Energy Absorption and Failure Modes of Different Composite Open-Section Crush Elements under Axial Crushing Loading.

In order to study the energy absorption characteristics of the open-section thin-walled composite structures with different cross-sections, axial compression tests were carried out at loading speeds of 0.01 m/s, 0.1 m/s, and 1 m/s. Finite element models were built to predict the crushing response and energy absorption behaviors of these open-section structures. The effects of the cross-section's shape, cross-section aspect ratio, trigger mechanism, and loading speed on the energy absorption characteristics of the composite structures were analyzed. The results show that the average crushing loads of the hat-shaped and Ω-shaped open-section structures are 14.1% and 14.6% higher than those of C-shaped open-section structures, and the specific energy absorption (SEA) values are 14.3% and 14.8% higher than that of C-shaped open-section structures, respectively. For the C-shaped open-section structures, a 45° chamfer trigger is more effective in reducing the initial peak load, while a 15° steeple trigger is more appropriate for the hat-shaped open-section structures. The average crushing loads and SEA of C-shaped, hat-shaped, and Ω-shaped open-section structures are reduced when the loading speed is increased from 0.01 m/s to 1 m/s. The increase in loading speed leads to the splashing of debris and thus reduces the loading area and material utilization of open-section structures, leading to a decrease in energy absorption efficiency.

Construction of Inverse-Opal ZnIn2S4 with Well-Defined 3D Porous Structure for Enhancing Photocatalytic H2 Production.

The conversion of solar energy into hydrogen using photocatalysts is a pivotal solution to the ongoing energy and environmental challenges. In this study, inverse opal (IO) ZnIn2S4 (ZIS) with varying pore sizes is synthesized for the first time via a template method. The experimental results indicate that the constructed inverse opal ZnIn2S4 has a unique photonic bandgap, and its slow photon effect can enhance the interaction between light and matter, thereby improving the efficiency of light utilization. ZnIn2S4 with voids of 200 nm (ZIS-200) achieved the highest hydrogen production rate of 14.32 µ mol h-1. The normalized rate with a specific surface area is five times higher than that of the broken structures (B-ZIS), as the red edge of ZIS-200 is coupled with the intrinsic absorption edge of the ZIS. This study not only developed an approach for constructing inverse opal multi-metallic sulfides, but also provides a new strategy for enriching efficient ZnIn2S4-based photocatalysts for hydrogen evolution from water.

Compressive Fracture Behavior of Zirconia/Resin Composites Prepared by Fused Deposition Modeling Combined with Vacuum Infiltration.

Although bioceramic materials exhibit good biocompatibilities and bone conductivities, their high brittleness and low toughness properties limit their applications. Zirconia (ZrO2)/resin composites with idealized structures and properties were prepared by fused deposition modeling (FDM) combined with a vacuum infiltration process. The porous structure was prepared using the FDM three-dimensional printing technology, with granular zirconia as the raw material, and the relationship between the pore shape, pore size, and deformation was discussed. The results showed that square pores were more suitable than honeycomb pores for printing small pore sizes, and the resolution was high. Scanning electron microscopy observations showed that the superposition of multiple printing paths promoted the emergence of hole defects. The effects of the resin and the pore shape on the compressive strengths of the composites were studied. It was found that the compressive strengths of the honeycomb pore ZrO2/resin composites and porous ceramics were superior to those of the square pore samples. The introduction of the resin had a significant effect on the compressive strengths of the composites. The compressive strength increased in the direction perpendicular to the pores, while it decreased in the direction parallel to the pores.

Discovery of diverse Pectocaris species at the Cambrian series 2 Hongjingshao formation Xiazhuang section (Kunming, SW China) and its ecological, taphonomic, and biostratigraphic implications.

Pectocaris species are intermediate- to large-sized Cambrian bivalved arthropods. Previous studies have documented Pectocaris exclusively from the Cambrian Series 2 Stage 3 Chengjiang biota in Yu'anshan Formation, Chiungchussu Stage in SW China. In this study, we report Pectocaris paraspatiosa sp. nov., and three other previously known Pectocaris from the Xiazhuang section in Kunming, which belongs to the Hongjingshao Formation and is a later phase within Cambrian Stage 3 than the Yu'anshan Formation. The new species can be distinguished from its congeners by the sparsely arranged endopodal endites and the morphologies of the abdomen, telson, and telson processes. We interpret P. paraspatiosa sp. nov. as a filter-feeder and a powerful swimmer adapted to shallow, agitated environments. Comparison among the Pectocaris species reinforces previous views that niche differentiation had been established among the congeneric species based on morphological differentiation. Our study shows the comprehensive occurrences of Pectocaris species outside the Chengjiang biota for the first time. With a review of the shared fossil taxa of Chengjiang and Xiaoshiba biotas, we identify a strong biological connection between the Yu'anshan and Hongjingshao Formations.

Regulate transportation of ions and polysulfides in all-solid-state Li-S batteries using ordered-MOF composite solid electrolyte.

A dilemma arises when striving to balance the maximum desired ion conductivity and minimize the undesired lithium polysulfide shuttling effect for all-solid-state lithium-sulfur batteries (ASSLSBs). Here, we introduce a strategy of using ordered MIL-125-NH2 as fillers for poly(ethylene oxide)-based electrolytes to simultaneously regulate the transportation of lithium ions and polysulfides. When compared to electrolytes lacking metal-organic frameworks (MOFs) and those containing disordered MOFs, the electrolyte featuring an ordered-MOF structure, denoted as three-dimensional (3D) MPPL composite solid electrolyte (CSE), exhibits the highest ion conductivity of 8.3 × 10-4 siemens per centimeter at 60°C. As a result, pouch-type ASSLSBs with 3D MPPL CSE maintains stable cycling for 400 cycles at 0.5 C at 60°C, showcasing the successful implementation of this strategy in simultaneously regulating ion and polysulfide transport. This approach opens up alternative avenues to achieve high-performance ASSLSBs with exceptional energy density.

Genome-wide identification and comparative analysis of YABBY transcription factors in oil tea and tea tree.

The plant-specific transcription factor gene family, YABBY, plays an important role in plant development and stress response. Although YABBY genes have been identified in numerous species, a comprehensive characterization of YABBYs in tea tree and oil tea has been lacking. In this study, ten and three YABBY genes were identified in Camellia sinensis and C. oleifera, respectively. YABBY proteins could be divided into five subfamilies. Most YABBY genes in the same clade had similar structures and conserved motifs. Protein evolutionary analysis revealed that FIL/YAB3 displayed high conservation in all positions, followed by INO, YAB2, YAB5, and CRC. Specific site analysis suggested that the YABBY family was polyphyletic during the evolution. Compared to C. oleifera, two segmentally duplicated gene pairs were formed in C. sinensis during recent WGD events generated 30.69 and 45.08 Mya, respectively. Cis-acting element indicated that most YABBY genes contain box4, ARE, and MYB elements. A total of 120 SSR loci were found within CsYABBYs, consisting of six types, while 48 SSR loci were identified within CoYABBY, consisting of three types. Transcriptome results revealed that CRC and INO clades were specifically expressed in floral organs. The expression of CsYABBY10 and CsYABBY5 was significantly up-regulated under drought and salt treatments, respectively, as confirmed by qRT-PCR. CoYABBY genes were more susceptible to salt stress, as CoYABBY3 increased by about 15-fold. Furthermore, functional differentiation may have occurred in duplicated genes. These discoveries provide important information for further research on YABBYs in tea tree and oil tea. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03940-9.

Glycerol-3-phosphate acyltransferase 3-mediated lipid droplets accumulation confers chemoresistance of colorectal cancer.

Colorectal cancer (CRC) is the third most common malignancy worldwide. It is well known that lipid metabolism reprogramming contributes to the tumor progression. However, the lipid metabolic alterations and potential remodeling mechanism underlying the chemoresistance of CRC remain largely unclear. In this study, we compared the gene expression profiles of chemoresistant versus control CRC cells from the GEO database and identified a key factor, Glycerol-3-phosphate acyltransferase 3 (GPAT3), that promotes lipid droplet (LD) production and confers chemoresistance of CRC. With applying of HPLC-MS and molecular dynamics simulation, we also demonstrated that the activity of lysophosphatidic acid synthesis by GPAT3 was dependent on its acetylation at K316 site. In particular, GPAT3-mediated LD accumulation inhibited immunogenic cell death of tumor, and thus facilitated CD8+ T-cell exhaustion and malignant progression in mouse xenografts and hepatic-metastasis tumors in CRC patients. High GPAT3 expression turned CRC cells into nonimmunogenic cells after (Oxaliplatin) Oxa treatment, which was supported by a decrease in cytotoxic IFN-γ release and CD8+ T-cell exhaustion. In conclusion, these findings revealed the role of GPAT3-associated LD accumulation, which conferred a malignant phenotype (chemoresistance) and regulated the tumor microenvironment of CRC. These results suggest that GPAT3 is a potential target to enhance CRC chemosensitivity and develop novel therapeutic interventions.

Atomically Dispersed ZnN4 Sites Anchored on P-Functionalized Carbon with Hierarchically Ordered Porous Structures for Boosted Electroreduction of CO2.

Tuning the coordination structures of metal sites is intensively studied to improve the performances of single-atom site catalysts (SASC). However, the pore structure of SASC, which is highly related to the accessibility of active sites, has received little attention. In this work, single-atom ZnN4 sites embedded in P-functionalized carbon with hollow-wall and 3D ordered macroporous structure (denoted as H-3DOM-ZnN4 /P-C) are constructed. The creation of hollow walls in ordered macroporous structures can largely increase the external surface area to expose more active sites. The introduction of adjacent P atoms can optimize the electronic structure of ZnN4 sites through long-rang regulation to enhance the intrinsic activity and selectivity. In the electrochemical CO2 reduction reaction, H-3DOM-ZnN4 /P-C exhibits high CO Faradaic efficiency over 90% in a wide potential window (500 mV) and a large turnover frequency up to 7.8 × 104  h-1 at -1.0 V versus reversible hydrogen electrode, much higher than its counterparts without the hierarchically ordered structure or P-functionalization.

Decreased grey matter volume in dorsolateral prefrontal cortex and thalamus accompanied by compensatory increases in middle cingulate gyrus of premature ejaculation patients.

INTRODUCTION: The prefrontal-cingulate-thalamic areas are associated with ejaculation control. Functional abnormalities of these areas and decreased grey matter volume (GMV) in the subcortical areas have been confirmed in premature ejaculation (PE) patients. However, no study has explored the corresponding GMV changes in the prefrontal-cingulate-thalamic areas, which are considered as the important basis for functional abnormalities. This study aimed to investigated whether PE patients exhibited impaired GMV in the brain, especially the prefrontal-cingulate-thalamic areas, and whether these structural deficits were associated with declined ejaculatory control. METHODS: T1-weighted structural magnetic resonance imaging (MRI) data were acquired from 50 lifelong PE patients and 50 age-, and education-matched healthy controls (HCs). The PE diagnostic tool (PEDT) was applied to assess the subjective symptoms of PE. Based on the method of voxel-based morphometry (VBM), GMV were measured and compared between groups. In addition, the correlations between GMV of brain regions showed differences between groups and PEDT scores were evaluated in the patient group. RESULTS: PE patients showed decreased GMV in the right dorsolateral superior frontal gyrus (clusters = 13, peak T-values = -4.30) and left thalamus (clusters = 47, T = -4.33), and increased GMV in the left middle cingulate gyrus (clusters = 12, T = 4.02) when compared with HCs. In the patient group, GMV of the left thalamus were negatively associated with PEDT scores (r = -0.35; P = 0.01). Receiver operating characteristic (ROC) analysis showed that GMV of the right dorsolateral superior frontal gyrus (AUC = 0.71, P < 0.01, sensitivity = 60%, specificity = 78%), left thalamus (AUC = 0.72, P < 0.01, sensitivity = 92%, specificity = 46%) and middle cingulate gyrus (AUC = 0.69, P < 0.01, sensitivity = 50%, specificity = 90%), and the combined model (AUC = 0.84, P < 0.01, sensitivity = 78%, specificity = 80%) all had the ability to distinguish PE patients from HCs. CONCLUSION: Disturbances in GMV were revealed in the prefrontal-cingulate-thalamic areas of PE patients. The findings implied that decreased GMV in the dorsolateral prefrontal cortex and thalamus might be associated with the central pathological neural mechanism underlying the declined ejaculatory control while increased GMV in the middle cingulate gyrus might be the compensatory mechanism underlying PE.

Herpetogaster collinsi from the Cambrian of China elucidates the dispersal and palaeogeographic distribution of early deuterostomes and the origin of the ambulacrarian larva.

The Cambrian Radiation represents one of the largest diversification events in Earth history. While the resulting taxonomic diversity is exceptional, relatively few of these novel species can be traced outside the boundaries of a single palaeocontinent. Many of those species with cosmopolitan distributions were likely active swimmers, presenting opportunity and means to conquer new areas, but this would not have been the case for sessile organisms. Herpetogaster is a lower to middle Cambrian (Series 2-Miaolingian, Stage 3-Wuliuan) genus of sessile, stalked, filter-feeding deuterostomes with two species, H. collinsi and H. haiyanensis, known respectively from Laurentia and Gondwana. Here, we expand the distribution of H. collinsi to Gondwana with newly discovered specimens from the Balang Formation of Hunan, China. This discovery raises questions on the origin of the genus and how sessile organisms were able to disperse over such a broad distance in the lower Cambrian. As Herpetogaster has been recovered at the base of the Ambulacrarian tree in recent phylogenies, a planktonic larval stage is suggested, which implies, that the last common ancestor of the Ambulacraria might have already had planktonic larvae or that such larvae developed multiple times within the Ambulacraria.

Diagnostic error and bias in the department of radiology: a pictorial essay.

Diagnostic imaging is an essential and indispensable part of medical diagnosis and treatment, and diagnostic errors or biases are also common in the department of radiology, sometimes even having a severe impact on the diagnosis and treatment of patients. There are various reasons for diagnostic errors or biases in imaging. In this review, we analyze and summarize the causes of diagnostic imaging errors and biases based on practical cases. We propose solutions for dealing with diagnostic imaging errors and reducing their probability, thereby helping radiologists in their clinical practice.Critical relevance statement Diagnostic errors or bias contribute to most medical errors in the radiology department. Solutions for dealing with diagnostic imaging errors are pivotal for patients.Key points• Diagnostic errors or bias contribute to most medical errors in radiology department.• Solutions for dealing with diagnostic imaging errors are pivotal for patients.• This review summarizes the causes of diagnostic errors and offers solutions to them.

Defect Engineered Metal-Organic Framework with Accelerated Structural Transformation for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) have been increasingly applied in oxygen evolution reaction (OER), and the surface of MOFs usually undergoes structural transformation to form metal oxyhydroxides to serve as catalytically active sites. However, the controllable regulation of the reconstruction process of MOFs remains as a great challenge. Here we report a defect engineering strategy to facilitate the structural transformation of MOFs to metal oxyhydroxides during OER with enhanced activity. Defective MOFs (denoted as NiFc'x Fc1-x ) with abundant unsaturated metal sites are constructed by mixing ligands of 1,1'-ferrocene dicarboxylic acid (Fc') and defective ferrocene carboxylic acid (Fc). NiFc'x Fc1-x series are more prone to be transformed to metal oxyhydroxides compared with the non-defective MOFs (NiFc'). Moreover, the as-formed metal oxyhydroxides derived from defective MOFs contain more oxygen vacancies. NiFc'Fc grown on nickel foam exhibits excellent OER catalytic activity with an overpotential of 213 mV at the current density of 100 mA cm-2 , superior to that of undefective NiFc'. Experimental results and theoretical calculations suggest that the abundant oxygen vacancies in the derived metal oxyhydroxides facilitate the adsorption of oxygen-containing intermediates on active centers, thus significantly improving the OER activity.

Three-Dimensional (3D) Ordered Macroporous Bimetallic (Mn,Fe) Selenide/Carbon Composite with Heterojunction Interface for High-Performance Sodium Ion Batteries.

Transition-metal selenides have captured significant research attention as anode materials for sodium ion batteries (SIBs) due to their high theoretical specific capacities and excellent electronic conductivity. However, volumetric expansion and inferior cycle life still hinder their practical application. Herein, a three-dimensional (3D) ordered macroporous bimetallic (Mn,Fe) selenide modified by a carbon layer (denoted as 3DOM-MnFeSex@C) composite containing a heterojunction interface is fabricated through selenizing a 3D ordered macroporous Mn-based Prussian Blue analogue single crystal. The 3DOM-MnFeSex@C exhibits hierarchically porous architecture with enhanced mass-transfer efficiency; MnSe and FeSe2 particles are encapsulated into macroporous carbon framework, which can significantly promote the electronic conductivity and maintain the structural integrity. The density functional theory calculation indicates that the heterojunction interface between MnSe and FeSe2 has been successfully engineered so that Na+ can be readily adsorbed and rapidly converted, thus promoting the reaction kinetics and extending the cyclic life. As expected, the 3DOM-MnFeSex@C composite delivers excellent rate performance (277.6 mA h g-1 at 10 A g-1), and prolonged cycling life (191.6 mA h g-1 even after 1000 cycles at 2 A g-1) as a sodium storage anode. The sodium storage mechanism of the composite was further investigated by in situ X-ray diffraction and ex situ high-resolution transmission electron microscopy characterization techniques.

Correction: Catalytically active designer crown-jewel Pd-based nanostructures encapsulated in metal-organic frameworks.

Correction for 'Catalytically active designer crown-jewel Pd-based nanostructures encapsulated in metal-organic frameworks' by Liyu Chen et al., Chem. Commun., 2017, 53, 1184-1187, https://doi.org/10.1039/C6CC09270E.

Induction of Axillary Bud Swelling of Hevea brasiliensis to Regenerate Plants through Somatic Embryogenesis and Analysis of Genetic Stability.

To overcome rubber tree (RT) tissue culture explant source limitations, the current study aimed to establish a new Hevea brasiliensis somatic embryogenesis (SE) system, laying the technical foundation for the establishment of an axillary-bud-based seedling regeneration system. In this study, in vitro plantlets of Hevea brasiliensis Chinese Academy of Tropical Agricultural Sciences 917 (CATAS 917) were used as the experimental materials. Firstly, the optimum conditions for axillary bud swelling were studied; then, the effects of phenology, the swelling time of axillary buds (ABs), and medium of embryogenic callus induction were studied. Plantlets were obtained through somatic embryogenesis. Flow cytometry, inter-simple sequence repeat (ISSR molecular marker) and chromosome karyotype analysis were used to study the genetic stability of regenerated plants along with budding seedlings (BSs) and secondary somatic embryo seedlings (SSESs) as the control. The results show that the rubber tree's phenology period was mature, and the axillary bud induction rate was the highest in the 2 mg/L 6-benzyladenine (6-BA) medium (up to 85.83%). Later, 3-day-old swelling axillary buds were used as explants for callogenesis and somatic embryogenesis. The callus induction rate was optimum in MH (Medium in Hevea) + 1.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) + 1.5 mg/L 1-naphthalene acetic acid (NAA) + 1.5 mg/L Kinetin (KT) + 70 g/L sucrose (56.55%). The regenerated plants were obtained after the 175-day culture of explants through callus induction, embryogenic callus induction, somatic embryo development, and plant regeneration. Compared with the secondary somatic embryo seedling control, axillary bud regeneration plants (ABRPs) were normal diploid plants at the cellular and molecular level, with a variation rate of 7.74%.

Low-coordinated Co-N3 sites induce peroxymonosulfate activation for norfloxacin degradation via high-valent cobalt-oxo species and electron transfer.

The identification of reactive species in peroxymonosulfate (PMS) activation triggered by carbon-based single atom catalysts is the key to reveal the pollutant degradation mechanism. Herein, carbon-based single atom catalyst with low-coordinated Co-N3 sites (CoSA-N3-C) was synthesized to active PMS for norfloxacin (NOR) degradation. The CoSA-N3-C/PMS system exhibited consistent high performance for oxidizing NOR over a wide pH range (3.0-11.0). The system also achieved complete NOR degradation in different water matrixes, high cycle stability and excellent degradation performance for other pollutants. Theoretical calculations confirmed that the catalytic activity was derived from the favorable electron density of low-coordinated Co-N3 configuration, which was more conductive to PMS activation than other configurations. Electron paramagnetic resonance spectra, in-situ Raman analysis, solvent exchange (H2O to D2O), salt bridge and quenching experiments concluded that high-valent cobalt(IV)-oxo species (56.75%) and electron transfer (41.22%) contributed dominantly to NOR degradation. Moreover, 1O2 was generated in the activation process while not involved in pollutant degradation. This research demonstrates the specific contributions of nonradicals in PMS activation over Co-N3 sites for pollutant degradation. It also offers updated perceptions for rational design of carbon-based single atom catalysts with appropriate coordination structure.

A Janus heteroatom-doped carbon electrocatalyst for hydrazine oxidation.

The trade-off between the intrinsic activity and electronic conductivity of carbon materials is a major barrier for electrocatalysis. We report a Janus-type carbon material combining electrically conductive nitrogen-doped carbon (NC) and catalytically active boron, nitrogen co-doped carbon (BNC). The integration of NC with BNC can not only ensure high electronic conductivity of the hybrid, but also achieve an enhancement in the intrinsic activity of the BNC side due to the electron redistribution on their coupling interfaces. In the electrocatalytic hydrazine oxidation reaction (HzOR), the Janus carbon electrocatalyst exhibits superior activity than their single counterparts and simple physical mixtures. Density functional theory calculations reveal that the NC/BNC interfaces simultaneously promote efficient electron transport and decrease the free energy of the rate-determining step in the HzOR process.

Hierarchically Ordered Macro-Mesoporous Electrocatalyst with Hydrophilic Surface for Efficient Oxygen Reduction Reaction.

Metal-organic frameworks (MOFs) offer versatile templates/precursors to prepare supported metal catalysts. However, the afforded catalysts usually exhibit microporous structures and unsuitable wettability, which will restrict the accessibility of active sites in liquid-phase reactions. Herein, an etching-functionalization strategy is developed for the construction of a tannic-acid-functionalized MOF with a unique hollow-wall and 3D-ordered macroporous (H-3DOM) structure. The functional MOF can be further employed as an ideal precursor for the synthesis of cobalt supported on oxygen/nitrogen-co-doped carbon composites with H-3DOM structures, and hydrophilic surface. The H-3DOM structure can improve the external surface area to maximize the exposure of active sites. Moreover, the oxygen-containing functional groups can enhance the surface wettability to guarantee the external active sites to be more electrochemically accessible in aqueous electrolyte. Benefitting from these outstanding characteristics, H-3DOM-Co/ONC exhibits high electrocatalytic activity in the oxygen reduction reaction, superior to its counterparts without the hierarchically ordered structure and surface functionalization.

Impact of COVID-19 on traffic safety from the "Lockdown" to the "New Normal": A case study of Utah.

During the past several years, the COVID-19 pandemic has had pronounced impacts on traffic safety. Existing studies found that the crash frequency was reduced and the severity level was increased during the earlier "Lockdown" period. However, there is a lack of studies investigating its impacts on traffic safety during the later stage of the pandemic. To bridge such a gap, this study selects Salt Lake County, Utah as the study area and employs statistical methods to investigate whether the impact of COVID-19 on traffic safety differs among different stages. Negative binomial models and binary logit models were utilized to study the effects of the pandemic on the crash frequency and severity respectively while accounting for the exposure, environmental, and human factors. Welch's t-test and Pairwise t-test are employed to investigate the possible indirect effect of the pandemic by influencing other non-pandemic-related factors in the statistical models. The results show that the crash frequency is significantly less than that of the pre-pandemic during the whole course of the pandemic. However, it significantly increases during the later stage due to the relaxed restrictions. Crash severity levels were increased during the earlier pandemic due to the increased traffic speed, the prevalence of DUI, reduced use of seat belts, and increased presence of commercial vehicles. It reduced to a level comparable to the pre-pandemic later, owing to the reduction of speed and increased seat-belt-used to the pre-pandemic level. As for the incoming "New Normal" stage, stakeholders may need to take actions to deter DUI and reduce commercial-vehicle-related crashes to improve traffic safety.

The MAX2-KAI2 module promotes salicylic acid-mediated immune responses in Arabidopsis.

Arabidopsis MORE AXILLARY GROWTH2 (MAX2) is a key component in the strigolactone (SL) and karrikin (KAR) signaling pathways and regulates the degradation of SUPPRESSOR OF MAX2 1/SMAX1-like (SMAX1/SMXL) proteins, which are transcriptional co-repressors that regulate plant architecture, as well as abiotic and biotic stress responses. The max2 mutation reduces resistance against Pseudomonas syringae pv. tomato (Pst). To uncover the mechanism of MAX2-mediated resistance, we evaluated the resistance of various SL and KAR signaling pathway mutants. The resistance of SL-deficient mutants and of dwarf 14 (d14) was similar to that of the wild-type, whereas the resistance of the karrikin insensitive 2 (kai2) mutant was compromised, demonstrating that the KAR signaling pathway, not the SL signaling pathway, positively regulates the immune response. We measured the resistance of smax1 and smxl mutants, as well as the double, triple, and quadruple mutants with max2, which revealed that both the smax1 mutant and smxl6/7/8 triple mutant rescue the low resistance phenotype of max2 and that SMAX1 accumulation diminishes resistance. The susceptibility of smax1D, containing a degradation-insensitive form of SMAX1, further confirmed the SMAX1 function in the resistance. The relationship between the accumulation of SMAX1/SMXLs and disease resistance suggested that the inhibitory activity of SMAX1 to resistance requires SMXL6/7/8. Moreover, the exogenous application of KAR2 enhanced resistance against Pst, but KAR-induced resistance depended on salicylic acid (SA) signaling. Inhibition of karrikin signaling delayed SA-mediated defense responses and inhibited pathogen-induced protein biosynthesis. Together, we propose that the MAX2-KAI2-SMAX1 complex regulates resistance with the assistance of SMXL6/7/8 and SA signaling and that SMAX1/SMXLs possibly form a multimeric complex with their target transcription factors to fine tune immune responses.