Search Results (3,677)

Shallot (Allium hirtifolium Boiss.) is of considerable nutritional and medical significance due to its strong antioxidant properties; however, no nanophytotoxicity studies have assessed whether the use of nanofertilizers would improve shallot performance, micronutrient iron (Fe) enrichment, and yield in semi-arid regions. Herein, we evaluated the effects of magnetite nanoparticles (nFe₃O₄) on shallot grown for a full lifecycle in two semi-arid regions through bulb-priming followed by foliar application and compared them with conventional ferrous sulfate (FeSO₄) fertilizer and untreated control. Our results showed remarkable cellular adaptations to semi-arid climate upon nFe₃O₄ treatment as leaves displayed thickened cell walls, distinct chloroplasts featuring organized thylakoid grana and stroma, normal mitochondria, abundant starch grains, and plastoglobuli around chloroplasts compared to FeSO₄ or untreated control. At 900 mg/L nFe₃O₄, chlorophyll-a, chlorophyll-b, and carotenoid increased by 27–55%, 108–126%, and 77–97%, respectively, compared to FeSO₄ applied at recommended field rate (1800 mg/L). Significant increments in bulb diameter (38–39%) and sister bulb number (300–500%) were observed upon 900 mg/L nFe₃O₄ treatment compared to FeSO₄ (1800 mg/L) and control. Furthermore, with 900 mg/L nFe₃O₄ treatment, total phenol, flavonoids, and Fe in bulbs increased by 27–46%, 29–73%, and 486–549%, respectively, compared to FeSO₄ (1800 mg/L). These findings demonstrate that bulb-priming followed by foliar application of 900 mg/L of nFe₃O₄ could significantly promote cellular adaptation, thereby improving photosynthetic efficiency, bulb yield, antioxidant activities, and Fe biofortification in shallot, and may serve as a novel approach for improving shallot production in semi-arid regions. Full article

Agriculture faces increasing challenges in ensuring food security under a changing climate, where abiotic stresses such as salinity and drought represent major constraints to crop productivity. These stresses induce complex physiological and biochemical alterations in plants, including osmotic imbalance, oxidative damage, and disruption of metabolic pathways, ultimately impairing growth and yield. In this context, the application of biostimulants has emerged as a sustainable strategy to enhance plant resilience. While synthetic products are widely available, growing attention is being directed toward natural bio-based products, particularly those derived from renewable biomasses and organic wastes, in line with circular economy principles. This review critically examines the current literature on bio-based products with biostimulant properties, with particular emphasis on vermicompost-derived extracts, humic-like substances, and macro- and microalgae extracts, focusing on their role in mitigating salt and drought stress in plants. The reviewed studies consistently demonstrate that these bio-products enhance plant tolerance to abiotic stress by modulating key physiological and biochemical processes, including hormonal regulation, activation of antioxidant defence systems, accumulation of osmoprotectants, and regulation of secondary metabolism. Moreover, evidence indicates that these bio-based inputs can improve nutrient use efficiency, photosynthetic performance, and overall plant growth under stress conditions. Overall, this review highlights the potential of non-microbial bio-based biostimulants as effective and sustainable tools for climate-resilient agriculture, while also underlining the need for further research to standardize formulations, clarify mechanisms of action, and validate their performance under field conditions. Full article

Cadmium (Cd) pollution poses significant threats to ecosystems and human health, with agricultural soils in China particularly affected. Ilex verticillata, a popular ornamental plant, has not been extensively studied for its response to Cd stress. This study investigated the physiological and molecular mechanisms underlying Cd stress tolerance in I. verticillata, focusing on auxin signaling pathways. Under Cd stress (500 mmol/kg soil), I. verticillata exhibited inhibited stem growth, reduced photosynthetic capacity, and elevated oxidative stress markers such as malondialdehyde, H₂O₂, ·O₂⁻, and antioxidant enzyme activities. Transcriptomic analysis revealed 3750 differentially expressed genes (DEGs) with significant enrichment in auxin signaling pathways. Six nucleus-localized IvIAA genes were identified and shown to interact with the transcription factor IvMYB77, suggesting a regulatory module in Cd stress responses. These findings highlight the role of auxin signaling in mediating Cd stress tolerance and provide insights into the molecular adaptation of I. verticillata to heavy metal pollution. Full article

We used chlorophyll fluorescence techniques to investigate seasonal variations in photosystem II (PSII) quantum yield in five-year-old saplings of the sclerophyllous Peumus boldus Molina (evergreen) and Colliguaja odorifera Molina (semideciduous) planted in a semiarid site with a Mediterranean-type climate. Chlorophyll fluorescence rise kinetics (OJIP) were monitored monthly for one year (September 2024 to September 2025). With this information, we estimated the relative deviation of the performance index (PI_ABS) of each species from the average PI_ABS in each season (denoted as ∆PI_ABS). P. boldus was associated with destruction of PSII reaction centers and incapacity for electron transport, i.e., higher values of parameters ABS/RC (effective antenna size of an active reaction center) and F₀ (minimal fluorescence), whereas C. odorifera was associated with higher photosynthetic performance i.e., higher values of PI_ABS, PI_TOT (total performance index), F_V/F₀ (ratio between variable and minimal fluorescence), and F_V/F_M (maximum quantum yield of primary PSII photochemistry). P_IABS exhibited a 52 and 38% reduction (i.e., −∆PI_ABS) during spring and winter in P. boldus, but an increase (i.e., +∆PI_ABS) of 52 and 37% in the same seasons for C. odorifera. P. boldus was considerably more depressed during the winter–spring season than the summer months. This suggests that PSII function in P. boldus is more sensitive to low temperatures in winter and spring than the lack of water and high temperatures during summer. Full article

Monitoring stem sap flow is essential for understanding plant water-use strategies and eco-physiological processes in the ecologically fragile karst region. In the study, we continuously monitored four co-occurring species—Cryptomeria japonica var. sinensis (LS), Liquidambar formosana (FX), Camptotheca acuminata (XS), and Melia azedarach (KL)—using the thermal dissipation probe method in a karst farmland-to-forest restoration area. We analyzed diurnal and nocturnal sap flow variations across different growth periods and their responses to environmental factors at an hourly scale. The results showed (1) A “high daytime, low nighttime” sap flow pattern during the growing season for all species. (2) The proportion of nocturnal sap flow was significantly lower in the growing than in the non-growing season. (3) Daytime sap flow was primarily driven by photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) during the growing season. In the non-growing season, daytime drivers were species-specific: relative humidity (RH, 39.39%) for LS; air temperature (Ta, 23.14%) for FX; PAR (33.03%) for XS; and soil moisture at a 10 cm depth (SM1, 25.2%) for KL. Nocturnal flow was governed by VPD and RH during the growing season versus soil moisture (SM1 and SM2) and RH in the non-growing season. These findings reveal interspecific differences in water-use strategies and provide a scientific basis for species selection and afforestation management in the karst ecological restoration of this research area. Full article

Salinity is a major constraint that compromises safflower performance by disrupting redox balance and metabolic homeostasis. Although hormonal mechanisms for improving plant resilience to abiotic stresses have been reported, the mechanistic role of gibberellic acid (GA₃)-induced regulation of safflower tolerance to salinity remains unclear. This study aimed to investigate the impact of exogenous GA₃ application under normal and saline conditions to evaluate its effects on growth, physiology, redox regulation, and flavonoid biosynthesis in safflower. Using phenotypic, physiological, biochemical, and gene expression analysis, it is suggested that GA₃ significantly alleviates salt stress by integrating antioxidant defense and flavonoid biosynthesis. The results of phenotypic and physiological assessments showed that GA₃ at 400 mg/L GA₃ in safflower seedlings suggests enhanced vegetative growth and photosynthetic performance. Under salt stress, GA₃ significantly alleviated oxidative damage by reducing H₂O₂, ${\mathrm{O}}_2^{-}$, and malondialdehyde (MDA) levels, while enhancing osmoprotective compounds such as proline, soluble sugars, proteins, and chlorophyll. GA₃ also significantly increased the activity of antioxidant enzymes (SOD, POD, CAT, APX, GST, DHAR, and Prx), accompanied by the transcriptional upregulation of their corresponding genes, indicating GA₃-mediated regulation of redox homeostasis at both biochemical and molecular levels. In parallel, GA₃ enhanced the accumulation of major flavonoids, particularly hydroxy safflor yellow A (HSYA), with strong induction of key HSYA biosynthetic genes (CtF6H, CtCGT, Ct2OGD1), whereas salinity alone suppressed their expression. In contrast, the quercetin branch displayed a regulatory bottleneck at CtF3H, which remained suppressed under all treatments, although upstream genes were GA₃-responsive. Together, these findings demonstrate that GA₃ enhances salinity tolerance in safflower by simultaneously activating antioxidant defenses and stimulating flavonoid biosynthesis, providing mechanistic insight with practical implications for developing salt-resilient safflower varieties. Full article

Wood vinegar (WV), a by-product of woody biomass pyrolysis, is increasingly used in agriculture as a sustainable biostimulant, although its effects on plant stress resistance and underlying mechanisms remain poorly understood. Recent studies propose that WV may act through a eustress-based mechanism, defined as a mild and controlled stress that activates adaptive physiological responses and enhances plant performance without causing structural or metabolic damage. This study investigated the physiological and biochemical effects of WV on strawberry plants grown under three water-deficit stress levels [no stress (NS), moderate stress (MS), and high stress (HS)] and treated with WV either via fertigation (0.5% v/v, WV₁) or foliar spray (0.2% v/v, WV₂). Gas exchange parameters (A, g_sw, E, Ci, WUE), total chlorophyll content, and nutrient balance ratios (Fe/Mn and K/Ca) were measured after a three-month growth period. PERMANOVA revealed significant effects of both WV and water-deficit stress, as well as their interaction, on most parameters. Under NS and MS conditions, WV reduced A, gsw, E, and Ci while increasing WUE, indicating enhanced water-use efficiency and improved physiological adjustment to water limitation. Chlorophyll content remained stable, demonstrating preserved photosynthetic integrity. Nutrient ratios further supported a controlled ion rebalancing associated with adaptive stress responses under NS and MS, whereas HS conditions indicated the onset of distress. Overall, the data demonstrate that WV enhances plant stress resistance primarily by inducing eustress-mediated physiological regulation rather than by directly stimulating growth. Full article

Leaves are the primary photosynthetic organs, and alterations in leaf color can affect photosynthesis and plant biomass. In an EMS-mutagenized SN9816 population, we identified two white-striped mutants, ws21-1 and ws21-2. Both mutants showed severely reduced pigment content, defective chloroplasts, and elevated reactive oxygen species. The ws21-2 allele caused a near-complete albino phenotype, while ws21-1 resulted in milder striping. Genetic mapping and cloning identified causal mutations in OsRNRS1, encoding the small subunit of ribonucleotide reductase. The G583R (ws21-1) and Y365F (ws21-2) mutations likely impair enzyme activity, disrupting the dNTP pool for plastid genome replication and causing aberrant chloroplast development. Correspondingly, the expression of genes for chlorophyll synthesis, photosynthesis, and ROS metabolism was altered. Our findings directly link nuclear-encoded nucleotide metabolism to chloroplast biogenesis and demonstrate that dNTP homeostasis is critical for maintaining photosynthetic capacity and redox balance in plants. Full article

Seed biopriming is increasingly recognized as a strategy capable of inducing molecular memory that enhances plant performance under heavy-metal stress. Here, we investigated how biopriming Silene sendtneri seeds with Paraburkholderia phytofirmans PsJN establishes a transcriptional state that predisposes seedlings for improved cadmium (Cd) tolerance. RNA-seq profiling revealed that primed seeds exhibited differential gene expression prior to Cd exposure, with strong upregulation of detoxification enzymes, antioxidant machinery, metal transporters, photosynthetic stabilizers, and osmoprotectant biosynthetic genes. Enrichment of gene ontology categories related to metal ion detoxification, redox homeostasis, phenylpropanoid metabolism, and cell wall organization indicated that biopriming imprints a preparatory transcriptional signature resembling early stress responses. Upon Cd exposure, primed plants displayed enhanced physiological performance, including preserved integrity, elevated antioxidant activity, particularly peroxidases in roots, higher osmolyte accumulation, stabilized micronutrient levels, and substantially increased Cd uptake and sequestration. These coordinated responses demonstrate that biopriming induces a sustained molecular memory that accelerates and strengthens downstream defense activation. These findings demonstrate that PGPR-based biopriming establishes a stable transcriptomic memory in seeds that enhances cadmium tolerance, metal sequestration, and stress resilience, highlighting its potential for improving hyperaccumulator performance in phytoremediation and stress adaptation strategies. Full article

The increasing demand for sustainable agriculture requires innovative strategies to enhance nitrogen use efficiency while minimizing environmental losses associated with conventional fertilizers. This study aimed to develop and compare ammonium chloride- and ammonium nitrate-modified nanobiochar as controlled-release nitrogen carriers and to elucidate their effects on nitrogen retention, soil properties, and physiological nitrogen utilization in spinach (Spinacia oleracea L.). Nitrogen-modified nanobiochar was synthesized using ammonium chloride (NB-AC) and ammonium nitrate (NB-AN) at three nitrogen rates (0.03, 0.06, and 0.12 g N g⁻¹ NB) and applied to soil at 1% (w/w). Soil properties, nutrient dynamics, and plant growth and physiological traits were analyzed after 15 and 30 days. Nitrogen modification significantly improved soil nitrogen retention and nutrient availability compared with unmodified nanobiochar. The highest nitrogen loading treatments (NB-AC3 and NB-AN3) notably improved spinach growth, photosynthetic efficiency, pigment content, nitrogen metabolism enzymatic activities, and accumulation of key metabolites (soluble sugars, flavonoids). Nitrogen-release assessments indicated a pronounced controlled-release with reduced nitrogen leaching and greater retention, particularly under NB-AN3. Overall, this study demonstrates that nitrogen-modified nanobiochar functions as an effective nitrogen carrier that enhances nitrogen utilization and growth. These findings provide mechanistic insights into its potential as a sustainable alternative to conventional nitrogen fertilizers. Full article

Background: Proteasomes are protein complexes that mediate proteolysis to degrade unneeded or damaged proteins, and they play an indispensable role in plant growth and development. However, their regulatory effects on tomato fruit quality and the underlying metabolic mechanisms remain largely elusive. This study aimed to elucidate the metabolic regulatory mechanisms of proteasomes in tomato fruits through untargeted metabolome analysis. Methods: An untargeted metabolomics approach was employed to profile the metabolic changes in tomato fruits. Metabolites were detected and identified under both positive and negative ion modes. Metabolic profiles were compared between wild-type (WT) tomato fruits and SlPBB2 RNA interference (SlPBB2-RNAi) lines. Specifically, the SlPBB2-RNAi line refers to a transgenic tomato line constructed via Agrobacterium-mediated transformation, where the expression of the proteasome component gene SlPBB2 was stably downregulated by RNA interference technology to clarify its regulatory role in fruit metabolism. KEGG enrichment analysis was performed to annotate the functions of differential metabolites. Results: A total of 568 and 333 metabolites were identified in positive and negative ion modes, respectively. Comparative analysis revealed 43 differentially abundant metabolites between WT and SlPBB2-RNAi fruits, including D-glucose, pyruvic acid, leucine, and naringenin. KEGG enrichment analysis further identified key metabolites involved in the carbon fixation pathway of photosynthetic organisms, with L-malic acid being a prominent representative. Reduced accumulation of D-glucose and pyruvic acid in SlPBB2-RNAi fruits suggested the inhibition of the citrate cycle, a core pathway in cellular energy metabolism. This metabolic perturbation was associated with decreased chlorophyll content in SlPBB2-RNAi plants, implying impaired photosynthetic carbon fixation and energy metabolism. Conclusions: This study uncovers the metabolic regulatory role of SlPBB2-mediated proteasome function in tomato fruits, providing novel insights into the link between proteasomal activity and fruit metabolic homeostasis from a metabolomic perspective. These findings offer new theoretical foundations for developing strategies to improve tomato nutritional quality. Full article

Soil co-contamination with cadmium (Cd) and zinc (Zn) poses serious threats to environmental safety and public health. This study investigates the enhancement effect and underlying mechanism of the biodegradable chelator Ethylenediamine-N,N′-disuccinic acid (EDDS) on phytoremediation of Cd-Zn contaminated soil using Sedum lineare. The results demonstrate that EDDS application (3.65 g·L⁻¹) effectively alleviated metal-induced phytotoxicity by enhancing chlorophyll synthesis, activating antioxidant enzymes (catalase and dismutase), regulating S-nitrosoglutathione reductase activity, and promoting leaf protein synthesis, thereby improving photosynthetic performance and cellular integrity. The combined treatment significantly increased the bioavailability of Cd and Zn in soil, promoted their transformation into exchangeable fraction, and resulted in removal rates of 30.8% and 28.9%, respectively. EDDS also modified the interaction patterns between heavy metals and essential nutrients, particularly the competitive relationships through selective chelation between Cd/Zn and Fe/Mn during plant uptake. Soil health was substantially improved, as evidenced by reduced electrical conductivity, enhanced cation exchange capacity, and enriched beneficial microbial communities including Sphingomonadaceae. Based on the observed ion antagonism during metal uptake and translocation, this study proposes a novel “Nutrient Regulation Assisted Remediation” strategy to optimize heavy metal accumulation and improve remediation efficiency through rhizosphere nutrient management. These findings confirm the EDDS–S. lineare system as an efficient and sustainable solution for remediation of Cd–Zn co-contaminated soils. Full article

Our main goal was to determine whether the accumulation of Cd and Cu is harmful for L. perenne or whether this plant can be used in the bioremediation, e.g., of wastewaters or contaminated soils. The IC50 values (concentration at which the tested parameter is inhibited to 50% against the control) for root and shoot inhibition after 14 days showed that Cu, as an essential element for plants, was more toxic than Cd. The translocation factor (TF), which refers to metal transport from the root to the shoot, did not exceed values of 0.228 and 0.353 for Cd and Cu, respectively, indicating their accumulation mostly in the roots rather than in the shoots. The protein thiol (-SH) groups as a parameter of the increased level of reactive oxygen species did not confirm the significantly higher level of oxidative stress for Cu, which is a redox-active cation. We confirmed a statistically significant positive correlation between -SH groups and chlorophyll a (r = 0.79; p < 0.05) and chlorophyll b (r = 0.84; p < 0.01) in the presence of Cd. We concluded that bioaccumulation of the tested metals occurred mostly in the roots, and the photosynthetic pigment content in the shoots was not significantly impaired by the increased presence of Cd or Cu in the shoots. Therefore, we suggest L. perenne as a suitable candidate for the phytomining or phytoextraction of metals, mostly from wastewater, in cooperation with other plant hyperaccumulators. Full article

Soybean (Glycine max L.) is an essential food and economic crop in China, yet its growth and yield are severely constrained by saline–alkali stress. A saline–alkali soil exacerbates root absorption barriers, leading to 30–50% yield losses. Understanding the mechanisms underlying alkali tolerance is therefore crucial for developing stress-resilient soybean varieties and improving the productivity of saline–alkali land. In our previous study, we evaluated 99 soybean germplasms from Northeast China and obtained the alkali-tolerant varieties HN48 and HN69, along with the alkali-sensitive varieties HNWD4 and HN83. In this study, fifteen-day-old soybean seedlings were subjected to (30 mM NaHCO₃) alkali stress for 72 h, and whole plants were sampled to assess their morphology and physiology, while leaf tissues were harvested for biochemical analysis. For transcriptomic analysis, soybean seedlings were exposed to alkali stress (50 mM NaHCO₃, pH 9.0) for 6 h, and leaf and root tissues were harvested for RNA sequencing. The results showed that alkali-tolerant varieties mitigated these effects by suppressing excessive ROS generation by 55–63%, decreasing malondialdehyde (MDA) accumulation by 37–39%, and increasing photosynthetic efficiency by 18.3%, as well as accumulating more osmoprotectants and activating antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) under alkaline stress. Transcriptome analysis showed that the alkali-tolerant variety HN69 exhibited cultivar-specific enrichment of metabolism cytochrome P450, estrogen signaling, and GnRH signaling pathways under alkali stress. These results collectively indicate that alkali-tolerant soybean varieties adapt to alkali stress through coordinated multi-pathway responses, with differential pathway enrichment potentially underlying the variation in alkali tolerance between cultivars. Overall, this study elucidates the physiological and molecular mechanisms of alkali tolerance in soybean, providing a theoretical foundation for breeding stress-tolerant germplasms. Full article

Drought stress and insecticide exposure are two significant environmental factors that can impact the physiology and behaviour of aphids, a major agricultural pest. An understanding of the mechanisms of green peach aphids’ response to insecticides under drought stress is a critical area of research that needs urgent attention. In view of this, we conducted this study to determine the impact of drought and insecticides on the activity of detoxification enzymes in green peach aphid. A 2 × 2 × 3 factorial experiment involving two levels of water treatments (drought and no drought), two levels of aphids infestation (aphids and no aphids), and three levels of pesticides applications (thiacloprid, flonicamid and no pesticide) was conducted. The treatments were arranged in a randomized complete block design with three replications. The results showed that there was a significant (p < 0.01) interaction effect of drought × insecticides on the green peach aphid performance under drought or no drought conditions. Generally, the highest aphids host acceptance, survival rate, colonization success, and average daily reproduction under drought and well-watered conditions occurred on flonicamid-treated plants, whereas thiacloprid-treated plants had the least. However, the thiacloprid-treated plants had higher photosynthetic rate, water use efficiency, lower stomatal conductance, and decreased transpiration rate. Moreover, flonicamid treatment increased the accumulation of glutathione–S-transferase, acetylcholinesterase, butyrylcholinesterase, 1-napthyle acetate, and 1-napthyle butyrate activities in aphids, compared to the thiacloprid treatments. The thiacloprid pesticide, which demonstrated higher efficacy against green peach aphid, can be used in areas where green peach aphids and drought stress are major concerns. Full article