Increased CO2 and light intensity regulate growth and leaf gas exchange in tomato.

Carbon dioxide concentration (CO2 ) and light intensity are known to play important roles in plant growth and carbon assimilation. Nevertheless, the underlying physiological mechanisms have not yet been fully explored. Tomato seedlings (Solanum lycopersicum Mill. cv. Jingpeng No. 1) were exposed to two levels of CO2 and three levels of light intensity and the effects on growth, leaf gas exchange and water use efficiency were investigated. Elevated CO2 and increased light intensity promoted growth, dry matter accumulation and pigment concentration and together the seedling health index. Elevated CO2 had no significant effect on leaf nitrogen content but did significantly upregulate Calvin cycle enzyme activity. Increased CO2 and light intensity promoted photosynthesis, both on a leaf-area basis and on a chlorophyll basis. Increased CO2 also increased light-saturated maximum photosynthetic rate, apparent quantum efficiency and carboxylation efficiency and, together with increased light intensity, it raised photosynthetic capacity. However, increased CO2 reduced transpiration and water consumption across different levels of light intensity, thus significantly increasing both leaf-level and plant-level water use efficiency. Among the range of treatments imposed, the combination of increased CO2 (800 µmol CO2 mol-1 ) and high light intensity (400 µmol m-2 s-1 ) resulted in optimal growth and carbon assimilation. We conclude that the combination of increased CO2 and increased light intensity worked synergistically to promote growth, photosynthetic capacity and water use efficiency by upregulation of pigment concentration, Calvin cycle enzyme activity, light energy use and CO2 fixation. Increased CO2 also lowered transpiration and hence water usage.

Phytochrome B1-dependent control of SP5G transcription is the basis of the night break and red to far-red light ratio effects in tomato flowering.

BACKGROUND: Phytochromes are dimeric proteins with critical roles in perceiving day length and the environmental signals that trigger flowering. Night break (NB) and the red to far-red light ratio (R:FR) have been used extensively as tools to study the photoperiodic control of flowering. However, at the molecular level, little is known about the effect of NB and different R:FR values on flowering in day-neutral plants (DNPs) such as tomato. RESULTS: Here, we show that tomato SP5G, SP5G2, and SP5G3 are homologs of Arabidopsis thaliana FLOWERING LOCUS T (FT) that repress flowering in Nicotiana benthamiana. NB every 2 h at intensities of 10 µmol m- 2 s- 1 or lower R:FR (e.g., 0.6) caused a clear delay in tomato flowering and promoted SP5G mRNA expression. The promoted SP5G mRNA expression induced by red light NB and low R:FR treatments was reversed by a subsequent FR light stimulus or a higher R:FR treatment. The tomato phyB1 mutation abolished the effects of NB and lower R:FR treatments on flowering and SP5G mRNA expression, indicating that the effects were mediated by phytochrome B1 in tomato. CONCLUSION: Our results strongly suggest that SP5G mRNA suppression is the principal cause of NB and lower R:FR effects on flowering in tomato.

Exposure to lower red to far-red light ratios improve tomato tolerance to salt stress.

BACKGROUND: Red (R) and far-red (FR) light distinctly influence phytochrome-mediated initial tomato growth and development, and more recent evidence indicates that these spectra also modulate responses to a multitude of abiotic and biotic stresses. This research investigated whether different R: FR values affect tomato growth response and salinity tolerance. Tomato seedlings were exposed to different R: FR conditions (7.4, 1.2 and 0.8) under salinity stress (100 mM NaCl), and evaluated for their growth, biochemical changes, active reactive oxygen species (ROS) and ROS scavenging enzymes, pigments, rate of photosynthesis, and chlorophyll fluorescence. RESULTS: The results showed that under conditions of salinity, tomato seedlings subjected to a lower R: FR value (0.8) significantly increased both their growth, proline content, chlorophyll content and net photosynthesis rate (Pn), while they decreased malondialdehyde (MDA) compared to the higher R: FR value (7.4). Under conditions of salinity, the lower R: FR value caused a decrease in both the superoxide anion (O2•-) and in hydrogen peroxide (H2O2) generation, an increase in the activities of superoxidase dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7) and catalase (CAT, EC 1.11.1.7). Tomato seedlings grown under the lower R: FR value and conditions of salinity showed a higher actual quantum yield of photosynthesis (ΦPSII), electron transport rate (ETR), and photochemical quenching (qP) than those exposed to a higher R: FR, indicating overall healthier growth. However, the salinity tolerance induced at the lower R: FR condition disappeared in the tomato phyB1 mutant. CONLUSION: These results suggest that growing tomato with a lower R: FR value could improve seedlings' salinity tolerance, and phytochrome B1 play an very important role in this process. Therefore, different qualities of light can be used to efficiently develop abiotic stress tolerance in tomato cultivation.

QTL Analysis for Downy Mildew Resistance in Cucumber Inbred Line PI 197088.

Downy mildew (DM), caused by Pseudoperonospora cubensis, is one of the major foliar diseases prevailing in cucumber-growing areas. The mechanism of DM resistance in cucumber, particularly the plant introduction (PI) 197088 from India, is presently unclear. Quantitative trait locus (QTL) mapping is an efficient approach to studying DM resistance genes in cucumber. In this study, we performed QTL mapping for DM resistance in PI 197088 with 183 F2-derived F3 (F2:3) families from the cross between PI 197088 (DM resistant) and Changchunmici (DM susceptible). A linkage map was constructed using 141 simple sequence repeat markers. Phenotypic data were collected from seven independent experiments. In total, five QTL were detected on chromosomes 1, 3, 4, and 5 with DM resistance contributed by PI 197088. The QTL on chromosome 4, dm4.1, was reproducibly detected in all indoor experiments, which could explain 27% of the phenotypic variance detected. Additionally, dm1.1 and dm5.2 showed moderate effects, while dm3.1 and dm5.1 were minor-effect QTL. This study revealed the unique genetic architecture of DM resistance in PI 197088, which may provide important guidance for efficient use in cucumber breeding for DM resistance.

Transmasseteric Anterior Parotid Approach for Treatment of Mandibular Subcondylar Fractures.

This study demonstrated the application of transmasseteric anterior parotid approach for open reduction of mandibular subcondylar fractures depending on the basis of the anatomical study of the temporomandibular joint and parotid gland area. The anatomical study was performed on 5 Chinese adult cadavers fixed by 10% formalin. The temporomandibular joints and parotid regions were studied. In the clinical study, 26 patients with mandibular subcondylar fractures were recruited between July 2014 and December 2017. All 26 patients with mandibular subcondylar fractures received satisfactory occlusions and normal mouth opening: no postoperative facial paralysis occurred in these patients. It is crucial to know the anatomy of both temporomandibular joint and parotid region for reducing significantly the surgical trauma and complications. Transmasseteric anterior parotid approach is a feasible approach for the surgical treatment of the mandibular subcondylar fractures. This method can provide adequate exposure, minimal facial nerve injury, open reduction easily, and inconspicuous scarring.

Centipede venom peptide SsmTX-I with two intramolecular disulfide bonds shows analgesic activities in animal models.

Pain is a major symptom of many diseases and results in enormous pressures on human body or society. Currently, clinically used analgesic drugs, including opioids and nonsteroidal anti-inflammatory drugs, have adverse reactions, and thus, the development of new types of analgesic drug candidates is urgently needed. Animal venom peptides have proven to have potential as new types of analgesic medicine. In this research, we describe the isolation and characterization of an analgesic peptide from the crude venom of centipede, Scolopendra subspinipes mutilans. The amino acid sequence of this peptide was identical with SsmTX-I that was previously reported as a specific Kv2.1 ion channel blocker. Our results revealed that SsmTX-I was produced by posttranslational processing of a 73-residue prepropeptide. The intramolecular disulfide bridge motifs of SsmTX-I was Cys1-Cys3 and Cys2-Cys4. Functional assay revealed that SsmTX-I showed potential analgesic activities in formalin-induced paw licking, thermal pain, and acetic acid-induced abdominal writhing mice models. Our research provides the first report of cDNA sequences, disulfide motif, successful synthesis, and analgesic potential of SsmTX-I for the development of pain-killing drugs. It indicates that centipede peptide toxins could be a treasure trove for the search of novel analgesic drug candidates. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

24-Epibrassinoslide enhances plant tolerance to stress from low temperatures and poor light intensities in tomato (Lycopersicon esculentum Mill.).

Brassinosteroids (Brs) are a newly recognized group of active steroidal hormones that occur at low concentrations in all plant parts and one of the active and stable forms is 24-epibrassinolide (EBR). We investigated the effect of EBR on tomato (Lycopersicon esculentum Mill.) and its mechanism when seedlings were exposed to low temperature and poor light stress conditions. Leaves of stress-tolerant 'Zhongza9' and stress-sensitive 'Zhongshu4' cultivars were pre-treated with spray solutions containing either 0.1 µM EBR or no EBR (control). The plants were then transferred to chambers where they were exposed to low temperatures of 12 °C/6 °C (day/night) under a low light (LL) level of 80 µmol · m(-2) · s(-1). Exogenous application of EBR significantly increased the antioxidant activity of superoxide dismutase, catalase and peroxidase, and decreased the rate of O2 · (-) formation and H2O2 and malondialdehyde contents. Additionally, the ATP synthase ß subunit content was increased by exogenous hormone application. Based on these results, we conclude that exogenous EBR can elicit synergism between the antioxidant enzyme systems and the ATP synthase ß subunit so that scavenging of reactive oxygen species becomes more efficient. These activities enable plants to cope better under combined low temperature and poor light stresses.

Beneficial role of spermidine in chlorophyll metabolism and D1 protein content in tomato seedlings under salinity-alkalinity stress.

Polyamines are important in protecting plants against various environmental stresses, including protection against photodamage to the photosynthetic apparatus. The molecular mechanism of this latter effect is not completely understood. Here, we have investigated the effects of salinity-alkalinity stress and spermidine (Spd) on tomato seedlings at both physiological and transcriptional levels. Salinity-alkalinity stress decreased leaf area, net photosynthetic rate, maximum net photosynthetic rate, light saturation point, apparent quantum efficiency, total chlorophyll, chlorophyll a and chlorophyll a:chlorophyll b relative to the control. The amount of D1 protein, an important component of photosystem II, was reduced compared with the control, as was the expression of psbA, which codes for D1. Expression of the chlorophyll biosynthesis gene porphobilinogen deaminase (PBGD) was reduced following salinity-alkalinity stress, whereas the expression of Chlase, which codes for chlorophyllase, was increased. These negative physiological effects of salinity-alkalinity stress were alleviated by exogenous Spd. Expression of PBGD and psbA were enhanced, whereas the expression of Chlase was reduced, when exogenous Spd was included in the stress treatment compared with when it was not. The protective effect of Spd on chlorophyll and D1 protein content during stress may maintain the photosynthetic apparatus, permitting continued photosynthesis and growth of tomato seedlings (Solanum lycopersicum cv. Jinpengchaoguan) under salinity-alkalinity stress.

Bottle-in-bottle reaction device: Portable gas pressure meter for rapid and on-site analysis of oxalate in spinach and tea beverages.

A gas pressure meter-based portable/miniaturized analytical kit was established for rapid and on-site detection of oxalate. Potassium permanganate (KMnO4) and oxalate solution were mixed together in bottle-in-bottle reaction device, a simple oxidation reaction process occurred within 6 min and carbon dioxide (CO2) was generated, inducing the pressure of the sealed bottle changed, which was measured by a portable gas pressure meter. A detectable range of 0.1-6 µmol mL-1 and a detection limit of 0.064 µmol mL-1 were achieved. The proposed analytical method was further used for the analysis of several real samples (spinach, beverages and water samples), with the recoveries of 89-111%. Considering the interferences from the complicated matrix, calcium chloride (CaCl2) was served as a precipitant, oxalate (C2O4 2-) was precipitated with Ca2+ to form precipitation (CaC2O4), CaC2O4 was then separated from the matrix by centrifuge/filter, eliminating the interferences. It is a rapid, easy-used and interference-free analytical system/device for oxalate on-site and real time analysis.

A portable/miniaturized analytical kit for on-site analysis: Chemical vapor generation-visual colorimetric and smartphone RGB dual-mode for detection of sulfide ion in water and food additives.

Chemical vapor generation (CVG) was used as a gaseous sample introduction technique for the visual/smartphone RGB readout colorimetric system, with the advantages of efficient matrix elimination and high vapor generation efficiency, this analytical system exhibits a good selectivity and sensitivity. Sulfide ion (S2-) in solution was transformed to its volatile form (H2S), the generated H2S reacted with a silver-containing metal organic framework (Ag-BTC) selectively, Ag2S was thus generated. Ag-BTC (fabricated on paper sheet) changed from white to dark brown, the color variance was identified by smartphone and naked-eye simultaneously. Under the optimized conditions, a limit of detection of 0.02 µg/mL was obtained by naked-eye. Several water samples and commercial food additives were analyzed for confirming its accuracy and potential application for on-site detection, recoveries ranging 94-110 % were obtained. To meet the demand of on-site analysis of S2-, this colorimetric system was integrated in a portable/miniaturized analytical kit. It is an easy-used, affordable and portable analytical kit for S2- detection in field.

[Clinical anatomy of the free latissimus dorsi myocutaneous flap and its application in the restoration of giant defects of the head and neck].

PURPOSE: To investigate the feasibility and effect of free latissimus dorsi myocutaneous flap in the reconstruction of giant head and neck defects. METHODS: Free latissimus dorsi myocutaneous flap on the cadaver was simulated dissected, and measured by Image-Pro Plus 6.0 to assess the feasibility of repairing giant head and neck defects. Between May 2011 and September 2022, seven patients with giant head and neck defects of different causes repaired with the latissimus dorsi myocutaneous flap were retrospectively analyzed. RESULTS: The diameter of the initiating thoracodorsal artery was (4.03±0.56) mm, and the mean lengths of the arteriolar and venous pedicles of the latissimus dorsi myocutaneous flaps obtained from human specimens were (85.5±10.5) mm and (104±4.2) mm, respectively. Among 7 patients, 5 cases had scalp defects, the remaining 2 cases had neck defects. There were no substantial postoperative problems in the donor site, and all seven latissimus dorsi myocutaneous flaps were successfully transplanted. CONCLUSIONS: For the treatment of considerable head and neck deformities, the latissimus dorsi myocutaneous flap is an optimal muscle flap due to its abundance of tissue, enough length of vascular pedicles, and sufficient venous drainage.

Microplasma-enabled carbon dots composited with multi-walled carbon nanotubes for dopamine detection.

Composited carbon nanomaterials have attracted wide attention and are used for high-sensitivity biological assays due to their low toxicity, good biocompatibility, and excellent electrical conductivity. To further promote electron transfer and enhance electrocatalytic activity to detect dopamine (DA), this study proposed carbon dots (CDs) based on glycerol synthesized by liquid dielectric barrier discharge (DBD) microplasma. Combined with the multi-walled carbon nanotubes (MWCNTs) with excellent electrical conductivity, a composited carbon nanomaterial electrode of CDs/MWCNTs was constructed. As a DA biosensor, the interaction and electron exchange between MWCNTs, CDs, and DA can be enhanced thanks to the π-π stacking force, thereby facilitating the sensitive electrochemical detection of DA. The sensor exhibits good sensing performance toward DA detection with a linear range of 2.0-100 µM, a limit of detection (LOD) of 11.08 nM (S/N = 3), and a sensitivity of 29020 µA cm-2 mM-1. The proposed electrode successfully detected DA levels in human serum samples with satisfactory selectivity and recovery rate. The microplasma-enabled synthesized method provides a promising path for preparing and applying carbon-based nanomaterials.

Ag-containing metal organic framework reacted with AsH3: Mechanism and application for inorganic arsenic detection by hydride generation-smartphone RGB readout colorimetric system.

The reaction mechanism of Ag-containing metal organic framework (Ag-BTC) and hydrogen arsenide (AsH3) was discussed in detail in this work. Silver ions in Ag-BTC were reacted with AsH3, and silver nanoparticles were generated on the surface of Ag-BTC, causing its color changed. This property was further applied to a hydride generation-colorimetric analytical system. As(III) was converted to AsH3via hydride generation and then reacted with the Ag-BTC (immobilized on test paper), leading to the test paper changed from white to black. Visual colorimetric and smartphone RGB readout mode were used for this analytical system. The results could be readout by naked-eye in visual colorimetric mode and a smartphone in RGB readout mode. Under the optimized conditions, As(III) concentration as low as 10 µg/L and 50 µg/L could be readout by smartphone and naked-eye, respectively. This method was further successful applied to As(III) determination in real samples (drinking water samples and scented tea samples), with recoveries of 91-113%.

Construction of rose flower-like NiCo-LDH electrode derived from bimetallic MOF for highly sensitive electrochemical sensing of hydrazine in food samples.

It is necessary to efficient detection hydrazine in food. Exploring highly sensitive, low-cost and fast response electrochemical hydrazine sensing methods has been a challenge in this field. In this paper, a conformal transformation method is used to prepare rose flower-like NiCo-LDH derivating from the bimetallic NiCo-MOFs, and the N2H4 sensing platform with a large electrocatalytic area, high conductivity and good stability was constructed. Based on the synergy between Ni and Co and the remarkable catalytic activity of the rough 3D flower-like structure, the N2H4 sensor has a linear response in the concentration range of 0.001-1 mmol/L and 1-7 mmol/L, with a sensitivity of 5342 µA L mmol-1 cm-2 and 2965 µA L mmol-1 cm-2 (S/N = 3), respectively, and low limit of detection of 0.043 µmol/L. This study opens a new door for the successful application of electrochemical sensors to detect N2H4 in real food samples.

One-step rapid synthesis of Ni0.5Co0.5-CPO-27 nanorod array with oxygen vacancies based on DBD microplasma: As an effective non-enzymatic glucose sensor for beverage and human serum.

The rational design of high-efficiency catalysts for non-enzymatic glucose sensing is extremely important for the timely and effective monitoring of glucose content in beverages and human blood. A 3D bimetallic organic framework (Coordination Polymer of Oslo, CPO) nanorod array with oxygen vacancies was green fabricated on carbon cloth (Ni0.5Co0.5-CPO-27 NRA/CC) using dielectric barrier discharge (DBD) microplasma for the first time. Density functional theory (DFT) calculations demonstrated that the oxygen vacancy of Ni0.5Co0.5-CPO-27 can be effectively induced under DBD microplasma conditions. Based on the 3D nanorod arrays with rich oxygen vacancies and bimetallic synergistic effects, as a non-enzyme glucose sensor, the Ni0.5Co0.5-CPO-27 electrode exhibited a sensitivity of 8499.5 µA L/mmol cm-2 and 3239.2 µA L/mmol cm-2 and a limit of detection (LOD) of 0.16 µmol/L (S/N = 3). It has been successfully applied to the determination of glucose levels in real samples such as cola, green tea and human serum.

Microplasma and quenching-induced Co doped NiMoO4 nanorods with oxygen vacancies for electrochemical determination of glucose in food and serum.

In this paper, Co-doped NiMoO4 nanorods with oxygen vacancies are synthesized on carbon cloth (Co-NiMoO4 NRs/CC) via microplasma and quenching-induced method.Owing to the surface defects and metal ion doping, the electronic structure and surface properties of the catalyst are tuned.Cyclic voltammetry (CV) and amperometry are used to investigate the electrocatalytic behavior of the glucose sensor in an alkaline medium with sensitivities of 7411 and 3125 µA L mmol-1 cm-2 in the linear range 1.0 µmol L-1 to 1.0 mmol L-1 and 1.0 mmol L-1 to 7.0 mmol L-1, respectively. The detection limit is 0.079 µmol L-1 at S/N = 3. Moreover, the as-prepared catalyst electrode is also successfully used in real food and serum samples, with a recovery rate of 97.1%-107.4%.The DFT calculations show that the Co site of the catalyst significantly influenced glucose sensing performance. This idea expands the application of quenching chemistry in electrochemical sensing.

Self-assembled ZnO microspheres coated with carbon dot-doped CoNi LDH wrinkled films as electrochemical sensors for highly sensitive detection of hydrazine.

In this study, a 3D surface-folded composite was prepared in situ as a hydrazine sensor by loading a hybrid film of CoNi-layered double hydroxides (LDHs) with nitrogen-doped carbon dots on self-assembled ZnO microspheres. The nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), and the electrochemical behavior of the sensors was investigated by cyclic voltammetry (CV), amperometry and electrochemical impedance spectroscopy (EIS). The results showed that ZnO microspheres with nitrogen-doped carbon dots strongly coupled with LDHs can significantly reduce the charge transfer resistance, accelerate the oxidation kinetics of hydrazine, and effectively increase the electrochemically active surface area (ECSA). The sensor achieved ultra-sensitive (13 040 µA mM-1 cm-2 (S/N = 3)) detection of hydrazine in the concentration range of 0.7 µM to 4 mM, exhibited excellent selectivity, reproducibility and high stability, and was successfully applied to the determination of hydrazine in actual environmental water samples and landfill leachate samples.

Hydride generation-smartphone RGB readout and visual colorimetric dual-mode system for the detection of inorganic arsenic in water samples and honeys.

A miniaturized/portable dual-mode colorimetric analytical system was established for inorganic arsenic determination in honey and drinking water samples. Hydride generation (HG) was utilized as a sampling technique for this colorimetric system, because of its high generation efficiency and efficient matrix separation. AsH3 was generated via HG and then reacted with HAuCl4, gold nanoparticles (Au NPs) were formed on the paper sheet, leading the paper color changed from light yellow to dark blue, it could be readout by naked-eye (visual colorimetric mode) and a smartphone (RGB readout mode) simultaneously. The accuracy and potential application for field analysis were further confirmed by the analysis of two water samples, four honey samples and two certified reference water samples (BWB2440-2016 and GBW08650), good recoveries (90-116%) were obtained for those samples and their spiked samples.

In situ formation of silver nanoparticles via hydride generation: A miniaturized/portable visual colorimetric system for arsenic detection in environmental water samples.

A miniaturized/portable visual colorimetric system based on hydride generation headspace solid phase extraction (HG-HS-SPE) was proposed for arsenic detection by naked eyes. As(III) was transformed into AsH3via hydride generation process, the volatile AsH3 was introduced into reaction bottle and reacted with AgNO3 subsequently. Silver nanoparticles (Ag NPs) were generated in situ, resulting in the color changed from white to black, it could be readout by naked eyes or a smartphone application (color extraction, for RGB readout). The interferences from 9 common ions and 10 conventional hydride generation elements were discussed, the results demonstrated that the proposed method exhibit a good anti-interference. The proposed visual colorimetric method was further applied to seven water samples and their spiked samples, and a certified reference water sample (GBW08605) for demonstrating its accuracy and applicability.

Ultrafast construction of 3D ultrathin NiCo-LDH@Cu heteronanosheet array by plasma magnetron sputtering for non-enzymatic glucose sensing in beverage and human serum.

In this work, a 3D ultra-thin NiCo-LDH nanosheet array coated Cu nanoparticles on carbon cloth (NiCo-LDH@Cu NSA/CC) was ultrafast synthesized by plasma magnetron sputtering for the first time. This method has low toxicity and is easy to operate. As a durable and efficient 3D heteronanoarray electrocatalyst for glucose detection, NiCo-LDH@Cu NSA/CC has higher stable conductivity and faster electron transport rate than NiCo-LDH NSA/CC and Cu nanoparticles, which work through synergistic effect to form a high-performance sensing platform. The NiCo-LDH@Cu NSA/CC heteronanosheet structure has good electrocatalytic performance for glucose oxidation, with the sensitivity of the two linear ranges (0.001-1 mmol L-1 and 1-6 mmol L-1) being 9710 µA L mmol-1 cm-2 and 4870 µA L mmol-1 cm-2, respectively, and the detection limit (LOD) is 157 nmol L-1 (S/N = 3). The sensor has been successfully applied to detect glucose in beverages and serum.