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Functional two-dimensional (2D) structured nanomaterials, such as, graphene oxide (GO) and molybdenum disulfide (MoS2), exhibit many advantages, including large surface areas and excellent electronic/mechanical/catalytic properties, and have shown to be strong candidates for the development of advanced electrochemical sensors for determining a variety of chemical and biological analytes in different samples. In this work, for the first time, we systematically investigated the effects of functional 2D nanomaterials, such as GO nanosheets, MoS2 nanosheets, and their GO–MoS2 hybrid nanostructures, with a special emphasis on synthesis methods (GO-Hummers, GO-CVD, GO-Ultrasound), active surface areas, layer number, defect density, and chemical groups on the surface of GO nanosheets toward electrochemical sensing performance using carbon-based screen-printed electrodes (SPEs) for the determination of chloramphenicol (CAP) antibiotic residues in food samples. Under the same experimental conditions, GO-Hummers with the largest interlayer distance and the lowest defect density showed higher electrochemical performance than GO-CVD and GO-Ultrasound due to a more active surface area. Moreover, the combination of layers-by-layers MoS2 and GO nanosheets could expose more active sites and facilitate the charge-transfer ability, leading to a significantly enhanced electrochemical performance. Based on obtained electrochemical results, we found that the active surface area, layer number and interlayer distance, and defect density were key factors in the CAP electrochemical sensing performance of these 2D nanomaterials. Also, the long-term stability, reproducibility, and applicability of these sensors for the determination of CAP in chicken and pork meat samples were also evaluated. These studies further contribute to a deeper understanding of the effects of 2D nanomaterials on the electrochemical sensing performance of SPE-based portable sensors for the rapid, accurate, and on-site determination of CAP in real samples.

Through a combination of physiological, pharmacological, molecular and targeted metabolomics approaches, we showed that retention of wheat (Triticum aestivum L.) seed dormancy levels induced by low and high seed development temperature during post-desiccation phases is associated with modulation of GA level and seed responsiveness to ABA and GA via expression of TaABI5 and TaGAMYB, respectively. Dormancy retention during imbibition, however, is associated with modulations of both ABA level and responsiveness via expression of specific ABA metabolism (TaNCED2 and TaCYP707A1) and signaling (TaPYL2, TaSnRK2, TaABI3, TaABI4 and TaABI5) genes, and alterations in GA levels and responsiveness through expression of specific GA biosynthesis (TaGA20ox1, TaGA20ox2 and TaGA3ox2) and signaling (TaGID1 and TaGID2) genes, respectively. Expression patterns of GA signaling genes, TaRHT1 and TaGAMYB, lacked positive correlation with that of GA regulated genes and dormancy level observed in seeds developed at the two temperatures, implying their regulation at posttranscriptional level. Our results overall implicate that a shift in ABA/GA balance underlies retention of dormancy levels induced by seed development temperature during post-desiccation and imbibition phases. Consistently, genes regulated by ABA and GA during imbibition overlapped with those differentially expressed between imbibed seeds developed at the two temperatures and mediate different biological functions. This article is protected by copyright. All rights reserved.

This work investigates the effect of the ratio of the explored Pt area in the electrolyte medium and the photoanode area (REP) on the performance of dye-sensitized solar cells (DSCs). It is found that the power conversion efficiency of DSCs increases by the ascending REP. The highest power conversion efficiency, which was obtained for the cell with the REP of 64/49, was 8.40%. Furthermore, a relationship between the efficiency and fabrication cost is analyzed in terms of reducing or enhancing the surface area of CE compared to the photoanode's surface area. These findings may provide a way for the development of efficient and large-scale DSCs.

Ethylene controls post-germination starch degradation and seedling growth, but not radicle protrusion, in wheat through spatiotemporal alteration of the balance between abscisic acid and gibberellin., This study aimed to gain insights into the molecular mechanisms underlying the role of ethylene in regulating germination and seedling growth in wheat by combining pharmacological, molecular, and metabolomics approaches. Our study showed that ethylene does not affect radicle protrusion but controls post-germination endospermic starch degradation through transcriptional regulation of specific α-amylase and α-glucosidase genes, and this effect is mediated by alteration of endospermic bioactive gibberellin (GA) levels, and GA sensitivity via expression of the GA signaling gene, TaGAMYB. Our data implicated ethylene as a positive regulator of embryo axis and coleoptile growth through transcriptional regulation of specific TaEXPA genes. These effects were associated with modulation of GA levels and sensitivity, through expression of GA metabolism (TaGA20ox1, TaGA3ox2, and TaGA2ox6) and signaling (TaGAMYB) genes, respectively, and/or the abscisic acid (ABA) level and sensitivity, via expression of specific ABA metabolism (TaNCED2 or TaCYP707A1) and signaling (TaABI3) genes, respectively. Ethylene appeared to regulate the expression of TaEXPA3 and thereby root growth through its control of coleoptile ABA metabolism, and root ABA signaling via expression of TaABI3 and TaABI5. These results show that spatiotemporal modulation of ABA/GA balance mediates the role of ethylene in regulating post-germination storage starch degradation and seedling growth in wheat.

In this paper we study a classical monotone and Lipschitz continuous variational inequality in real Hilbert spaces. Two projection type methods, Mann and its viscosity generalization are introduced with their strong convergence theorems. Our methods generalize and extend some related results in the literature and their main advantages are: the strong convergence and the adaptive step-size usage which avoids the need to know apriori the Lipschitz constant of variational inequality associated operator. Primary numerical experiments in finite and infinite dimensional spaces compare and illustrate the behaviors of the proposed schemes.

This study reports a scalable green electrochemical synthesis of novel biogenic silver nanoparticles colloid (biogenic AgNPs) in large scale up to 5 liters using the bulk silver bar and the green tea leaves (Camellia sinensis) extract (GTE) as reducing agent during the electrochemical process. Under a direct-current voltage source, the biomolecules in GTE can release electrons to promote the reducing process of Ag+ to Ag0. More interestingly, the formation of the intermediate complex helps to cap on the nanoparticles, which leads to stabilizing AgNPs. The as-synthesized biogenic AgNPs with the size of 34 nm exhibit the outstanding electrochemical properties due to the presence of biomolecules on the biogenic AgNPs surface, which facilitates the effective attaching of AgNPs on the carbon surface of the screen-printed carbon electrode (SPE) through the formation of the strong C-O coordinate bonds between O atom of oxygen functional groups and C atom of SPE. The electrochemical properties of the biogenic AgNPs-modified SPE are enhanced significantly in comparison with bare SPE and pure AgNPs-SPE. The biogenic AgNPs-SPE is applied successfully to the detection of 4-nitrophenol (4-NP). The electrochemical sensor using biogenic AgNPs can reliably detect 4-NP in the linear range from 0.1 to 25 μM with the sensitivity about 6.69 μA μM-1 cm-2. The present work reveals, as the greener synthesis method with ultra-large scalable ability, high purity, and excellent electrochemical properties of biogenic AgNPs is very promising for technological applications in high-sensitive electrochemical chemosensors, nanopharmaceuticals, and other fields.

This study examined the expression patterns of antioxidative genes and the activity of the corresponding enzymes in the excess moisture-stressed seedlings of soybean in response to seed treatment with polyamines, spermine (Spm) and spermidine (Spd). At the 4 day after planting (DAP) stage, the excess moisture impaired the embryo axis growth, and this effect is associated with the downregulation of superoxide dismutase (GmSOD1) expression and SOD activity in the cotyledon. Seed treatment with Spm reversed the effects of excess moisture on embryo axis growth partly through enhancing glutathione reductase (GR) activity, in both the cotyledon and embryo axis, although no effect on the GmGR expression level was evident. Excess moisture inhibited the shoot and root growth in 7 DAP seedlings, and this is associated with decreased activities of GR in the shoot and SOD in the root. The effect of excess moisture on shoot and root growth was reversed by seed treatment with Spd, and this was mediated by the increased activities of ascorbate peroxidase (APX), catalase (CAT) and GR in the shoot, and APX in the root, however, only GR in the shoot appears to be regulated transcriptionally. Root growth was also reversed by seed treatment with Spm with no positive effect on gene expression and enzyme activity.

Scutellaria lateriflora is well known for its medical applications because of the presence of flavanoids and alkaloids. The present study aimed to explore the molecular aspects and regulations of flavanoids. Five partial cDNAs encoding genes that are involved in the flavonoid biosynthetic pathway: phenylalanine ammonia lyase (SlPAL), cinnamate 4-hydroxylase (SlC4H), 4-coumaroyl CoA ligase (Sl4CL), chalcone synthase (SlCHS), and chalcone isomerase (SlCHI) were isolated from S. lateriflora. Organ expression analysis showed that these genes were expressed in all organs analyzed with the highest levels correlating with the richest accumulation of wogonin in the roots. Baicalin and baicalein differentially accumulated in S. lateriflora plants, with the highest concentration of baicalin and baicalein detected in the leaves and stems, respectively. Exogenous methyl jasmonate (MeJA) significantly enhanced the expression of SlCHS and SlCHI, and accumulation of baicalin (22.54 mg/g), baicalein (1.24 mg/g), and wogonin (5.39 mg/g) in S. lateriflora hairy roots. In addition, maximum production of baicalin, baicalein, and wogonin in hairy roots treated with MeJA was approximately 7.44-, 2.38-, and 2.12-fold, respectively. Light condition increased the expression level of SlCHS, the first committed step in flavonoid biosynthesis in hairy roots of S. lateriflora after 3 and 4 weeks of development compared to the dark condition. Dark-grown hairy roots contained a higher content of baicalin and baicalein than light-grown hairy roots, while light-grown hairy roots accumulated more wogonin than dark-grown hairy roots. These results may helpful for the metabolic engineering of flavonoids biosynthesis in S. lateriflora. Keywords: Flavonoids, Gene characterization, Light/dark regulation, Methyl jasmonate, Scutellaria lateriflora

Acclimation of wheat to waterlogging is mediated by regulation of hormonal metabolism and transport in adventitious roots and during their emergence., To gain insights into the molecular mechanisms underlying hormonal regulation in adventitious roots and during their emergence under waterlogged conditions in wheat, the present study investigated transcriptional regulation of genes related to hormone metabolism and transport in the root and stem node tissues. Waterlogging-induced inhibition of axile root elongation and lateral root formation, and promotion of surface adventitious and axile root emergence and aerenchyma formation are associated with enhanced expression levels of ethylene biosynthesis genes, ACS7 and ACO2, in both tissues. Inhibition of axile root elongation is also related to increased root indole acetic acid (IAA) and jasmonate (JA) levels that are associated with up-regulation of specific IAA biosynthesis/transport (TDC, YUC1, and PIN9) and JA metabolism (LOX8, AOS1, AOC1, and JAR1) genes, and transcriptional alteration of gibberellin (GA) metabolism genes (GA3ox2 and GA2ox8). Adventitious root emergence from waterlogged stem nodes is associated with increased levels of IAA and GA but decreased levels of cytokinin and abscisic acid (ABA), which are regulated through the expression of specific IAA biosynthesis/transport (TDC, YUC1, and PIN9), cytokinin metabolism (IPT5-2, LOG1, CKX5, and ZOG2), ABA biosynthesis (NCED1 and NCED2), and GA metabolism (GA3ox2 and GA2ox8) genes. These results enhance our understanding of the molecular mechanisms underlying the adaptive response of wheat to waterlogging.

A novel magnetic nanocomposite of iron oxide nanoparticles encapsulated by carbon layer (Fe3O4@C) was prepared by using a two-step process of coprecipitation and hydrothermal method. The iron oxide nanoparticles with an average crystalline diameter of ∼20 nm was used, whereas the concentration of C was varied from 1.25 to 10% by adjusting the mass ratio of glucose as a carbon source. We found that the arsenate removal efficiency of the Fe3O4@C nanocomposite increased with increasing C concentration, reached a maximum at 1.25% C concentration, and finally decreased for further increase in the C content. The adsorption kinetics process of the Fe3O4@C nanocomposite was well fitted with both Langmuir and pseudo-second-order kinetic models. In contrast, the heating efficiency of Fe3O4 nanoparticles was progressively reduced with increasing C content, regardless of the AC field value. Our study indicates the use of carbon as an encapsulator for iron oxide nanoparticles is very promising as an advanced absorbent for removal of environmental pollutants, such as arsenate As(V) while it is not ideal for magnetic hyperthermia based cancer therapy.

Magnetic nanomaterials, as a promising platform for the fast and sensitive detection of bacterial pathogens, have attracted increasing interest from researchers in recent years. In this work, by utilizing a two-step synthetic technique consisting of co-precipitation and subsequent hydrothermal reaction, followed by functionalization steps with (3-aminopropyl)triethoxysilane (APTES) and the antibody against Salmonella enteritidis, antibody-conjugated Fe3O4–Ag@APTES hetero-nanocomposites were successfully prepared. Due to the specific antibody, the developed Fe3O4–Ag@APTES@SE-Ab conjugates are capable of selectively capturing S. enteritidis at a low concentration of about 101 CFU/mL. Moreover, the prepared magnetic conjugates also revealed that the S. enteritidis could be rapidly removed from water solution in 20 min by using an external magnetic field with a removal efficiency obtained of ∼ 91.36%. These results indicated that the Fe3O4–Ag@APTES@SE-Ab conjugates are promising for the rapid selective capture and removal of bacterial pathogens from aqueous environments, and can be used for improving the detection quality of pathogens in water samples using immunosensor-based diagnostic tests.

An efficient colorimetric probe based on surface-functionalized silver nanoparticles (AgNPs) was prepared for sensitive thiram pesticide detection in water samples. The influence of various surface capping agents including polyhexamethylene biguanide hydrochloride (PHMB), polyvinylpyrrolidone (PVP) and anion BH4− on the performance of colorimetric probe in the detection of thiram was evaluated. Among the investigated capping agents, the amine-functionalized AgNPs exhibited higher stability and sensitivity response in thiram detection. The higher performance of the amine-functionalized AgNPs was hypothesized due to the synergistic effect of formation Ag-S bonds and hydrogen interactions of amine groups with electronegative atoms in thiram which craving the proton. The calibration curve for thiram determination through amine-functionalized AgNPs probe showed a linear range from 0.1−100 μM with a detection limit of about 0.036 μM (8.64 μg.kg-1). Along with that, the excellent stability and highly selective sensing of thiram, amine-functionalized AgNPs could be seen as the most promising platform for colorimetric probes in the highly efficient detection of thiram in environmental water solutions.

In the present study, efforts were made to determine effect of different light wavelengths on carotenoid biosynthesis in Scutellaria baicalensis, a promising traditional herbal medicine used in North America and Asia. The variation in the transcriptional level of carotenoid biosynthesis genes and carotenoid contents in the callus was analyzed after exposure to light from red (wavelength, 660 nm), blue (wavelength, 470 nm), or white (wavelength, 380 nm) light-emitting diodes. The transcription levels of phytoene synthase (SbPSY), ξ-carotene desaturase (SbZDS), β-ring carotene hydroxylase (SbCHXB), and zeaxanthin epoxidase (SbZEP) were upregulated on exposure to all three lights, with the greatest increase in expression observed upon exposure to blue light. In contrast, the transcriptional levels of two carotenoid cleavage dioxygenases (SbCCD1 and SbCCD4) decreased under all three light treatments. Increased production of zeaxanthin, β-carotene, and 9-cis-β-carotene was observed on exposure to all 3 lights. The total carotenoid production rose by 27.35% under blue light treatment, while the white and red lights did not have any considerable effect. Our findings may establish new approaches for increasing carotenoid production in S. baicalensis as well as in other plants.

Seed germination is a complex process regulated by intrinsic hormonal cues such as abscisic acid (ABA) and gibberellin (GA), and environmental signals including temperature. Using pharmacological, molecular and metabolomics approaches, we show that supraoptimal temperature delays wheat seed germination through maintaining elevated embryonic ABA level via increased expression of ABA biosynthetic genes (TaNCED1 and TaNCED2), increasing embryo ABA sensitivity through upregulation of genes regulating ABA signalling positively (TaPYL5, TaSnRK2, ABI3 and ABI5) and decreasing embryo GA sensitivity via induction of TaRHT1 that regulates GA signalling negatively. Endospermic ABA and GA appeared to have minimal roles in regulating germination at supraoptimal temperature. Germination inhibition by suboptimal temperature is associated with elevated ABA level in the embryo and endosperm tissues, mediated by induction of TaNCEDs and decreased expression of endospermic ABA catabolic genes (TaCYP707As), and increased ABA sensitivity in both tissues via upregulation of TaPYL5, TaSnRK2, ABI3 and ABI5 in the embryo and TaSnRK2 and ABI5 in the endosperm. Furthermore, suboptimal temperature suppresses GA synthesis in both tissues and GA sensitivity in the embryo via repressing GA biosynthetic genes (TaGA20ox and TaGA3ox2) and inducing TaRHT1, respectively. These results highlight that spatiotemporal modulation of ABA and GA metabolism and signalling in wheat seeds underlies germination response to temperature.

Iron oxide-silver nanocomposites are of great interest for their antibacterial and antifungal activities. We report a two-step synthesis of functional magnetic hetero-nanocomposites of iron oxide nanoparticles and silver nanoparticles (Fe3O4-Ag). Iron oxide nanoparticles were prepared first by a co-precipitation method followed by the deposition of silver nanoparticles via a hydrothermal route. The prepared Fe3O4-Ag hetero-nanocomposites were characterized by x-ray diffraction, transmission electron microscopy, high resolution transmission electron microscopy and vibrating sample magnetometry. Their antibacterial activities were investigated by using paper-disc diffusion and direct-drop diffusion methods. The results indicate that the Fe3O4-Ag hetero-nanocomposites exhibit excellent antibacterial activities against two Gram-negative bacterial strains (Salmonella enteritidis and Klebsiella pneumoniae).

Cu(In,Ga)S2 (CIGS) nanoparticles were synthesized by hot-injection method at temperature of 240°C under nitrogen ambient, then dispersed in hexanethiol to form stable ink. CIGS thin films were prepared by doctor-blade method and annealed under different amounts of selenium at 540°C for 20 min. After annealing, the Cu(In,Ga)(S,Se)2 (CIGSSe) films showed increasing crystallinity, particle size, and Se concentration with increasing amount of selenium. In addition, only CIGSSe phase existed in the film after annealing. The properties of CIGSSe cells were improved with increasing amount of selenium. The optimal results were obtained for the sample prepared with 0.2 g Se, showing short-circuit photocurrent density (JSC) of 27.36 mA/cm2, open-circuit voltage (VOC) of 0.42 V, fill factor (FF) of 0.36, and conversion efficiency (η) of 4.2%. These results provide important insights into economically feasible production of CIGS-based solar cells.

The phytopathogenic fungus Leptosphaeria maculans causes the blackleg disease on Brassica napus, resulting in severe loss of rapeseed production. Breeding of resistant cultivars containing race-specific resistance genes is provably effective to combat this disease. While two allelic resistance genes LepR3 and Rlm2 recognizing L. maculans avirulence genes AvrLm1 and AvrLm2 at plant apoplastic space have been cloned in B. napus, the downstream gene expression network underlying the resistance remains elusive. In this study, transgenic lines expressing LepR3 and Rlm2 were created in the susceptible "Westar" cultivar and inoculated with L. maculans isolates containing different sets of AvrLm1 and AvrLm2 for comparative transcriptomic analysis. Through grouping the RNA-seq data based on different levels of defense response, we find LepR3 and Rlm2 orchestrate a hierarchically regulated gene expression network, consisting of induced ABA acting independently of the disease reaction, activation of signal transduction pathways with gradually increasing intensity from compatible to incompatible interaction, and specifically induced enzymatic and chemical actions contributing to hypersensitive response with recognition of AvrLm1 and AvrLm2. This study provides an unconventional investigation into LepR3 and Rlm2-mediated plant defense machinery and adds novel insight into the interaction between surface-localized receptor-like proteins (RLPs) and apoplastic fungal pathogens.

Molybdenum (Mo) films (~1 μm) as back contacts for chalcopyrite solar cells are usually deposited onto the glass substrate by DC-sputtering because of their high deposition rate with a column structure. During selenization, selenium (Se) is infiltrated deeply into the column structure of Mo films. Although the difference in sheet resistance and resistivity values before and after selenization is negligible, the selenized Mo films are easily peeled off from the glass substrate even with the tape testing. The existence of Se in Mo films with a column structure was investigated by scanning electron microscopy cross-section, energy-dispersive X-ray spectroscopy, and X-ray diffraction measurement. To overcome this obstacle, a 200-nm-thick Mo compact layer was deposited by RF-sputtering on top of the Mo film to prevent Se infiltration. Finally, the bilayer of Mo was passed with tape testing for both films before and after selenization. The results may be helpful to further achieve highly stable fabrication processes of chalcopyrite solar cells.

Paper-bagging treatment can transform non-transcribed MdMYB1 - 2 and MdMYB1 - 3 alleles into transcribed alleles through epigenetic regulations, resulting in the red pigmentation of a normally non-red apple cultivar 'Mutsu.' Anthocyanin biosynthesis in apples is regulated by MdMYB1/A/10, an R2R3-Type MYB gene. 'Mutsu,' a triploid apple cultivar harboring non-transcribed MdMYB1-2 and MdMYB1-3 alleles, retains green skin color under field conditions. However, it can show red/pink pigmentation under natural or artificial ultraviolet-B (UV-B) light exposure after paper-bagging and bag removal treatment. In the present study, we found that in 'Mutsu,' paper bagging-induced red pigmentation was due to the activation of non-transcribed MdMYB1-2/-3 alleles, which triggered the expression of downstream anthocyanin biosynthesis genes in a UV-B-dependent manner. By monitoring the epigenetic changes during UV-B-induced pigmentation, no significant differences in DNA methylation and histone modifications in the 5' upstream region of MdMYB1-2/-3 were recorded between the UV-B-treated fruit skin (red) and the fruit skin treated only by white light (green). In contrast, bag treatment lowered the DNA methylation in this region of MdMYB1-2/-3 alleles. Similarly, higher levels of histone H3 acetylation and trimethylation of H3 tail at lysine 4, and lower level of trimethylation of H3 tail at lysine 27 were observed in the 5' upstream region of MdMYB1-2/-3 in the skin of the fruit immediately after bag removal. These results suggest that bagging treatment can induce epigenetic changes, facilitating the binding of trans factor(s) to MdMYB1-2/-3 alleles, resulting in the activation of these MYBs after bag removal.

Ru nanoparticles with a range size of 2∼6 nm are successfully immobilized on the surface of carbon nanotubes (CNTs) through liquid plasma reduction. The CNT-Ru nanohybrid exhibits an excellent catalyst for the redox reaction in dye-sensitized solar cells with the electrolyte of triiodide/iodide ions.

Seed dormancy is an adaptive trait that does not allow the germination of an intact viable seed under favorable environmental conditions. Non-dormant seeds or seeds with low level of dormancy can germinate readily under optimal environmental conditions, and such a trait leads to preharvest sprouting, germination of seeds on the mother plant prior to harvest, which significantly reduces the yield and quality of cereal crops. High level of dormancy, on the other hand, may lead to non-uniform germination and seedling establishment. Therefore, intermediate dormancy is considered to be a desirable trait as it prevents the problems of sprouting and allows uniformity of postharvest germination of seeds. Induction, maintenance, and release of seed dormancy are complex physiological processes that are influenced by a wide range of endogenous and environmental factors. Plant hormones, mainly abscisic acid (ABA) and gibberellin (GA), are the major endogenous factors that act antagonistically in the control of seed dormancy and germination; ABA positively regulates the induction and maintenance of dormancy, while GA enhances germination. Significant progress has been made in recent years in the elucidation of molecular mechanisms regulating ABA/GA balance and thereby dormancy and germination in cereal seeds, and this review summarizes the current state of knowledge on the topic.

In this study, manganese ferrite-graphene oxide (MFO-GO) nanocomposites were prepared via a co-precipitation reaction of Fe3+ and Mn2+ ions in a GO suspension. The effects of graphene oxide on the physicochemical characteristics, magnetic properties and adsorption activities of the MFO-GO nanocomposites were studied. Methylene blue (MB) and arsenic(V) were used in this study as model water pollutants. With an increase in the GO content in the range of 10 wt% to 50 wt%, the removal efficiency for both MB dye and arsenic(V) ions was improved. Our adsorption data revealed that the adsorption behavior of MB dye showed good agreement with the Langmuir isotherm model and pseudo-second-order equation, whereas the Freundlich isotherm model was more suitable for simulating the adsorption process of arsenic(V) ions on the MFO-GO nanocomposites. In addition, an important role of the GO content in the adsorption mechanisms of both MB dye and arsenic(V) ions was found, in which GO nanosheets play a key role in the mechanisms of electrostatic/ionic interactions, oxygen-containing groups and π–π conjugation in the case of the adsorption of MB dye, whereas the role of the GO content is mainly related to the mechanism of electrostatic/ionic interactions in the case of the adsorption of arsenic(V). Graphene oxide has the functions of increasing the number of active binding sites comprising oxygen-containing functional groups, reducing the agglomeration of MFO nanoparticles, increasing the number of adsorption sites, and improving the electrostatic/ionic interactions between adsorbents and adsorbates in order to enhance the adsorption performance of cationic organic dyes and/or heavy metal anions from aqueous solutions.

Transgenic approach is an excellent way for the clarification of gene function, but it is generally difficult to create transgenic plants for most of the fruit trees including peach. Even if transgenic lines are successfully obtained, it will be extremely difficult to evaluate fruit traits due to the long juvenile phase of the plants. To overcome this problem, usage of virus vector is one of the excellent approaches. In this study, we evaluated gene function related to fruit traits in peaches via virus-induced gene silencing (VIGS). Carotenoid cleavage dioxygenase 4 (CCD4) is proposed to be the key factor responsible for carotenoid degradation in white flesh peaches. Then, we knocked down the CCD4 gene in the white flesh peaches (“Akatsuki” and “Manami”) via VIGS system. Resultantly, yellow pigmentation and increased contents of carotenoids including lutein, s-carotene, s-cryptoxanthin, zeaxanthin, and violaxanthin were observed in the agroinfiltration portions of the white flesh peaches, which is a direct evidence that CCD4 is a determinant for yellow flesh trait of peach. Our results suggested the possible application of VIGS system for functional studies of the genes related to fruit traits.

In the pear 'Kosui' (Pyrus pyrifolia Nakai), the dormancy-associated MADS-box (PpDAM1 = PpMADS13-1) gene has been reported to play an essential role in bud endodormancy. Here, we found that PpDAM1 up-regulated expression of 9-cis-epoxycarotenoid dioxygenase (PpNCED3), which is a rate-limiting gene for ABA biosynthesis. Transient assays with a dual luciferase reporter system (LUC assay) and electrophoretic mobility shift assay (EMSA) showed that PpDAM1 activated PpNCED3 expression by binding to the CArG motif in the PpNCED3 promoter. PpNCED3 expression was increased toward endodormancy release in lateral flower buds of 'Kosui', which is consistent with the induced levels of ABA, its catabolism (ABA 8'-hydroxylase) and signaling genes (type 2C protein phosphatase genes and SNF1-related protein kinase 2 genes). In addition, we found that an ABA response element (ABRE)-binding transcription factor, PpAREB1, exhibiting high expression concomitant with endodormancy release, bound to three ABRE motifs in the promoter region of PpDAM1 and negatively regulated its activity. Taken together, our results suggested a feedback regulation between PpDAM1 and the ABA metabolism and signaling pathway during endodormancy of pear. This first evidence of an interaction between a DAM and ABA biosynthesis in vitro will provide further insights into bud endodormancy regulatory mechanisms of deciduous trees including pear.

The leaf, stem, and floral essential oils of Crassocephalum crepidioides growing wild in central Vietnam were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The...

Full-length cDNAs encoding &xi, carotene desaturase (CmZDS), lycopene &epsilon, cyclase (CmLCYE), &beta, ring carotene hydroxylase (CmCHXB), and zeaxanthin epoxidase (CmZEP), and partial-length cDNA encoding &epsilon, ring carotene hydroxylase (CmCHXE) were isolated in Chamoe (Cucumis melo L. var. makuwa), an important commercial fruit. Sequence analyses revealed that these proteins share high identity and common features with other orthologous genes. Expression levels of entire genes involved in the carotenoid biosynthetic pathway were investigated in the peel, pulp, and stalk of chamoe cultivars Ohbokggul and Gotgam. Most of the carotenoid biosynthetic genes were expressed at their highest levels in the stalk, whereas carotenoids were highly distributed in the peel. The expression levels of all carotenoid biosynthetic genes in fruits of the native cultivar Gotgam chamoe were higher than those in the cultivar Ohbokggul chamoe, consistent with the abundant carotenoid accumulation in Gotgam chamoe fruits and trace carotenoid content of Ohbokggul chamoe fruit. Lutein and &beta, carotene were the dominant carotenoids, high levels (278.05 &mu, g g&minus, 1 and 112.02 &mu, 1 dry weight, respectively) were found in the peel of Gotgam chamoe. Our findings may provide a foundation for elucidating the carotenoid biosynthetic mechanism in C. melo and inform strategies for developing new chamoe cultivars with improved characteristics.

The large Stokes shifts and long lifetimes observed for lanthanide complexes are especially important for bioimaging. To incorporate the benefits of lanthanide lumophores into nanoscale probes, size-tunable gold nanoparticles (GNPs) coated with luminescent europium(III) complexes were synthesized using a modified Stober method with in␣situ doping of europium(III) complexes with tri-n-octylphosphineoxide (TOPO) and naphthoyl trifluoroacetone (NTA) ligands. The results show that the integration of europium(III) complexes with GNPs significantly extends their absorption band towards the visible region. Emission spectrum of these GNPs coated with europium(III) complexes shows the characteristic 5D0 → 7Fn (n = 1, 2, 3, 4) transitions of an Eu(III) ion. Their fluorescence lifetime of 460 μs was observed. The effect of different sizes of GNPs on their photophysical properties was also investigated.

In the Japanese pear (Pyrus pyrifolia Nakai) 'Kosui', three developmental stages of lateral flower buds have been proposed to occur during ecodormancy to the flowering phase, i.e. rapid enlargement, sprouting and flowering. Here, we report an APETALA2/ethylene-responsive factor (AP2/ERF) transcription factor gene, named pear EARLY BUD-BREAK (PpEBB), which was highly expressed during the rapid enlargement stage occurring prior to the onset of bud break in flower buds. Gene expression analysis revealed that PpEBB expression was dramatically increased during the rapid enlargement stage in three successive growing seasons. PpEBB transcript levels peaked 1 week prior to onset of bud break in 'Kosui' potted plants treated with hydrogen cyanamide or water under forcing conditions. Chromatin immunoprecipitation-quantitative PCR showed that higher levels of active histone modifications (trimethylation of the histone H3 tail at Lys4) in the 5'-upstream and start codon regions of the PpEBB gene were associated with the induced expression level of PpEBB during the rapid enlargement stage. In addition, we provide evidence that PpEBB may interact with and regulate pear four D-type cyclin (PpCYCD3) genes during bud break in 'Kosui' lateral flower buds. PpEBB significantly increased the promoter activities of four PpCYCD3 genes in a dual-luciferase assay using tobacco leaves. Taken together, our findings uncovered aspects of the bud break regulatory mechanism in the Japanese pear and provided further evidence that the EBB family plays an important role in bud break in perennial plants.