Salinity and soil water limitation frequently co-occur in semi-arid environments, yet their combined effects on plant water regulation remain insufficiently understood. In this study, we examined how soil moisture influences the physiological responses of beet (Beta vulgaris L.) to increasing salinity, focusing on water relations, osmotic adjustment, and leaf succulence. Beet (B. vulgaris L.) plants were grown in a controlled soil system under a 5 × 3 factorial arrangement with four replicates, combining five irrigation water salinity levels (0–8 dS m⁻¹) and three soil moisture conditions (100
Intensive cucumber cultivation favors the occurrence of pests, particularly Tetranychus urticae (Koch) (Acari: Tetranychidae), which causes damage to leaf tissues, impairing photosynthesis and cellular integrity. Management of this pest is commonly based on chemical control; however, this strategy may intensify oxidative stress in plants. In this context, biological control emerges as a sustainable alternative. This study aimed to evaluate the effects of chemical and biological control on oxidative stress in cucumber plants infested by T. urticae, assessing the action of the pesticide abamectin (Vertimec®) and the predator Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) on the modulation of oxidative responses and the maintenance of redox homeostasis. The experiment was conducted under controlled conditions with five experimental groups: untreated control plants, plants infested with T. urticae, infested plants subjected to biological control with N. californicus, infested plants treated with abamectin, and non-infested plants treated with abamectin. Photosynthetic pigments, oxidative stress indicators, and antioxidant enzyme activities were evaluated. Data were subjected to analysis of variance (ANOVA) followed by Tukey’s test (p ≤ 0.05). Biological control effectively suppressed mite populations while mitigating oxidative damage, whereas chemical control intensified oxidative response, with higher accumulation of reactive oxygen species and increased antioxidant enzyme activity, evidencing an additional metabolic cost to the plants. In contrast, biological control mitigated oxidative damage, maintaining lipid peroxidation levels and enzymatic activity similar to those observed in the control treatment. The use of N. californicus proved to be an efficient and environmentally sustainable strategy for managing T. urticae in cucumber cultivation.
Naga-King chilli suffers from poor and erratic seed germination, which affects its production and productivity as seedling germination and growth is a crucial and sensitive stage affecting overall crop yield. Considering the cultivation niches of Naga-King chili i.e. the Northeastern parts of India, which is characterized by eco-friendly and sustainable farming, there is a need to evaluate the natural plant extracts as a priming medium. It is aimed to improve seed germination and seedling growth using naturally occurring plant material without using any synthetic chemical. Considering this, the extracts from six locally available plants in Sikkim were used to prime the Naga-King chilli seeds and the performance was compared with check (GA3). The results showed that Alnus nepalensis at 5
This study aimed to (i) classify soybean genotypes related to P uptake and utilization efficiencies and responsiveness to P supply; (ii) investigate plant morphological and physiological characteristics related to P efficiencies; and (iii) identify plant traits for selecting P–efficient genotypes. Sixteen soybean genotypes grew under deficient and sufficient P supply (10 and 100 µmol P L− 1). Phosphorus absorption kinetic parameters, root morphology, growth, photosynthetic, and nutritional parameters were determined to investigate the P acquisition efficiency (PAE) and P utilization efficiency (PUE). Soybean genotypes with high PAE exhibited a twofold greater P influx, and approximately 25
Perennial species frequently experience repeated droughts; however their physiological and biochemical responses to sequential drought exposure remain poorly understood. This study investigated whether prior drought exposure enhances subsequent drought tolerance in Karelinia caspia seedlings by comparing primed [double drought: 50-day drought followed by 60-daydrought] and unprimed [single 60-day drought] treatments. Compared with unprimed seedlings, primed seedlings exhibited significantly higher shoot biomass, leaf relative water content, and chlorophyll a, and Rubisco activity. These improvements were associated with enhanced antioxidant defense system, including increased activities of superoxide dismutase, peroxidase, monodehydroascorbate peroxidase, and ascorbate peroxidase, together with higher ascorbate/dehydroascorbate and glutathione/oxidized glutathione ratios, resulting in lower superoxide anion, hydrogen peroxide and lipid peroxidation. Roots showed stronger antioxidant responses than leaves, with increased catalase, polyphenol oxidase, glutathione peroxidase, and glutathione reductase activities under double drought. Hormonal regulation also contributed to priming-induced drought-tolerance. Primed seedlings showed increased levels of growth- promoting hormones, including indole-3-acetic acid, gibberellin, zeatin riboside, and brassinosteroids, which likely supported growth under stress conditions. Moreover, proline, and glycine betaine, accumulation increased significantly in primed seedlings, contributing to improved osmotic adjustment. Elevated strigolactones levels further suggested a role in drought adaptation and root shoot functional responses. Principal component analysis demonstrated that drought priming enhanced antioxidant defense and osmotic regulation, protecting leaf photosynthetic machinery, while strengthening root antioxidant capacity. Collectively, these coordinated responses enabled primed K. caspia seedlings to maintain better growth and physiological stability under repeated drought. These findings improve our understanding of drought acclimation in perennial plants under hyper-arid environments and may support future ecological restoration strategies under climate change.
A cDNA of VvTrx h4 was isolated from leaf tissue of grape (Vitis vinifera L. cv. Askari) by rapid amplification of cDNA ends (RACE) technique. The VvTrx h4 was heterologously expressed in a bacterial host (Escherichia coli) and its catalytic properties were investigated. The VvTrx h4 showed the disulfide reductase function by reduction of insulin and DTNB as substrates. Under high temperature treatment, the structure of the VvTrx h4 protein was shifted from low molecular weight (LMW) forms to high molecular weight (HMW) species and its disulfide reductase activity subsequently decreased at high temperatures. In addition, the high temperature treatment-dependent structural and functional changes of the VvTrx h4 were induced by treatment with H2O2. Moreover, further incubation of the VvTrx h4 in H2O2 after elimination of DTT almost returned the oligomeric structures of the VvTrx h4, suggesting that the structural alterations of the VvTrx h4 are affected by redox status. Using protein–protein interaction (PPI) network and molecular docking assays, several target proteins were specified for the VvTrx h4, indicating that the VvTrx h4 is able to provide reducing power for peroxidases (POXs) in order to reduce H2O2 in vitro. Nevertheless, with NADPH-thioredoxin system (NTS), horseradish peroxidase (HRP) catalyzed the reduction of H2O2 more efficiently than glutathione peroxidase (GPX), showing that the VvTrx h4 may act as a regulator for enzymes scavenging reactive oxygen species (ROS). Moreover, the GPX may be indirectly reduced by the NTS pathway through reduced glutathione (GSH), proposing a crosstalk between the NTS and the GSH/GSSG pathways.
Drought stress severely limits lentil (Lens culinaris Medik.) productivity in dryland farming systems, necessitating effective and sustainable mitigation strategies. This field study evaluated the individual and combined effects of the plant growth-promoting rhizobacteria (PGPR) Pseudomonas fluorescens inoculation and foliar applications of melatonin and spermidine on growth, physiological traits, antioxidant responses, yield, and drought-related gene expression under rainfed conditions. Bacterial inoculation significantly increased plant height (45
Soil salinization is an increasing global concern, demanding sustainable strategies for agricultural recovery and food security. Halophytes such as Alternanthera littoralis P. Beauv. represent a promising alternative for phytoremediation and forage production in saline environments. This study evaluated gas exchange, effective quantum yield of PSII (ΦPSII), electron transport rate (ETR), antioxidative enzyme activity, and nutritional composition of A. littoralis under 0, 100, 200, and 300 mM NaCl. The species showed high salinity tolerance, with preferential Na⁺ accumulation in shoots (up to 84.51 g kg⁻¹ dry mass at 300 mM NaCl) and maximum accumulation in roots (21.94 g kg⁻¹ at 200 mM), highlighting its potential for Na⁺ phytoextraction. Despite increasing salinity, A. littoralis maintained stable ΦPSII and electron transport rate (ETR) values under saline conditions, indicating maintenance of photochemical activity. Leaf SOD activity increased under saline conditions, whereas MDA, H₂O₂, and electrolyte leakage did not differ among treatments, suggesting activation of antioxidative defense response without evidence of severe oxidative damage. Bromatological analyses revealed high protein content, reduced acid detergent fiber, and increased concentrations of essential minerals. These compositional changes were associated with higher in vitro dry matter digestibility under increasing NaCl concentrations, suggesting a potential forage application for the species under saline conditions. Collectively, these findings demonstrate the remarkable salinity tolerance of A. littoralis, highlighting its ability to maintain physiological functionality under saline conditions. In addition, the species shows potential as a multifunctional resource for the recovery of salt-affected soils and as a nutritious forage in saline environments.
Sugar metabolism is a central determinant of grape berry quality, influencing sweetness, texture, and consumer preference. Comparative insights into enzymatic and transcriptional regulation of sugar accumulation among muscadine (Vitis rotundifolia Michx), hybrid bunch (Vitis spp.), and bunch (Vitis vinifera L) grapes remain limited. We examined: four representative genotypes two muscadines (Black Beauty, Regale), one hybrid bunch (Blanc du Bois), and one bunch grape (Barbera) across four developmental stages: pea, green, veraison, and ripe. Berry weight and diameter increased progressively, with muscadines producing the largest berries, particularly Black Beauty ( 13.1 g; 29.6 mm). Total soluble solids rose from 4.0 to 15.8 °Brix, whereas titratable acidity declined during ripening. Sucrose accumulated exclusively in muscadines at veraison and ripening, while glucose and fructose dominated all genotypes and rose sharply at ripening, with total sugar concentration ranking Barbera > Blanc du Bois > Black Beauty > Regale. Muscadines exhibited enhanced sucrose synthesis and retention, reflected by higher sucrose-phosphate synthase and sucrose synthase activities and concomitant invertase inhibition. In contrast, hybrid and bunch grapes favored invertase-driven sucrose cleavage and hexose accumulation. Elevated expression of invertase inhibitor genes (VvInvI15, VvInvI2(1), and VvInvI18(1)) in muscadines supports post-translational suppression of invertase activity, while reduced VvSWEET15 expression suggests lower sugar import capacity during late development. Multivariate analyses, including principal component and heatmap clustering, revealed distinct metabolic and transcriptional signatures separating muscadine from bunch grapes. These findings provide a mechanistic link between domestication and sugar metabolism and highlight key enzymatic and regulatory nodes for improving berry sweetness in grape breeding programs.
Olive mill waste (OMW) presents a complex environmental challenge due to its high phenolic content and acidity, yet its precise impact on integrated plant metabolic networks remains poorly understood. This study investigates the physiological and biochemical plasticity of broad bean (Vicia faba L.) in response to increasing concentrations (0
This study explored the efficacy of methyl jasmonate (MJ) in reinforcing the immune system, affecting epigenetic regulation, influencing gene transcription, and conferring cadmium (Cd) tolerance. Basil seedlings were grown in the hormone-free culture medium containing MJ (0 or 10 µM) and/or Cd (0 or 100 µM). The results showed that MJ treatment significantly increased the fresh weight of leaves (31.6
Cluster beans (Cyamopsis tetragonoloba L.) are economically valuable vegetables, but their growth is severely affected by (root rot and wilt) rhizosphere pathogens. Rhizospheric soil samples were collected for the first time to study soil-borne pathogens (Macrophomina phaseolina, Rhizoctonia solani, and Fusarium solani) associated with cluster beans. A growth experiment was performed to isolate and colonize these pathogens, and antioxidant enzyme activities were measured at 2, 5, 10, and 15 days after infection (DAI). R. solani, M. phaseolina, and F. solani have reduced plant growth, but root development was more deteriorated than the shoot. Root colonization by R. solani, M. phaseolina, and F. solani significantly increased over time. Protein levels, polyphenoloxidase, and phenylalanine ammonia lyase activities were enhanced in infected plants at 10 and 15 DAI compared to those in non-infected controls. Catalase, ascorbate peroxidase, and guaiacol peroxidase activities were higher at 10 and 15 DAI in diseased plants than in the controls. Root colonization by R. solani, M. phaseolina, and F. solani increased enzyme activity. Pathogens residing in the soil rhizosphere are critical for reducing cluster bean growth, and increased activation of antioxidant enzyme activities can enhance disease resistance and crop fitness, thereby promoting long-term plant survival. .
Elevated atmospheric CO2 (eCO2) will reshape crop physiology, yet genotypic differences in responsiveness remain poorly resolved. We compared nine Raphanus sativus cultivars grown at 400, 800 and 1200 ppm CO2 to quantify coordinated changes in leaf gas exchange, pigment composition and stomatal traits. Across cultivars, CO2 enrichment significantly increased net assimilation (P < 0.05) while stomatal conductance declined and intercellular CO2 rose. Chlorophyll a and b increased with CO2, and zeaxanthin generally accumulated, whereas β-carotene changed only slightly, revealing cultivar-dependent reallocation within the photosynthetic pigment system. Stomatal density responded in a genotype-specific manner, increasing in several cultivars but remaining stable or decreasing in others, highlighting plasticity in epidermal patterning under CO2 enrichment. Parallel-analysis PCA identified a single dominant axis integrating assimilation (Ci), pigments, and stomatal traits, with elevated CO2 shifting cultivars toward higher PC1 scores. Several traits showed significant CO2 x cultivar interactions, confirming differential responsiveness among genotypes. Together, these results identify cultivars differing in CO2-driven physiological responsiveness and trait coordination under elevated CO2.
Carrot (Daucus carota L.) is widely known for its nutritional composition but its growth and development are severely affected by heat stress. The study was executed to identify the mechanisms underlying the carrot plants’ ability to tolerate heat stress to mitigate challenges imposed by climate change. Eight carrot genotypes including PC-100, PC-ABR, PC-CPUR and, PC-DJAL (tolerant) and PC-163, Desi Red, CCJ-2 and, PC-172 (sensitive) were grown under early (heat stress) and main (control) conditions. PC-100 demonstrated heat tolerance in terms of yield and yield-contributing traits in the field, followed by PC-DJAL, PC-ABR, and PC-CPUR. Genotypes PC-CPUR and PC-100 depicted highest chlorophyll content during both the seasons. Superoxide dismutase (SOD) was found to be maximum in the roots and leaves of PC-100 during both the seasons. Heat stress activated Asada-Halliwell pathway in PC-100, PC-CPUR, and PC-ABR revealing higher activities of ascorbate peroxidase (APX) and glutathione reductase (GR) alongwith higher Reduced/Oxidised glutathione content (GSH/GSSG ratio). These genotypes were negatively correlated with Hydrogen peroxide (H2O2) content while showed positive correlation with carrot yield. PC-ABR, another tolerant genotype depicted more than 2.2 folds increase in CAT activity during heat stress. PC-100, PC-ABR, PC-CPUR and PC-DJAL showed higher proline and glycine betaine contents during both seasons. These carrot genotypes displaying tolerant behaviour in response to heat stress may be exploited by plant breeders to develop improved thermotolerant varieties.
This study investigates the gender-specific response mechanisms of Populus cathayana and Salix babylonica to strontium (Sr) stress using controlled pot experiments. The research focused on Sr enrichment traits and physiological reactions under varying Sr²⁺ concentrations. Results indicated that the translocation coefficient was higher in S. babylonica than in P. cathayana, particularly in females. The value in female S. babylonica (3.026) was 1.36 times that in P. cathayana. Gender-based differences in translocation were significant in both species. Under high Sr²⁺ stress (100 mg·L⁻¹), leaf area was inhibited in both species, whereas the height of P. cathayana was promoted, with males growing 1.22 times taller than females. Low Sr²⁺ treatment (10 mg·L⁻¹) enhanced stomatal conductance (Gs), transpiration rate (E), and net photosynthetic rate (A) in females of both species. Antioxidant enzyme activities in male P. cathayana and female S. babylonica showed an initial increase followed by a decrease with rising Sr²⁺ levels. The PLS-PM model further elucidated the relationships among biological enrichment, osmotic regulators, soil enzyme activities, and photosynthetic parameters. These findings provide a theoretical basis for breeding Sr-resistant woody plants and contribute to understanding the interaction between plant gender and environmental stress.
Soil salinity hampers crop growth and productivity by impairing root functions due to nutrient deficiency and/or reduced water uptake. The carbon-rich soil amendments may reduce these adverse effects of salinity on plants. Based on this hypothesis, the objective of this study was to evaluate the physiological changes and growth of safflower (Carthamus tinctorius L.) roots under salt stress (non-saline, 6, and 12 dS m⁻¹) in response to various biochar treatments (control, 30 g kg⁻¹ solid biochar, 30 g kg⁻¹ nano-silicon dioxide enriched biochar, 30 g kg⁻¹ nano-calcium carbonate enriched biochar, and a combination of 15 g kg⁻¹ nano-silicon dioxide + 15 g kg⁻¹ nano-calcium carbonate enriched biochars). The biochar-related treatments greatly reduced sodium uptake and enhanced soil pH, cation exchange capacity, and nutrient contents of plant roots. Root length, weight, and density were noticeably enhanced by solid and especially enriched biochars under both saline and non-saline conditions. The biochar-related treatments decreased root lignification and osmolytes such as proline, glycine betaine, soluble carbohydrates, and proteins by increasing root water content, which helped to improve shoot mass and grain yield under salt stress. The findings of this study demonstrate that pure and particularly nanoparticle-enriched biochars have great potential to enhance root and shoot growth of safflower plants under salinity by improving soil properties and reducing salt toxicity.
In their natural habitat, plants confront a diverse array of pathogens including bacteria, viruses, nematodes, and fungi, collectively referred to as biotic stress, Distinguished multilayered response mechanisms are part of the intricate defense system in plants that evolved through time. The initial line of defense is Pattern-triggered immunity (PTI), which involves the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), followed by effector-triggered immunity (ETI) mediated by resistance (R) proteins. At the heart of these defense mechanisms, phytohormones such as salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and abscisic acid (ABA) orchestrate intricate regulatory networks. Additionally, phytohormones commonly known for plant growth, such as auxin (AUX), cytokinin (CK), gibberellic acid (GA), and brassinosteroids (BR) have emerged as key players in immune responses. As the plant deploys various defense strategies, pathogens employ clever molecular tactics to disrupt hormone biogenesis and signaling pathways, thereby creating a constant interplay in the struggle for dominance. Therefore, understanding these regulatory mechanisms is essential for deciphering the plant defense network and developing strategies to enhance crop resilience against pathogens. This review explores the roles of defense hormones and pathogen-mediated disruptions in shaping plant responses to biotic stress.
Environmental stress negatively impacts grain yields, crucial for food security. Several studies have reported influences of salinity on shoots and roots metabolites in spring wheat, but there is a paucity of in-depth information on the extent of these influences on grain metabolome. This study examines metabolome changes in grains from two spring wheat cultivars, GS6058 (salt-sensitive) and JS7 (salt-tolerant), under varying salinity (0 and 80 mM NaCl) and photoperiods (22L:2D and 12L:12D). Results indicate that long light duration increases several yield parameters regardless of cultivar. Metabolomic analysis highlighted key metabolites, with amino acids and derivatives constituting the largest group. Twenty-two metabolites were significantly modified between conditions, influencing critical metabolic pathways related to sulphur, purine, and cysteine metabolism. Candidate biomarkers identified include L-cysteine and adenosine, which are implicated in salt and photoperiod adaptations. Our results also present a baseline information which could be useful in gene expression analysis to further understand the roles played by these candidate biomarkers in grain metabolome alterations under combined salinity and photoperiod effects.
Salvia miltiorrhiza Bunge, a perennial herb of the Lamiaceae, is renowned for its principal bioactive ingredient, tanshinone, which possesses substantial pharmacological value in the treatment of cardiovascular and cerebrovascular diseases. Studies have shown that exogenous elicitor treatments can elevate tanshinone accumulation in S. miltiorrhiza; however, most of these investigations have focused on the transcriptional control of target genes by specific transcription factors. However, the relationship between endogenous phytohormones and tanshinone biosynthesis remains poorly understood. In this study, S. miltiorrhiza seedlings were treated with 200 mg L⁻¹ yeast extract (YE) and the accumulation of tanshinones. Concurrently, the contents of indole-3-acetic acid (IAA) and gibberellin (GA) were significantly up-regulattion, while the content of abscisic acid (ABA) was significantly decreased. TAR2 is a key gene in IAA biosynthesis, and its expression is significantly up-regulated in S. miltiorrhiza following YE treatment. Consequently, hairy root lines overexpressing SmTAR2 were established (designated TAR-OE lines). High-performance liquid chromatography (HPLC) analysis revealed that the tanshinone content in SmTAR2 overexpression lines was significantly higher than that in the wild-type lines. The results indicated that YE optimally promoted tanshinones accumulation by up-regulating the expression of SmTAR2. In summary, this work not only defined a more appropriate YE concentration for eliciting tanshinone biosynthesis in S. miltiorrhiza, but also identified the auxin-synthesis gene SmTAR2 as a potent enhancer of tanshinone accumulation.
Potassium (K) is an essential nutrient for plant growth, yet both deficiency and excess limit crop productivity. Understanding the metabolic mechanisms underlying genotypic variation in K utilization efficiency (KUE) is critical for improving soybean performance under variable K supply. We compared two soybean cultivars, Glycine max cv. Satonohohoemi (K-efficient) and Tachinagaha (K-sensitive), grown under 6, 60, and 120 mg L⁻¹ K, and performed untargeted CE-TOF-MS metabolomics of roots and shoots at 7 and 14 days after transplanting. Satonohohoemi maintained higher shoot biomass and KUE under K deficiency despite lower tissue K, demonstrating superior physiological efficiency. Metabolomic profiling revealed genotype-specific metabolic reprogramming: Satonohohoemi selectively activated nitrogen-associated amino-acid pathways, central carbon metabolism including TCA and glyoxylate cycles, and redox-related metabolites such as 5-oxoproline and trehalose-6-phosphate, whereas Tachinagaha exhibited widespread metabolite depletion under stress. Root metabolomes exhibited the greatest genotypic differentiation, with Satonohohoemi sustaining arginine/proline metabolism, nucleotide turnover, and central carbon flux, reflecting coordinated root–shoot integration. Pathway enrichment analysis indicated that Satonohohoemi maintains conserved metabolic networks under both low and high K, underpinning its superior KUE. These findings reveal that KUE in soybean is driven by targeted, coordinated metabolic rewiring rather than broad metabolite accumulation, and identify potential metabolic biomarkers for screening K-efficient genotypes.
