Proteomic analysis of protein lysine 2-hydroxyisobutyrylation (Khib) in soybean leaves.

BACKGROUND: Protein lysine 2-hydroxyisobutyrylation (Khib) is a novel post-translational modification (PTM) discovered in cells or tissues of animals, microorganisms and plants in recent years. Proteome-wide identification of Khib-modified proteins has been performed in several plant species, suggesting that Khib-modified proteins are involved in a variety of biological processes and metabolic pathways. However, the protein Khib modification in soybean, a globally important legume crop that provides the rich source of plant protein and oil, remains unclear. RESULTS: In this study, the Khib-modified proteins in soybean leaves were identified for the first time using affinity enrichment and high-resolution mass spectrometry-based proteomic techniques, and a systematic bioinformatics analysis of these Khib-modified proteins was performed. Our results showed that a total of 4251 Khib sites in 1532 proteins were identified as overlapping in three replicates (the raw mass spectrometry data are available via ProteomeXchange with the identifier of PXD03650). These Khib-modified proteins are involved in a wide range of cellular processes, particularly enriched in biosynthesis, central carbon metabolism and photosynthesis, and are widely distributed in subcellular locations, mainly in chloroplasts, cytoplasm and nucleus. In addition, a total of 12 sequence motifs were extracted from all identified Khib peptides, and a basic amino acid residue (K), an acidic amino acid residue (E) and three aliphatic amino acid residues with small side chains (G/A/V) were found to be more preferred around the Khib site. Furthermore, 16 highly-connected clusters of Khib proteins were retrieved from the global PPI network, which suggest that Khib modifications tend to occur in proteins associated with specific functional clusters. CONCLUSIONS: These findings suggest that Khib modification is an abundant and conserved PTM in soybean and that this modification may play an important role in regulating physiological processes in soybean leaves. The Khib proteomic data obtained in this study will help to further elucidate the regulatory mechanisms of Khib modification in soybean in the future.

Natural ursolic acid based self-therapeutic polymer as nanocarrier to deliver natural resveratrol for natural therapy of acute kidney injury.

Acute kidney injury (AKI) is a common kidney disease associated with excessive reactive oxygen species (ROS). Unfortunately, due to the low kidney targeting and undesired side effects, the existing antioxidant and anti-inflammatory drugs are unavailable for AKI management in clinic. Therefore, it's essential to develop effective nanodrugs with high renal targeting and biocompatibility for AKI treatment. Herein, we reported a novel nanodrug for AKI treatment, utilizing poly(ursolic acid) (PUA) as a bioactive nanocarrier and resveratrol (RES) as a model drug. The PUA polymer was synthesized form ursolic acid with intrinsic antioxidant and anti-inflammatory activities, and successfully encapsulated RES through a nanoprecipitation method. Subsequently, we systemically investigated the therapeutic potential of RES-loaded PUA nanoparticles (PUA NPs@RES) against AKI. In vitro results demonstrated that PUA NPs@RES effectively scavenged ROS and provided substantial protection against H2O2-induced cellular damage. In vivo studies revealed that PUA NPs significantly improved drug accumulation in the kidneys and exhibited favorable biocompatibility. Furthermore, PUA NPs alone exhibited additional anti-inflammatory and antioxidant effect, synergistically enhancing therapeutic efficacy in AKI mouse models when combined with RES. Overall, our study successfully developed an effective nanodrug using self-therapeutic nanocarriers, presenting a promising option for the treatment of AKI.

The introduction of team-based learning into the clinical pharmacology section of the endodontics clinical course.

Team-based learning (TBL) has been widely applied and evaluated to produce better student outcomes. TBL has been introduced into the clinical pharmacology section of the endodontics clinical course at the School of Stomatology, Wuhan University since 2021. Here, the teaching experience in this course was summarized. The TBL course consisted of a knowledge assignment, intrateam and interteam discussion, practicing, evaluation, cases discussion and examination. The topics of the TBL class included cavity preparation and filling for treatment of dental caries, disinfection, and shaping and filling of root canal for root canal therapy. A total of 64 students participated in the TBL course. The students completed course work and hands-on practice to the satisfaction of the instructor. Furthermore, most participants held positive attitudes toward the TBL course because TBL provided the opportunity for teamwork to enable them to acquire and understand the therapeutic drug and material more quickly and made them more confident in the following practice. Our experience suggested that the application of the TBL contributed to the authentic practice of the endodontics clinical course.

RESIN INFILTRATION MAY BE A FEASIBLE OPTION TO ESTHETICALLY MASK ENAMEL WHITE SPOT LESIONS.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Bourouni S, Dritsas K, Kloukos D, Wierichs RJ. Efficacy of resin infiltration to mask post-orthodontic or non-post-orthodontic white spot lesions or fluorosis - a systematic review and meta-analysis. Clin Oral Investig. 2021 Aug;25(8):4711-4719. SOURCE OF FUNDING: University of Bern. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

DNA-based plasmonic nanostructures and their optical and biomedical applications.

In the past few decades, DNA nanotechnology has been developed a lot due to their appealing features such as structural programmability and easy functionalization. In the emerging field of DNA nanotechnology, DNA molecules are regarded not only as biological information carriers but also as building blocks in the assembly of various two-dimensional and three-dimensional nanostructures, serving as outstanding templates for the bottom-up fabrication of plasmonic nanostructures. By arranging nanoparticles with different components and morphologies on the predesigned DNA templates, various static and dynamic plasmonic nanostructures with tailored optical properties have been obtained. In this review, we summarized recent advances in the design and construction of static and dynamic DNA-based plasmonic nanostructures. In addition, we addressed their emerging applications in the fields of optics and biosensors. At the end of this review, the open questions and future directions of DNA-based plasmonic nanostructure are also discussed.

Resveratrol inhibits the proliferation of melanoma cells by modulating cell cycle.

The aim of this study was to evaluate the inhibitory effects of resveratrol (RSV) in A375 and A431 melanoma cells, by assessing cell viability (CCK-8 assay), apoptosis through flow cytometer and cell morphology, cell cycle assay by flow cytometer and western blot (Cyclin D1, Rac1 and PCDH9). Our results demonstrated that RSV strongly inhibited A375 cells proliferation, by decreasing cell viability, promoting apoptosis and arresting cell cycle. Besides, to clarify the main factor - duration or concentration of RSV, the double variance analysis of independent factors was operated after Bartlett's test for homogeneity by R project. According to the outcomes obtained from statistical analyses, Cyclin D1 and PCDH9 were strongly affected by RSV duration while Rac1 was not influenced. In conclusion, RSV can inhibit A375 proliferation and trigger apoptosis by influencing cell cycle proteins; for these effects, treatment duration of RSV played more important role than concentration.

Optimal Energy-Delay in Energy Harvesting Wireless Sensor Networks with Interference Channels.

In this work, we investigate the capacity allocation problem in the energy harvesting wireless sensor networks (WSNs) with interference channels. For the fixed topologies of data and energy, we formulate the optimization problem when the data flow remains constant on all data links and each sensor node harvests energy only once in a time slot. We focus on the optimal data rates, power allocations and energy transfers between sensor nodes in a time slot. Our goal is to minimize the total delay in the network under two scenarios, i.e., no energy transfer and energy transfer. Furthermore, since the optimization problem is non-convex and difficult to solve directly, by considering the network with the relatively high signal-to-interference-plus-noise ratio (SINR), the non-convex optimization problem can be transformed into a convex optimization problem by convex approximation. We attain the properties of the optimal solution by Lagrange duality and solve the convex optimization problem by the CVX solver. The experimental results demonstrate that the total delay of the energy harvesting WSNs with interference channels is more than that in the orthogonal channel; the total network delay increases with the increasing data flow for the fixed energy arrival rate; and the energy transfer can help to decrease the total delay.

An Intelligent Wireless System for Field Ecology Monitoring and Forest Fire Warning.

Based on Internet-of-Things and multi-sensor technology, an intelligent wireless monitoring system was developed to obtain field ecological parameters and provide forest fire warning in real-time. The GPRS and China's Beidou satellite communication were selectively used for date transmission in the field with weak cell phone signals. This monitoring system is mainly composed of several field ecological monitoring stations, a cloud server, and online system software. Atmosphere, soil, sunlight and plant parameters of different regions are obtained real-time by sensors stably and reliably. This system has functions such as field ecological data storage, dynamic query, report generation, and data analysis. As an example of typical application, the forest fire weather grade, which was supplemented with the litter layer soil humidity, was calculated to realize the early warning of the local forest fire in this system through continuous experiments at Beijing Jiufeng National Forest Park from March to May 2017 and Inner Mongolia from March to June 2018. The success ratios of data transmission through Beidou satellite were 98.57%, 99.43%, 99.59%, and 98.85%, respectively, in Beijing, and through GPRS were 99.89% and 99.90% in Inner Mongolia. Long-term real-time field ecological monitoring and forest fire warning were successfully realized. This system can be widely used for big data field acquisition and analysis in forest and agriculture regions.

A novel exopolysaccharide from deep-sea bacterium Zunongwangia profunda SM-A87: low-cost fermentation, moisture retention, and antioxidant activities.

Many marine microorganisms can secrete exopolysaccharides (EPSs) which have important applications in biotechnology. We have purified a novel EPS from deep-sea bacterium Zunongwangia profunda SM-A87, identified its glycosyl composition and linkage, and optimized its production to 8.9 g/l in previous studies. To reduce the fermentation cost, an economical fermentation medium containing 60.9 % whey, 10 g/l soybean meal, and 2.9 % NaCl was developed. The EPS yield of batch fermentation in this medium reached 12.1 ± 0.3 g/l. Fed-batch fermentation was conducted and led to an EPS yield of 17.2 ± 0.4 g/l, which represents the highest EPS yield ever reported for a marine bacterium. The EPS was extracted and it displayed good rheological properties, moisture-retention ability, and antioxidant activity. Particularly, its moisture-retention ability is superior to that of other marine bacterial EPSs reported to date. SM-A87 EPS also showed high antioxidant activity. These results suggest that SM-A87 EPS has promising potentials in biotechnology.

[Study on effect of huatuo zaizao extractum on focal cerebral ischemia/reperfusion neurogenesis in rats and its mechanisms].

OBJECTIVE: To observe the effect of Huatuo Zaizao extractum (HTZZ) on focal cerebral ischemia/reperfusion (I/R) neurogenesis in rats induced by middle cerebral artery occlusion (MCAO) and its mechanism. METHOD: Totally 55 healthy adult male Sprague-Dawley rats were divided into the sham operation group, the MCAO model group and HTZZ high, middle and low dose groups (5, 2.5, 1.25 g x kg(-1)), with 11 rats in each group, and orally administered with drugs. The focal cerebral ischemia model was established by performing a middle cerebral artery occlusion (MCAO, 90 min) followed by a seven-day reperfusion (once a day). The neurogenesis and expressions of extracellular signal-regulated kinase (ERK) and cAMP response element binding protein (CREB) were detected by the immunofluorescent staining. The enzyme linked immunosorbent assay (ELISA) was adopted to determine the vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF). RESULT: MCAO (90 min) followed by a seven-day reperfusion resulted in the significant increase in the number of penumbra cortex newborn neurons (BrdU(+) -NeuN(+)), which was accompanied by the growth of ERK and CREB phosphorylation and VEGF and BDNF levels. HTZZ could promote the generation of newborn neurons (BrdU(+)-NeuN(+)) and the ERK and CREB phosphorylation and increase VEGF and BDNF levels at the ischemic side. CONCLUSION: HTZZ could promote the neurogenesis, which may be the interventional targets of effective traditional Chinese medicine Huatuo Zaizao extractum in promoting the self-repair function of the cerebral ischemic areas.

Structure and ecological roles of a novel exopolysaccharide from the arctic sea ice bacterium Pseudoalteromonas sp. Strain SM20310.

The structure and ecological roles of the exopolysaccharides (EPSs) from sea ice microorganisms are poorly studied. Here we show that strain SM20310, with an EPS production of 567 mg liter(-1), was screened from 110 Arctic sea ice isolates and identified as a Pseudoalteromonas strain. The EPS secreted by SM20310 was purified, and its structural characteristics were studied. The predominant repeating unit of this EPS is a highly complicated α-mannan with a molecular mass greater than 2 × 10(6) Da. The backbone of the EPS consists of 2-α-, 6-α-mannosyl residues, in which a considerable part of the 6-α-mannosyl residues are branched at the 2 position with either single t-mannosyl residues or two mannosyl residues. The structure of the described EPS is different from the structures of EPSs secreted by other marine bacteria. Analysis of the ecological roles of the identified EPS showed that the EPS could significantly enhance the high-salinity tolerance of SM20310 and improve the survival of SM20310 after freeze-thaw cycles. These results suggest that the EPS secreted by strain SM20310 enables the strain to adapt to the sea ice environment, which is characterized by low temperature, high salinity, and repeated freeze-thaw cycles. In addition to its functions in strain SM20310, this EPS also significantly improved the tolerance of Escherichia coli to freeze-thaw cycles, suggesting that it may have a universal impact on microorganism cryoprotection.

[Effect and mechanism of huatuo zaizao extractum on focal cerebral ischemia/reperfusion-induced blood-brain barrier injury in rats].

OBJECTIVE: To observe the effect and mechanism of Huatuo Zaizao extractum (HTZZ) on focal ischemia/reperfusion (I/R) blood-brain barrier injury induced by middle cerebral artery occlusion. METHOD: Sixty healthy male adult Sprague-Dawley rats was randomly divided into the sham operation group, the MCAO model group, the Tanakan (20 mg x kg(-1)) group, and high, middle and low-dose HTZZ groups (5, 2.5, 1.25 g x kg(-1)), with 10 in each group and single-dose duodenal administration. Middle cerebral artery occlusion was adopted to establish the rat focal I/R model. After ischemia for 90 min and reperfusion for 24 h, the pathological injury at the ischemia side was observed by HE staining. The blood-brain barrier structure was observed under transmission electron microscope. Expressions of G protein-coupled receptor kinases 2 (GRK2), matrix metalloproteinases 2 (MMP-2) and MMP-9 were detected by western blotting technique. RESULT: After 90 min MCAO/24 h reperfusion, penumbra cerebral cortical micro-vessels showed edema, mitochondrial injury, vacuolation, membrane injury and reduction. Along with the changes, sub-cells of G protein-coupled receptor kinase 2 (GRK2) in cortical penumbra brain tissues transferred from cytoplasm to membrane, with increase in expressions of MMP-2 and MMP-9. HTZZ could effectively recover cerebral micro-vascular endothelial edemaand blood-brain barrier ultrastructure injury induced by I/R, reduce expression of functional (membrane coupling) GRK2, and inhibit expressions of MMP-2 and MMP-9. CONCLUSION: Cell membrane coupling GRK2 may be the effective target of Huatuo Zaizao extractum.

Development and validation of the intellectual property services scale in China.

Existing studies have emphasized the crucial role of intellectual property services (IPS) in the advancement of science and technology, but there was still a lack of a valid scale for assessing IPS. Accordingly, this study aimed to develop a reliable instrument to fill this gap. A three-step process of scale development was described: item generation through grounded theory research (n = 14), scale development through exploratory factor analysis (n = 219) and scale assessment through confirmatory factor analysis (n = 191). By analyzing and coding the interview data drawn from IPS agencies in China, the study verified that IPS could be represented as a three-dimensional construct consisting of vocational skills services (VSS), commercial operation services (COS), and value-added business services (VBS). The subsequent exploratory factor analysis and confirmatory factor analysis were conducted to test and modify the IPS scale with 11 items was shown to have acceptable internal consistency reliability, as well as convergent and discriminant validity. The IPS scale could serve as an operational tool for IPS practitioners to measure and identify the problems of service quality and service mode. Additionally, it held significant theoretical value and practical implications for the advancement of intellectual property services industry in China.

Use of left atrial automated functional myocardial imaging to identify patients with paroxysmal atrial fibrillation at high risk of stroke.

Background: Left atrial automated functional myocardial imaging (AFILA) is a new software program for analyzing the structure and function of the left atrium (LA). The present study sought to analyze the correlation between the LA function parameters as measured by AFILA echocardiography and the risk of cerebral ischemic stroke (CIS) in patients with non-valvular paroxysmal atrial fibrillation (NVPAF) to explore the diagnostic value of LA strain in patients with congestive heart failure, hypertension, age of ≥75 years (doubled), diabetes mellitus, stroke or transient ischemic attack (TIA) (doubled), age of 65-74 years, and sex category (female) (CHA2DS2-VASc) scores of <2. Methods: A total of 205 patients with NVPAF were included in the study and divided into the no-CIS group (154 patients) and the CIS group (51 patients). The baseline clinical data for the 2 groups were analyzed, and routine echocardiography examinations were performed. AFILA was used to evaluate the LA function of all the patients. Results: Compared to the no-CIS group, the LA emptying fraction and the LA reservoir strain were decreased, the LA contractile strain (S_CT) was increased, and the S_CT value changed from negative to positive in the CIS group, and the difference between the 2 groups were statistically significant (P<0.001). However, there were no significant differences in the volume at the onset of LA contraction, LA evacuation volume, LA minimum volume, LA maximum volume, and LA conduit strain between the 2 groups. The multifactorial regression analysis showed that age, hypertension, and the S_CT were independently associated risk factors for patients with CIS. After correcting for the clinical factors included in the CHA2DS2-VASc score, the S_CT was shown to predict to NVPAF with stroke [odds ratio (OR): 1.234, 95% confidence interval (CI): 1.101-1.383, P=0.000]. In addition, we included the CHA2DS2-VASc score (instead of age, diabetes, coronary artery disease, and hypertension) in a multiple regression analysis, and found that the S_CT was still significant (OR: 1.252, 95% CI: 1.118-1.402, P=0.000). The difference between the 2 groups in the CHA2DS2-VASc score for the S_CT was statistically significant, especially when the CHA2DS2-VASc score was <2. The S_CT equaled -4.5% was the cut-off value for the presence or absence of CIS in the NVPAF patients, with an area under the curve (AUC) of 0.866, sensitivity of 0.80, and specificity of 0.75 (P<0.0001). Conclusions: Comparison with LA volume parameter, measuring LA strain by AFILA provides a better index for the dynamic assessment of impaired LA function in patients with NVPAF combined with CIS, especially in those with a CHA2DS2-VASc score of <2. In addition, a LA S_CT of >-4.5% is a valuable cut-off for patients with NVPAF. The results of the current study may form the basis for a large prospective multicenter interventional study in which patients with impaired LA S_CT are randomized to receive oral anti-coagulant (OAC) therapy or no OAC therapy for the primary prevention of stroke.

Copper-Based Electrocatalysts for Nitrate Reduction to Ammonia.

Ammonia (NH3) is a highly important industrial chemical used as fuel and fertilizer. The industrial synthesis of NH3 relies heavily on the Haber-Bosch route, which accounts for roughly 1.2% of global annual CO2 emissions. As an alternative route, the electrosynthesis of NH3 from nitrate anion (NO3-) reduction (NO3-RR) has drawn increasing attention, since NO3-RR from wastewater to produce NH3 can not only recycle waste into treasure but also alleviate the adverse effects of excessive NO3- contamination in the environment. This review presents contemporary views on the state of the art in electrocatalytic NO3- reduction over Cu-based nanostructured materials, discusses the merits of electrocatalytic performance, and summarizes current advances in the exploration of this technology using different strategies for nanostructured-material modification. The electrocatalytic mechanism of nitrate reduction is also reviewed here, especially with regard to copper-based catalysts.

Point Cloud Completion of Plant Leaves under Occlusion Conditions Based on Deep Learning.

The utilization of 3-dimensional point cloud technology for non-invasive measurement of plant phenotypic parameters can furnish important data for plant breeding, agricultural production, and diverse research applications. Nevertheless, the utilization of depth sensors and other tools for capturing plant point clouds often results in missing and incomplete data due to the limitations of 2.5D imaging features and leaf occlusion. This drawback obstructed the accurate extraction of phenotypic parameters. Hence, this study presented a solution for incomplete flowering Chinese Cabbage point clouds using Point Fractal Network-based techniques. The study performed experiments on flowering Chinese Cabbage by constructing a point cloud dataset of their leaves and training the network. The findings demonstrated that our network is stable and robust, as it can effectively complete diverse leaf point cloud morphologies, missing ratios, and multi-missing scenarios. A novel framework is presented for 3D plant reconstruction using a single-view RGB-D (Red, Green, Blue and Depth) image. This method leveraged deep learning to complete localized incomplete leaf point clouds acquired by RGB-D cameras under occlusion conditions. Additionally, the extracted leaf area parameters, based on triangular mesh, were compared with the measured values. The outcomes revealed that prior to the point cloud completion, the R2 value of the flowering Chinese Cabbage's estimated leaf area (in comparison to the standard reference value) was 0.9162. The root mean square error (RMSE) was 15.88 cm2, and the average relative error was 22.11%. However, post-completion, the estimated value of leaf area witnessed a significant improvement, with an R2 of 0.9637, an RMSE of 6.79 cm2, and average relative error of 8.82%. The accuracy of estimating the phenotypic parameters has been enhanced significantly, enabling efficient retrieval of such parameters. This development offers a fresh perspective for non-destructive identification of plant phenotypes.

Radiation-sensitive genetic prognostic model identifies individuals at risk for radiation resistance in head and neck squamous cell carcinoma.

BACKGROUND: The advantages of radiotherapy for head and neck squamous cell carcinoma (HNSCC) depend on the radiation sensitivity of the patient. Here, we established and verified radiological factor-related gene signature and built a prognostic risk model to predict whether radiotherapy would be beneficial. METHODS: Data from The Cancer Genome Atlas, Gene Expression Omnibus, and RadAtlas databases were subjected to LASSO regression, univariate COX regression, and multivariate COX regression analyses to integrate genomic and clinical information from patients with HNSCC. HNSCC radiation-related prognostic genes were identified, and patients classified into high- and low-risk groups, based on risk scores. Variations in radiation sensitivity according to immunological microenvironment, functional pathways, and immunotherapy response were investigated. Finally, the expression of HNSCC radiation-related genes was verified by qRT-PCR. RESULTS: We built a clinical risk prediction model comprising a 15-gene signature and used it to divide patients into two groups based on their susceptibility to radiation: radiation-sensitive and radiation-resistant. Overall survival was significantly greater in the radiation-sensitive than the radiation-resistant group. Further, our model was an independent predictor of radiotherapy response, outperforming other clinical parameters, and could be combined with tumor mutational burden, to identify the target population with good predictive value for prognosis at 1, 2, and 3 years. Additionally, the radiation-resistant group was more vulnerable to low levels of immune infiltration, which are significantly associated with DNA damage repair, hypoxia, and cell cycle regulation. Tumor Immune Dysfunction and Exclusion scores also suggested that the resistant group would respond less favorably to immunotherapy. CONCLUSIONS: Our prognostic model based on a radiation-related gene signature has potential for application as a tool for risk stratification of radiation therapy for patients with HNSCC, helping to identify candidates for radiation therapy and overcome radiation resistance.

A homologous and molecular dual-targeted biomimetic nanocarrier for EGFR-related non-small cell lung cancer therapy.

The abnormal activation of epidermal growth factor receptor (EGFR) drives the development of non-small cell lung cancer (NSCLC). The EGFR-targeting tyrosine kinase inhibitor osimertinib is frequently used to clinically treat NSCLC and exhibits marked efficacy in patients with NSCLC who have an EGFR mutation. However, free osimertinib administration exhibits an inadequate response in vivo, with only ∼3% patients demonstrating a complete clinical response. Consequently, we designed a biomimetic nanoparticle (CMNP@Osi) comprising a polymeric nanoparticle core and tumor cell-derived membrane-coated shell that combines membrane-mediated homologous and molecular targeting for targeted drug delivery, thereby supporting a dual-target strategy for enhancing osimertinib efficacy. After intravenous injection, CMNP@Osi accumulates at tumor sites and displays enhanced uptake into cancer cells based on homologous targeting. Osimertinib is subsequently released into the cytoplasm, where it suppresses the phosphorylation of upstream EGFR and the downstream AKT signaling pathway and inhibits the proliferation of NSCLC cells. Thus, this dual-targeting strategy using a biomimetic nanocarrier can enhance molecular-targeted drug delivery and improve clinical efficacy.

Leaf shape, planting density, and nitrogen application affect soybean yield by changing direct and diffuse light distribution in the canopy.

When attempting to maximize the crop yield from field-grown soybean (Glycine max (L.) Merr.) by means of improving the light conditions for photosynthesis in the canopy, it is crucial to find the optimal planting density and nitrogen application rate. The soybean plants that were the subject of our experiment were cultivated in N-dense mutual pairs, and included two cultivars with different leaf shapes; one cultivar sported ovate leaves (O-type) and the other lanceolate leaves (L-type). We analyzed the results quantitatively to determine the amount of spatial variation in light distribution and photosynthetic efficiency across the canopy, and to gauge the effect of the experimental parameters on the yield as well as the photosynthetic light and nitrogen use efficiency of the crop. Results indicate that the different leaf shapes were responsible for significant disparities between the photosynthetic utilization of direct and diffuse light. As the nitrogen fertilizer rate and the planting density increased, the soybean plants responded by adjusting leaf morphology in order to maximize the canopy apparent photosynthetic light use efficiency, which in turn affected the leaf nitrogen distribution in the canopy. Despite the fact that the light interception rate of the canopy of the L-type cultivar was lower than that of the canopy of the O-type cultivar, we found its canopy apparent photosynthetic nitrogen and light use efficiency were higher. It was interesting to note, however, that the nitrogen and light use efficiency contributions associated with exposure to diffuse light were greater for the latter than for the former.