High atmospheric carbon dioxide-dependent alleviation of salt stress is linked to RESPIRATORY BURST OXIDASE 1 (RBOH1)-dependent H2O2 production in tomato (Solanum lycopersicum)

Plants acclimate rapidly to stressful environmental conditions. Increasing atmospheric CO2 levels are predicted to influence tolerance to stresses such as soil salinity but the mechanisms are poorly understood. To resolve this issue, tomato (Solanum lycopersicum) plants were grown under ambient (380 μmol mol–1) or high (760 μmol mol–1) CO2 in the absence or presence of sodium chloride (100 mM). The higher atmospheric CO2 level induced the expression of RESPIRATORY BURST OXIDASE 1 (SlRBOH1) and enhanced H2O2 accumulation in the vascular cells of roots, stems, leaf petioles, and the leaf apoplast. Plants grown with higher CO2 levels showed improved salt tolerance, together with decreased leaf transpiration rates and lower sodium concentrations in the xylem sap, vascular tissues, and leaves. Silencing SlRBOH1 abolished high CO2 -induced salt tolerance and increased leaf transpiration rates, as well as enhancing Na+ accumulation in the plants. The higher atmospheric CO2 level increased the abundance of a subset of transcripts involved in Na+ homeostasis in the controls but not in the SlRBOH1-silenced plants. It is concluded that high atmospheric CO2 concentrations increase salt stress tolerance in an apoplastic H2O2 dependent manner, by suppressing transpiration and hence Na+ delivery from the roots to the shoots, leading to decreased leaf Na+ accumulation

Sea Ranching Feasibility of the Hatchery-Reared Tropical Sea Cucumber Stichopus monotuberculatus in an Inshore Coral Reef Island Area in South China Sea (Sanya, China)

Sea ranching of tropical edible sea cucumbers is an effective way to relieve the overfishing stress on their natural resources and protect the coral reef ecosystem, yet only a few species have been applied in the sea ranching practice based on hatchery-reared juveniles around the world. In this study, an 8-month (April to December) sea ranching study for hatchery-reared edible sea cucumber Stichopus monotuberculatus juveniles was carried out at a tropical coral reef island area in Sanya, China. Several growth performance indexes and basal nutritional components were monitored. Results revealed that the sea cucumbers had a growth rate of 0.35~0.78 mm day-1 during the experimental period, reaching 15.9 cm long before winter. The weight gain reached 491.13% at the end, and most sea cucumbers were able to grow to the commercial size (over 150 g WW) in the first year of sea ranching. The overall specific growth rate (SGR) and survival rates were 0.73 and 27.5%. Most of the death occurred in the first month after release (25.0%–37.5%), and this is probably due to inadaptation to the sudden change of the environment from the hatchery to the wild, which is proved by the remarkable decrease in nutritional indexes (amino acids, total lipid, and crude protein). Stable isotope and lipid biomarkers revealed that the food source mainly comes from water deposits (with microbes), Sargassum sanyaense seaweed debris, phytoplankton, and coral mucus-derived organics. The study proved the feasibility of the sea ranching of the hatchery-reared S. monotuberculatus juveniles in the tropical coral reef island area. Also, it is highly recommended that appropriate acclimation operation before release should be carried out to improve the survival rate of this species

Optimization of NiFe2O4/rGO composite electrode for lithium-ion batteries

The combination of carbon compositing and the proper choice of binders in one system offer an effective strategy for improving electrode performance for lithium ion batteries (LIBs). Here, we focus on the optimization of reduced graphene oxide content in NiFeO/reduced graphene oxide (abbreviated to NiFeO/rGO) composites and the proper choice of binders to enhance the cycling stability of the NiFeO electrode. The NiFeO/rGO composites were fabricated by a hydrothermal-annealing method, in which the mean size of spinel NiFeO nanoparticles was approximately 20\ua0nm. When tested as anode materials for LIBs, the NiFeO/rGO electrodes with carboxymethylcellulose (CMC) binder exhibited excellent lithium-storage performance including high reversible capacity, good cycling durability and high-rate capability. The capacity could be retained as high as 1105\ua0mAh\ua0g at a current density of 100\ua0mA\ua0g for over 50 cycles, even cycled at higher current density of 1000\ua0mA\ua0g, a capacity of 800\ua0mAh\ua0gcan be obtained, whereas the electrode with the polyvinylidene fluoride (PVDF) binder suffered from rapid capacity decay under the same test conditions. As a result, the NiFeO/rGO composites with CMC binder electrode in this work are promising as anodes for high-performance LIBs, resulting from the synergistic effect of optimal graphene content and proper choice of binder

Integrated CdTe PV glazing into windows: energy and daylight performance for different window-to-wall ratio

When integrated photovoltaics into building windows, the solar cells will absorb a fraction of solar radiation that hit on the window surface to generate electrical power and thus obstruct the solar energy and natural daylight that would have penetrated into inside space. In this paper, a window system integrated with thin film CdTe solar cells with 10% transparency was electrically characterised by Sandia model. The annual energy performance of a typical office with this PV window applied to different façade design was investigated using EnergyPlus under five typical climatic conditions in China. The dynamic daylight performance of the office has been assessed using RADIANCE. The result shows that when compared to a conventional double glazed system, the application of PV window can result in significant energy saving potential if the office has a relative large window-to-wall ratio (i.e. WWR≥45%). The simulation results also show that this PV window offers better daylight performance than conventional double-glazing

A Combined Approach of High-Throughput Sequencing and Degradome Analysis Reveals Tissue Specific Expression of MicroRNAs and Their Targets in Cucumber

MicroRNAs (miRNAs) are endogenous small RNAs playing an important regulatory function in plant development and stress responses. Among them, some are evolutionally conserved in plant and others are only expressed in certain species, tissue or developmental stages. Cucumber is among the most important greenhouse species in the world, but only a limited number of miRNAs from cucumber have been identified and the experimental validation of the related miRNA targets is still lacking. In this study, two independent small RNA libraries from cucumber leaves and roots were constructed, respectively, and sequenced with the high-throughput Illumina Solexa system. Based on sequence similarity and hairpin structure prediction, a total of 29 known miRNA families and 2 novel miRNA families containing a total of 64 miRNA were identified. QRT-PCR analysis revealed that some of the cucumber miRNAs were preferentially expressed in certain tissues. With the recently developed ‘high throughput degradome sequencing’ approach, 21 target mRNAs of known miRNAs were identified for the first time in cucumber. These targets were associated with development, reactive oxygen species scavenging, signaling transduction and transcriptional regulation. Our study provides an overview of miRNA expression profile and interaction between miRNA and target, which will help further understanding of the important roles of miRNAs in cucumber plants

Overexpression of brassinosteroid synthesis gene DWARF promotes resistance to Botrytis cinerea by inhibiting gibberellin synthesis in Solanum lycopersicum L.

Brassinosteroids (BRs) are a group of steroid hormones that play essential roles in plant growth and development. However, the roles of BRs in plant defense to pathogens are mainly studied in Arabidopsis, and there are few studies reporting the effects of BRs on plant resistance to Botrytis cinerea, an important pathogen in horticulture. Here, we found that high levels of BRs increased B. cinerea resistance in tomato (Solanum lycopersicum). Enhancing the expression of DWARF (DWF), a rate-limiting gene in BRs synthesis, in tomato resulted in a decrease in lesion area in detached leaf assay, and attenuated the leaf damages in the intact plants assay, as compared to wild type. Application of 24-epibrassinolide (EBL) at a saturation level also induced the B. cinerea resistance, with the upregulation of protease inhibitor encoding genes. Silencing of BAK1, which encodes the coreceptor of BR receptor BRI1 and the critical regulator of innate immunity, could not suppress BR-induced B. cinerea resistance. Interestingly, the bioactive gibberellins (GAs) were strongly decreased, while the expression of GAI, the tomato homologue of DELLA which suppresses GA signaling, was increased in DWF-OE plants. Silencing of GAI strongly compromised BR-induced B. cinerea resistance. The results indicated that increasing the BRs levels by either overexpression of DWF or application of high dose of EBL enhanced tomato resistance to B. cinerea. BRs levels exceeding the optimum may inhibit GA synthesis and signaling, and thus enhance the defense response

Biodegradable Polymeric Architectures via Reversible Deactivation Radical Polymerizations

Reversible deactivation radical polymerizations (RDRPs) have proven to be the convenient tools for the preparation of polymeric architectures and nanostructured materials. When biodegradability is conferred to these materials, many biomedical applications can be envisioned. In this review, we discuss the synthesis and applications of biodegradable polymeric architectures using different RDRPs. These biodegradable polymeric structures can be designed as well-defined star-shaped, cross-linked or hyperbranched via smartly designing the chain transfer agents and/or post-polymerization modifications. These polymers can also be exploited to fabricate micelles, vesicles and capsules via either self-assembly or cross-linking methodologies. Nanogels and hydrogels can also be prepared via RDRPs and their applications in biomedical science are also discussed. In addition to the synthetic polymers, varied natural precursors such as cellulose and biomolecules can also be employed to prepare biodegradable polymeric architectures

Light-induced excitation energy redistribution in Spirulina platensis cells: “spillover” or “mobile PBSs”?

AbstractState transitions induced by light and redox were investigated by observing the 77 K fluorescence spectra for the intact cells of Spirulina platensis. To clarify if phycobilisomes (PBSs) take part in the state transition, the contributions of PBSs to light-induced state transition were studied in untreated cells and the cells treated by betaine which fixed PBSs firmly on the thylakoid membranes. It was observed that the betaine-treated cells did not show any light-induced state transition. This result definitely confirmed that the light-induced excitation energy regulation between the two photosystems is mainly dependent on a spatial movement of PBSs on the thylakoid membranes, which makes PBS cores partially decoupled from photosystem II (PSII) while PBS rods more strongly coupled with photosystem I (PSI) during the transition from state 1 to state 2. On the other hand, an energy exchange between the two photosystems was observed in both untreated and betaine-treated cells during redox-induced state transition. These observations suggested that two different mechanisms were involved in the light-induced state transition and the redox-induced one. The former involves only a physical movement of PBSs, while the latter involves not only the movement of PBS but also energy spillover from PSII to PSI. A model for light-induced state transition was proposed based on the current results as well as well known knowledge

Preparation of cellulose based microspheres by combining spray coagulating with spray drying

Porous microspheres of regenerated cellulose with size in range of 1-2 μm and composite microspheres of chitosan coated cellulose with size of 1-3 μm were obtained through a two-step spray-assisted approach. The spray coagulating process must combine with a spray drying step to guarantee the formation of stable microspheres of cellulose. This approach exhibits the following two main virtues. First, the preparation was performed using aqueous solution of cellulose as precursor in the absence of organic solvent and surfactant; Second, neither crosslinking agent nor separated crosslinking process was required for formation of stable microspheres. Moreover, the spray drying step also provided us with the chance to encapsulate guests into the resultant cellulose microspheres. The potential application of the cellulose microspheres acting as drug delivery vector has been studied in two PBS (phosphate-buffered saline) solution with pH values at 4.0 and 7.4 to mimic the environments of stomach and intestine, respectively

The Band Structures of Zn1−xMgxO(In) and the Simulation of CdTe Solar Cells with a Zn1−xMgxO(In) Window Layer by SCAPS

Wider band-gap window layers can enhance the transmission of sunlight in the short-wavelength region and improve the performance of CdTe solar cells. In this work, we investigated the band structure of In-doped Zn1−xMgxO (ZMO:In) by using first-principles calculations with the GGA + U method and simulated the performance of ZMO:In/CdTe devices using the SCAPS program. The calculation results show that with the increased Mg doping concentration, the band gap of ZMO increases. However, the band gap of ZMO was decreased after In incorporation due to the downwards shifted conduction band. Owing to the improved short circuit current and fill factor, the conversion efficiency of the ZMO:In-based solar cells show better performance as compared with the CdS-based ones. A highest efficiency of 19.63% could be achieved owing to the wider band gap of ZMO:In and the appropriate conduction band offset (CBO) of ~0.23 eV at ZMO:In/CdTe interface when the Mg concentration x approaches 0.0625. Further investigations on thickness suggest an appropriate thickness of ZMO:In (x = 0.0625) in order to obtain better device performance would be 70–100 nm. This work provides a theoretical guidance for designing and fabricating highly efficient CdTe solar cells