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Summary: Leaf senescence is a complex process strictly regulated by various external and endogenous factors. However, the key signaling pathway mediating leaf senescence remains unknown.Here, we show that Arabidopsis SPX1/2 negatively regulate leaf senescence genetically downstream of the strigolactone (SL) pathway. We demonstrate that the SL receptor AtD14 and MAX2 mediate the age‐dependent degradation of SPX1/2.Intriguingly, we uncover an age‐dependent accumulation of SLs in leaves via transcriptional activation of SL biosynthetic genes by the transcription factors (TFs) SPL9/15. Furthermore, we reveal that SPX1/2 interact with the WRKY75 subclade TFs to inhibit their DNA‐binding ability and thus repress transcriptional activation of salicylic acid (SA) biosynthetic gene SA Induction‐Deficient 2, gating the age‐dependent SA accumulation in leaves at the leaf senescence onset stage.Collectively, our new findings reveal a signaling pathway mediating sequential activation of SL and salicylate biosynthesis for the onset of leaf senescence in Arabidopsis. [ABSTRACT FROM AUTHOR]

The BRASSINAZOLE‐RESISTANT 1 (BZR1) transcription factor family plays an essential role in plant brassinosteroid (BR) signaling, but the signaling mechanism through which BZR1 and its homologs cooperate with certain coactivators to facilitate transcription of target genes remains incompletely understood. In this study, we used an efficient protein interaction screening system to identify blue‐light inhibitor of cryptochromes 1 (BIC1) as a new BZR1‐interacting protein in Arabidopsis thaliana. We show that BIC1 positively regulates BR signaling and acts as a transcriptional coactivator for BZR1‐dependent activation of BR‐responsive genes. Simultaneously, BIC1 interacts with the transcription factor PIF4 to synergistically and interdependently activate expression of downstream genes including PIF4 itself, and to promote plant growth. Chromatin immunoprecipitation assays demonstrate that BIC1 and BZR1/PIF4 interdependently associate with the promoters of common target genes. In addition, we show that the interaction between BIC1 and BZR1 is evolutionally conserved in the model monocot plant Triticum aestivum (bread wheat). Together, our results reveal mechanistic details of BR signaling mediated by a transcriptional activation module BIC1/BZR1/PIF4 and thus provide new insights into the molecular mechanisms underlying the integration of BR and light signaling in plants. Synopsis: BZR1 and PIF4 are core transcription factors in brassinosteroid (BR) and light signaling, respectively. Here, Blue‐light Inhibitor of Cryptochromes 1 (BIC1) is found as a common coactivator linking BZR1 and PIF4 to synergistically and interdependently activate transcription of common target genes and promote cell elongation. BIC1 positively regulates BR responses.BIC1 interacts with BZR1 and PIF4 to synergistically co‐activate transcription of target genes, including PIF4 itself.BIC1 and BZR1/PIF4 interdependently associate with the promoters of common target genes.The interaction between BIC1 and BZR1 is evolutionally conserved in monocot and dicot plants. [ABSTRACT FROM AUTHOR]

• A new calibration method of non-source temperature area is proposed. • A modified exponential function model with quadratic polynomial is derived. • The extrapolation range of the model is given. For the temperature measurement of high temperature targets, the use of multispectral pyrometers has a great advantage. However, with the increase of the measured target temperature, the research on the high-precision calibration method in the non-source temperature area falls far behind. Therefore, in order to break through the bottleneck of the calibration method of the non-source temperature area for high temperature targets, a new non-source temperature area calibration method is proposed in this paper. In this method, a temperature-gray/voltage (T - G / U) model based on the modified exponential function is established by using the close relationship between the change trend of the extrapolated temperature curve and the modified exponential curve model. There will be a large error in the prediction of the high temperature section in the non-source temperature area, so a quadratic polynomial term with error compensation is introduced on the basis of this model. The method of fitting estimation is employed to obtain the estimated temperature value of the predicted point in the high temperature section of the non-source temperature area. For the prediction of the entire non-source temperature area, the genetic algorithm is used to adaptively select the model parameter t , and the high-precision extrapolation calibration of the high temperature target in the entire non-source temperature area is realized. Both theoretical and experimental data verify the effectiveness and feasibility of the new method. [ABSTRACT FROM AUTHOR]

Low water availability is a major abiotic factor limiting photosynthesis and the growth and yield of crops. Maize ( Zea mays ) is among the most drought-sensitive cereal crops. Herein, the physiological and proteomic changes of maize seedlings caused by polyethylene-glycol-induced water deficit were analyzed. The results showed that malondialdehyde and proline contents increased continuously in the treated seedlings. Soluble sugar content and superoxide dismutase activity were upregulated initially but became downregulated under prolonged water deficit. A total of 104 proteins were found to be differentially accumulated under water stress. The identified proteins were mainly involved in photosynthesis, carbohydrate metabolism, stress defense, energy production, and protein metabolism. Interestingly, substantial incongruence between protein and transcript levels was observed, indicating that gene expression in water-stressed maize seedlings is controlled by complex mechanisms. Finally, we propose a hypothetical model that includes the different molecular, physiological, and biochemical changes that occurred during the response and tolerance of maize seedlings to water deficiency. Our study provides valuable insight for further research into the overall mechanisms underlying drought response and tolerance in maize and other plants. [ABSTRACT FROM AUTHOR]

Jet electrochemical deposition is a relatively new technology for selective electrochemical deposition. Its advantages include high deposition accuracy and a quick deposition rate. However, the hydrogen embrittlement phenomenon and tip effect during the deposition process become more obvious when using jet electrochemical deposition to obtain higher deposited layer quality. To improve this phenomenon, we developed pulse-assisted technology based on the jet electrochemical deposition process. Its benefit is that the deposition rate is successfully increased while the diffusion layer thickness is reduced further, assuring deposited layer uniformity and compactness and so improving deposited layer quality. By using an orthogonal test, the effect of current density, pulse duty cycle, and pulse frequency on the microstructure and microhardness of the Ni–P deposited layer was investigated, and the ideal process parameters were identified preliminarily. In this study, SEM and hardness tester were used to evaluate the surface morphology and microhardness of the deposited layer. The results revealed that the Ni–P deposited layer has a better microscopic shape and a higher microhardness of 670HV when the current density is 30A/dm2, the pulse duty ratio is 60%, and the pulse frequency is 1500 Hz. The control variable method was used to further explore the influence of pulse frequency on the properties of the deposited layer and compared with the Ni–P deposited layer prepared under the condition of DC jet electrochemical deposition. The results show that the introduction of pulse technology is of great help to improve the quality of Ni–P deposited layers prepared by jet electrochemical deposition. With the increase of the pulse frequency, the surface defects are reduced, the density is enhanced, and the toughness and corrosion resistance are improved. When the pulse frequency is 1500 Hz, the resistance to deformation is the best, and the elastic recovery ratio he/hmax reaches the maximum at this time, and its value is 0.336. At the same time, the Ni–P deposition layer has good corrosion performance under this condition. The corrosion potential and corrosion current density measured in 3.5% sodium chloride solution are − 0.33 V and 1.04 × 10–6 A/cm2, respectively. [ABSTRACT FROM AUTHOR]

To improve the comprehensive performance of the material surface in the complex working environment, Ni–P–Al2O3–PTFE nanocomposite coatings were prepared by a pulsed electrodeposition process in this study. The effects of pulsed duty ratio on the microscopic morphology and mechanical properties of the prepared composite coatings were investigated. The microstructure and element content of the composite coatings were evaluated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD). The microhardness, wear resistance and elastic–plastic properties of the composite coatings were analyzed by Vickers hardness tester, rotary friction and wear tester and nanoindentation tester, respectively. The results show that the introduction of pulsed current can improve the surface quality of composite coatings, a lower pulse duty ratio can increase the nucleation rate, hinder grain growth and obtain the nanocomposite coatings with sufficient grain refinement. When the pulse duty ratio is 30%, the surface morphology of composite coating is excellent, the deposition rate reaches 14.94 μm/h, the microhardness reaches the maximum value of 671 HV, the friction coefficient reaches the minimum value of 0.0923, the elastic recovery ratio he/hmax reached the maximum value of 0.34, and the ratio of H3/E2 reached the maximum value of 0.046. The combination of hard Al2O3 nanoparticles and solid self-lubricating polytetrafluoroethylene (PTFE) particles can significantly improve the comprehensive performance of nanocomposite coatings, and the results of this study can provide theoretical and technical support for the preparation of multi-nanoparticle synergistic enhanced Ni–P-based composite coatings. [ABSTRACT FROM AUTHOR]

High-speed electrochemical discharge drilling (ECDD) offers substantial benefits for efficient, high-quality fabrication of film cooling holes. One shortfall of this technique is the lack of a visual model for simulations. The determination of optimal machining parameters predominantly depends on trial-and-error methodologies. In order to develop a visual model for simulations, an in-depth analysis of the machining mechanism is necessary. This entails direct observation of the machining phenomena and a thorough understanding of the surface topography evolution processes. The study focuses on machining Ni-based single-crystal materials that are used in turbine blades, employing experiments to investigate the material removal mechanism. Based on the relevant conclusions, a visualized simulation model is developed for the first time. The results show that discharge and electrochemical dissolution occur alternately at the microscopic level. Besides, the discharge in low conductivity solutions is similar to pure electrical discharge drilling (EDD) rather than a gas film discharge. Discrepancies in the elemental distribution of the matrix and recast layer cause changes in the electrochemical dissolution behavior. The current efficiency of the recast layer is significantly lower than that of the matrix. Based on the mechanistic exploration, this study integrates discrete discharge with continuous electrochemical dissolution to construct a visual model of high-speed ECDD, by leveraging a dead grid method and explicit differential. This model can precisely anticipate the distribution of the recast layer and the diameter of the hole, thereby contributing valuable insights towards achieving zero recast layer machining and enhancing the use of ECDD in the aerospace industry. [Display omitted] • Developing a simulation model to achieve the prediction of ECDD. • Discharge and electrochemical dissolution is alternating happen. • No gas film discharge occurs by high-speed photography. • Various of electrochemical dissolution morphology between recast layer and matrix. • The current efficiency of the recast layer is lower than that of the matrix. [ABSTRACT FROM AUTHOR]