenolics and anthocyanin. Compared with control fruit, lower activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR), were observed in fruit receiving p-CPA. Additionally, p-CPA suppressed the expression levels of genes encoding oxidized protein repair-related enzymes, including LcMsrA1, LcMsrA2, LcMsrB1 and LcMsB2. These results suggest that endogenous MEL might confer a protective role against chilling stress by modulating cellular redox status in harvested litchi fruit during refrigeration.

Litchis are tasty fruit with economic importance. However, the extreme susceptibility of harvested litchis to litchi downy blight caused by Peronophythora litchii leads to compromised quality. This study aimed to study the effects of melatonin on postharvest resistance to P. litchii in 'Feizixiao' litchis. Results showed that melatonin restricted lesion expansion in litchis after P. litchi inoculation. Melatonin enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase and 4-hydroxycinnamate CoA ligase while promoting the accumulations of phenolics and flavonoids. Nicotinamide adenine dinucleotide phosphate content and glucose-6-phosphate dehydrogenase and 6-phosphogluconic acid dehydrogenase activities were higher in treated fruit than control fruit. Higher energy status along with elevated H+-ATPase, Ca2+-ATPase, succinate dehydrogenase and cytochrome C oxidase activities were observed in treated fruit. Ultrastructural observation showed reduced damage in mitochondria in treated fruit. The results suggest that melatonin induced resistance in litchis by modulating the phenylpropanoid and pentose phosphate pathways as well as energy metabolism. .

Senescence is a key factor resulting in deterioration of non-climacteric fruit. NAC transcription factors are important regulators in plant development and abiotic stress responses, yet little information regarding the role of NACs in regulating non-climacteric fruit senescence is available. In this study, we cloned 13 NAC genes from litchi (Litchi chinensis) fruit, and analyzed subcellular localization and expression profiles of these genes during post-harvest natural and low-temperature-delayed senescence. Of the 13 NAC genes, expression of LcNAC1 was up-regulated in the pericarp and pulp as senescence progressed, and was significantly higher in senescence-delayed fruit than that in naturally senescent fruit. LcNAC1 was induced by exogenous ABA and hydrogen peroxide. Yeast one-hybrid analysis and transient dual-luciferase reporter assay showed that LcNAC1 was positively regulated by the LcMYC2 transcription factor. LcNAC1 activated the expression of LcAOX1a, a gene associated with reactive oxygen species regulation and energy metabolism, whereas LcWRKY1 repressed LcAOX1a expression. In addition, LcNAC1 interacted with LcWRKY1 in vitro and in vivo. These results indicated that LcNAC1 and LcWRKY1 form a complex to regulate the expression of LcAOX1a antagonistically. Taken together, the results reveal a hierarchical and co-ordinated regulatory network in senescence of harvested litchi fruit.

Anthocyanin accumulation is crucial for the development of quality for most fruit. The mechanism underlying the regulation of anthocyanin biosynthesis by transcription factors in litchi fruit remains largely unknown. In this study, we isolated one NAC (NAM, ATAF1/2 and CUC2) TF gene, LcNAC13. Expression of LcNAC13 was upregulated as ripening proceeded, followed by the accumulation of anthocyanins. Electrophoretic mobility shift assay (EMSA) and transient expression assay showed that LcNAC13 could negatively regulate the expression of anthocyanin biosynthesis-related genes, including LcCHS1/2, LcCHI, LcF3H, LcF3&rsquo, H, LcDFR, and LcMYB1. Furthermore, LcR1MYB1, as one R1-MYB type MYB, was identified to physically interact with LcNAC13 and reverse the effect of LcNAC13. Taken together, these results suggested that LcNAC13 and LcR1MYB1 may act together to antagonistically regulate anthocyanin biosynthesis during litchi fruit ripening, which helps to provide new insights into the regulatory networks of anthocyanin biosynthesis.

Isolated peanut protein (PPI) dispersions were pretreated by high pressure at 100, 300, and 500 MPa prior to enzymatic hydrolysis with alkaline protease (Alcalase). The degree of hydrolysis (DH) was determined by the pH‐stat method, the hydrolysates profiles were analyzed by high‐performance liquid chromatography (HPLC), the molecular weight distribution (MWD) was analyzed by gel filtration chromatogram (GFC), and content of SH/S‐S and antioxidant activity of hydrolysates were evaluated. Results showed that HP pretreatment improved effectively the enzymatic hydrolysis of PPI, with an effective sequence of 300 > 100 > 500 MPa. However, no significant differences were observed in the peak pattern of HPLC profiles, but the peak times were earlier in HPLC profiles of the HP‐treated protein. GFC analysis showed that more peptide fractions with low molecular weight appeared in the hydrolysates of the HP‐treated PPI with increasing pressure. Moreover, the level of free SH of hydrolysates of the HP‐treated PPI was relatively higher than non‐HP‐treated PPI. The hydrolysates of the HP‐treated PPI exerted higher antioxidant activity (reducing power and DPPH radical scavenging) than the hydrolysates of non‐HP‐treated PPI. The results indicated that high pressure treatment affected the enzymatic hydrolysis of peanut protein and some protein structure properties and improved antioxidant activity of PPI hydrolysates.

Melatonin acts as a crucial signaling and antioxidant molecule with multiple physiological functions in organisms. To explore effects of exogenous melatonin on postharvest browning and its possible mechanisms in litchi fruit, 'Ziniangxi' litchi fruits were treated with an aqueous solution of melatonin at 0.4 mM and then stored at 25 °C for 8 days. The results revealed that melatonin strongly suppressed pericarp browning and delayed discoloration during storage. Melatonin treatment reduced relative membrane-leakage rate and inhibited the generation of superoxide radicals (O2-·), hydrogen peroxide (H2O2), and malondialdehyde (MDA). Melatonin treatment markedly promoted the accumulation of endogenous melatonin; delayed loss of total phenolics, flavonoids, and anthocyanins; and enhanced the activities of antioxidant enzymes, including superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2). By contrast, the activities of browning-related enzymes including polyphenoloxidase (PPO, EC 1.10.3.1) and peroxidase (POD, EC 1.11.1.7) were reduced. In addition, melatonin treatment up-regulated the expression of four genes encoding enzymes for repair of oxidized proteins, including LcMsrA1, LcMsrA2, LcMsrB1, and LcMsB2. These findings indicate that the delay of pericarp browning and senescence by melatonin in harvested litchi fruit could be attributed to the maintenance of redox homeostasis by the improvement of the antioxidant capacity and modulation of the repair of oxidatively damaged proteins.

Fusarium proliferatum is a worldwide fungal pathogen that produces fumonisins which are harmful to animal and human health. However, environmental factors affecting fumonisin biosynthesis in F. proliferatum are not well understood. Based on our preliminary results, in this study, we investigated the effect of sucrose or mannose as the sole carbon source on fumonisin B (FB) production by F. proliferatum and studied their underlying mechanisms via proteome and gene expression analysis. Our results showed that mannose, used as the sole carbon source, significantly blocked fumonisin B1 and B2 production by F. proliferatum as compared with the use of sucrose. Fifty-seven differentially expressed proteins were successfully identified. The downregulated proteins in the mannose-cultured strain were mainly involved in carbon metabolism, response to stress, and methionine metabolism, as compared with the sucrose-cultured strain. Moreover, quantitative real-time PCR analysis indicated that expression of several key genes involved in FB biosynthetic pathway and in transcription regulation were significantly downregulated in the mannose-cultured F. proliferatum, whereas expression of histone deacetylation-related genes were significantly upregulated. These results suggested that the blockage of FB biosynthesis by mannose was associated with the decreases in conversion of acetyl-CoA to polyketide, methionine biosynthesis, and NADPH regeneration. More importantly, milder oxidative stress, downregulated expression of genes involved in biosynthetic pathway and transcription regulation, and upregulated expression of genes with histone deacetylation possibly were responsible for the blockage of FB biosynthesis in F. proliferatum.

Litchi (Litchi chinensis Sonn.) is a well-known traditional medicine since ancient times. The crude extract of litchi leaf exhibited good bioactivity against cancer cells. In this work, three sesquilignans, ehletianol C (1), sesquipinsapol B (2) and sesquimarocanol B (3), and one lignan glycoside schizandriside (4) were isolated from the ethyl acetate-soluble extract of litchi leaf by column chromatography. Their structures were further elucidated by ESI-MS and NMR spectral studies. Ehletianol C, sesquipinsapol B and sesquimarocanol B were detected from this species for the first time. Sesquipinsapol B (EC50 values less than 2.0 μg/mL) and sesquimarocanol B (EC50 values less than 2.4 μg/mL) showed very high cytotoxicities against nasopharynx carcinoma cells CNE1 and CNE2 cells, respectively. Thus, they could be utilized as good drug candidates against nasopharynx cancer. Moreover, three sesquilignans showed effective in vitro cytotoxicities against human cancer cells HepG2 and Hela. Four lignans showed better antioxidant activities than butylated hydroxytoluene (BHT).