Search Results (1,514)

Wheat dust, an underutilized agro-industrial by-product, is rich in nutrients and may serve as a sustainable soil amendment. This study evaluated its effects on wheat (Triticum durum L.) growth, nitrogen metabolism, and drought tolerance. Two greenhouse experiments were conducted. First, a dose–response trial (0, 2, 5, 10, 20% w/w) assessed biomass, chlorophyll content (SPAD), and expression of nitrogen-related genes (NR, NRT1, NRT2, GS2). Second, a factorial experiment (0, 10, 20% × well-watered or 50% water capacity) examined growth, yield components, oxidative stress markers (MDA), antioxidant enzymes, soil enzymatic activities, and multivariate responses. Wheat dust elicited concentration-dependent, context-specific effects. Under well-watered conditions, 10% was optimal, increasing shoot biomass (+39%) and chlorophyll (+10–15%), accompanied by upregulation of NR, NRT1, and NRT2, indicating enhanced nitrogen acquisition. Under drought, 20% produced the strongest effects: biomass increased by +313%, seed number per spike by +3900%, and seed weight per spike by +1650% relative to the stressed control. Lipid peroxidation declined by 83%, while chlorophyll increased by +215%, reflecting strong protection of membrane integrity and photosynthetic capacity. Soil biological activity was markedly stimulated at 20% under drought, with FDA hydrolysis (+1320%) and protease activity (+8250%) indicating enhanced microbial functioning and nitrogen cycling. Principal component analysis confirmed a systemic shift from stress-dominated profiles in controls to growth- and metabolism-oriented profiles at 20%, with convergence of stressed and non-stressed plants. Thus, wheat dust improves productivity at moderate doses and confers pronounced drought resilience at higher rates, supporting its valorization within climate-resilient, circular agricultural systems. Full article

Understanding how trees coordinate carbon acquisition and allocation under warming is essential for predicting forest–carbon dynamics; however, whether warming induces common or species-specific source–sink regulation strategies remains unresolved. We conducted a field warming experiment (+2 °C and +4 °C above ambient) to investigate photosynthetic responses, organ-specific non-structural carbohydrate (NSC) dynamics, and carbon allocation strategies in two temperate tree species, Fraxinus mandschurica and Juglans mandshurica. Moderate warming (+2 °C) initially enhanced carbon assimilation in both species, whereas severe warming (+4 °C) progressively inhibited photosynthetic performance during the later growing season. In F. mandschurica, +2 °C warming promoted carbon storage by increasing starch accumulation across leaves, stems, and roots, with starch concentrations 2.5–38.0% higher than those in control plants from July to September. These enhanced NSC reserves were positively associated with photosynthetic performance and survival, indicating an effective source-driven carbon storage strategy. In contrast, J. mandshurica exhibited a distinct carbon allocation pattern under warming, characterized by preferential soluble sugar accumulation in leaves and reduced carbon investment in storage tissues. Specifically, leaf soluble sugar-to-starch ratios increased by 6.0–162.3%, whereas root soluble sugar content decreased by up to 55.7% under warming, suggesting a shift toward short-term carbon regulation rather than long-term storage. Structural equation modeling further demonstrated that photosynthetic performance and leaf NSC pools were central regulators of warming responses, but their effects on downstream carbon allocation differed between species. Our results reveal that warming does not induce a uniform carbon response among temperate trees; instead, species-specific source–sink regulation strategies determine carbon resilience under elevated temperatures. These findings improve understanding of how coexisting tree species may diverge in their adaptive capacity under future climate warming. Full article

Brackish water utilization provides an alternative strategy for alleviating freshwater scarcity in arid agricultural regions; however, the synergistic regulation of salinity, irrigation, and nitrogen management remains unclear. A two-year field experiment was conducted in 2025 and 2026 to investigate the effects of water–nitrogen–salinity interactions on growth, yield formation, resource use efficiency, and fruit quality of pigment pepper (Capsicum annuum L.) under arid conditions in Xinjiang, China. An L9(3³) orthogonal experimental design was adopted with three levels of brackish water salinity, irrigation amount, and nitrogen application rate. The comprehensive production performance of different management strategies was further evaluated using a combined weighting Cloud–TOPSIS approach. The results showed that water–nitrogen–salinity interactions significantly regulated pigment pepper growth, yield formation, and resource utilization, with consistent responses observed across the two experimental years. Increasing irrigation water salinity reduced leaf chlorophyll content (CHL) and nitrogen balance index (NBI), whereas flavonoid content (FLAV) exhibited an increasing trend under moderate salinity stress. Low-salinity irrigation combined with appropriate water and nitrogen inputs maintained higher photosynthetic capacity and nitrogen nutritional status. Yield, water use efficiency (WUE), and partial factor productivity of nitrogen (PFPN) were jointly affected by salinity, irrigation, and nitrogen supply. Excessive salinity significantly reduced crop productivity, while optimized irrigation and nitrogen management alleviated salt stress effects. The T2 treatment (1 g L⁻¹ salinity, 2400 m³ ha⁻¹ irrigation, and 300 kg ha⁻¹ nitrogen application) achieved the highest yield and maintained favorable WUE and PFPN values in both years. Fruit quality responses demonstrated that moderate salinity promoted capsaicinoid accumulation, whereas excessive salinity restricted biomass production and quality improvement. Correlation analysis revealed that photosynthetic nitrogen metabolism indicators were closely associated with yield formation, while flavonoid accumulation showed stronger relationships with quality attributes. The Cloud–TOPSIS evaluation identified T2 as the optimal management strategy under the experimental conditions by balancing yield, quality, and resource use efficiency. These findings indicate that coordinated regulation of irrigation water salinity, water supply, and nitrogen input is essential for achieving efficient brackish water utilization and sustainable pigment pepper production in arid regions. Full article

This study compared net photosynthesis (A), water-use efficiency (WUE), intrinsic water-use efficiency (iWUE), and A–${\mathrm{C}}_i$ curve-derived photosynthetic parameters (maximum carboxylation rate, $V_{\mathrm{cmax}}$; maximum electron transport rate, $J_{\max }$) across nine mangrove and semi-mangrove species at a tropical coastal site in Bali, Indonesia. Gas exchange measurements were conducted using portable photosynthesis systems (LI-6400 and LI-6800), and A–${\mathrm{C}}_i$ curves were fitted to the Farquhar–von Caemmerer–Berry (FvCB) model. Sonneratia alba Sm. exhibited the highest A (15.29 ± $2.39$ μmol ${\mathrm{m}}^{-2}{\mathrm{s}}^{-1}$), suggesting comparatively high photosynthetic performance, while Hibiscus tiliaceus L. and Pongamia pinnata (L.) Pierre showed the highest iWUE values (88–$97$ μmol ${\mathrm{mol}}^{-1}$), indicating relatively efficient carbon gain per unit stomatal conductance. Significant overall interspecific variation was detected in $V_{\mathrm{cmax}}$ and $J_{\max }$ ($p=0.003$ and $p=0.016$, respectively). The observed interspecific variation in A, iWUE, $V_{\mathrm{cmax}}$, and $J_{\max }$ suggests differences in photosynthetic characteristics and leaf-level water-use efficiency among species. These ecophysiological baseline data may contribute to species selection for mangrove restoration and to understanding physiological responses to environmental change in tropical coastal forests. Full article

Melatonin (MT), a potent antioxidant, can mitigate abiotic stress. The objective of this study was to determine if foliar spraying of MT can alleviate the stress of Trichosanthes kirilowii seedlings under drought conditions. The results showed that drought stress significantly inhibited the growth of T. kirilowii seedlings, whereas exogenous MT alleviated this inhibition. Compared with the treatment with drought stress alone, the addition of MT significantly increased the stem length, net photosynthetic rate, chlorophyll content, maximum photochemical efficiency, and relative leaf water content of T. kirilowii seedlings after 20 days of drought stress. Under drought stress, the addition of MT significantly reduced the levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), and reduced electrolyte leakage (EL) in the leaves of T. kirilowii seedlings. Compared with the control group, the antioxidant enzyme activity was significantly enhanced under drought stress, and the contents of soluble sugars (SSs) and proline (Pro) increased significantly. The antioxidant enzyme activity was strongest in the group treated with MT, and the SS and Pro contents were the highest in this group. The results indicate that the addition of MT can maintain the relative water content (RWC) of the leaves of T. kirilowii seedlings under drought stress, significantly enhance antioxidant capacity, reduce drought-induced damage, maintain the stability of the photosynthetic system, and promote the growth of T. kirilowii seedlings. Full article

Plateau environments are characterized by low temperatures, intensive radiation and drastic diurnal temperature fluctuations, all of which greatly suppress rooting and seedling establishment of tea chrysanthemum cuttings. To compare the regulatory effects of different rooting regulators on tea chrysanthemum cuttings under plateau cultivation conditions, this study conducted a 60-day plug-tray cultivation experiment from late July to late September with three biological replicates. All the cuttings, including the IBA-pre-treated control (CK), were uniformly pretreated with 500 mg·L⁻¹ indole-3-butyric acid (IBA). On this basis, four treatments, including 5-aminolevulinic acid hydrochloride (5-ALA, T1), γ-aminobutyric acid (GABA, T2), Bacillus amyloliquefaciens (T3) and Bacillus velezensis (T4), were applied to determine root morphology, seedling growth, physiological stress metabolism, photosynthetic capacity and rhizosphere substrate characteristics. The different rooting promoters exerted distinct regulatory effects on cutting performance. The GABA treatment significantly improved leaf gas exchange, seedling growth, antioxidant status and rhizosphere nutrient conditions, with net photosynthetic rate, stomatal conductance and transpiration rate improved by 316.34%, 92.31% and 168.00%, respectively, and significantly increased seedling vigor index, plant height and stem diameter by 21.74%, 60.85% and 46.08%, respectively. It also elevated the soluble sugar content and the ascorbate peroxidase (APX) activity, reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, and optimized rhizosphere available nitrogen and phosphorus levels, as well as related enzyme activities. Nevertheless, the 5-ALA treatment exhibited unique advantages in improving rooting rate and seedling survival. Mantel tests confirmed that the seedling vigor index closely correlated with the root architecture, the total chlorophyll and the transpiration rate. A principal component analysis (PCA) and a cluster heatmap both identified GABA as the treatment with relatively balanced overall performance. A comprehensive D-value evaluation ranked the treatments as GABA > B. amyloliquefaciens > 5-ALA > B. velezensis > control. The treatment with 5-ALA mainly improved the antioxidant capacity, the B. amyloliquefaciens treatment favored root elongation and total nutrients, and the B. velezensis treatment only produced mild improvements. This study indicates that the different exogenous regulators target divergent growth and physiological processes, and the GABA treatment could coordinately boost root development, photosynthetic performance, antioxidant defense and rhizosphere nutrient cycling, thus presenting great application potential for tea chrysanthemum cutting propagation under plateau cultivation conditions. Full article

Amorphophallus spp., valued as both crops and medicinal plants, are highly susceptible to soft rot disease, causing substantial yield and economic losses during cultivation and storage. Calcium nanoparticle (CaNP) fertilizer not only has the potential to enhance crop yields but also plays a crucial role in the control of crop pests and diseases. However, its application in the control of soft rot disease in konjac has not yet been investigated. In this study, the antibacterial efficacy of CaNP fertilizer against the typical soft rot pathogen P. aroidearum MY11 in Amorphophallus konjac (A. konjac) was investigated. It was found that CaNP fertilizer significantly inhibited the growth, motility ability and the activity of cell wall-degrading exoenzymes of P. aroidearum MY11. Transmission electron microscopy revealed that the morphology of bacterial cells treated with CaNPs did not change significantly, but significant particle deposition was observed within the cells. Furthermore, CaNPs pretreatment could reduce the reactive oxygen species (ROS) content, activate the antioxidant enzyme system, and enhance the photosynthetic capacity of A. konjac plants. qRT-PCR analysis revealed that CaNPs pretreatment might enhance the resistance of A. konjac plants to the soft rot pathogen MY11 by activating the jasmonic acid (JA), salicylic acid (SA) signaling pathway and the cell wall stress response pathway. This research provides a new candidate for nanopesticides that can be used to control the bacterial soft rot disease of konjac. Full article

Drought stress is a primary abiotic constraint limiting potato productivity. While polyphenol oxidase (PPO) is known to participate in stress responses, the specific role of StuPPO9 in drought tolerance remains poorly understood. In this study, we generated StuPPO9-overexpressing (OE) and CRISPR/Cas9-mediated knockout (C4) lines in the potato cultivar ‘Atlantic’. Under sustained drought stress, OE lines exhibited significantly superior growth phenotypes compared to wild-type (WT) and C4 plants, characterized by increased leaf and root relative water content, root number and enhanced photosynthetic efficiency (Pn and Gs). OE plants also maintained lower levels of MDA and ROS through elevated antioxidant enzyme activities. Notably, transcriptomic analysis revealed that StuPPO9 triggers a global reprogramming of metabolic pathways. Key drought-responsive genes associated with phenylpropanoid biosynthesis (e.g., anthocyanin acyltransferase), terpenoid metabolism, and hormone signaling (e.g., HPt protein) were significantly upregulated in OE plants. These findings suggest that StuPPO9 confers drought resilience through a multi-layered network involving optimized carbon allocation, reinforced cell wall integrity, and enhanced ROS scavenging capacity. This study provides a promising genetic target and theoretical foundation for breeding drought-resistant potato varieties. Full article

Optimization of holdfast-based asexual propagation is critical for scalable, the genetically uniform seedling production in Sargassum fusiforme aquaculture owing to its capacity to preserve genetic uniformity. Although exogenous auxin can be applied to promote juvenile regeneration, the optimal concentration and associated physiological mechanisms remain insufficiently characterized. In this study, fine strains of S. fusiforme were selected to systematically investigate the concentration-dependent effects and regulatory mechanisms of exogenous indole-3-acetic acid (IAA) on holdfast regeneration. Results revealed that treatment with 2.0 mg·L⁻¹ exogenous IAA significantly enhanced the photosynthetic performance relative to untreated controls. Specifically, this treatment resulted in increased accumulation of chlorophyll a, chlorophyll c, and fucoxanthin as well as elevated maximum relative electron transport rate, maximum quantum yield of PSI, light utilization efficiency, and net photosynthetic rate. Concurrently, nitrogen assimilation and metabolic utilization were markedly stimulated, as evidenced by significant increases in the activities of nitrogen synthesis-related enzymes and substantial accumulation of soluble proteins and total carbohydrates. These coordinated physiological improvements collectively contributed to a 185.4% increase in relative growth rate and 417.1% increase in holdfast regeneration rate as compared with the control group, thereby supplying abundant energy and biosynthetic precursors essential for photosynthesis and juvenile development. Ultimately, the holdfasts exhibited accelerated differentiation into morphologically mature juvenile thalli. Overall, application of 2.0 mg·L⁻¹ exogenous IAA represent a highly effective strategy for enhancing holdfast regeneration efficiency and improving the viable seedling output. This study provides a mechanistic foundation and an expandable solution for addressing the supply of S. fusiforme seedlings. Full article

Frequent marine heatwaves (MHWs) pose significant threats to and have a profound impact on the structure and functioning of marine ecosystems. The response of marine organisms to MHWs may depend on the background temperature of their habitats. Saccharina japonica is a cold-temperate species that is vulnerable to thermal stress. However, it remains unclear how habitat-related temperatures impact responses of S. japonica to MHWs. In this study, the algae were exposed to MHWs (+∆4 °C) under two background temperatures (control level, 8 °C; warmer level, 12 °C), and the growth, photosynthetic performance, and biochemical composition were measured at the end of the MHW and the recovery periods. The results showed that a warmer background temperature increased the growth and pigment contents (Chlorophyll c and fucoxanthin) of S. japonica, but decreased chlorophyll fluorescence parameters, including the effective quantum yield, relative electron transport rate, non-photochemical quenching, and photochemical quenching. The MHWs had no significant effect on growth rate, photosynthetic performance, or biochemical compositions at the background temperature of 8 °C. In contrast, MHWs reduced growth and biochemical composition contents (Chlorophyll a, Chlorophyll c, fucoxanthin and soluble protein) at a warmer level, but the negative influence was alleviated after the recovery period. Furthermore, there was a considerable increase in the total antioxidative capacity caused by MHWs under warmer conditions. Overall, the stimulation in growth demonstrated that warmer conditions (12 °C) may provide a better growth temperature for young S. japonica but also increase the risks of biomass losses and physiological damage triggered by MHWs. These findings deepen our understandings of the tolerance and resistance of S. japonica to heatwaves and provide useful information for managing and modulating the cultivation of this important commercial seaweed. Full article

This study investigated the effects of thinning intensity on tree radial growth and physiological responses to drought in an approximately 43-year-old Pinus koraiensis plantation. To analyze tree-ring width, a total of sixty wood cores (5 mm) were collected from three thinning treatments applied in 2007: control (Con), light thinning (LT), and heavy thinning (HT). Drought vulnerability indices were examined across three distinct drought periods (2000–2001, 2007, and 2014–2016), and intrinsic water use efficiency (WUE_i) was estimated from stable carbon isotope analysis (Con vs. HT). Thinning increased basal area increment (BAI) in both the LT and HT groups, with the strongest and most persistent response observed in the HT group. During the 2007 drought, trees in thinned plots, particularly those in the HT group, showed higher resistance and resilience than trees in the Con group. The increased indices during the 2000 and 2007 drought periods predominantly reflected immediate thinning-induced growth release. WUE_i in the HT group increased relative to the Con group during both the 2007 and 2014–2016 drought periods; however, the underlying physiological mechanisms differed, with enhanced net photosynthetic capacity immediately after thinning in 2007 and a likely consistent reduction in stomatal conductance during the 2014–2016 drought. Although constrained by a non-replicated stand design, this site-specific long-term case study provides valuable insights into the multi-decadal growth and physiological trajectories of conifer plantations responding to climate stress. Full article

The nutritional and functional quality of eggplants is heavily influenced by biological and technological factors. This study evaluated the effects of cultivar, rootstock, and fertilizers on the nutritional and functional quality of eggplant (Solanum melongena L.). Two commercial hybrids (Mirval and Black Pearl) were assessed with respect to two rootstocks (Solanum sylvatica and Rezistar F1) and three fertilization regimes: biological (Micoseed^®), organic (Orgevit^®), and chemical (Nutrispore^®). These were compared with ungrafted and unfertilized cultivars. Fruit samples were analyzed for total polyphenol content (TPC), antioxidant capacity (ABTS and DPPH assays), chlorophyll a and b, lycopene, and tannin concentrations. Mirval exhibited significantly higher levels of TPC, antioxidant activity, photosynthetic pigments, and lycopene than Black Pearl. Ungrafted plants and those grafted onto S. sylvatica showed superior fruit quality, particularly when combined with organic or chemical fertilization. The highest concentrations of polyphenols (3.61 mg·100 g⁻¹ DW), lycopene (3.18 mg·100 g⁻¹ DW), and total chlorophylls were recorded for Mirval fruits from ungrafted or S. sylvatica-grafted plants under organic or chemical fertilization. These findings indicate that optimizing cultivar–rootstock combinations and fertilization management can significantly enhance the functional quality of eggplant fruits. The findings also support the use of organic fertilization as a sustainable strategy in protected vegetable production systems. Full article

Polyploidy is widely used in plant breeding to increase phenotypic variation and potentially improve stress-related traits; however, its effects in common bean remain poorly characterized. Here, colchicine-induced polyploidy was evaluated in Phaseolus vulgaris cv. Zorzal to determine whether tetraploid lines exhibit coordinated changes in stomatal anatomy, physiology, pigment composition, oxidative balance, and ploidy inheritance. Polyploidy was induced using different colchicine exposure regimes and confirmed by flow cytometry. Stomatal traits, gas-exchange parameters, photosynthetic pigments, oxidative stress markers, antioxidant capacity, and multivariate phenotypic relationships were subsequently analyzed in confirmed tetraploid lines. Colchicine treatments successfully generated tetraploid and mixoploid plants, although induction efficiency was highly variable among replicates. Tetraploid lines showed heterogeneous physiological responses, including increases in the photosynthetic rate and stomatal conductance in some genotypes, but no consistent reduction in stomatal pore area index. Pigment composition and antioxidant-related traits also varied among lines, without a uniform response pattern. Multivariate analyses revealed coordinated but highly divergent phenotypic profiles among tetraploid genotypes. Importantly, the induced tetraploids were not stably transmitted to the C1 generation, with a predominance of diploid progeny among the evaluated offspring. Overall, colchicine-induced polyploidization generated substantial physiological variability among independently derived tetraploid plants of P. vulgaris cv. ‘Zorzal’; however, the predominance of diploid individuals among the evaluated C1 progeny indicates limited transmission of the induced tetraploid state to the subsequent generation. Full article

High temperature can impair leaf water status, photosynthetic function, and membrane stability in ornamental woody seedlings. However, integrated evidence combining gas exchange, chlorophyll fluorescence, oxidative injury, antioxidant activity, and osmotic-adjustment-related responses in heat-stressed Syringa oblata remains limited. One-year-old seedlings from a single nursery batch were exposed for 7 d to 25/18 °C or 40/30 °C day/night conditions and sprayed with either a solvent solution or 0.5 mM salicylic acid. Growth, leaf water status, photosynthetic pigments, gas exchange, pulse-amplitude-modulated fluorescence, OJIP/JIP-test parameters, oxidative-injury markers, antioxidant enzyme activities, and osmotic-adjustment-related compounds were evaluated. Heat treatment reduced leaf relative water content, photosynthetic performance, and photosystem II function and increased reactive oxygen species accumulation, lipid peroxidation, and electrolyte leakage. Compared with heat treatment alone, seedlings receiving salicylic acid under heat showed an 82.2% higher net photosynthetic rate, a 12.2% higher maximum quantum efficiency of photosystem II, and a 116.4% higher performance index on an absorption basis. Hydrogen peroxide, malondialdehyde, and electrolyte leakage were 35.1%, 35.8%, and 32.5% lower, respectively. Antioxidant enzyme activities were also higher under heat plus salicylic acid than under heat alone, whereas additional increases in proline and soluble sugars were not statistically confirmed; soluble protein was partially maintained. Gas exchange was measured after treatment at a common leaf-chamber temperature of 25 °C and therefore represented retained photosynthetic capacity under standardized conditions. Overall, foliar application of 0.5 mM salicylic acid was associated with partial maintenance of photosynthetic function and lower oxidative injury during short-term heat exposure. Because one chamber was assigned to each treatment combination in a single experimental run, possible chamber-specific effects could not be statistically separated from treatment-related differences. Independent validation is therefore required. Full article

Chlorophyll content is a key determinant of photosynthetic efficiency and grain yield in rice (Oryza sativa L.), while premature chlorophyll degradation during the reproductive stage can markedly reduce crop productivity. However, the genetic basis underlying chlorophyll degradation and its environmental responsiveness remains incompletely understood. In this study, an F₂ population derived from a cross between the japonica cultivar Shennong0530-9 and the indica cultivar Habataki was used to identify quantitative trait loci (QTLs) associated with chlorophyll content at different developmental stages. A total of 22 QTLs were detected; among these, qCD2 consistently showed a major and stable effect on chlorophyll degradation after heading. Fine mapping using residual heterozygous lines delimited qCD2 to a 54.0 kb genomic interval on the short arm of chromosome 2 containing nine predicted genes. Near-isogenic lines (NIL-qCD2) carrying the qCD2 allele exhibited accelerated chlorophyll loss after heading, accompanied by disrupted chloroplast ultrastructure, reduced photosynthetic capacity, and significant decreases in grain yield and grain quality compared with the recurrent parent. Furthermore, the chlorophyll-deficient phenotype became progressively more severe under elevated temperature conditions, indicating that the phenotypic effect associated with qCD2 is temperature sensitive. Consistent with these physiological changes, the expression patterns of genes involved in chloroplast development, photosynthesis, and leaf senescence were significantly altered in NIL-qCD2. Collectively, these results identify qCD2 as a stable QTL associated with chlorophyll degradation during the reproductive stage and provide a foundation for future identification of the causal gene, providing valuable genetic resources for the molecular breeding of rice with improved photosynthetic efficiency, grain yield, and grain quality. Full article