Search Results (3,895)

Salinization of agricultural soils is a global problem causing crop yield declines. This impact is caused by osmotic and oxidative stress, which plants often rely on endophytic bacteria to overcome. A bacterial isolate from the roots of the halophyte Plantago salsa was studied between 2024 and 2026, and its ability to increase barley tolerance to moderate salt stress was determined. Based on 16S rRNA gene sequencing (1410 bp), the isolate PS-50.1 was identified as Providencia sp. It demonstrated key plant growth-promoting properties, including indole-3-acetic acid production (21.4 mg L⁻¹) and phosphate solubilization (69.0 mg L⁻¹). The strain supported barley growth at 7% NaCl. Inoculation of barley seeds with this strain (10⁸ CFU L⁻¹) significantly reduced moderate salt stress in plants both in vitro and in a pot experiment. Inoculated plants under salinity conditions had greater shoot length (+11.6%) compared to non-inoculated; higher pre-flag leaf fresh weight; demonstrated decreased levels of prooxidants (H₂O₂ by 44.8% and malondialdehyde by 31.8%), higher proline accumulation (up to 2.0-fold), and increased antioxidant enzyme activity (catalase by 26.6% and ascorbate peroxidase by 191%). Furthermore, inoculated plants showed 9.4% higher water use efficiency and photosynthetic rate (+5.5%) under salt stress compared to uninoculated plants. These results indicate that the halophytic strain Providencia sp. PS-50.1 is a promising candidate for the development of microbial preparations aimed at increasing crop productivity under saline conditions. Full article

Global crop production faces serious threats from soil salinization. Microbial resources are often exploited to be used as fertilizers or seed coatings to address this issue. Parametarhizium changbaiense, as a novel beneficial microorganism, has been discovered to be capable of assisting limited crops such as mung bean in resisting salt–alkali stress. To investigate the effects of P. changbaiense on sugar beet under salt–alkali stress, the salt (NaCl:Na₂SO₄, molar ratio 9:1) and alkali (NaHCO₃:Na₂CO₃, molar ratio 9:1) stress were set on sugar beet germplasm 780016B. Results demonstrated that P. changbaiense improved the phenotypic characteristics of sugar beet seedlings under salt–alkali stress. The biomass parameters such as plant height and fresh weight significantly increased by growth-promoting effect. The elevated antioxidant enzyme activity could help protect plants from ROS damage induced by stress. Relative electrical conductivity and MDA content decreased with inoculation, thereby mitigating membrane lipid peroxidation and improving membrane system stability. The higher content of soluble sugar could maintain cell turgor pressure and alleviate osmotic stress. Inoculation with P. changbaiense enhanced chlorophyll content, fluorescence, and photosynthetic capacity. The more superior root vitality and architecture were suitable for the functions of metabolism and absorption. P. changbaiense could promote the growth and physiological characteristics under salt–alkali stress, so it has practical application value in agricultural production. Full article

No data to date are available on the underlying mechanisms by which coumarin (COU) alleviates plant aluminum (Al) toxicity. Citrus grandis (L.) Osbeck seedlings were submitted to 0 (Al0) or 1.2 (Al1.2 or Al³⁺ toxicity) mM AlCl₃·6H₂O and 0 (COU0) or 50 (COU50) μM COU for 18 weeks. The results demonstrated that COU50 attenuated Al1.2-induced decreases of seedling growth, chlorophyll (Chl) level, and CO₂ assimilation (A_CO2) and impairment of the photosynthetic electron transport chain (PETC). Further analysis suggested that reduced tissue Al concentration and enhanced capability to maintain nutrient and redox homeostasis played a role in COU-mediated amelioration of seedling growth inhibition, leaf Chl and A_CO2 decline, and PETC impairment. Notably, seedlings treated with COU0 showed some adaptive responses to Al1.2. For example, Al1.2 decreased the biosynthesis and accumulation of proteins and amino acids to meet the increased need for energy; increased the diphenylpicrylhydrazyl (DPPH) scavenging activity and phenolic compound accumulation to meet the elevated demand for reactive oxygen species (ROS) and Al detoxification; and increased the accumulation of soluble sugars (glucose, fructose, and sucrose) to meet the augmented demand for ROS scavenging and energy. To conclude, the research revealed some mechanisms for COU-mediated amelioration of plant Al³⁺ toxicity. Full article

Drought severely restricts the growth and secondary metabolism of medicinal plants. Blumea balsamifera is a water-sensitive and economically important medicinal species, yet its molecular regulatory mechanisms in response to drought remain largely unclear, which is worthy of in-depth investigation. In this study, four-month-old B. balsamifera seedlings were subjected to three treatments; normal irrigation (CK), drought stress (DS), and rehydration recovery (RW). Leaf photosynthetic parameters, L-Borneol content, and root physiological indices were determined, and transcriptomic and proteomic analyses were integrated to explore its drought response mechanism. Under drought stress, leaf net photosynthetic rate, transpiration rate, and stomatal conductance decreased sharply, while intercellular CO₂ concentration increased; L-Borneol content showed a biphasic change, and root malondialdehyde content accumulated continuously, accompanied by significant increases in antioxidant enzyme activities and osmotic regulator contents. A total of 9917 differentially expressed genes and 736 differentially expressed proteins were identified, which were mainly enriched in phenylpropanoid biosynthesis, photosynthesis and other pathways, with photosynthesis-related genes and proteins coordinately downregulated. B. balsamifera adapts to drought stress by activating the antioxidant defense system, regulating osmotic substances, and reprogramming photosynthetic networks. The key candidate genes obtained provide important targets for drought-tolerant breeding of this species, and their reliability was verified by RT-qPCR. Full article

Salt stress is one of the main abiotic stress factors affecting plant growth and development. Acetylcholine (ACh) is a potential signaling molecule involved in plant stress resistance and growth, but its role in grapevine stress tolerance remains poorly understood, largely because its exogenous application has not been investigated in grapevines. In this study, we found that 40 μmol/L ACh significantly alleviated salt stress induced by 200 mM NaCl in the Vitis hybrid ‘Summer Black’ (V. vinifera × V. labrusca). Exogenous application of ACh significantly improved plant growth under salt stress, including plant height, stem diameter, root fresh weight, and dry weight, while also increasing chlorophyll content and enhancing photosynthetic efficiency. Additionally, exogenous ACh substantially increased antioxidant enzyme activity and considerably reduced the accumulation of reactive oxygen species and malondialdehyde. Moreover, exogenous application of ACh decreased Na⁺ uptake and dramatically lowered relative electrical conductivity. Comparative transcriptomic analysis revealed that although salt stress repressed genes involved in photosynthesis and carbon fixation, ACh application effectively reversed this suppression by up-regulating transcriptional programs associated with photosystem, carbon metabolism, peroxisome and hormone signal transduction. Collectively, exogenous ACh enhances salt tolerance in grapevines, providing preliminary insights into ACh-mediated stress tolerance signaling in woody plants. Full article

Nitric oxide (NO) and hydrogen sulfide (H₂S) are key gasotransmitters that regulate multiple aspects of plant growth, development, and stress adaptation. Although their individual signaling pathways have been extensively investigated, the integrated mechanisms underlying NO–H₂S crosstalk and its potential agronomic applications remain unclear. This review summarizes current advances in understanding the biochemical interplay between NO and H₂S in plants, emphasizing their synergistic roles in redox regulation, antioxidant activation, ion homeostasis, and photosynthetic protection under abiotic and biotic stresses. Special attention has been given to recent progress in nanotechnology-based delivery systems that enable the controlled, localized, and sustained release of gasotransmitters, thereby improving bioavailability and minimizing environmental losses. Studies on foliar, seed, and nutrient-solution applications have demonstrated that combined NO/H₂S treatments increase stress tolerance by activating the ascorbate–glutathione (AsA–GSH) cycle, reducing the expression of oxidative markers such as hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), and improving both short-term (Fv/Fm, antioxidant enzyme activity) and long-term (biomass, SPAD index, yield) physiological outcomes. By integrating molecular insights with applied strategies, this review outlines the emerging potential of NO–H₂S signaling as a sustainable tool for crop management in the context of climate change and food security. Full article

This study evaluated the phytoremediation potential of the halophytic plant Sesuvium portulacastrum (L.) L. for treating industrial wastewater (IWW) in a hydroponic system over a nine-day exposure period. After treatment, the physicochemical analysis of IWW revealed a significant decrease in chemical oxygen demand (COD), biological oxygen demand (BOD), TSs (total solids), total dissolved solids (TDSs), TSSs (total suspended solids), ammonia, phosphate, and nitrate. The COD and BOD were reduced by 90.7% and 82.9%, respectively. The metal analysis indicated a significant decrease in Fe (95%), Mn (87.4%), and Al (93.9%) and complete removal of Ni, Pd, and Zn. The plant stress responses were assessed through the estimation of photosynthetic pigments (Chlorophyll-a, Chlorophyll-b, Total chlorophyll), phenolic and flavonoid contents, and antioxidant activity. Total chlorophyll declined from 1.449 mg/g (control) to 1.20 mg/g on Day 3, followed by partial recovery to 1.25 mg/g by Day 9, indicating physiological acclimatization. Total phenolic content reached 14 mg GAE/g in leaves and 12 mg GAE/g in stems on Day 6, while Total flavonoid content increased from ~70 µg/g (control) to 115 µg/g on in leaves. The metabolic profiling using GC-MS/MS revealed distinct time- and tissue-specific metabolic responses, with 53 metabolites identified in roots and 62 metabolites in leaves. The major differentially accumulated metabolites were sucrose, pinitol, talose and psicose, with peak accumulation at Day 6. A biphasic metabolic response pattern, characterized by early stress perception followed by adaptability, was observed. Phytotoxicity assays using Vigna radiata demonstrated improved germination from 15% (untreated IWW) to 95% after treatment. Overall, the study highlights the strong phytoremediation potential of halophyte S. portulacastrum as an environmentally friendly alternative for industrial wastewater remediation. Full article

A two-year field experiment was conducted in an organic vineyard in Tuscany (Italy), to evaluate the effects of micronized biochar (0.5% v/v) applied via fertigation on soil fertility/biological quality and Vitis vinifera performance. The biochar, derived from pyrogasified mixed wood, was compared to watered controls (CTR) following a randomized plot design. Soil chemical properties, dehydrogenase (DHA) and alkaline phosphatase (APA) activities, and plant parameters (biomass, leaf area, gas exchange, chlorophyll, flavonols, and foliar nutrients) were assessed in samples collected in July and September (2021 and 2022). Biochar did not significantly alter total and dissolved organic carbon contents or nitrogen fractions but enhanced DHA and APA activities, alongside increased available phosphorous content (+37.5%) and exchangeable potassium content (+7.1 and +19.7% in September 2021 and July 2022, respectively), indicating improved microbial activity and nutrient availability. Conversely, exchangeable calcium and magnesium contents decreased, likely due to biochar adsorption properties. Plant responses included increased leaf area and dry biomass in 2022, elevated net photosynthesis rate (+14.4%) and apparent carboxylation efficiency, and transient increases in foliar nitrogen, phosphorous and potassium contents, with reduced magnesium concentration (–27%) but stable chlorophyll levels. These findings suggest that low doses of micronized biochar may enhance soil quality and vine physiology, supporting its efficient and effective use in organic vineyards. Full article

Urbanization significantly alters microclimatic and environmental conditions, thereby affecting the physiological functioning of urban trees. This study aimed to evaluate whether leaf-level physiological measurements and satellite-based remote sensing indicators consistently detect similar physiological response patterns across contrasting urban and park environments in Novi Sad, Serbia, using three tree species (Platanus × acerifolia, Celtis australis, and Tilia tomentosa). Leaf gas exchange parameters, including stomatal conductance (g_s), net photosynthesis (A), transpiration rate (E), water use efficiency (WUE), and intercellular CO₂ concentration (Ci), were measured using a CIRAS-3 portable photosynthesis system. Satellite-derived variables included vegetation indices (NDVI, NDRE, NDMI) and land surface temperature (LST), which were used to construct proxy indicators of physiological processes. Results revealed consistent differences between urban and park environments, with urban conditions associated with reduced photosynthetic activity, stomatal conductance, and transpiration, alongside increased physiological stress. These patterns were consistently captured by satellite-derived proxies, demonstrating strong agreement in the direction of physiological responses across species and environments. Species-specific responses were evident, with P. × acerifolia showing the highest sensitivity to urban conditions, C. australis exhibiting intermediate responses, and T. tomentosa suggesting comparatively greater tolerance. The integration of leaf-level measurements with satellite-derived proxies provides a robust framework for scaling physiological processes and monitoring urban tree performance, highlighting the potential of remote sensing for assessing urban vegetation stress and supporting evidence-based urban forestry management. Full article

Xanthophylls are oxygenated carotenoids widely distributed in photosynthetic microorganisms, plants, algae, and certain invertebrates, where they function as key photoprotective and antioxidant pigments. Among them, xanthophylls containing vicinal 1,2-diol moieties exhibit unique chemical reactivity that enables reversible coordination with boron species naturally present in marine and terrestrial environments. The formation of cyclic borate esters between boron and diol-containing xanthophylls induces structural and electronic modifications that may enhance pigment stability and functional performance. Emerging evidence suggests that boron–xanthophyll complexes display improved resistance to photooxidative degradation, enhanced singlet oxygen quenching capacity, and increased radical-scavenging activity compared with their uncomplexed counterparts. In addition, boron coordination can influence molecular conformation, polarity, and supramolecular organization within lipid bilayers, thereby promoting membrane stabilization under conditions of high light exposure and oxidative stress. Together, these effects indicate a cooperative role of boron complexation in amplifying the intrinsic photoprotective and antioxidant properties of xanthophylls. A deeper understanding of the structural basis and biological implications of boron–xanthophyll interactions may provide new insights into adaptive stress tolerance in marine and photosynthetic organisms, as well as guide the development of advanced photoprotective systems for biomedical and technological applications. Full article

Allelopathy means that one plant produces chemical substances to affect the growth of other plants. Crop rotation is considered as a potential strategy to alleviate the allelopathic inhibition. So, it is important to identify rotation crops with wide availability and low inhibitory effects. In this study, the allelopathic potential of soil extracts was investigated on the germination, seedling growth, biomass, and biochemical parameters (malondialdehyde, photosynthetic pigments, and antioxidant enzyme activities) of five crops, by a series of laboratory experiments. Firstly, both soil water extracts (SWE) and soil ethanol extracts (SEE) exhibited allelopathic inhibition on the seed germination and the root length of all seedlings in a dose-dependent relationship. The SWE significantly promoted the shoot length of bok choy and Chinese lettuce, while the SEE had no significant effect in bok choy. The application of SEE resulted in a significant increase in the dry weight of bok choy and rocket. In contrast, SWE had a negligible effect on bok choy and lettuce. Both of them caused decrease in the dry weight of the other seedlings. Then, the allelopathic synthetic effect index of water/ethanol extracts was chemo-inhibitory, and the inhibitory effect increased with increasing extract concentration. The SWE had the strongest inhibition on rocket and the SEE on lettuce. Both of them had the weakest effect on bok choy. The extracts significantly inhibited the photosynthetic capacity in five crops, manifested as decrease in photosynthetic pigments and dose-dependent effects. The malondialdehyde (MDA) content in all crops increased in a dose-dependent manner, confirming that the extracts caused lipid peroxidation. However, the defense strategies of different crops vary significantly. There is crop with active defense, such as bok choy treated with SWE. It delayed oxidative damage by continuously upregulating the activities of superoxide dismutase (SOD) and catalase (CAT). This is the key physiological mechanism for tolerance. There is also the oxidative stress failure type, as follows: CAT activity of rocket and cabbage increased, but the SOD activity did not increase by SEE. This reveals the physiological essence of their sensitivity—the lack of persistent scavenging ability for reactive oxygen species. Based on the inhibition of peroxidase (POD) and ascorbic acid peroxidase (APX), it is speculated that the extracts may inhibit the hydrogen peroxide scavenging pathway, which centered on the ascorbate–glutathione cycle. It is the fundamental reason why the continuous accumulation of MDA though SOD/CAT is up. This study confirmed the allelopathic effects of the water and ethanol extracts on five vegetable crops, and found that bok choy was less affected by them. The soil extracts affected the growth and development of seedlings by regulating their oxidative metabolism and photosynthetic capacity. These results support recommending pak choi as a rotation crop. This provides crops for subsequent field experiments and a new direction for next-step research on continuous cropping obstacles. Full article

The performance of native landraces of Capsicum annuum L. under contrasting production systems remains poorly understood, limiting their evaluation under locally relevant production scenarios. This study evaluated the phenological and productive responses of five genotypes (four native landraces and one commercial cultivar) under two systems representing locally relevant production conditions: open-field (OF) and a substrate-based hydroponic system under low-technology, passively ventilated tunnel-type greenhouse conditions (GH), to describe genotype-specific responses under contrasting production conditions during the 2023 growing season in Puebla, Mexico. Agroclimatic and agronomic variables were analyzed using independent ANOVA by system and canonical correlation analysis (CCA). The GH system exhibited restrictive microclimatic conditions, with maximum temperatures exceeding 48 °C and photosynthetically active radiation reduced by approximately 53% compared to OF conditions. Environmental conditions were not standardized between systems; therefore, the results reflect the contrasting microclimates of locally relevant production systems and provide a context-specific assessment of genotype performance. Under the specific conditions evaluated, yield was lower in GH compared to OF across all genotypes. The commercial cultivar Serrano Tampico achieved the highest yield (1.118 kg per plant under OF), while Mixteco Largo and Cola de Ratón produced the highest number of fruits. The CCA identified genotype-specific associations between environmental and agronomic variables, suggesting distinct performance patterns under contrasting production conditions, with native landraces exhibiting better agronomic performance under OF conditions. Overall, the results provide a context-specific characterization of genotype performance under contrasting production conditions. Full article

Solanum lycopersicum is highly sensitive to water deficits, which negatively affect photosynthesis and increase oxidative stress. Although chitosan nanoparticles (ChNPs) offer a sustainable solution, research on their effects on this species is scarce. This study evaluated whether ChNPs mitigate the physiological and biochemical effects of water deficit on S. lycopersicum seedlings. Thirty-day-old seedlings were grown under greenhouse conditions, and two irrigation levels were established: 80% of substrate water-holding capacity (well-watered, WW), and 50% of water-holding capacity (mild-to-moderate water deficit, WD). Spherical ChNPs with a size of 39.52 ± 10.9 nm were suspended in 1% acetic acid and foliar-applied at 0, 60, or 120 mg L⁻¹. After 10 days, biomass accumulation, chlorophyll fluorescence parameters (F_v′/F_m′, ΦPSII, and ETR), gas exchange, and non-enzymatic antioxidant traits were determined. Even under this early-stage stress regime, water deficit significantly reduced shoot and root biomass, net photosynthesis, and stomatal conductance, while increasing lipid peroxidation. Foliar application of ChNPs, particularly at 60 mg L⁻¹, restored dry matter production and improved photochemical efficiency and electron transport rate by 14%; likewise, net CO₂ assimilation increased by 11.7%. In addition, this dose enhanced antioxidant activity and total phenols by 66% and 1.6-fold, respectively. ChNPs at 60 mg L⁻¹ mitigated the effects of WD in S. lycopersicum by increasing antioxidant and photosynthetic performances. Nevertheless, additional molecular studies, including enzymatic antioxidant characterization and compatible solute profiling, are required to elucidate the mechanisms involved. Full article

Winter wheat (Triticum aestivum L.) production in the Yellow River Delta is limited by saline–alkali soils and freshwater scarcity, while the responses of different straw-returning modes under contrasting irrigation regimes remain unclear. A field experiment was conducted with two irrigation regimes, normal irrigation (W1) and deficit irrigation (W2), and four straw-returning modes, direct straw return (RS), straw-derived cattle manure return (RM), straw biochar return (RB), and straw pellet return (RG). The experiment followed a split-plot randomized block design with three replicates. Soil properties, leaf physiology, photosynthetic performance, grain yield, and irrigation water use efficiency (IWUE) were evaluated. Compared with W2, W1 increased mean grain yield by 9.4%, whereas W2 increased mean IWUE by 36.7%. Among the straw-returning modes, RS showed the most consistent performance. Under W1, W1RS produced the highest grain yield (3509.72 kg ha⁻¹). The stable performance of RS was characterized by relatively favorable soil moisture status, lower MDA content, higher antioxidant enzyme activity, and better maintenance of Pn. Pearson correlation analysis showed that grain yield was positively correlated with Pn and CAT activity, whereas MDA was negatively correlated with Pn. These results suggest that RS may be a feasible straw-returning mode for winter wheat production in saline–alkali soil. Full article

Chloroplasts are the primary sites of photosynthesis, but growing evidence highlights their broader role as central hubs that coordinate plant responses to environmental challenges. They retain a semi-autonomous genetic system and communicate extensively with the nucleus through anterograde and retrograde signalling pathways, enabling coordinated cellular regulation. Beyond energy conversion, chloroplasts host key biosynthetic pathways and dynamically adjust their metabolic and redox states in response to developmental and environmental cues. This review summarizes the current knowledge of chloroplast functions in response to abiotic and biotic stresses, emphasizing their contribution to plant resilience, productivity and sustainability. Under abiotic stress, chloroplasts undergo structural, metabolic and redox reprogramming to maintain photosynthetic efficiency and metabolic homeostasis. During biotic stress, they act as a powerful signalling platform that integrates immune responses with metabolic and redox regulation. These functions rely on overlapping signalling pathways that are differentially tuned to support acclimation or defence. By coordinating stress responses with photosynthetic activity and metabolic efficiency, chloroplasts play a central role in sustaining plant productivity and represent promising targets for enhancing crop resilience and agricultural sustainability under climate change and increasing pathogen pressure. Full article