Stresses, Volume 6, Issue 2 (June 2026) – 12 articles

Rice cultivation faces major environmental challenges due to climate change, particularly soil salinity, which limits plant growth and productivity. Salt tolerance in rice is typically evaluated using physiological and biochemical traits, whereas leaf anatomical traits combined with advanced statistical analyses remain underexplored. This study investigated leaf anatomical characteristics of the rice cultivar Tubtim Chumphae at the seedling stage under different salinity levels (0, 25, 50, 75, and 100 mM NaCl). Seedlings were cultivated in a soil-based pot system for 42 days prior to treatment, and salinity stress was applied for 4 weeks. Data were analyzed using the Kruskal–Wallis test and multivariate approaches, including Discriminant Analysis of Principal Components (DAPC) and Partial Least Squares Discriminant Analysis (PLS-DA). The results revealed that several anatomical traits significantly varied with salinity, including vertical epidermal cell size of long cells (Epi-VL-LC), major vascular bundle size in the lamina (MVB-la-HL), major vascular bundle size in the midrib (MVB-mid-HL and MVB-mid-VL), as well as stomatal size (St-HL and St-VL) and stomatal density (StD) (p < 0.01). DAPC effectively distinguished salinity levels based on leaf anatomical traits, and the PLS-DA results further supported the robustness of the classification. Epidermal cell size, cell wall and cuticle thickness, stomatal traits, and vascular bundle dimensions were identified as key candidate anatomical biomarkers of salt tolerance. S75 (75 mM NaCl treatment) was suitable as a screening level and S100 (100 mM NaCl treatment) as a confirmation level. The findings provide a useful reference for evaluating salt tolerance in this rice cultivar and may be integrated with morphological, physiological, and biochemical traits to support future rice breeding programs. These findings provide a reference for evaluating salt tolerance in this cultivar and may complement morphological, physiological, and biochemical traits in future rice breeding programs. Full article

The role of endogenous salicylic acid (SA), a major signaling molecule, was addressed in relation to the waterlogging (WL) stress response, including redox homeostasis and senescence. Wild-type and salicylate hydroxylase-expressing (NahG) tobacco plants were studied to reveal the stress-related effects of the transgene, which is known to deplete the endogenous SA pool. In control conditions, SA levels of the top leaves of NahG plants were moderately lower than those of wild-type, while SA was considerably reduced in the bottom leaves. WL conditions triggered a rise in H₂O₂ concentrations in young leaves, which was exaggerated in NahG plants, pointing to a mitigating effect of SA against the stress-associated oxidative burden. The NahG transgenic leaves displayed lower protein levels than their wild-type counterparts, indicating a role of SA in protein retention. In non-stressed NahG plants, young (top) leaves showed an increased level of protein nitration. WL treatment triggered decreased protein contents in the leaves of both genotypes. This coincided with the high H₂O₂ content of old leaves exceeding that of young leaves in most cases. The expression of the senescence marker gene Cysteine protease 1 was upregulated in WL-stressed bottom leaves. According to this marker, senescence progressed faster in NahG leaves. Links between SA, protein nitration, and leaf senescence were discussed. Additionally, a stimulating effect of the NahG transgene was confirmed on adventitious roots (AR) formation, which may have helped root functions and thus probably contributed to maintaining the growth of the WL-stressed plants. Our results have implications for how endogenous SA levels influence plants in a WL stress situation. According to our findings, the depletion of SA may trigger protein loss and tyrosine nitration, but at the same time accelerates AR formation in WL-stressed tobacco. Full article

Methane (CH₄) is the second most important greenhouse gas after carbon dioxide (CO₂), and its atmospheric concentration is on the rise. Soil CH₄ consumption (=absorption) capacity is declining due to reduced forests and green spaces, as well as other environmental factors and anaerobic stresses. Environmental and stand structure parameters were cross-referenced with publicly available international ecosystem databases, such as FLUXNET, ICOS, NEON, AmeriFlux, the TRY plant trait database and the Oak Ridge FACE site. Searches were conducted using keywords such as region, water level, and stand density. The data indicate that under high-CO₂ conditions, the increase of forest canopy density leads to increased litter accumulation on the forest floor and reduced sunlight penetration, creating anaerobic conditions. This can cause forests to shift from CH₄ consumption to CH₄ release. Based on these findings, we discussed methods to maintain and enhance the CH₄-absorbing capacity of forest soils. This can be achieved through management practices that improve environmental conditions and increase soil fauna’s activity, such as those associated with thinning operations in overmature forest stands across various regions. This ecological manipulation through thinning practices promotes ground-level temperature increases and the activities of soil fauna, as well as maintaining aerobic conditions near the soil surface. Full article

Polystyrene nanoplastics (PS-NPs) are emerging environmental contaminants increasingly linked to male reproductive toxicity; however, the molecular mechanisms underlying testicular damage remain unclear. This study evaluated PS-NP-associated testicular damage in rats after 55 days of exposure and assessed the modulatory effects of Nelumbo nucifera leaf, flower, and rhizome extracts, with quercetin as a reference. PS-NP exposure reduced spermatogenic cell populations, testicular, epididymal weights, and sperm motility. These changes were accompanied by increased NOX4 and NF-κB expression, upregulation of intrinsic apoptosis-related genes (Tp53, Bax, Caspase-9, and Caspase-3), elevated caspase-3 and caspase-9 protein levels, and enhanced cleaved caspase-3 immunoreactivity. In contrast, Fas and Caspase-8 were downregulated, confirming intrinsic mitochondrial apoptosis. PS-NP exposure also altered reproductive hormone receptor expression (LHr, FSHr, and AR) and dysregulated chromatin-regulatory genes, with increased Dnmt1, Dnmt3a, and Ehmt2 (G9a) and decreased Hdac1 and Ep300. Co-administration of N. nucifera attenuated most of these alterations, with the rhizome extract exhibiting the most pronounced protective effect. GO and PPI network analyses suggested functional connectivity among stress-responsive, apoptotic, and chromatin-modifying proteins. Docking simulations indicated phytochemical-apoptosis-related protein interactions. PS-NPs may impair testicular homeostasis through coordinated stress, apoptosis, endocrine disturbance, and epigenetic dysregulation, with possible relevance to male reproductive health, while N. nucifera shows promise as a protective modulator. Full article

Reactive oxygen species (ROS) are integral components of plant signaling networks that mediate interactions between plants and their environment, thereby regulating diverse physiological and biochemical processes. While controlled ROS production is essential for stress perception and signal transduction, excessive ROS accumulation induces oxidative damage. ROS-mediated lipid peroxidation of polyunsaturated fatty acids leads to the formation of highly electrophilic α,β-unsaturated carbonyl compounds collectively referred to as reactive carbonyl species (RCS). Under severe abiotic stress conditions, excessive RCS accumulation exerts cytotoxic effects and causes widespread cellular dysfunction. In contrast, at subtoxic levels, RCS function as important secondary messengers that modulate stress-responsive signaling pathways, including programmed cell death, stomatal regulation, and adaptive responses to abiotic stresses. This review critically synthesizes current advances in understanding the dual roles of ROS and RCS as both damaging agents and signaling molecules in plants. Particular emphasis is placed on the mechanistic basis of ROS-RCS crosstalk and their interactions in abiotic stress tolerance. Furthermore, this review highlights emerging research gaps and outlines future perspectives aimed at translating redox signaling insights into strategies for improving plant stress resilience under changing environmental conditions. Full article

Oleanolic acid (OA) is a hydrophobic pentacyclic triterpene widely distributed in the plant kingdom and characterized by broad biological activity, including antioxidant, anti-inflammatory, neuroprotective, renoprotective, and anticancer effects. Increasing evidence suggests, however, that many of these actions are better explained not by single molecular targets, but by OA-dependent modulation of an integrated organelle stress network involving mitochondria, the endoplasmic reticulum (ER), autophagy, mitophagy, and apoptosis. This review critically analyzes the available evidence on the effects of OA on the mitochondria–ER–autophagy–apoptosis axis, with particular emphasis on mechanisms governing the transition between cellular adaptation and cell death. The available literature indicates that, in non-cancer models, OA most commonly lowers reactive oxygen species (ROS), stabilizes mitochondrial function, attenuates the ER stress signature, and promotes adaptive autophagy and mitophagy. In contrast, in many cancer models, OA may enhance mitochondrial dysfunction, lower the threshold for mitochondrial apoptosis, and induce autophagy that can be either protective or cytotoxic depending on the biological context. Overall, the current evidence supports a model in which OA acts as a context-dependent modulator of the organelle stress threshold, shifting the balance of an integrated mitochondria–ER–autophagy–apoptosis network rather than functioning as a uniformly cytoprotective or uniformly proapoptotic compound. At the same time, the literature remains heterogeneous with respect to models, doses, exposure times, and markers used, while poor aqueous solubility and limited bioavailability continue to constrain translation. Future studies should therefore integrate analyses of mitochondria, ER, mitochondria–ER contact sites (MERCS), autophagy, apoptosis, pharmacokinetics, formulation, and safety in order to define the true potential of OA as a modulator of biological stress. Full article

Cadmium (Cd) accumulation in plant tissues causes several damages, including disturbances in anatomical structures, negative impacts on photochemical reactions, and reducing the efficiency of the photosynthetic apparatus. 24-Epibrassinolide (EBR) is a plant steroid that regulates multiple physiological and biochemical processes to counteract the harmful effects of metal stress. The aim of this research was to investigate whether exogenous EBR application affects leaf and root anatomical structures, including stomatal responses, redox-metabolism-related biochemical responses intrinsically related to photosynthetic apparatus, and nutritional status in soybean plants under Cd excess. The experiment was randomized with four treatments: two cadmium concentrations (0 and 500 µM Cd, described as −Cd and +Cd, respectively) and two EBR levels (0 and 100 nM EBR, described as −EBR and +EBR, respectively). Results demonstrated that EBR positively regulated root and leaf structures and stomatal performance, with significant increases in epidermis and cortex (root) and benefits for spongy parenchyma and stomatal density (leaf), clearly protecting the photosynthetic apparatus against Cd excess. Simultaneously, this steroid mitigated Cd-induced oxidative stress by stimulating the activities of superoxide dismutase (25%), catalase (28%), ascorbate peroxidase (30%) and peroxidase (48%), while simultaneously reducing the content of oxidative compounds, including superoxide (16%), hydrogen peroxide (8%), malondialdehyde (12%) and electrolyte leakage (14%). The dual mechanism modulated by EBR protected anatomical structures and stimulated antioxidant defense. Therefore, the results prove that exogenous EBR application effectively attenuates the adverse effects of Cd excess in soybean plants. Full article

Smoking is a major lifestyle factor associated with impaired male reproductive health, affecting both active smokers and individuals exposed to secondhand smoke. It also represents a significant source of cadmium (Cd) exposure, a toxic metal associated with altered sperm quality. This study aimed to evaluate the association between active and passive smoking and semen parameters, sperm DNA fragmentation, and chromatin decondensation, as well as cadmium (Cd) and zinc (Zn) levels in seminal plasma. A total of 280 men from infertile couples were included and categorized into three groups: 104 non-smokers (control), 90 active smokers, and 86 passive smokers. Semen samples were analyzed according to the WHO 2021 guidelines. Cadmium and zinc concentrations in seminal plasma were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and sperm DNA fragmentation and chromatin decondensation were evaluated. The findings indicated that both active and passive smoking were associated with impaired semen parameters, increased sperm DNA fragmentation and chromatin decondensation, decreased zinc levels, and elevated cadmium concentrations in seminal plasma. Full article

Water deficit is a major abiotic constraint limiting peanut (Arachis hypogaea L.) production. This study evaluated the combined effects of filter cake, foliar application of an amino acid-based biostimulant, microbial consortium inoculation, on peanut growth, physiology, and yield under water scarcity conditions. Treatments were arranged in a split-plot design with four replicates, where filter cake (0 and 5 t ha⁻¹) was assigned to main plots, amino acid application to subplots (0.25 and 0.50 L ha⁻¹), and microbial consortium to sub-subplots (100 and 200 mL m⁻²). At 50 days after sowing, plant growth parameters, relative chlorophyll content, and aboveground biomass were assessed, while yield components and seed yield were determined at harvest. Results indicated that the combined treatment with 5 t ha⁻¹ filter cake, 0.50 L ha⁻¹ amino acids, and 200 mL m⁻² microbial consortium, consistently produced the highest main stem length (increase of 40%), aboveground biomass accumulation (increase of 41%), number of matured pods per plant (increase of 38%), seed mass per plant (increase of 87%), and final seed yield (increase of 86%) compared to the lowest-input treatment (F₀A_0.25M₁₀₀) under water-limited conditions. These findings indicate that the integrated fertilization can improve phenological, physiological, and yield responses and represents a sustainable approach to improve peanut resilience and productivity under water scarcity. Full article

Cross-kingdom pathogenesis—human and animal pathogens colonizing and persisting in plants—is transforming our understanding of microbial ecology, food safety, and public health. This review translates incoming research that demonstrates plants as more than mute carriers to dynamic ecological interfaces where human and zoonotic pathogens, such as Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes, will adhere, internalize, and, in some cases, potentially evade host defenses. Such pathogens exploit evolutionarily conserved molecular processes like Type III secretion system 1 (TTSS), biofilm formation, quorum sensing, and small RNA-mediated immune sabotage that have allowed them to cross biological kingdom boundaries. To provide an entry point for pathogens, environmental conditions (e.g., contaminated irrigation water, manure application, wildlife access, and mechanical wounding) promote pathogen transfer to and penetration into plant tissues through stomata hydathodes above ground or roots below ground. Once inside, pathogens confront a range of plant immune responses, indigenous microbiota, and abiotic stresses such as UV radiation exposure, nutrient starvation, and osmotic fluctuations. Nonetheless, biofilm production, metabolic versatility, and virulence gene expression contribute to their persistence. Interactions with plant pathogens and microbiomes additionally shape colonization dynamics, for example, through co-survival and niche manipulation. With the acceleration of these processes due to climate change, urbanization, and intensified agriculture, cross-kingdom pathogenesis becomes a rising concern for One Health. Critical knowledge gaps, including seedborne transmission, microbiome engineering, and predictive modeling, are pointed out in the review along with emerging mitigation strategies, including point-of-care diagnostics and microbial biocontrol. In conclusion, this review advocates for interdisciplinary collaboration from microbiology, plant science, and One Health perspectives to predict and mitigate cross-kingdom threats to global food production. Full article

Harsh environments and climate change hamper industrial hemp productivity. Under stress conditions, uniform germination and vigorous seedlings are key to sustaining crop establishment and performance. Trichoderma spp. are beneficial micromycetes, able to colonize plant roots and promote plant development even under abiotic stress conditions. Thus, the seed treatment with specifically selected Trichoderma isolates could be a useful strategy to enhance hemp seed germination and plantlet growth. In this view, a preliminary screening was performed with ‘Eletta campana’ cv. Nine out of 20 Trichoderma isolates enhanced the radicle growth (+66–111%); most of them resulted in good root colonization, but only four isolates significantly enhanced the shoot DW (+18–22%). Three isolates were selected for a pot experiment, compared to T. afroharzianum T22, to evaluate the effect on plant growth, root architecture, accumulation of photosynthetic pigments and stress-related compounds, and variation in antioxidant activity in 20-day-old plantlets. T. afroharzianum OR4 significantly promoted plantlet growth (+9% shoot DW and +11% leaf DW). The seed treatment had a low impact on the other variables studied, except in the case of foliar proline content, a marker of stress tolerance, that was greatly increased with T. afroharzianum T22 and T. atrobrunneum X44 (+32% and +17% DW). Full article

Chronic stress is defined as a prolonged state of emotional disturbance and psychological strain resulting from an inability to maintain internal homeostasis. It is recognized as a significant risk factor for breast cancer, primarily through the chronic activation of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis. This neuroendocrine activation leads to elevated systemic levels of epinephrine, norepinephrine, and glucocorticoids. By binding to their respective adrenergic and glucocorticoid receptors, these hormones disrupt immune homeostasis and exacerbate oxidative stress within the tumor microenvironment. Such physiological shifts promote critical oncogenic processes, including angiogenesis and tumor cell proliferation, thereby driving the development, progression, and distant metastasis of breast cancer. Mastication, or the act of chewing, serves as a practical and effective behavioral strategy for modulating the deleterious effects of chronic psychological stress. Recent animal studies have provided compelling evidence that chewing can attenuate excessive stress responses. Specifically, it has been shown to mitigate stress-induced breast cancer progression and metastasis by modulating the expression of stress hormones, their corresponding receptors, and key downstream signaling pathways. These findings suggest that the rhythmic activity of chewing may exert a protective effect against stress-related tumor exacerbation. Consequently, further clinical research is warranted to determine whether chewing interventions can serve as a viable complementary strategy alongside conventional breast cancer prevention and treatment protocols. Full article