Autophagy-related protein PlATG2 regulates the vegetative growth, sporangial cleavage, autophagosome formation, and pathogenicity of peronophythora litchii.

Autophagy is an intracellular degradation process that is important for the development and pathogenicity of phytopathogenic fungi and for the defence response of plants. However, the molecular mechanisms underlying autophagy in the pathogenicity of the plant pathogenic oomycete Peronophythora litchii, the causal agent of litchi downy blight, have not been well characterized. In this study, the autophagy-related protein ATG2 homolog, PlATG2, was identified and characterized using a CRISPR/Cas9-mediated gene replacement strategy in P. litchii. A monodansylcadaverine (MDC) staining assay indicated that deletion of PlATG2 abolished autophagosome formation. Infection assays demonstrated that ΔPlatg2 mutants showed significantly impaired pathogenicity in litchi leaves and fruits. Further studies have revealed that PlATG2 participates in radial growth and asexual/sexual development of P. litchii. Moreover, zoospore release and cytoplasmic cleavage of sporangia were considerably lower in the ΔPlatg2 mutants than in the wild-type strain by FM4-64 staining. Taken together, our results revealed that PlATG2 plays a pivotal role in vegetative growth, sporangia and oospore production, zoospore release, sporangial cleavage, and plant infection of P. litchii. This study advances our understanding of the pathogenicity mechanisms of the phytopathogenic oomycete P. litchii and is conducive to the development of effective control strategies.

Operation-robust SiO2-based memristive application in air.

In recent years, neuromorphic computing is recognized as a promising path to further improve the efficiency of integrated computing system in the post-Moore era, relying on its high parallelism. As a key fundamental element in hardware-implementing neuromorphic system, the synaptic device has made substantial research progress. Among these, SiO2 trapping-based memristive devices generally have systematically integrated merits, such as ease of fabrication and high CMOS process compatibility, but electrochemical activity to oxygen makes them unreliable for operating in air. Here, by using ultrathin Si3N4 as a physical isolation layer, we have obtained a robust memristive device based on SiO2 trapping although operating in air. Further study of Si3N4 thickness dependence has demonstrated that 7 nm is suggested as the most favorable thickness for reliable and flexible programming, and that an inherent isolating mechanism is 'switching-on' for an electron but 'switching-off' for large-sized oxygen molecules. Based on a device with 7 nm Si3N4, we have mimicked various modes of synaptic plasticities. These results could thus not only increase the prospects of using SiO2 trapping in memristive applications but also provide an effective path to improve the robustness of these SiO2-based applications against ambient air.

PlAtg8-mediated autophagy regulates vegetative growth, sporangial cleavage, and pathogenesis in Peronophythora litchii.

IMPORTANCE: Peronophythora litchii is the pathogen of litchi downy blight, which is the most serious disease in litchi. Autophagy is an evolutionarily conserved catabolic process in eukaryotes. Atg8 is a core protein of the autophagic pathway, which modulates growth and pathogenicity in the oomycete P. litchii. In P. litchii, CRISPR/Cas9-mediated knockout of the PlATG8 impaired autophagosome formation. PlATG8 knockout mutants exhibited attenuated colony expansion, sporangia production, zoospore discharge, and virulence on litchi leaves and fruits. The reduction in zoospore release was likely underpinned by impaired sporangial cleavage. Thus, in addition to governing autophagic flux, PlAtg8 is indispensable for vegetative growth and infection of P. litchii.

Doping-modulated lateral asymmetric Schottky diode as a high-performance self-powered synaptic device.

In the post-Moore era, the gradually saturated computational capability of conventional digital computers showing the opposite trend as the exponentially increasing data volumes imperatively required a platform or technology to break this bottleneck. Brain-inspired neuromorphic computing promises to inherently improve the efficiency of information processing and computation by means of the highly parallel hardware architecture to reduce global data transmission. Here, we demonstrate a compact device technology based on the barrier asymmetry to achieve zero-consumption self-powered synaptic devices. In order to tune the device behaviors, the typical chemical doping is used to tailor the asymmetry for energy harvesting. Finally, in our demonstrated devices, the open-circuit voltage (VOC) and power-conversion efficiency (PCE) can be modulated up to 0.77 V and 6%, respectively. Optimized photovoltaic features affords synaptic devices with an outstanding programming weight states, involving training facilitation, stimulus reinforce and consolidation. Based on self-powered system, this work further presents a highly available modulation scheme, which achieves excellent device behaviors while ensuring the zero-energy consumption.

Mn-Oxygen Compounds Coordinated Ruthenium Sites with Deprotonated and Low Oxophilic Microenvironments for Membrane Electrolyzer-Based H2 -Production.

Among the platinum-group metals, ruthenium (Ru), with a low water dissociation energy, is considered a promising alternative to substitute Pt for catalyzing hydrogen evolution reaction (HER). However, optimizing the adsorption-desorption energies of H* and OH* intermediates on Ru catalytic sites is extremely desirable but remains challenging. Inspired by the natural catalytic characteristics of Mn-oxygen complex, this study reports to design Mn-oxygen compounds coordinated Ru sites (MOC-Ru) with deprotonated and low oxophilic microenvironments for modulating the adsorption-desorption of H* and OH* to promote HER kinetics. Benefiting from the unique advantages of MOC structures, including weakened HOH bond at interface, electron donation ability, and deprotonation capability, the MOC-Ru exhibits extremely low overpotential and ultralong stability in both acidic and alkaline electrolytes. Experimental observations and theoretical calculations elucidate that the MOC can accelerate water dissociation kinetics and promote OH* desorption in alkaline conditions and trigger the long-range H* spillover for H2 -release in acid conditions. The outstanding activity and stability of membrane electrolyzer display that the MOC-Ru catalyst holds great potential as cathode for H2 -production. This study provides essential insights into the crucial roles of deprotonated and low oxophilic microenvironments in HER catalysis and offers a new pathway to create an efficient water-splitting cathode.

Metal Alloys-Structured Electrocatalysts: Metal-Metal Interactions, Coordination Microenvironments, and Structural Property-Reactivity Relationships.

Metal alloys-structured electrocatalysts (MAECs) have made essential contributions to accelerating the practical applications of electrocatalytic devices in renewable energy systems. However, due to the complex atomic structures, varied electronic states, and abundant supports, precisely decoding the metal-metal interactions and structure-activity relationships of MAECs still confronts great challenges, which is critical to direct the future engineering and optimization of MAECs. Here, this timely review comprehensively summarizes the latest advances in creating the MAECs, including the metal-metal interactions, coordination microenvironments, and structure-activity relationships. First, the fundamental classification, design, characterization, and structural reconstruction of MAECs are outlined. Then, the electrocatalytic merits and modulation strategies of recent breakthroughs for noble and non-noble metal-structured MAECs are thoroughly discussed, such as solid solution alloys, intermetallic alloys, and single-atom alloys. Particularly, unique insights into the bond interactions, theoretical understanding, and operando techniques for mechanism disclosure are given. Thereafter, the current states of diverse MAECs with a unique focus on structural property-reactivity relationships, reaction pathways, and performance comparisons are discussed. Finally, the future challenges and perspectives for MAECs are systematically discussed. It is believed that this comprehensive review can offer a substantial impact on stimulating the widespread utilization of metal alloys-structured materials in electrocatalysis.

IrPd Nanoalloy-Structured Bifunctional Electrocatalyst for Efficient and pH-Universal Water Splitting.

The lack of high efficiency and pH-universal bifunctional electrocatalysts for water splitting to hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) hinders the large-scale production of green hydrogen. Here, an IrPd electrocatalyst supported on ketjenblack that exhibits outstanding bifunctional performance for both HER and OER at wide pH conditions is presented. The optimized IrPd catalyst exhibits a specific activity of 4.46 and 3.98 A mgIr -1 in the overpotential of 100 and 370 mV for HER and OER, respectively, in alkaline conditions. When applied to the anion exchange membrane electrolyzer, the Ir44 Pd56 /KB catalyst shows a stability of >20 h at a current of 250 mA cm-2 for water decomposition, indicating promising prospects for practical applications. Beyond offering an advanced electrocatalyst, this work also guides the rational design of desirable bifunctional electrocatalysts for HER and OER by regulating the microenvironments and electronic structures of metal catalytic sites for diverse catalysis.

Electronic Structure-Dependent Water-Dissociation Pathways of Ruthenium-Based Catalysts in Alkaline H2 -Evolution.

Ruthenium (Ru)-based catalysts have displayed compelling hydrogen evolution activities, which hold the promising potential to substitute platinum in alkaline H2 -evolution. In the challenging alkaline electrolytes, the water-dissociation process involves multistep reactions, while the profound origin and intrinsic factors of diverse Ru species on water-dissociation pathways and reaction principles remain ambiguous. Here the fundamental origin of water-dissociation pathways of Ru-based catalysts in alkaline media to be from their unique electronic structures in complex coordination environments are disclosed. These theoretical results validate that the modulated electronic structures with delocalization-localization coexistence at their boundaries between the Ru nanocluster and single-atom site have a profound influence on water-dissociation pathways, which push H2 O* migration and binding orientation during the splitting process, thus enhancing the dissociation kinetics. By creating Ru catalysts with well-defined nanocluster, single-atom site, and also complex site, the electrocatalytic data shows that both the nanocluster and single-atom play essential roles in water-dissociation, while the complex site possesses synergistically enhanced roles in alkaline electrolytes. This study discloses a new electronic structure-dependent water-dissociation pathway and reaction principle in Ru-based catalysts, thus offering new inspiration to design efficient and durable catalysts for the practical production of H2 in alkaline electrolytes.

Modulating Electronic Environment of Ru Nanoclusters via Local Charge Transfer for Accelerating Alkaline Water Electrolysis.

Compared to platinum catalysts, ruthenium (Ru) is disclosed as a promising alternative for alkaline water electrolysis due to its similar hydrogen adsorption energy and relatively lower water dissociation barrier. However, in the challenging alkaline media, the dissatisfied Volmer step during water dissociation of Ru metal prohibits its practical applications. Here, a new pathway to modulate the electronic environment of Ru catalysts via a local charge transfer strategy for tuning the water dissociation kinetics and accelerating the alkaline water electrolysis is proposed. The obtained catalysts are engineered by assembling and subsequently pyrolyzing the layer-stacked and 2D porphyrin-based Ru-N coordination polymers on nanocarbon supports. Benefiting from the well-defined Ru nanocluster-Nx -coordination bonds (Runc -Nx ), unique electronic environments, and local charge transfer properties, the catalysts exhibit the exceptional activity of 17 mV overpotential at 10 mA cm-2 and robust stability in water, which is more efficient than state-of-the-art Ru catalysts. The theoretical calculation suggests that the Runc -Nx sites enhance the nucleophilic attack of water and weaken the HOH bond. This study manifests that tailoring the bond environments of Ru clusters can significantly modulate their intrinsic catalytic activities and stabilities, which may open new avenues for developing high-active and durable catalysts for water electrolysis.

Crystalline Lattice-Confined Atomic Pt in Metal Carbides to Match Electronic Structures and Hydrogen Evolution Behaviors of Platinum.

Platinum-based catalysts occupy a pivotal position in diverse catalytic applications in hydrogen chemistry and electrochemistry, for instance, the hydrogen evolution reactions (HER). While adsorbed Pt atoms on supports often cause severe mismatching on electronic structures and HER behaviors from metallic Pt due to the different energy level distribution of electron orbitals. Here, the design of crystalline lattice-confined atomic Pt in metal carbides using the Pt-centered polyoxometalate frameworks with strong PtO-metal covalent bonds is reported. Remarkably, the lattice-confined atomic Pt in the tungsten carbides (Ptdoped @WCx , both Pt and W have atomic radii of 1.3 Å) exhibit near-zero valence states and similar electronic structures as metallic Pt, thus delivering matched energy level distributions of the Pt 5dz 2 and H 1s orbitals and similar acidic hydrogen evolution behaviors. In alkaline conditions, the Ptdoped @WCx exhibits 40 times greater mass activity (49.5 A mgPt -1 at η = 150 mV) than the Pt@C because of the favorable water dissociation and H* transport. These findings offer a universal pathway to construct urgently needed atomic-scale catalysts for broad catalytic reactions.

Tizoxanide Promotes Apoptosis in Glioblastoma by Inhibiting CDK1 Activity.

The antiparasitic drug nitazoxanide (NTZ) has received considerable attention for its potential in cancer therapy. In this study, we demonstrate that tizoxanide (TIZ), an active metabolite of NTZ, exhibits antiglioma activity in vitro and in vivo by inducing G2/M cell cycle arrest and apoptosis. In vitro, TIZ dose-dependently inhibited the proliferation of U87, U118, and A172 human glioblastoma (GBM) cells at 48 h with IC50 values of 1.10, 2.31, and 0.73 µM, respectively. Treatment with TIZ (1 and 10 µM) also dose-dependently inhibited the colony formation of these GBM cells and accumulated ROS damage in the nucleus. In silico target fishing combined with network pharmacological disease spectrum analyses of GBM revealed that cycle-dependent kinase 1 (CDK1) is the most compatible target for TIZ and molecular docking by Molecule Operating Environment (MOE) software confirmed it. Mechanistically, TIZ inhibited the phosphorylation of CDK1 at Thr161 and decreased the activity of the CDK1/cyclin B1 complex, arresting the cell cycle at the G2/M phase. TIZ may induce apoptosis via the ROS-mediated apoptotic pathway. In vivo, TIZ suppressed the growth of established subcutaneous and intracranial orthotopic xenograft models of GBM without causing obvious side effects and prolonged the survival of nude mice bearing glioma. Taken together, our results demonstrated that TIZ might be a promising chemotherapy drug in the treatment of GBM.

A Putative P-Type ATPase Regulates the Secretion of Hydrolytic Enzymes, Phospholipid Transport, Morphogenesis, and Pathogenesis in Phytophthora capsici.

Phytophthora capsici is an important plant pathogenic oomycete with multiple hosts. The P4-ATPases, aminophospholipid translocases (APTs), play essential roles in the growth and pathogenesis of fungal pathogens. However, the function of P4-ATPase in P. capsici remains unclear. This study identified and characterized PcApt1, a P4-ATPase Drs2 homolog, in P. capsici. Deletion of PcAPT1 by CRISPR/Cas9 knock-out strategy impaired hyphal growth, extracellular laccase activity. Cytological analyses have shown that PcApt1 participates in phosphatidylserine (PS) transport across the plasma membrane. Also, we showed that targeted deletion of PcAPT1 triggered a significant reduction in the virulence of P. capsici. Secretome analyses have demonstrated that secretion of hydrolytic enzymes decreased considerably in the PcAPT1 gene deletion strains compared to the wild-type. Overall, our results showed that PcApt1 plays a pivotal role in promoting morphological development, phospholipid transport, secretion of hydrolytic enzymes, and the pathogenicity of the polycyclic phytopathogenic oomycete P. capsici. This study underscores the need for comprehensive evaluation of subsequent members of the P-type ATPase family to provide enhanced insights into the dynamic contributions to the pathogenesis of P. capsici and their possible deployment in the formulation of effective control strategies.

A Library of ROS-Catalytic Metalloenzyme Mimics with Atomic Metal Centers.

MetalN-coordinated centers supported by carbonaceous substrates have emerged as promising artificial metalloenzymes (AMEs) to mimic the biocatalytic effects of their natural counterparts. However, the synthesis of well-defined AMEs that contain different atomic metalN centers but present similar physicochemical and coordination structures remains a substantial challenge. Here, 20 different types of AMEs with similar geometries and well-defined atomic metalN-coordinated centers are synthesized to compare and disclose the catalytic activities, substrate selectivities, kinetics, and reactive oxygen species (ROS) products. Their oxidase (OXD)-, peroxidase (POD)-, and halogen peroxidase (HPO)-mimetic catalytic behaviors are systematically explored. The Fe-AME shows the highest OXD- and HPO-mimetic activities compared to the other AMEs due to its high vmax (0.927 × 10-6 m s-1 ) and low Km (1.070 × 10-3 m), while the Cu-AME displays the best POD-like performance. Furthermore, theoretical calculation reveals that the ROS-catalytic paths and activities are highly related to the electronic structures of the metal centers. Benefiting from its facile adsorption of H2 O2 molecule and lower energy barrier to generating •O2 - , the Fe-AME displays higher ROS-catalytic performances than the Mn-AME. The engineered AMEs show not only remarkably high ROS-catalytic performances but also provide new guidance toward developing metalN-coordinated biocatalysts for broad application fields.

The Small GTPase FgRab1 Plays Indispensable Roles in the Vegetative Growth, Vesicle Fusion, Autophagy and Pathogenicity of Fusarium graminearum.

Rab GTPases are key regulators of membrane and intracellular vesicle transports. However, the biological functions of FgRab1 are still unclear in the devastating wheat pathogen Fusarium graminearum. In this study, we generated constitutively active (CA) and dominant-negative (DN) forms of FgRAB1 from the wild-type PH-1 background for functional analyses. Phenotypic analyses of these mutants showed that FgRab1 is important for vegetative growth, cell wall integrity and hyphal branching. Compared to the PH-1 strain, the number of spores produced by the Fgrab1DN strain was significantly reduced, with obviously abnormal conidial morphology. The number of septa in the conidia of the Fgrab1DN mutant was fewer than that observed in the PH-1 conidia. Fgrab1DN was dramatically reduced in its ability to cause Fusarium head blight symptoms on wheat heads. GFP-FgRab1 was observed to partly localize to the Golgi apparatus, endoplasmic reticulum and Spitzenkörper. Furthermore, we found that FgRab1 inactivation blocks not only the transport of the v-SNARE protein FgSnc1 from the Golgi to the plasma membrane but also the fusion of endocytic vesicles with their target membranes and general autophagy. In summary, our results indicate that FgRab1 plays vital roles in vegetative growth, conidiogenesis, pathogenicity, autophagy, vesicle fusion and trafficking in F. graminearum.

Assembling and Regulating of Transition Metal-Based Heterophase Vanadates as Efficient Oxygen Evolution Catalysts.

Developing efficient, durable, and low-cost earth-abundant elements-based oxygen evolution reaction (OER) catalysts by rapid and scalable strategies is of great importance for future sustainable electrochemical hydrogen production. The earth-abundant high-valency metals, especially vanadium, can modulate the electronic structure of 3d metal oxides and oxyhydroxides and offer the active sites near-optimal adsorption energies for OER intermediates. Here, the authors propose a facile assembling and regulating strategy to controllably synthesize a serial of transition metal (CoFe, NiFe, and NiCo)-based vanadates for efficient OER catalysis. By tuning the reaction concentrations, NiFe-based vanadates with different crystallinities can be facilely regulated, where the catalyst with moderate heterophase (mixed crystalline and amorphous structures) shows the best OER catalytic activity in terms of low overpotential (267 mV at the current density of 10 mA cm-2 ), low Tafel slope (38 mV per decade), and excellent long-term durability in alkaline electrolyte, exceeding its noble metal-based counterparts (RuO2 ) and most current existing OER catalysts. This work not only reports a facile and controllable method to synthesize a series of vanadates-based catalysts with heterophase nanostructures for high-performance OER catalysis, but also may expand the scope of designing cost-effective transition metal-based electrocatalysts for water splitting.

Trans-spectral vector beam nonlinear conversion via parametric four-wave mixing in alkali vapor.

Coherent frequency conversion of vector beams (VBs) without distorting their intensity profile or spatial polarization distribution is important for novel applications in quantum and classical regimes. Here, we experimentally and theoretically investigate VB transfer from near-infrared to blue light using a Sagnac interferometer, combining the parametric four-wave mixing process in atomic vapor. The vector probe beam is converted into a completely different wavelength, and the vector mode of the generated blue beam is highly similar to the incident probe beam. These results may provide a feasible solution for communication interfaces in classical and quantum science fields based on atomic ensembles.

Trehalose Phosphate Synthase Complex-Mediated Regulation of Trehalose 6-Phosphate Homeostasis Is Critical for Development and Pathogenesis in Magnaporthe oryzae.

Trehalose biosynthesis pathway is a potential target for antifungal drug development, and trehalose 6-phosphate (T6P) accumulation is widely known to have toxic effects on cells. However, how organisms maintain a safe T6P level and cope with its cytotoxicity effects when accumulated have not been reported. Herein, we unveil the mechanism by which the rice blast fungus Magnaporthe oryzae avoids T6P accumulation and the genetic and physiological adjustments it undergoes to self-adjust the metabolite level when it is unavoidably accumulated. We found that T6P accumulation leads to defects in fugal development and pathogenicity. The accumulated T6P impairs cell wall assembly by disrupting actin organization. The disorganization of actin impairs the distribution of chitin synthases, thereby disrupting cell wall polymer distribution. Additionally, accumulation of T6P compromise energy metabolism. M. oryzae was able to overcome the effects of T6P accumulation by self-mutation of its MoTPS3 gene at two different mutation sites. We further show that mutation of MoTPS3 suppresses MoTps1 activity to reduce the intracellular level of T6P and partially restore ΔMotps2 defects. Overall, our results provide insights into the cytotoxicity effects of T6P accumulation and uncover a spontaneous mutation strategy to rebalance accumulated T6P in M. oryzae. IMPORTANCE M. oryzae, the causative agent of the rice blast disease, threatens rice production worldwide. Our results revealed that T6P accumulation, caused by the disruption of MoTPS2, has toxic effects on fugal development and pathogenesis in M. oryzae. The accumulated T6P impairs the distribution of cell wall polymers via actin organization and therefore disrupts cell wall structure. M. oryzae uses a spontaneous mutation to restore T6P cytotoxicity. Seven spontaneous mutation sites were found, and a mutation in MoTPS3 was further identified. The spontaneous mutation in MoTPS3 can partially rescue ΔMotps2 defects by suppressing MoTps1 activity to alleviate T6P cytotoxicity. This study provides clear evidence for better understanding of T6P cytotoxicity and how the fungus protects itself from T6P's toxic effects when it has accumulated to severely high levels.

Anchoring Fe-N-C Sites on Hierarchically Porous Carbon Sphere and CNT Interpenetrated Nanostructures as Efficient Cathodes for Zinc-Air Batteries.

Engineering efficient zinc-air batteries have attracted tremendous attention because of their essential role in the field of renewable energy systems. However, the sluggish reaction kinetics of the oxygen reduction reaction (ORR) at the air cathode impair the battery performance significantly. Recently, metal-N-C-based porous carbon nanoarchitectures have emerged as promising ORR electrocatalysts in zinc-air batteries. Herein, taking advantage of metal-organic complexation and mesoporous silica templates, we successfully anchor Fe-N-C sites on hierarchically porous carbon sphere and carbon nanotube interpenetrated nanostructures (Fe-N-C/HPCS@CNT) to serve as efficient cathodes for zinc-air batteries. Benefiting from its synergistic effects between the highly active Fe-N-C sites, ultrahigh surface areas, and unique hierarchically porous nanostructures, Fe-N-C/HPCS@CNT exhibits preferable ORR performance (E1/2 = 0.873 V) compared to commercial Pt/C (E1/2 = 0.841 V). Most importantly, when used as a cathode catalyst for homemade zinc-air batteries, Fe-N-C/HPCS@CNT exhibits gratifying peak power density (164.0 mW cm-2), large specific capacity (762.0 mAh g-1), superior long-term stability, extraordinary rate capability, and excellent charge/discharge performance. We believe that this report will not only offer new insights into the design of Fe-N-C-based catalysts but also promote the practical utilization of Fe-N-C-based cathodes for a wide range of energy applications.

Activity Trends and Mechanisms in Peroxymonosulfate-Assisted Catalytic Production of Singlet Oxygen over Atomic Metal-N-C Catalysts.

We synthesized a series of carbon-supported atomic metal-N-C catalysts (M-SACs: M=Mn, Fe, Co, Ni, Cu) with similar structural and physicochemical properties to uncover their catalytic activity trends and mechanisms. The peroxymonosulfate (PMS) catalytic activity trends are Fe-SAC>Co-SAC>Mn-SAC>Ni-SAC>Cu-SAC, and Fe-SAC displays the best single-site kinetic value (1.65×105  min-1 mol-1 ) compared to the other metal-N-C species. First-principles calculations indicate that the most reasonable reaction pathway for 1 O2 production is PMS→OH*→O*→1 O2 ; M-SACs that exhibit moderate and near-average Gibbs free energies in each reaction step have a better catalytic activity, which is the key for the outstanding performance of Fe-SACs. This study gives the atomic-scale understanding of fundamental catalytic trends and mechanisms of PMS-assisted reactive oxygen species production via M-SACs, thus providing guidance for developing M-SACs for catalytic organic pollutant degradation.