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Users of big data analytics systems want the execution time of tasks to be as short as possible.However,during task execution,both network and computational moments may become resource bottlenecks that hinder task execution.Through the observation and analysis of the big data analysis system,the following conclusions are drawn:1)the data-parallel framework should switch between multiple working modes depending on the current resource bottlenecks;2)the scheduling of subtasks should fully consider the new tasks that may arrive in the future,not only the currently submitted tasks.Based on the above observations,a new task scheduling system Duopoly is designed and implemented,which consists of two parts:cans,a network scheduler that senses computational resources,and nats,a sub-task scheduler that senses network resources.The effectiveness of Duopoly is evaluated by small-scale physical clusters and large-scale simulation experiments,and the experimental results show that Duopoly can reduce the average task completion time by 37.30%~76.16% compared with existing work.

[Objectives] To improve the optimal content ratio of artificial dietfor adults of Coccinella septempunctata. [Methods] An artificial diet for adult was optimized by using an orthogonal design. Shrimp, pollen, lard, and honey were selected as the key factors, and their effects on adult weight gain, preoviposition, survival, egg production and incubation were assessed. [Results] The results showed that an increased shrimp content of 22.53% in the diet could increase weight gain, survival and egg production. Increased pollen content of 3.76% improved both survival and egg production, and shortened preoviposition. A lard content of 4.69% increased survival, and egg production and hatchability. A honey content of 6.89% could promote egg production and hatching rate of adult. The survival rate and hatchability of C. septempunctata fed the optimized diet were higher than that fed the basal diet (P>0.05), and the weight gain and fecundity of female adults were significantly increased (P<0.05), which were 128.15% and 122.15% higher than that fed the basal diet, respectively. The weight gain of female adults fed the optimized diet were higher than that fed the aphids (P>0.05); and the survival rate, fecundity and hatchability of female adults were reduced, which were 94.44%, 63.97% and 88.30% lower than that fed the aphids, respectively. [Conclusion] Compared with the basic diet, the artificial diet optimized by orthogonal design was suitable for feeding ladybird adults, which increased body weight, shortened preoviposition, and improved survival rate, egg production and hatching rate. Compared with aphid feeding, the survival rate, egg production and hatchability were reduced, the optimized diet needs further improvement. [ABSTRACT FROM AUTHOR]

A 3D printer nozzle has been designed in order to improve the degree of homogenisation of the material melt and to enhance the mixing performance of the material. Based on the principle of single-screw extrusion, it is proposed to add shear elements to the metering section of the screw appropriately, and the materials processed by the screw are selected according to the working characteristics of the screw. Taking polypropylene as the fluid research object, the finite element method is applied, combined with POLYFLOW software to simulate and analyse the extrusion process of polypropylene. The results show that the pressure field provided by the screw with shear elements is increased by approximately 0.399%, and the shear rate is increased by approximately 94% compared to a normal screw. By adding shear element, the pressure building ability of the screw can be improved, the smooth extrusion of the material can be promoted, the degree of melting and homogenization of the material can be effectively improved, and the utilization rate of the material in the printing process can be improved. [ABSTRACT FROM AUTHOR]

Background: Polarization of microglia, the resident retinal immune cells, plays important roles in mediating both injury and repair responses post-retinal ischemia–reperfusion (I/R) injury, which is one of the main pathological mechanisms behind ganglion cell apoptosis. Aging could perturb microglial balances, resulting in lowered post-I/R retinal repair. Young bone marrow (BM) stem cell antigen 1-positive (Sca-1+) cells have been demonstrated to have higher reparative capabilities post-I/R retinal injury when transplanted into old mice, where they were able to home and differentiate into retinal microglia. Methods: Exosomes were enriched from young Sca-1+ or Sca-1− cells, and injected into the vitreous humor of old mice post-retinal I/R. Bioinformatics analyses, including miRNA sequencing, was used to analyze exosome contents, which was confirmed by RT-qPCR. Western blot was then performed to examine expression levels of inflammatory factors and underlying signaling pathway proteins, while immunofluorescence staining was used to examine the extent of pro-inflammatory M1 microglial polarization. Fluoro-Gold labelling was then utilized to identify viable ganglion cells, while H&E staining was used to examine retinal morphology post-I/R and exosome treatment. Results: Sca-1+ exosome-injected mice yielded better visual functional preservation and lowered inflammatory factors, compared to Sca-1−, at days 1, 3, and 7 days post-I/R. miRNA sequencing found that Sca-1+ exosomes had higher miR-150-5p levels, compared to Sca-1− exosomes, which was confirmed by RT-qPCR. Mechanistic analysis found that miR-150-5p from Sca-1+ exosomes repressed the mitogen-activated protein kinase kinase kinase 3 (MEKK3)/JNK/c-Jun axis, leading to IL-6 and TNF-α downregulation, and subsequently reduced microglial polarization, all of which contributes to reduced ganglion cell apoptosis and preservation of proper retinal morphology. Conclusion: This study elucidates a potential new therapeutic approach for neuroprotection against I/R injury, via delivering miR-150-5p-enriched Sca-1+ exosomes, which targets the miR-150-5p/MEKK3/JNK/c-Jun axis, thereby serving as a cell-free remedy for treating retinal I/R injury and preserving visual functioning. [ABSTRACT FROM AUTHOR]

Achieving efficient blue electroluminescence (EL) remains the fundamental challenge that impedes perovskite light‐emitting diodes (PeLEDs) towards commercial applications. The bottleneck accounting for the inefficient blue PeLEDs is broadly attributed to the poor‐emissive blue perovskite emitters based on either mixed halide engineering or reduced‐dimensional strategy. Herein, we report the high‐performing sky‐blue PeLEDs (490 nm) with the maximum EQE exceeding 15 % by incorporating a molecular modifier, namely 4,4′‐Difluorophenone, for significantly suppressing the non‐radiative recombination and tuning of the low‐dimensional phase distribution of quasi‐2D blue perovskites, which represents a remarkable paradigm for developing the new generation of blue lighting sources. [ABSTRACT FROM AUTHOR]

Unreacted/excess lead iodide is considered to be the archcriminal for the rapid degradation of hybrid perovskite solar cells. Meanwhile, a high‐quality perovskite film with uniform and large grain size is the basis for high‐performance perovskite modules. Herein, a dual‐site molecular additive 4‐Aniline Sulfonic Acid (4A) is developed to regulate the unreacted/excess PbI2 and passivate defects through hydrogen bonding and intermolecular interactions between amino, and a sulfate groups and PbI2, respectively. Furthermore, the introduction of the 4A additive can induce perovskite seeds to grow uniformly on the substrate, yielding dense, uniform and defect‐less perovskite films with large grain sizes. This enables the fabrication of perovskite photovoltaics with a maximum power conversion efficiency of 24.09% (0.09 cm2) and 20.87% (16 cm2), respectively. This work demonstrated a new strategy to deposit high‐quality large‐scale perovskite films for photovoltaic modules. [ABSTRACT FROM AUTHOR]

Perovskite light-emitting diodes (PeLEDs) have recently captured tremendous research attention owing to their outstanding semiconductor properties such as tunable bandgap, high defect tolerance, efficient carrier mobility and narrow emission line width. Significant developments have been made in PeLEDs, achieving an external quantum efficiency of over 20%. However, there is still a long way to go for commercial applications. Recently, alkali metals (Li+, Na+, K+, Rb+ and Cs+) have been used to obtain high-performance perovskite light-emitting diodes, presenting a thriving development trend. Herein, we comprehensively summarize the roles of alkali metals in the field of PeLEDs for better performance. The background and foundational concepts of PeLEDs are presented, and we discuss the introduction of alkali metals into PeLEDs as an effective strategy for adjusting energy level alignment, improving perovskite film properties and optimizing device performance. The incorporation of alkali metal ions into the charge transport layer is mentioned, which has been neglected in previous studies on PeLEDs. Several studies on high-performance PeLEDs based on alkali metals are also highlighted, and the challenges and perspectives are addressed. [ABSTRACT FROM AUTHOR]

Compared with green and red perovskite light‐emitting diodes (PeLEDs), the development of blue PeLEDs has been lagging due to high defect density and inferior carrier transport. Herein, a novel defect‐passivation strategy is proposed to fabricate efficient sky‐blue PeLEDs by using isocyanate molecules. This strategy not only significantly reduces the nonradiative recombination loss caused by defects but also improves the injection and transport capacities of carriers by reducing the confinement effect. Benefiting from the passivation engineering and the reduction of confinement effect, the prepared sky‐blue PeLEDs present a significantly improved external quantum efficiency of 12.5% at 489 nm, which is 1.5 times higher than that of the control device. Meanwhile, the universality of isocyanate‐based passivators to improve the performance of PeLEDs is also demonstrated. The finding of this study provides a new reference for the selection of novel passivation agents to construct highly efficient blue PeLEDs. [ABSTRACT FROM AUTHOR]

The main reason for large energy loss in all‐inorganic perovskites is ascribed to the slow nucleation and fast crystallization of all‐inorganic perovskite films. Herein, a manipulating strategy is demonstrated to simultaneously realize rapid nucleation and slow crystal growth of CsPbI3 perovskite films by employing solvent molecular sieves in the antisolvent. First, the antisolvent treatment of mixed chlorobenzene and ethyl alcohol can induce the instantaneous supersaturation of perovskites to achieve rapid nucleation. Subsequently, the molecular layer of phthalimide (2‐N) molecules on the perovskite surface can be used as solvent molecular sieves to precisely control the evaporation of the solvent through molecule–solvent interactions. In addition, the molecules remaining on the surface can also effectively passivate the surface defects and improve the device performance. By this strategy, a synchronous regulation of rapid nucleation and slow crystal growth of perovskite films is realized for the first time. As a result, the CsPbI3 film with 2‐N treatment presents high‐quality crystallinity with large grains and less defects. The champion device exhibits an outdoor power conversion efficiency (PCE) up to 20.14% under AM1.5G illumination, and an indoor PCE up to 40.07% (Pout:133.9 µW cm–2) under a commonly used light‐emitting diode light source (2956 K, 1062 lux). [ABSTRACT FROM AUTHOR]

Metal halide perovskite materials have shown excellent optoelectronic properties suitable for light‐emitting diodes. With the development of technology in recent years, the performance of perovskite light‐emitting diodes (PeLEDs) has been improved rapidly, which can be almost comparable with that of the organic light‐emitting diodes (OLEDs) and quantum‐dot light‐emitting diodes counterparts. However, the toxicity of lead in perovskites may be unacceptable to consumers, which severely hinders the commercial applications of PeLEDs. Therefore, massive efforts on more environment‐friendly PeLEDs should be invested, prompting them potential candidates for next‐generation display devices. In this review, the synthesis methods and preparation processes of perovskite emitting layers that are successfully utilized in environment‐friendly PeLEDs are first summarized. Then, a comprehensive analysis of development on the applications of both less‐lead and lead‐free PeLEDs is reported. Finally, the possible strategies to further improve the performance of environment‐friendly PeLEDs are given. [ABSTRACT FROM AUTHOR]

We investigated the mechanism of hysteresis and uncontrolled deflection in jet vectoring control based on the Coanda effect. Thrust vectoring control based on the Coanda effect is highly applicable in the field of fluid dynamics because they can achieve jet deflection control with a simple geometric structure and low energy consumption. However, the hysteresis and uncontrolled deflection phenomena considerably hinder the practical application of these technologies. We designed a new passive fluidic thrust vectoring control model to analyze the mechanism of these disadvantages. We developed a synchronous pressure, force, and flow field measurement system to investigate the evolutions of flow structures and their effects on wall pressure distribution and vectoring force. The characteristics of the key flow structures, including the separation bubble, the secondary flow, and the backflow, were investigated. The transient features of jet attachment and jet detachment were researched to identify the transition of near-wall flow structures and wall pressure distribution during jet uncontrolled deflection. The mechanism of uncontrolled deflection is that the formation/breakdown of the separation bubble changes the flow state of the backflow, and the near-wall mass flux balance is collapsed. This causes a dramatic change in the jet vectoring angle, which is out of the valve's control. During attachment, the shear layer first touches the wall and forms a separation bubble, and then, the bubble shrinks. During detachment, the bubble first enlarges and then breaks down. Therefore, the formation and breakdown of the separation bubble correspond to different valve positions, which is the mechanism of hysteresis. [ABSTRACT FROM AUTHOR]

Compared with highly efficient green, red, and near-infrared perovskite light-emitting diodes (PeLEDs), the performance of blue PeLEDs is still unsatisfactory due to the serious spectral instability issue at high working voltages. In this work, a multidentate amine-based ligand with four amino groups is utilized to achieve spectral stable blue quasi-2D PeLEDs. As a result, the optimized quasi-2D perovskite films exhibit stable photoluminescence spectra under continuous UV illumination and heating. Finally, the blue quasi-2D PeLEDs emitting at 478 nm with the peak external quantum efficiency up to 4.8% are achieved. Meanwhile, there is no obvious peak shift of the electroluminescence spectral under high external working voltages, exhibiting excellent spectral stability. The findings in this work confirm the validity of this strategy, providing a strategy to achieve steady blue PeLEDs. [ABSTRACT FROM AUTHOR]

Oxidative dissolution of stibnite (Sb2S3), one of the most prevalent geochemical processes for antimony (Sb) release, can be promoted by Sb-oxidizing microbes, which were studied under alkaline and neutral conditions but rarely under acidic conditions. This work is dedicated to unraveling the enhancement mechanism of stibnite dissolution by typical acidophile Acidithiobacillus ferrooxidans under extremely acidic conditions. The results of solution behavior showed that the dissolution of Sb2S3 was significantly enhanced by A. ferrooxidans, with lower pH and higher redox potential values and higher [Sb(III)] and [Sb(V)] than the sterile control. The surface morphology results showed that the cells adsorbed onto the mineral surface and formed biofilms. Much more filamentous secondary minerals were formed for the case with A. ferrooxidans. Further mineral phase compositions and Sb/S speciation transformation analyses showed that more secondary products Sb2O3/SbO2−, Sb2O5/SbO3−, SO42−, as well as intermediates, such as S0, S2O32− were formed for the biotic case, indicating that the dissolution of Sb2S3 and the Sb/S speciation transformation was promoted by A. ferrooxidans. These results were further clarified by the comparative transcriptome analysis. This work demonstrated that through the interaction with Sb2S3, A. ferrooxidans promotes S/Sb oxidation, so as to enhance S/Sb transformation and thus the dissolution of Sb2S3. [ABSTRACT FROM AUTHOR]

Perovskite light-emitting diodes (PeLEDs) have attracted much attention in the past few years due to their excellent photoelectric performance. Owing to the advantages of adjustable bandgaps, high photoluminescence quantum yields, and excellent charge transfer properties, PeLEDs have emerged as next-generation candidates for use in light-emitting devices. However, efficiency and stability issues have always been problems restricting their development. Different approaches such as device structure optimization, interface engineering, solvent engineering, annealing treatment, additive engineering, and humidity control have been recently reported for overcoming the challenges facing PeLEDs. In this review, solvent-based strategies for obtaining high-performance perovskite light-emitting diodes are the main topic of discussion. In addition, an outlook focusing on solvent-based strategies to further enhance the performances of PeLEDs is proposed. [ABSTRACT FROM AUTHOR]

It is well known that speciation transformations of As(III) vs. As(V) in acid mine drainage (AMD) are mainly driven by microbially mediated redox reactions of Fe and S. However, these processes are rarely investigated. In this study, columns containing mine water were inoculated with two typical acidophilic Fe/S-oxidizing/reducing bacteria [the chemoautotrophic Acidithiobacillus (At.) ferrooxidans and the heterotrophic Acidiphilium (Aph.) acidophilum ], and three typical energy substrates (Fe2+, S0, and glucose) and two concentrations of As(III) (2.0 and 4.5 mM) were added. The correlation between Fe/S/As speciation transformation and bacterial depth distribution at three different depths, i.e., 15, 55, and 105 cm from the top of the columns, was comparatively investigated. The results show that the cell growth at the top and in the middle of the columns was much more significantly inhibited by the additions of As(III) than at the bottom, where the cell growth was promoted even on days 24–44. At. ferrooxidans dominated over Aph. acidophilum in most samples collected from the three depths, but the elevated proportions of Aph. acidophilum were observed in the top and bottom column samples when 4.5 mM As(III) was added. Fe2+ bio-oxidation and Fe3+ reduction coupled to As(III) oxidation occurred for all three column depths. At the column top surfaces, jarosites were formed, and the addition of As(III) could lead to the formation of the amorphous FeAsO4⋅2H2O. Furthermore, the higher As(III) concentration could inhibit Fe2+ bio-oxidation and the formation of FeAsO4⋅2H2O and jarosites. S oxidation coupled to Fe3+ reduction occurred at the bottom of the columns, with the formations of FeAsO4⋅2H2O precipitate and S intermediates. The formed FeAsO4⋅2H2O and jarosites at the top and bottom of the columns could adsorb to and coprecipitate with As(III) and As(V), resulting in the transfer of As from solution to solid phases, thus further affecting As speciation transformation. The distribution difference of Fe/S energy substrates could apparently affect Fe/S/As speciation transformation and bacterial depth distribution between the top and bottom of the water columns. These findings are valuable for elucidating As fate and toxicity mediated by microbially driven Fe/S redox in AMD environments. [ABSTRACT FROM AUTHOR]

Compared with red and green perovskite light‐emitting diodes (PeLEDs), blue PeLEDs are still unable to well control spectral stability due to the issues of ion migration and phase separation under external operating conditions. Herein, a strategy using organometallic ligands is reported to achieve spectrally stable PeLEDs. The obtained perovskite film exhibits stable photoluminescence spectra under UV excitation (365nm) and continuous heating of 70 °C. The device delivers an external quantum efficiency (EQE) of 6.7% with 50% lifetime (T50) of 21.6 min. Under high driving voltage (from 2 to 7.5 V), no obvious spectral shift has occurred for the electroluminescence spectrum at 481 nm. This work confirms the positive effect of organometallic ligands in quasi‐2D perovskite and provides a new idea for proposing effective ligands to act on the perovskite luminescence layer in the future. [ABSTRACT FROM AUTHOR]

The white-backed planthopper, Sogatella furcifera (Horváth), causes substantial damage to crops by direct feeding or virus transmission, especially southern rice black-streaked dwarf virus, which poses a serious threat to rice production. Cycloxaprid, a novel cis -nitromethylene neonicotinoid insecticide, has high efficacy against rice planthoppers, including imidacloprid-resistant populations. However, information about the influence of cycloxaprid on S. furcifera (Hemiptera: Delphacidae) at the molecular level is limited. Here, by de novo transcriptome sequencing and assembly, we constructed two transcriptomes of S. furcifera and profiled the changes in gene expression in response to cycloxaprid at the transcription level. We identified 157,906,456 nucleotides and 131,601 unigenes using the Illumina technology from cycloxaprid-treated and untreated S. furcifera. In total, 38,534 unigenes matched known proteins in at least one database, accounting for 29.28% of the total unigenes. The number of coding DNA sequences was 28,546 and that of amino acid sequences in the coding region was 22,299. In total, 15,868 simple sequence repeats (SSRs) were identified. The trinucleotide repeats accounted for 45.1% (7,157) of the total SSRs and (AAG/CTT) n were the most frequent motif. There were 359 differentially expressed genes that might have been induced by cycloxaprid. There were 131 upregulated and 228 downregulated genes. Twenty-two unigenes might be involved in resistance against cycloxaprid, such as cytochrome P450, glutathione S -transferase (GST), acid phosphatase (ACP), and cadherin. Our study provides vital information on cycloxaprid-induced resistance mechanisms, which will be useful to analyze the molecular mechanisms of cycloxaprid resistance and may lead to the development of novel strategies to manage S. furcifera. [ABSTRACT FROM AUTHOR]

In many real-world applications, different types of misclassification usually suffer from different costs, but the accurate cost is often hard to be determined and usually one can only get an interval-estimation like that one type of mistake is about 5 to 10 times more serious than the other type. On the other hand, there are usually abundant unlabeled data available, leading to great research effort about semi-supervised learning. It is noticeable that cost interval and unlabeled data usually appear simultaneously in practice tasks; however, there is rare study tackling them together. In this paper, we propose the cisLDM approach which is able to handle cost interval and exploit unlabeled data in a principled way. Rather than maximizing the minimum margin like traditional large margin classifiers, cisLDM tries to optimize the margin distribution on both labeled and unlabeled data when minimizing the worst-case total-cost and the mean total-cost simultaneously according to the cost interval. Experiments on a broad range of datasets and cost settings exhibit the impressive performance of cisLDM. In particular, cisLDM is able to reduce 47 percent more total-cost than standard SVM and 27 percent more total-cost than cost-sensitive semi-supervised SVM which assumes the true cost value is known in advance. [ABSTRACT FROM PUBLISHER]

Arsenic often coexists with metal sulfide minerals and occurs in different speciation and different toxicity in responding to Fe/S biooxidation. The differential inhibitive effects and fates of As(III) and As(V) during biooxidations of elemental sulfur (S0), ferrous ions (Fe2+) and pyrite (FeS 2) by Sulfobacillus thermosulfidooxidans were studied. The results revealed that the arsenic species hardly changed for the biooxidation of S0, but dramatically changed for the biooxidation of Fe2+ and FeS 2. Different transformation degree between As(III) and As(V) occurred for biooxidation of FeS 2 in the presence of arsenic, where about 72% of As(III) was transformed to As(V) for the group with As(III) added, and 16% of As(V) was transformed to As(III) for that with As(V) added. Both formation and dissolution of amorphous ferric arsenate occurred during biooxidation of FeS 2 with the addition of As(III) or As(V) and for the group grown on Fe2+ with added As(V), which were controlled by the changes of Fe/As molar ratio and pH value in the solution. Jarosite was detected for the group grown on Fe2+ and could adsorb As(III) and As(V). The inhibitive effects of As(V) were higher than As(III) when the strain grew on FeS 2 , which was contrary to those when the strain grew on S0 and Fe2+. The above results signify that the fates and inhibitive effects of arsenic are much related to each other, and such a relationship is significantly affected by the utilization of Fe/S energy substrates by the sulfur- and ferrous-oxidizing microorganisms. [Display omitted] • S0, Fe2+, FeS 2 - biooxidation mediated arsenic fates and inhibitions were studied. • The inhibitive effects and fates of arsenic are much co-related each other. • Transformation between As(III) and As(V) occurred under bio-oxidation of FeS 2. • As(V) is more inhibitive than As(III) under mediation of bio-oxidation of FeS 2. • Fe/As molar ratio plays key role in mediating arsenic fates and inhibitive effects. [ABSTRACT FROM AUTHOR]

Mechanical activation as a means of accelerating the mineral dissolution may play an important role in chalcopyrite bioleaching. In the present work, the mechanical activation by ball-milling with 10 min, 30 min, 60 min, 90 min, 120 min and 180 min time periods of bioleaching of chalcopyrite was studied, and then evaluated by a Density Functional Theory (DFT) calculation. The results showed that the specific surface area increased sharply in the very beginning of mechanical activation and then increased slowly until the agglomeration of the particles occurred, while the chalcopyrite lattices increased with the mechanical activation. The reaction activity analyzed by cyclic voltammetry (CV) increased slowly in 30 min, increased quickly in the following 90 min, and then decreased, while the hydrophobicity analyzed by contact angles of the chalcopyrite after activation showed less of a change. The results showed that after 15 days of bioleaching, the Cu leaching by Sulfobacillus thermosulfidooxidans (S. thermosulfidooxidans) increased from 9.39% in the 0 min of mechanical activation to 87.41% in the 120 min of mechanical activation, and the copper leaching rate increased by about 78%. The DFT results provide solid proof that the activated chalcopyrite can be adsorbed more easily by cells with higher adsorption energies and stronger bonds. [ABSTRACT FROM AUTHOR]

Pure molybdenum sheets were prepared by powder metallurgy and unidirectional rolling process. The microstructure, texture, grain orientation, mechanical properties and fracture mechanism of sintered samples were investigated. The results show that tensile strength and microhardness of 95% rolled sheet are 1028.095 ± 19.32 MPa and 323.2 ± 11.68 HV. The main texture components of (011)〈110〉 is Goss texture with reduction in the range of 70–95%. Two grain orientations of 〈111〉 fiber & 〈100〉 fiber and 〈100〉 fiber & 〈110〉 fiber are formed in the 47% and 95% rolled molybdenum sheets, respectively. Meanwhile, the fiber structure become more refined and oriented in the rolled molybdenum sheets when the rolling reduction is >87%. Brittle characteristics show typical cleavage failure. • Tensile strength and microhardness of 95% rolled sheet are 1028.095±19.32 MPa and 323.2±11.68 HV. • The main texture intensity value of Goss texture is 9.52 in the 95% rolled sheet. • Two grain orientations of <111> fiber & <100> fiber and <100> fiber & <110> fiber are formed in the 47% and 95% rolled molybdenum sheets, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Phylogenetic and expression analyses of all the 70 homeobox genes in peach fruits. • A homeobox gene, PpHB.G7, mediates ethylene biosynthesis during fruit ripening. • The PpHB.G7 could interact with the promoters of ethylene biosynthesis genes. • Seven HD-ZIP homeobox genes are differentially expressed in the developmental fruits. Abstract Homeobox transcription factors belong to a superfamily that has been widely studied in plant growth and development, but little is known regarding their role in fruit development and ripening. Using a genome-wide expression analysis of homeobox (HB) genes and quantitative real-time PCR, a HD-ZIP II member, PpHB.G7 , which presented higher levels of expression in ripening fruits than in developing fruits in all of the tested cultivars, was isolated from peach. Transient transformations showed that PpHB.G7 affects ethylene production and the expression of ethylene biosynthesis genes (PpACS1 and PpACO1). Both dual-luciferase and yeast one-hybrid assays confirmed that PpHB.G7 interacts with the promoters of PpACS1 and PpACO1. Thus, PpHB.G7 mediates ethylene biosynthesis by stimulating PpACS1 and PpACO1 activities. Furthermore, we also found that the other eight HB genes were differentially expressed in the developing fruits, with seven of these genes belonging to the HD-ZIP family. These results suggest that the HB genes in the HD-ZIP family play important roles in fruit development and ripening. [ABSTRACT FROM AUTHOR]