Search Results (367)

(1) Background: Posterior crossbite associated with maxillary transverse deficiency is commonly managed with maxillary expansion, yet the correspondence between laboratory activation behavior and the clinical response of nickel–titanium leaf-spring expanders remains insufficiently defined; therefore, this study aimed to compare in vitro and in vivo performance of the Leaf Expander^® and to assess their agreement. (2) Methods: A retrospective sample of 15 mixed-dentition patients (7–10 years) treated at two university centers with a Leaf Expander^® (6 mm screw; 900 g) was evaluated; interpremolar (E–E), intermolar (6–6), and intercanine (C–C) distances were recorded at baseline (T0, digital models) and at follow-up visits (T1–T5, caliper measurements), while mechanical compression testing (Instron 3365) quantified force release across the activation sequence; normality (Shapiro–Wilk), parametric analyses, and Pearson correlation were used. (3) Results Posterior crossbite correction was achieved in all completed cases, with mean total increases (T0–T5) of 5.4 mm (E–E), 4.4 mm (6–6), and 6.0 mm (C–C); early expansion (T1–T0) averaged 2.5 mm at E–E, and laboratory curves showed an activation peak followed by sustained force release (~6.5–9 N) and a residual-load phase. Agreement between declared activation and clinical response was higher for E–E and 6–6 than for C–C, which showed greater variability. (4) Conclusions: These findings support the Leaf Expander^® as an effective compliance-free slow expansion device and indicate that laboratory force behavior can help interpret the clinical expansion timeline, including delayed expression after activation. Full article

Jasmonates (JAs) are a diverse group of jasmonic acid (JA)-linked metabolites, including the biosynthetic intermediate 12-oxophytodienoic acid (OPDA). Although changes in JAs have been associated with plant responses to abiotic stress, the involvement and kinetics of specific forms such as JA, JA-Ile and OPDA require further clarification. This study analyzed jasmonate profiles in roots and leaves of two oat genotypes differing in drought tolerance. Jasmonates were quantified using UPLC-MS/MS, expression of key biosynthetic genes was assessed by qRT-PCR, and JA/OPDA treatments were applied to evaluate their effects on physiological and morphological responses to drought. Drought induced contrasting jasmonate dynamics in roots and leaves, with overall JA levels increasing in leaves and decreasing in roots, with genotype- and compound-specific differences. JA and JA-Ile ((+)-7-iso-jasmonoyl-L-isoleucine) showed similar trends, whereas OPDA displayed a distinct pattern. The tolerant genotype exhibited an early and marked reduction in root OPDA, while the susceptible one showed minimal change. Exogenous OPDA increased drought symptoms, reduced leaf relative water content and strongly decreased root length by limiting the formation of new thin roots. In contrast, JA application alleviated drought symptoms, reflected in a lower area under the drought progress curve, without affecting root length. Results suggest that under water deficit, reduced OPDA, likely due to its conversion into JA and JA-Ile, is associated with the development of small-diameter roots essential for maintaining water status in oat. Together, these results highlight tissue-specific differences in jasmonate dynamics during drought and show that OPDA and JA treatments lead to distinct drought-related responses in both leaves and roots. Full article

The objective of this study was to evaluate the effects of potassium (K) on disease severity and the chemical composition of Megathyrsus maximus cultivars. The experiment was conducted in a randomized block design in a 6 × 4 factorial arrangement, consisting of six Megathyrsus maximus cultivars (Massai, Mombaça, Tamani, Tanzânia, Quênia, and Zuri) and four K doses (0, 205, 410, and 820 mg dm⁻³). The severity of the leaf spot complex, caused by Bipolaris maydis and B. yamadae, was assessed using a diagrammatic scale. A significant interaction between K doses and cultivars was observed for all evaluated diseases. At K doses of 0 and 205 mg dm⁻³, the Tanzânia cultivar showed lower leaf spot severity compared with the other cultivars, whereas at higher doses, no disease symptoms were observed in any cultivar. The area under the disease progress curve (AUDPC) for mosaic followed a linear model only for the Tanzânia cultivar, whereas quadratic regression models best described the response for the remaining cultivars, with maximum mosaic severity values of 67.74% for Quênia, 72.34% for Mombaça, 76.99% for Zuri, 74.88% for Massai, and 68.93% for Tamani. Increasing K doses reduced the severity of both the leaf spot complex and mosaic. However, the leaf spot complex did not affect the nutritional value of the evaluated cultivars. Full article

Efficient crop health monitoring is crucial for global food security. Supervised deep learning approaches are often impractical due to the scarcity of large, labeled datasets. To address this limitation, this study adapts EfficientAD, an unsupervised, label-free anomaly detection framework originally designed for industrial inspection, for agricultural imagery on small datasets. The method utilizes a Patch Description Network (PDN) for localized feature extraction, a student network for local anomalies, and an autoencoder for global structural constraints. Benchmarked against AnoGAN, Pix2Pix, InTra, and Teacher–Student models, the framework demonstrated superior performance on the MVTec AD, PlantVillage, Coffee Leaf, and a custom real-world Sweet Potato dataset. The model achieved perfect area under the receiver operating characteristic curve (AUROC) scores of up to 100% in categories like “Pongamia”, “Potato”, and “Coffee Leaf”. While image-level classification was exceptionally robust, pixel-level localization (AUPRO) proved sensitive to complex agricultural backgrounds. To overcome this, a background interference analysis was conducted using Background Removed (BGRM) and out-of-distribution Background Replaced-Green (BGRP-G) strategies on the custom dataset. Notably, the BGRP-G strategy remarkably improved the image-level AUROC from 88.9% to 99.5% and substantially boosted the pixel-level AUPRO from 47.1% to 61.9%, successfully preserving the boundary integrity of severe structural defects. Achieving millisecond-level latency without complex data augmentation, this adapted label-free framework offers a versatile, highly efficient solution for real-time crop health diagnostics on resource-constrained Edge AI devices. Full article

The two-spot cotton leafhopper (TSCL), Amrasca biguttula (Hemiptera: Cicadellidae), is an emerging invasive pest in the southeastern United States. Although TSCL has historically been associated with cotton and vegetable crops, recent detections on ornamental hibiscus have raised regulatory concern, including “Stop Sale and Hold” orders and an emergency quarantine in Texas. Despite increasing pressure on hibiscus, no insecticide efficacy data exist for ornamental systems. We evaluated the acute (0–24 h) and residual (24–96 h) toxicity of bifenthrin, flupyradifurone, and tolfenpyrad against adult and immature TSCL using a sequential-cohort leaf-disc bioassay. New insects were introduced at 24 h and 72 h to isolate residue-based mortality from prolonged exposure effects. Bifenthrin caused the highest acute mortality at 24 h, whereas flupyradifurone and tolfenpyrad exhibited slower initial activity but strong residual performance. Immatures were more susceptible than adults across all doses. By 72 h, all three insecticides produced near-complete mortality, with significant treatment and dose effects confirmed by ANOVA and binomial GLM analyses. Dose–response curves showed steep concentration-dependent mortality for bifenthrin and tolfenpyrad and a time-dependent response for flupyradifurone. These results provide the first insecticide efficacy data for TSCL on ornamental hibiscus and offer immediate guidance for nursery producers and regulatory agencies. The findings establish a foundation for whole-plant and greenhouse evaluations to support integrated management and interstate plant-movement compliance. Full article

Accurately quantifying the inequality of plant organ size distributions, such as leaf area, is essential for understanding plant resource allocation strategies, and this is commonly achieved using Lorenz curves. Previous studies have shown that the performance equation (PE) and its generalized form (GPE) effectively describe Lorenz curves that are rotated 135° counterclockwise around the origin and shifted rightward by $\sqrt{2}$ units. However, few studies have compared the fitting performance of PE (and GPE) with other traditional equations generating Lorenz curves in modeling empirical leaf area distributions, and even fewer have considered the validity of linear approximation assumptions in these nonlinear models. To address this gap, we quantified the inequality of leaf area distributions in Semiarundinaria densiflora, a bamboo species for which the abundant and measurable leaves per culm provide an ideal system for examining the ecological strategies underlying leaf allocation patterns. Five nonlinear models were employed to fit the leaf area distribution: PE, GPE, the Sarabia equation (SarabiaE), the Sarabia–Castillo–Slottje equation (SCSE), and the Sitthiyot–Holasut equation (SHE). Model performance was assessed using root-mean-square error (RMSE) and Akaike information criterion (AIC), while nonlinearity curvature measures were applied to evaluate the close-to-linear behavior of parameter estimates. In addition, the Lorenz asymmetry coefficient (LAC) was used to quantify the asymmetry of the Lorenz curves. Our results showed a clear trade-off between predictive accuracy and linear approximation behavior. Among the five models, GPE achieved the best fit, with the lowest RMSE and AIC values, yet did not show good close-to-linear behavior. In contrast, SHE provided the poorest fit but demonstrated the strongest close-to-linear properties. LAC values indicated that relatively abundant, larger leaves disproportionately contributed to the inequality in leaf area distribution. These findings highlight an inherent trade-off in using Lorenz-based models to describe leaf area frequency distributions: predictive accuracy does not necessarily align with statistical validity. By integrating model fit, nonlinearity diagnostics, and asymmetry assessment, this study provides new perspectives and methodological tools for future investigations into inequality in plant organ size distributions and their ecological significance. Full article

Photosynthesis is of pivotal significance to the growth, development, and survival of plants. The conservation of endangered plant species represents a significant challenge within the broader context of biodiversity conservation. Analysis of the photosynthetic, physiological, and ecological characteristics of endangered plants is of significant value in understanding their survival mechanisms under adverse conditions, and can also provide key scientific support for the development of effective conservation measures. This study selected one-year-old Michelia guangdongensis seedlings to measure diurnal photosynthetic variations across different asexual lines. Using entropy-weighted TOPSIS evaluation and statistical analysis, we aimed to investigate photosynthetic differences among asexual lines and their relationship with environmental factors, thereby revealing the physiological characteristics of photosynthesis in M. guangdongensis seedlings. The results showed that the daily net photosynthetic rate variation of asexual lines CG3 and 1 of M. guangdongensis had asymmetric double-peak curves. Moreover, strains 9073, 8898, 8812, and 5 showed single-peak curves. Leaf transpiration rate (Trmmol) and CO₂ concentration (Ca) pathway analysis indicated these as the primary factors influencing the net photosynthetic rate of M. guangdongensis, with effective values of 1.17 and 0.9, respectively. TOPSIS entropy-weighted analysis indicated that the Ci values for CG3 and Leaf 1 exceeded 0.7, which indicated strong photosynthetic capacity. Additionally, the underside of the leaves exhibited superior coloration, thereby enhancing their ornamental value. This study provides a scientific basis and practical guidance for the breeding of asexual lines of M. guangdongensis. Full article

Coloured and variegated leaves are common in shade-tolerant ornamentals. However, it remains unclear whether their photosynthetic performance is determined mainly by pigment abundance or by the organisation of chloroplasts and thylakoids. We tested this in three Epipremnum aureum phenotypes (‘Neon’, ‘Golden’ and ‘Jade’) that share a genetic background but contrast in leaf colour, chloroplast density and thylakoid membrane abundance. Plants were grown in a greenhouse and assessed by hyperspectral and thermal imaging, infrared gas exchange analysis, chlorophyll a fluorescence measurements, and structural, ultrastructural and biochemical analyses. Traits were integrated by principal component analysis, with the quantum yield of CO₂ assimilation per absorbed photon (αCO_2,abs) as the response variable. ‘Neon’ leaves had high specific leaf area and approximately 55% lower maximum Rubisco carboxylation (Vc_MAX) and electron transport capacity (J_MAX) than ‘Jade’, as well as reduced chloroplast and thylakoid abundance and warmer canopies, despite carotenoid enrichment. JIP-test parameters and fluorescence light–response curves showed high absorption and dissipation per PSII reaction centre, elevated excitation pressure, modest non-photochemical quenching (NPQ), low αCO_2,abs, small carbohydrate pools and low intrinsic water-use efficiency. ‘Jade’ leaves developed thick mesophyll with dense chloroplast populations, extensive thylakoid networks, highest NPQ, cool canopies and large carbohydrate reserves, whereas ‘Golden’ leaves combined thin laminae and intermediate chloroplast–thylakoid organisation with early light saturation of CO₂ assimilation and the highest intrinsic water-use efficiency. Principal component analysis revealed a structural axis of chloroplast and thylakoid organisation that better predicted αCO_2,abs, net carbon gain and canopy temperature than pigment abundance. In variegated E. aureum, ‘photon economy’ is therefore governed primarily by chloroplast and thylakoid membrane organisation and abundance rather than by carotenoid accumulation. Full article

Stress caused by suboptimal temperatures (ST) represents a stress that limits growth in all grasses without inhibiting their activity and induces alterations in photosynthetic performance. We evaluated the responses of photosynthetic parameters and leaf elongation between two groups of grass genotypes with different levels of tolerance to ST, belonging to phylogenetically distant species. Responses to ST depended on the type of parameter and on the genotypic group. Leaf elongation traits showed discriminatory power, especially the area under the leaf elongation curve, which integrated the early and transient effects of stress over time. The photosynthetic parameter PI_ABS showed lower discriminatory power compared with the area under the leaf elongation curve. However, a deeper analysis of other photosynthetic parameters revealed an increase in energetic connectivity between Photosystem II centers in tolerant, but not in sensitive, genotypes. A subsequent analysis of leaf and cellular parameters of early leaf elongation dynamics indicated that ST reduced meristematic activity in all genotypes, but the tolerant genotype group maintained a greater accumulation of mature cells compared with the sensitive genotype group. Overall, the results suggested a response to ST in tolerant genotypes, but not in sensitive genotypes, related to the early dynamics of leaf and cellular growth parameters to partially compensate for the restrictive effect of ST on leaf elongation not recorded. In parallel, they also indicated a response of the tolerant genotypes to ST in terms of photosynthetic parameters, probably as a pathway to maintain cellular homeostasis, to prevent photooxidative damage in PSII under stress. However, the relationship between both responses does not appear to be strictly linear, but rather would be mediated by coordinated adjustments in the temporal dynamics of growth, suggesting a functional integration between photosynthetic performance and the cellular mechanisms that regulate leaf expansion under ST stress. Full article

Urban roadside environments are characterized by altered microclimate and soil conditions that impose recurrent drought stress on trees, affecting their physiological performance and adaptive capacity. Understanding species-specific physiological and structural responses to drought stress is crucial for selecting tree species that are suitable for urban environments. In the present study, we investigated the species-specific and temporal (monthly) patterns of the in situ leaf physiological status and structural traits of two riparian tree species, Quercus robur L. and Carpinus betulus L., cultivated as urban roadside trees in Novi Sad, Serbia, throughout the growing season (from June to September). This was achieved by assessing leaf gas exchange and rapid light curves of chlorophyll a fluorescence together with leaf structural traits. Under drought stress, Q. robur exhibited sustained photosynthetic activity and transpiration rates due to reduced stomatal sensitivity, indicative of a more anisohydric behavior with respect to its water relations strategy. In contrast, C. betulus exhibited tighter stomatal regulation and showed lower assimilation rates accompanied by reduced cooling capacity, indicating stricter, more conservative water-balance management indicative of isohydric species. Fluorescence indices revealed contrasting behavior: C. betulus showed enhanced NPQ values accompanied by a decline in photosynthetic efficiency, while Q. robur exhibited lower NPQ, suggesting better maintenance of photosynthetic performance and electron transport in PSII under the observed drought stress. These patterns were further supported by higher stomatal density combined with smaller stomatal size, indicating faster stomatal response rates in C. betulus compared to Q. robur. Overall, these results suggest that C. betulus is a more promising riparian tree species for urban landscapes, particularly under drought-prone conditions and predicted climate changes, in comparison to Q. robur. Full article

In protected horticultural production, tomato late blight shows strong environmental inducibility, with a short latent period, rapid risk accumulation, and a limited control window, which challenges conventional post-event disease monitoring. To address this, a tomato late blight risk perception and predictive control approach for protected production is proposed, integrating deep temporal modeling of environmental factors, visual symptom perception, and risk-driven greenhouse control to enable prospective assessment and proactive intervention. Based on disease mechanisms and real greenhouse conditions, an artificial intelligence (AI) framework covering perception, prediction, and regulation is constructed, moving beyond reliance on visible symptoms alone. Long-term evolution of key variables, including temperature, air humidity, leaf wetness, and light intensity, is modeled using deep temporal networks, while early weak lesions and subtle texture changes are captured by visual models. Cross-modal fusion in a unified risk space generates continuous risk scores to drive greenhouse regulation. Experiments on a multimodal dataset from a real greenhouse in Bayannur, Inner Mongolia, show that the proposed method outperforms vision-based and environment-based baselines in recognition and risk prediction. It achieves about 0.95 accuracy, 0.94 F1-score, and over 0.97 area under the receiver operating characteristic curve (AUC), while providing more than 20 h of early warning before disease onset. In environmental modeling, the deep temporal model consistently surpasses threshold-based methods, logistic regression, and long short-term memory/gated recurrent unit (LSTM/GRU) baselines in risk lead time, false alert rate, and prediction stability. Full article

Purslane (Portulaca oleracea L.) is an important plant species that has been increasingly used in functional gene studies and molecular analyses. However, reference genes that exhibit stable expression across multiple tissues and stress conditions have not been systematically validated in purslane, which limits the accuracy of reverse transcription quantitative PCR (RT-qPCR) based gene expression analyses. In this study, ten candidate reference genes from six gene families (Actin, PP2A, CYP, eIF4A, Ubiquitin, and eIF5A) were selected based on transcriptome data. A combination of bioinformatic analyses and experimental validation was employed to comprehensively characterize these candidates, including their physicochemical properties, chromosomal localization, phylogenetic relationships, gene structures, and promoter cis-acting elements. Furthermore, the expression stability of the candidate genes was systematically evaluated across different tissues (seed, root, stem, leaf, and flower) and under multiple stress treatments, including salinity, temperature stress, drought, and hormone treatments. Based on conventional PCR amplification specificity, melting curve analysis, Ct value distribution, and amplification efficiency, ACT-2 and eIF5A-1 were identified as the most stably expressed reference genes under diverse experimental conditions. This study provides reliable reference gene candidates for accurate normalization of gene expression in purslane and establishes a systematic framework for reference gene selection in non-model plant species. Full article

Coffea canephora cultivation areas in Brazil are frequently exposed to successive cycles of water deficit, triggering plant stress responses. In addition to water deficit, increased air temperature can act as a second stress factor. The recurrence of these stress factors may induce plant tolerance mechanisms, potentially mitigating future stress responses even of a different stress nature. We hypothesized that repeated cycles of water deficit can trigger tolerance mechanisms that make C. canephora leaves more resilient to supra-optimal temperatures. To test this hypothesis, young C. canephora plants were grown under non-limited water conditions for seven months (Ψ_mSoil > −20 kPa), after which they were subjected to two consecutive cycles of water deficit (Ψ_mSoil < −300 kPa), followed by rehydration. Two clones were used, ‘A1’ and ‘3V’, previously classified as drought sensitive and tolerant, respectively, considering the dynamics of physiological and architectural responses. After the second cycle, leaf discs were collected from completely expanded leaves formed during the two stress cycles and exposed to heat treatments (35 °C, 40 °C, 45 °C, 50 °C, and 55 °C) for 15 min in a water bath. Chlorophyll a fluorescence emission was then monitored, and the results were analyzed using OJIP transient kinetics and the JIP_Test. High temperatures induced negative changes in both OJIP kinetics and JIP_Test-derived parameters. A significant increase in F₀ and a reduction in F_M were observed mainly at 50 °C and 55 °C, due to changes in the stages of the OJIP curve. These changes impacted the “energy connectivity” and consequently the electron transport along the electron transfer chain (ETC), increasing energy dissipation, as confirmed by the JIP_Test variables. Despite the high temperature impacts, previous water deficit induced heat tolerance in clone ‘A1’, while it increased sensitivity in clone ‘3V’. This study suggests that selecting drought-resistant varieties should consider their subsequent response to short high-temperature stress to avoid cross-sensitivity caused by selecting for a single environmental factor. Full article

The demand for biodegradable, recyclable, natural composites with lightweight structures is driven by the fact that advanced structures can withstand quasi-static and dynamic loadings. This study examined the energy-absorbing characteristics of interlocking periodic honeycomb sandwich structures made from short sugar palm, kenaf, and pineapple leaf fibres (PALFs) reinforced with a polylactic acid (PLA) composite. The biodegradable sugar palm, kenaf, and PALF/PLA composite sheets were subjected to hot compression and cut into single- and double-slot square plates. The interlocking technique was used to assemble periodic two-dimensional square-honeycomb sandwich structures. Moreover, new and recyclable PLA-based composites with three fibres were tested for tensile properties. The biodegradable PLA-based composite honeycomb sandwich structure underwent a quasi-static compression test. Finite element modelling was used to simulate the load–displacement curve, energy-absorption characteristics, and failure behaviour, incorporating tensile properties and geometric imperfections. The results revealed that the double-slot design of the pineapple/PLA sandwich structure significantly increased by 1.33 times compared to the sugar palm/PLA sandwich structure. Notably, it reduced the compressive strength of recyclable pineapple/PLA (66.4%) and recyclable sugar palm/PLA (31.5%) composite sandwich structures compared to the new pineapple/sugar palm PLA-based composite. In addition, finite element analysis (FEA) showed reasonable agreement with experimental data, with a 7.11% error in energy absorption (EA). It was highlighted that biodegradable, recyclable, interlocking sandwich-structured composites have potential for advanced, sustainable energy-absorbing structures. Full article

Leaf and spike diseases can significantly reduce wheat yield and grain quality. To mitigate these impacts, an integrated disease management approach can be adopted, incorporating measures such as the use of resistant cultivars, fungicides and nitrogen fertilization. This study aimed to evaluate the impact of these practices on chlorophyll a fluorescence, yield components, and the technological quality of wheat grains. The area under the disease progress curve (AUDPC) was correlated with the maximum efficiency of photosystem II (PSII) photochemistry (F_v/F_m), as measured at the dough development stage (ZGS80) under field conditions, which also affected quality parameters. Additionally, an increase in AUDPC values reduced the thousand kernel weight (TKW) and test weight (TW). Conversely, AUDPC values for tan spot, powdery mildew and leaf rust were positively related to ash content (affecting flour color), protein content (PC) and grain falling number. Both the recommended nitrogen rate (130 kg ha⁻¹) and the high rate (200 kg ha⁻¹) increased grain protein content (PC) and gluten index (GI), while maintaining dough stability and water absorption. Fungicide application increased flour lightness and yellowness. Overall, integrated disease management combining moderately resistant cultivars, fungicide applications and nitrogen fertilization reduced AUDPC values, increased F_v/F_m (indicating optimal physiological performance) and ensured yield components and maintenance of wheat technological quality. Full article