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Reaction-bonded silicon carbide (RB-SiC) is an important optical material used widely in the aerospace industry. The machining accuracy of RB-SiC optical elements must satisfy the requirements of high-performance system development. However, RB-SiC is typically hard and brittle, making precise machining difficult. Thus, the material removal and synergistic deformation mechanisms of SiC and silicon (Si) must be investigated for ultraprecision machining. In-situ laser-assisted diamond cutting is an effective method for the ultraprecision cutting of hard and brittle materials. In this research, we investigated the influence of temperature on the material deformation process in detail. Firstly, the physical properties of RB-SiC, including its hardness and depth of plastic deformation, were investigated through high-temperature nano-indentation experiments. Furthermore, grooving experiments were carried out to investigate the brittle-to-ductile transition under ordinary and in-situ laser-assisted diamond cutting, respectively. Finally, the deformation of the machined surface/subsurface was revealed via scanning electron microscopy and transmission electron microscopy observations. [ABSTRACT FROM AUTHOR]

• In-situ laser assisted diamond cutting was utilized for fused silica. • Temperature dependence of thermal parameters identified by algorithm. • The validity of temperature simulations was corroborated experimentally. • A Sa of 12.9 nm could be obtained under the optimized process parameters. Fused silica is typically a difficult material to machine using conventional methods due to its high brittleness and hardness, despite its significance in optical systems such as high-power lasers and astronomical telescopes. Laser assisted diamond cutting has emerged as a promising and cost-effective alternative for machining fused silica. This study investigated the machinability and thermal response of fused silica during in-situ laser assisted diamond cutting through finite element analysis and cutting experiments. The temperature dependence of thermal parameters, identified by Beetle Antennae Search, was taken into consideration in the thermal model. To minimize surface roughness and determine the optimal machining parameters, various methods were employed, including analysis of variance, signal-to-noise ratio, and Particle Swarm Optimization coupled with Artificial Neural Network. The results indicated that various factors involved in in-situ laser assisted diamond cutting had a significant impact on the thermal response of fused silica, resulting in different surface roughness. Among these factors, spindle speed, feed speed, cutting depth, and laser power contributed to surface roughness by 17.34 %, 12.28 %, 12.03 %, and 48.31 %, respectively. By utilizing the optimal combination of parameters, which comprised a spindle speed of 2700 rpm, feed speed of 1.7 mm/min, cutting depth of 2.7 μm, and laser power of 12.5 W, a smooth surface finish of Sa 12.9 nm could be obtained. [ABSTRACT FROM AUTHOR]

In this paper, a novel miniaturized planar antipodal Vivaldi antenna (AVA) with high gain and back radiation reduction for 5G millimeter‐wave (mm‐Wave) communication is presented. First, due to the use of the gradual corrugated edges (GCE), the operating band of the antenna is extended in the direction of lower frequencies and the overall gain is also improved as well. Second, its gain of the antenna is better enhanced at the high frequency band through I‐Shape Metal Director (IMD). Lastly, to further reduce the back radiation, the split ring resonance branches (SRB) are added to the ground. The antenna front‐back ratio has improved considerably to over 20 dB. Meanwhile the antenna gain is improved further. Furthermore, a prototype antenna array was fabricated and the measurement results clearly show that the antenna array gain varies in the range of 15.86–16.43 dB when operating in the 5G millimeter wave band (24.75–28.35 GHz). [ABSTRACT FROM AUTHOR]

In order to study the internal flow characteristics and external droplet velocity distribution characteristics of the swirl nozzle, the following methods were used: numerical simulations were used to study the internal flow characteristics of a swirl nozzle and phase Doppler particle velocimetry was used to determine the corresponding external droplet velocity distribution under medium and low pressure conditions. The distributions of pressure and water velocity inside the nozzle were obtained. Meanwhile, the velocities of droplets outside the nozzle in different sections were discussed. The results show that the flow rate in the swirl nozzle increases with the increase in inlet pressure, and the local pressure in the region decreases because of the excessive velocity at the internal outlet section of the swirl nozzle, resulting in cavitation. The experimental results show that under an external flow field, the minimum droplet velocity occurs in the axial direction; starting from the axis, the velocity first increases and then decreases along the radial direction. Swirling motion inside the nozzle and velocity variations in the external flow field occur under medium and low pressure conditions. The relationship between the inlet pressure and the distributions of water droplets' velocities was established, which provides a reference for the research and development of the swirl nozzle. [ABSTRACT FROM AUTHOR]

• Peroxidases produce o -quinones and form black or brown deleterious pigments. • Structure and catalytic sites of peroxidase from 'Zhongshu 1′ sweet potato were resolved. • Ascorbic acid, sodium metabisulfite, glutathione inhibited browning of sweet potato. • Mechanism and type between peroxidase and inhibitors were revealed by molecular docking. Browning is an obstacle in industrial development of sweet potato. Peroxidase from sweet potato cv. 'Zhongshu 1′ was purified and analyzed by chromatography and mass spectrometry. Peroxidase from 'Zhongshu 1′ sweet potato was a monomeric protein with 37.2 kDa. A binding site of peroxidase to guaiacol was discovered using molecular docking, with Arg61 and Ala191 being near the active region important for guaiacol catalysis. The IC 50 values of ascorbic acid, sodium metabisulfite and glutathione were (1.97 ± 0.03)×10−4, (2.99 ± 0.07)×10−4 and (6.87 ± 0.12)×10-3 mol L-1, respectively. These compounds were competitive (ascorbic acid, (1.96 ± 0.03) ×10−4 mol L-1), non-competitive (sodium metabisulfite, (1.08 ± 0.03) ×10−4 mol L-1) and uncompetitive inhibitors (glutathione, (10.78 ± 0.05)×10-3 mol L-1) of peroxidase. Fluorescence spectrum showed the static quenching type of three inhibitors. The change of residues near the active site in peroxidase contributed to prevention of browning. [ABSTRACT FROM AUTHOR]

Luteolin, a plant-derived flavonoid, was found to exert effective inhibitory effect to peroxidase activity in a non-competitive manner with an IC 50 of (6.62 ± 0.45) × 10−5 mol L−1. The interaction between luteolin and peroxidase induced the formation of a static complex with a binding constant (K sv) of 7.31 × 103 L mol−1 s−1 driven by hydrogen bond and hydrophobic interaction. Further, the molecular interaction between luteolin and peroxidase resulted in intrinsic fluorescence quenching, structural and conformational alternations which were determined by multispectroscopic techniques combined with computational molecular docking. Molecular docking results revealed that luteolin bound to peroxidase and interacted with relevant amino acid residues in the hydrophobic pocket. These results will provide information for screening additional peroxidase inhibitors and provide evidence of luteolin's potential application in preservation and processing of fruit and vegetables and clinical disease remedy. • HRP activity was inhibited by luteolin in a non-competitive manner. • The thermosensitivity of HRP decreased after treating with luteolin. • The conformation of HRP changed after treating with luteolin. • The surface of structure sharply decreased with treatment of luteolin. [ABSTRACT FROM AUTHOR]

• Raman spectroscopy identified the bright and dark SiC in the SEM image as 3C-SiC and 6H-SiC. • Large-grained SiC maintained ductile cutting while brittle fractures occurred at interfaces. • Cross slips and high-density stacking faults significantly enhance plastic deformation. • The intersection of the 3C-SiC/6H-SiC interfaces becomes the initiation of the lateral crack. • The lateral crack propagates along the [111]//[0001] direction of the FCC-HCP interface. Reaction-bonded silicon carbide (RB-SiC) is considered as an excellent optical material in aerospace engineering. However, the multiple complex interfaces and high hardness make it difficult to be precisely machined. In this research, the in-situ laser-assisted diamond cutting was applied to precisely machining RB-SiC. Firstly, Raman spectroscopy was adopted to identify 3C-SiC and 6H-SiC components in RB-SiC. As following, the in-situ laser-assisted diamond cutting was experimentally carried out to analyze the subsurface deformation and fracture in detail. It was clarified that the cross slips and high-density stacking faults significantly enhance the plastic deformation of RB-SiC. Moreover, the dislocations rapidly plugged at the intersection of 3C-SiC/6H-SiC interfaces resulting in the lateral crack which propagates along the [111]//[0001] direction. [ABSTRACT FROM AUTHOR]

• The preparation of composite materials is used to degrade organic pollutants. • The degradation rate of RhB by C/T composites prepared reached 99.4%. • The C/T composite photocatalyst formed a new nanoflower structure. In order to develop an efficient photocatalyst to solve the environmental pollution problem, in this work, g-C 3 N 4 nanosheets were mixed with TiO 2 by mechanical stirring method to successfully construct a binary composite photocatalyst C/T. After a series of test characterization analysis, the C/T composite photocatalyst degraded rhodamine B, and the degradation rate reached 99.4 % after 60 min of reaction. The binary composite formed a new nanoflower structure, which reduced the band gap value of the C/T composite photocatalyst to 2.20 V and promoted the separation efficiency of photogenerated electron-hole pairs and increased the number of active sites, so the photocatalytic performance of C/T was greatly enhanced. The capture measurement experiment was also carried out to determine that the degradation of pollutants by C/T mainly depended on two active substances, ·O 2 -and h+. [ABSTRACT FROM AUTHOR]

Single crystal silicon is an important optical material used widely in the infrared systems. The surface quality and subsurface damage of silicon seriously affect the service performance. In this study, an in-situ laser-vibration hybrid assisted diamond cutting technology is proposed. The properties of cutting device were tested as experimental parameters. A series of grooving experiments were carried out with different cutting methods and the microlenses on silicon were successfully fabricated based on better manufacturing parameters. The surface morphology and subsurface damage was investigated from sin-wave structure manufacturing. Experimental results show that in-situ laser-vibration hybrid assisted diamond cutting effectively improves surface quality and inhibits subsurface lattice distortion. Compared with conventional diamond cutting, the depth of brittle transition increases by about 10 times with 1075 nm. Under the same cutting parameters, the formation of surface cracks of microlenses and sin-wave structure are significantly inhibited by applying in-situ laser-vibration hybrid assisted diamond cutting. This new technology is an effective and promising method for ultra-precision machining silicon. [Display omitted] • In-situ laser-vibration hybrid assisted diamond cutting technology is proposed and used in machining single crystal silicon novelly. • Compared with conventional diamond cutting, the depth of brittle transition increases by about 10 times with 1075 nm. • Surface and subsurface quality is improved compared with single force- or heat-field assisted cutting. [ABSTRACT FROM AUTHOR]

The role of inflammation in disease promotion is significant, yet the precise association between a newly identified inflammatory biomarker and insulin resistance (IR) and mortality remains uncertain. We aim to explore the potential correlation between systemic immune-inflammation index (SII) and these factors. We used data from 2011 to 2016 of National Health and Nutrition Examination Survey, and multivariate logistic regression and restricted cubic spline were employed. Subgroup and interaction analysis were conducted to recognize the consistency of the results. The association between SII and mortality was described by survival analysis. 6734 participants were enrolled, of whom 49.3% (3318) exhibited IR and 7.02% experienced mortality. Multivariate logistic regression revealed that individuals in the highest quartile (Q4) of SII had a significantly increased risk of IR compared to those in the lowest quartile (Q1). We then identified a linear association between SII and IR with an inflection point of 407, but may be influenced by gender. Similarly, compared to Q1, people whose SII at Q4 showed a higher all-cause and cardiovascular mortality. It showed a significant association between SII and both all-cause and cardiovascular mortality, but the results need to be interpreted with caution. [ABSTRACT FROM AUTHOR]

Sweetpotato (Ipomoea batatas (L.) Lam.) is a globally significant storage root crop, but it is highly susceptible to yield reduction under severe drought conditions. Therefore, understanding the mechanism of sweetpotato resistance to drought stress is helpful for the creation of outstanding germplasm and the selection of varieties with strong drought resistance. In this study, we conducted a comprehensive analysis of the phenotypic and physiological traits of 17 sweetpotato breeding lines and 10 varieties under drought stress through a 48 h treatment in a Hoagland culture medium containing 20% PEG6000. The results showed that the relative water content (RWC) and vine-tip fresh-weight reduction (VTFWR) in XS161819 were 1.17 and 1.14 times higher than those for the recognized drought-resistant variety Chaoshu 1. We conducted RNA-seq analysis and weighted gene co-expression network analysis (WGCNA) on two genotypes, XS161819 and 18-12-3, which exhibited significant differences in drought resistance. The transcriptome analysis revealed that the hormone signaling pathway may play a crucial role in determining the drought resistance in sweetpotato. By applying WGCNA, we identified twenty-two differential expression modules, and the midnight blue module showed a strong positive correlation with drought resistance characteristics. Moreover, twenty candidate Hub genes were identified, including g47370 (AFP2), g14296 (CDKF), and g60091 (SPBC2A9), which are potentially involved in the regulation of drought resistance in sweetpotato. These findings provide important insights into the molecular mechanisms underlying drought resistance in sweetpotato and offer valuable genetic resources for the development of drought-resistant sweetpotato varieties in the future. [ABSTRACT FROM AUTHOR]

The transition of material removal mode of polycrystalline 3C-SiC cutting with temperature, i.e., from brittle mode cutting that is dominated by inter-granular fracture and grain pulling-out at low temperature to ductile mode cutting that is governed by intra-granular cracking and dislocation slip. [Display omitted] • Temperature-dependent mechanical properties of both grains and GBs in polycrystalline 3C-SiC at elevated temperatures are derived. • Temperature-dependent properties of 3C-SiC GBs are bridged between MD simulation and FE simulation with cohesive zone model. • There is transition from brittle mode by inter-granular fracture toductile mode by intra-granular cracking with temperature. While the deformation behavior of grain boundaries has a strong impact on the mechanical response of polycrystalline materials, investigating the coupled thermal–mechanical properties of grain boundaries in their real formats is crucial for enhancing the ductile machinability of hard brittle polycrystalline ceramic materials. In the present work, we report the thermal softening-suppressed inter-granular fracture, accompanied with enhanced stacking fault formation, increased healing ability of grain boundaries and promoted ductile material removal, in diamond cutting of polycrystalline 3C-SiC at elevated temperatures by multi-scale simulations. Molecular dynamics simulations and experiments of high temperature nanoindentations are performed to derive the temperature-dependent mechanical properties of bulk polycrystalline 3C-SiC. Furthermore, molecular dynamics simulations of Mode I (tension) and Mode II (shearing) loading of a Σ9<1 1 0>{1 2 2} symmetric tilt grain boundary at elevated temperatures are performed to extract the temperature-dependent mechanical properties of grain boundaries in polycrystalline 3C-SiC. A novel finite element model of heat treatment-assisted diamond cutting of polycrystalline 3C-SiC with the comprehensive consideration of thermal properties of both grains and grain boundaries at elevated temperatures is established to reveal the transition of material removal mode, grain boundary failure behavior, cutting force characteristics and chip profile with temperature. [ABSTRACT FROM AUTHOR]

Sweetpotato blades are rich in the functional secondary metabolite chlorogenic acid (CGA), which deepen potential for effective utilization of the blade in industry. In this study, we evaluated the type and content of CGA in the blades of 16 sweetpotato genotypes and analyzed the correlation between CGA content and antioxidant capacity. Then we isolated and characterized IbGLK1 , a GARP-type transcription factor, by comparative transcriptome analysis. A subcellular localization assay indicated that IbGLK1 is located in the nucleus. Overexpression and silencing of IbGLK1 in sweetpotato blade resulted in a 0.90-fold increase and 1.84-fold decrease, respectively, in CGA content compared to the control. Yeast one-hybrid and dual-luciferase assays showed that IbGLK1 binds and activates the promoters of IbHCT , IbHQT , IbC4H , and IbUGCT , resulting in the promotion of CGA biosynthesis. In conclusion, our study provides insights into a high-quality gene for the regulation of CGA metabolism and germplasm resources for breeding sweetpotato. • Chlorogenic acid content varies significantly among genotypes of sweetpotato. • Characterization of key transcription factor IbGLK1 in chlorogenic acid metabolism. • IbGLK1 promotes chlorogenic acid biosynthesis in sweetpotato. • IbGLK1 directly activates transcription of chlorogenic acid metabolism genes. [ABSTRACT FROM AUTHOR]

Sweetpotato (Ipomoea batatas (L.) Lam.), which has a complex genome, is one of the most important storage root crops in the world. Sweetpotato blades are considered as a potential source of natural antioxidants owing to their high phenolic content with powerful free radical scavenging ability. The molecular mechanism of phenolic metabolism in sweetpotato blades has been seldom reported thus far. In this work, 23 sweetpotato genotypes were used for the analysis of their antioxidant activity, total polyphenol content (TPC) and total flavonoid content (TFC). 'Shangshu19' and 'Wan1314-6' were used for RNA-seq. The results showed that antioxidant activity, TPC and TFC of 23 genotypes had significant difference. There was a significant positive correlation between TPC, TFC and antioxidant activity. The RNA-seq analysis results of two genotypes, 'Shangshu19' and 'Wan1314-6', which had significant differences in antioxidant activity, TPC and TFC, showed that there were 7810 differentially expressed genes (DEGs) between the two genotypes. Phenylpropanoid biosynthesis was the main differential pathway, and upregulated genes were mainly annotated to chlorogenic acid, flavonoid and lignin biosynthesis pathways. Our results establish a theoretical and practical basis for sweetpotato breeding with antioxidant activity and phenolics in the blades and provide a theoretical basis for the study of phenolic metabolism engineering in sweetpotato blade. [ABSTRACT FROM AUTHOR]

We report here a new cultivation system for sweetpotato [ Ipomoea batatas (L.) Lam.] production, named grafted overhead-sweetpotato cultivation (GOSC) system. In this system, sweetpotato (as scions) was grafted with convolvulaceae relatives (as stocks), and the stems of grafted sweetpotato were buried in a solid medium without any nutrient and hung in the air to regenerate overhead-sweetpotato (storage roots). The results showed that Ipomoea trifida (6×), Beinong5521 (5×) and SH-2 (6×) were the best stocks. All the tested sweetpotato cultivars could produce overhead-sweetpotato with different yields. The mixture of sand, perlite and vermiculite with a 1:1:1 (v/v/v) ratio was the best solid medium for the GOSC system. The key stage of overhead-sweetpotato formation was about 20 days to 55 days after stem buried. Since storage roots are not regenerated from stocks grown in fertilized soil but from scion stems buried in non-fertilized solid medium, it seemed that the grafted overhead-sweetpotato plants had root-function spatial division (RFSD), i.e. absorbing roots of stocks and storage roots of scions. The graft compatibility with sweetpotato, the stock without underground storage roots, and the stem-buried media without nutrient supply, are the key factors for RFSD and overhead-sweetpotato production. This system could be used as a model for the study of the interaction between stock and scion as well as the source-sink relationship in sweetpotato. [ABSTRACT FROM AUTHOR]

The detrimental impact of heavy metals on cardiovascular well-being is a global concern, and engaging in suitable physical activity has been shown to confer cardiovascular advantage. Nevertheless, the potential of exercise to mitigate the deleterious effects of heavy metals on stroke remains uncertain. We conducted a cross-sectional survey to assess the influence of blood cadmium and blood lead on stroke occurrence, while also examining the role of physical activity. Weighted multivariate regression analysis was employed to examine the potential correlation, while subgroup and interaction analyses were used to investigate the sensitivity and robustness of the results. After controlling risk factors, it revealed a positive correlation between blood cadmium and lead levels and the occurrence of stroke. Specifically, a 50% increase in blood cadmium was associated with a 28% increase in stroke incidence, while a 50% increase in blood lead was associated with a 47% increase in stroke incidence. To estimate the non-linear relationship, we employed restricted cubic models. The results demonstrate a gradual decrease in the slope of the model curve as the intensity of physical activity increases, implying that engaging in physical activity may contribute to a reduction in the occurrence of stroke caused by blood cadmium and lead. Our findings suggest that blood cadmium and lead could be considered an autonomous risk factor for stroke within the general population of the United States. Moreover, engaging in physical activity has the potential to mitigate the potential detrimental consequences associated with exposure to heavy metals. • Blood cadmium and lead are positively associated with stroke. • There exists a threshold effect between heavy metals and stroke. • Physical activity can reduce the risk of cadmium and lead on stroke. • Intense physical activity effectively mitigates the stroke risk posed by heavy metals. • Women have a higher vulnerability to stroke when exposed to heavy metals. [ABSTRACT FROM AUTHOR]

• PDA and PANI regulated N -doped graphene aerogel (NGA) for supercapacitor electrodes. • Industrial grade graphene oxide (GO, 2.67 m2/g) is used as raw material. • PANI and PDA can reconstruct mesoporous structure for higher specific capacitance. • The role of nitrogen atoms in NGA for SC electrodes was verified by DFT calculations. Graphene-based materials have been widely studied in the field of supercapacitors. However, their electrochemical properties and applications are still restricted by the susceptibility of graphene-based materials to curling and agglomeration during production. In this study, a nitrogen-doped graphene aerogel (NGA) based on the regulation of polydopamine (PDA) and polyaniline (PANI) is proposed for the development of supercapacitors using industrial grade graphene oxide (GO, 2.67 m2/g) as raw material. Due to the rigidity of the PANI, agglomeration is prevented during the reduction of GO sheets. Meanwhile, the flexibility and adhesion of the PDA ensure a stable interaction between the graphene sheets and the PANI. NGAs feature a well-developed mesoporous structure and a high content of nitrogen, which enables the rapid transfer of ions inside them. As revealed by density functional theory (DFT) calculations, NGA heterojunction is characterized by high electronic conductivity, fast electron transfer, and low adsorption energy. For this reason, the supercapacitor obtained with NGA as an electrode produces an excellent capacitive performance, achieving a high area capacitance (123.6 mF·cm−2 at 0.5 mA·cm−2) and a superior long-cycle compression performance (80.7%, 5000 cycles). This study provides an effective solution for the development of supercapacitor electrodes using low-cost GO as raw materials. [ABSTRACT FROM AUTHOR]

Sweetpotato [ Ipomoea batatas (L.) Lam.] storage roots tend to become brown due to damage incurred during harvest, transportation, processing and storage. Understanding the mechanism of sweetpotato browning is of great significance for breeding varieties with low browning, which have greater economic value. In this study, after analysis of the Browning Degree (BD) of 76 sweetpotato genotypes and analyzing the correlations between BD, the activities and contents of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) for 21 genotypes, two genotypes, S07 (browning-resistant) and S28 (easily browned), were selected to elucidate the differences in the browning mechanism after fresh-cutting by physiological and transcriptome analyses. Genotype S28 had higher PAL, POD and PPO activities and a higher phenolic content after fresh-cutting compared with the basal level and genotype S07. Cell compartmentalization was severely damaged in fresh-cut S28. An RNA-Seq analysis showed that the phenylpropanoid biosynthesis in S28 was more active and gene families of related enzymes were more actively expressed. In conclusion, sweetpotato browning is due to a high content of phenolic compounds, and the high activity of PPO and POD resulting from the up-regulation of related genes. This study provided high quality breeding materials and a relevant theoretical basis for breeding browning-resistant sweetpotato varieties. [Display omitted] • Significant differences in fresh-cut browning among different sweetpotato genotypes. • S28 had higher PAL, POD, PPO enzyme activity and phenolic contents. • Disruption of cellular compartmentalization accelerates fresh-cut browning of S28. • High expression of Phenylpropanoid biosynthesis promotes fresh-cut browning of S28. [ABSTRACT FROM AUTHOR]

Purple sweet potato ( Ipomoea batatas L.) is rich in anthocyanin pigments, which are valuable constituents of the human diet. Techniques to identify and quantify anthocyanins and their antioxidant potential are desirable for cultivar selection and breeding. In this study, we performed a quantitative and qualitative chemical analysis of 30 purple sweet potato (PSP) cultivars, using various assays to measure reducing power radical-scavenging activities, and linoleic acid autoxidation inhibition activity. Grey relational analysis (GRA) was applied to establish relationships between the antioxidant activities and the chemical fingerprints, in order to identify key bioactive compounds. The results indicated that four peonidin-based anthocyanins and three cyanidin-based anthocyanins make significant contributions to antioxidant activity. We conclude that the analytical pipeline described here represents an effective method to evaluate the antioxidant potential of, and the contributing compounds present in, PSP cultivars. This approach may be used to guide future breeding strategies. [ABSTRACT FROM AUTHOR]

• gsm1 was isolated from an Arabidopsis glucose-hypersensitive mutant screen. • GSM1 encodes a putative RNA helicase and was localized to the nucleus. • gsm1 was sensitive not only to glucose but also to ABA. • GSM1 negatively regulates Glc-induced ABA signaling. In plants, sugar acts as an essential signaling molecule that modulates various aspects of metabolism, growth and development, which are also controlled by phytohormones. However, the molecular mechanism of cross-talk between sugar and phytohormones still remains to be elucidated. We have identified gsm1 (glucose-hypersensitive mutant 1) as a mutant with impaired cotyledon development that shows sensitivity to exogenous abscisic acid (ABA). The addition of fluridone can reverse the glucose (Glc) inhibitory effect in gsm1 , implying that endogenous ABA is involved in the Glc response of gsm1. In 4.5% Glc, the expression of Glc-induced ABA-responsive genes in gsm1-1 was nearly two times higher than that in the wild type. Compared to gsm1-1 , the gsm1-1 abi4-1 double mutant exhibited reduced sensitivity to Glc and ABA, which was similar to the Glc and ABA insensitive phenotype of abi4-1 , suggesting that ABI4 is epistatic to GSM1. In the treatment with 4.5% Glc, the GSM1 transcript level was greatly increased in abi4-1 by almost 4-fold of that in the wild type. These data suggest that GSM1 plays an important role in the ABI4-regulated Glc-ABA signaling cascade during Arabidopsis early seedling growth. [ABSTRACT FROM AUTHOR]