Cadmium (Cd) contamination in soil threatens global food production and human health. This study investigated zinc (Zn) addition as a potential strategy to mitigate Cd stress using two barley genotypes, Dong-17 (Cd-sensitive) and WSBZ (Cd-tolerant). Hydroponically grown seedlings were treated with different Cd (0, 1.0, 10 mu M) and Zn (0, 5, 50 mu M) levels. Results showed that Zn addition effectively alleviated Cd induced growth inhibition, improving SPAD values, photosynthetic parameters, fluorescence efficiency (Fv/Fm), and biomass. Zn reduced Cd contents in roots and shoots, inhibited Cd translocation, and ameliorated Cd induced ultrastructural damage to organelles. Transcriptomic analysis revealed distinct gene expression patterns between genotypes, with WSBZ showing enhanced expression of metal transporters, antioxidant defense, and stress signaling genes. Significantly, cell wall related pathways were upregulated in WSBZ, particularly lignin biosynthesis genes (PAL, C4H, 4CL, COMT, CAD/SAD), suggesting cell wall reinforcement as a key Cd tolerance mechanism. Zn induced upregulation of ZIP family transporters and downregulation of Cd transporters (HvHMA) aligned with reduced Cd accumulation. These findings provide comprehensive insights into molecular mechanisms of Zn mediated alleviation of Cd toxicity in barley, supporting improved agronomic practices for Cd contaminated soils.

Among various abiotic stresses, secondary soil salinization poses a significant threat to plant productivity and survival. Cultivated chrysanthemums (Chrysanthemum morifolium), widely grown as ornamental crops, are highly susceptible to salt stress, and their complex polyploid genome complicates the identification of stress resistance genes. In contrast, C. indicum, a native diploid species with robust stress tolerance, serves as a valuable genetic resource for uncovering stress-responsive genes and improving the resilience of ornamental chrysanthemum cultivars. In this study, we cloned, overexpressed (OE-CiHY5), and silenced (RNAi-CiHY5) the CiHY5 gene in C. indicum. OE-CiHY5 plants exhibited larger leaves, sturdier stalks, and higher chlorophyll content compared to wild-type plants, while RNAi-CiHY5 plants displayed weaker growth. Under salt stress, OE-CiHY5 plants demonstrated significantly improved growth, enhanced osmotic adjustment, and effective ROS scavenging. In contrast, RNAi-CiHY5 plants were more sensitive to salinity, showing higher electrolyte leakage and impaired osmotic regulation. Transcriptomic analyses revealed that CiHY5 regulates key hormonal pathways such as zeatin (one of cytokinins), abscisic acid and jasmonic acid, as well as metabolic pathways, including photosynthesis, carbohydrate metabolism, which collectively contribute to the enhanced stress resilience of OE-CiHY5 plants. Promoter-binding assays further confirmed that CiHY5 directly interacts with the CiABF3 promoter, highlighting its critical role in ABA signaling. Evolutionary analyses showed that HY5 is conserved across plant lineages, from early algae to advanced angiosperms, with consistent responsiveness to salt and other abiotic stresses in multiple Chrysanthemum species. These findings establish CiHY5 as a key regulator of salt tolerance in C. indicum, orchestrating a complex network of hormonal and metabolic pathways to mitigate salinity-induced damage. Given the conserved nature of HY5 and its responsiveness to various stresses, HY5 gene provides valuable insights into the molecular mechanisms underlying stress adaptation and represents a promising genetic target for enhancing salt stress resilience in chrysanthemums.

BackgroundSoybean (Glycine max L. Merrill), a vital source of edible oil and protein, ranks seventh in global agricultural production, yet its productivity is significantly hindered by potential toxic metal/liods (PTM) stress. Arsenic (As), a highly toxic soil contaminant, poses substantial risks to both plants and humans, even at trace concentrations, particularly in China.ResultsThis research endeavor delves into the combined effect of arsenate (AsV), a common form of As in soil, and nano-selenium (nSe), on the transcriptional regulation of key genes and the modulation of signaling and metabolic cascades in young soybean seedlings. Our findings indicate that nSe mitigates AsV toxicity by modulating hormonal signaling cascades, particularly the phenylalanine and salicylic acid pathways, thereby augmenting antioxidant defenses and mitigating the damaging effects of reactive oxygen species (ROS) on soybean roots.ConclusionThis study offers valuable insights into the molecular mechanisms underlying metalloid tolerance in soybean, opening avenues for the development of strategies to bolster As resistance in contaminated soils. Nevertheless, further investigation is imperative to elucidate the intricate interplay of hormonal signaling in soybean roots during nSe supplementation under As stress conditions.

To address the issue of poor phytoremediation in Cd-contaminated saline soil caused by the biotoxicity of Cdsalinity, we constructed a symbiotic system of arbuscular mycorrhizal fungi (AMF) and the hyperaccumulator Solanum nigrum, and systematically elucidated the response strategies of Solanum nigrum and the enhancement mechanism of AMF for plant tolerance through cytological, physiological, and transcriptomic methods. The findings showed that Cd-salinity stress had synergistic aggravated Cd/Na enrichment, ultrastructural damage, photosynthetic inhibition, water loss, and reactive oxygen species (ROS) accumulation in plants. In response to the heterogeneity of Cd/salinity stress, AMF smartly regulated the Cd/salinity tolerance of host plants: AMF decreased intercellular CO2 concentration (Ci) under Cd stress to alleviate non-stomatal limitation induced by Cd, but increased Ci under salinity stress to alleviate the stomatal limitation induced by salinity; the role of AMF in strengthening the osmoregulation system was more prominent under salinity stress, thereby alleviated the more severe osmotic imbalance induced by salinity. AMF also enhanced signal transduction to consolidate resistance defense, upregulated antioxidant genes to activate antioxidant enzymes, and strengthened the AsAGSH cycle to mitigate oxidative damage. The enhancement of tolerance improved plant growth and Cd enrichment. Under high Cd-high salinity combined stress, Cd concentrations in shoots and roots increased by 14.28 % and 38.85 %, respectively, and the biomass also increased by over 30.00 % after AMF inoculation. In summary, inoculation with AMF serves as an effective and sustainable phytoremediation enhancement strategy that improves the host plants' stress resistance through multiple pathways, thereby increasing the phytoremediation potential.

Acanthamoeba castellanii is a widespread unicellular eukaryote found in diverse environments, including tap water, soil, and swimming pools. It is responsible for severe infections, such as Acanthamoeba keratitis and granulomatous amebic encephalitis, particularly in individuals with immunocompromisation. The ability of protozoans to form dormant and persistent cysts complicates treatment, as current therapies are ineffective against cyst stages and suffer from poor specificity and side effects. Nitroxoline, a quinoline derivative with well- established antibacterial, antifungal, and antiviral properties, is a promising therapeutic candidate. This study aimed to elucidate cellular signalling events that counteract the effects of nitroxoline. In this study, nitroxoline significantly reduced the viability of A . castellanii trophozoites in a dose- and time-dependent manner, inducing morphological changes and apoptosis. Transcriptomic analysis revealed substantial alterations in gene expression, including enrichment of metabolic pathways, DNA damage responses, and iron ion binding. Nitroxoline treatment upregulated genes involved in DNA repair and oxidative stress response while regulating genes in the methionine and cysteine cycles. It also decreased the mitochondrial membrane potential, HAS production, and total iron amount in A . castellanii. Bioinformatic analyses and molecular docking studies suggest direct interactions between nitroxoline and several A . castellanii proteins. Our research provides a comprehensive molecular map of the response of A . castellanii to nitroxoline, revealing significant changes in gene expression related to the stress response and metabolic pathways. These findings underscore the potential of nitroxoline as a potent anti- Acanthamoeba agent, offering new insights into its mechanism of action and paving the way for effective combinational therapeutic strategies.

Hexafluoropropylene oxide dimer acid (HFPO-DA), an emerging perfluoroalkyl substance (PFAS) that is replacing traditional PFASs, has a wide range of industrial applications and has been detected globally in the environment. However, it remains unclear whether HFPO-DA, is genuinely less toxic than perfluorooctanoic acid (PFOA) in terms of soil environmental hazards. Therefore, this study aimed to compare differences in toxicity between PFOA and its substitute, HFPO-DA, in a common species of earthworm, Eisenia fetida. Our findings revealed that both HFPO-DA and PFOA caused oxidative damage, apoptosis, reproductive disorders, and neurotoxicity in E. fetida at a concentration of 0.2 mg/kg following exposure for 28 d. Specifically, at the molecular level, PFOA resulted in a significant decline in total antioxidant capacity and lipid peroxidation, whereas HFPO-DA did not have the same effect. The Integrated Biomarker Response (IBR) index, based on the indicators studied, showed that HFPO-DA exhibited lower toxicity than PFOA. The transcriptomic results suggest that HFPO-DA can induce neurotoxicity, similar to PFOA; however, the specific mechanisms differ. Although HFPODA appears to be less toxic than PFOA to E. fetida, its potential hazards at the transcriptional level, affecting different pathways, require further investigation. This study provided new insights into the safety of HFPO-DA as a novel substitute for PFOA.

Cadmium (Cd) is a highly toxic agricultural pollutant that inhibits the growth and development of plants. Arbuscular mycorrhizal fungi (AMF) can enhance plant tolerance to Cd, but the regulatory mechanisms in Allium fistulosum (green onion) are unclear. This study used a Cd treatment concentration of 1.5 mg center dot kg-1, which corresponds to the risk control threshold for soil pollution in Chinese agricultural land, to examine the effects and molecular mechanisms of AMF inoculation on the growth and physiology of green onion under Cd stress. AMF formed an effective symbiotic relationship with green onion roots under Cd stress, increased plant biomass, improved root structure and enhanced root vitality. AMF-colonized green onion had reduced Cd content in roots and leaves by 63.00 % and 46.50 %, respectively, with Cd content being higher in the roots than in the leaves. The ameliorative effect of AMF on Cd toxicity was mainly due to a reduction in malondialdehyde content in leaves (30.12 %) and an enhancement of antioxidant enzyme activities (peroxidase, catalase, superoxide dismutase, glutathione reductase and reduced glutathione) that mitigated damage from excessive reactive oxygen species. In addition, AMF induced secretion of easily extractable glomalin soil protein and total glomalin-related soil protein and inhibited the translocation of Cd to the shoots. Transcriptomic and metabolomic correlation analyses revealed that differentially expressed genes and metabolites in AMF-inoculated green onion under Cd stress were predominantly enriched in the phenylpropanoid biosynthesis and phenylalanine metabolism pathways, upregulated the expression of the HCT, PRDX6, HPD, MIF, and HMA3 genes, and accumulation of the phenylalanine, L-tyrosine, and 1-O-sinapoyl-beta-glucose metabolites. Thus, AMF enhance Cd tolerance in green onions by sequestering Cd in roots, restricting its translocation, modulating antioxidant defenses and inducing the expression of genes involved in the phenylpropanoid biosynthesis and phenylalanine metabolism pathways. Collectedly, we for the first time revealed the mechanism of AMF alleviating the toxicity of Cd to green onion, providing a theoretical foundation for the safe production and sustainable cultivation of green onion in Cdcontaminated soils.

Fosthiazate (FOS) is a widely used organophosphorus insecticide effective against soil root-knot nematodes. However, its ecotoxicity to non-target soil organisms, particularly in combination with microplastics (MPs), is unclear. This study explores the toxic-effects and molecular mechanisms of co-exposure to FOS and MPs on earthworms (Eisenia fetida) using multilevel toxicity endpoints and transcriptomics. Results showed that both FOS and MPs elevated the intracellular levels of reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OHdG) in earthworms' cells. The superoxide dismutase (SOD) and catalase (CAT) activities followed a similar trend in all treatments, with changes observed at 14 and 28 days, indicating that co-exposure to FOS and MPs increased DNA oxidative damage. Notably, the co-exposure more significantly inhibited Ca2+-ATPase activity and exacerbated neurotoxicity compared to individual treatments, closely associated with changes in intracellular ROS levels that mediate neuroinhibition and lead to neurotoxicity. KEGG enrichment analysis revealed that MPs and FOS disrupted pathways related to metabolism, immunity, and apoptosis, while co-exposure primarily impaired endocrine and receptor pathways, showing higher toxicity. Our study offers novel insights into the ecotoxicological effects and mechanisms of pesticides and microplastics on earthworms, providing valuable data for evaluating the soil environmental health risks associated with compound pollution.

Heavy metal contamination, particularly from cadmium (Cd) and lead (Pb), poses significant risks to soil and water resources and leads to severe damage in plants. This study investigated the physiological and molecular mechanisms of the responses of tomato (Solanum lycopersicum L.) seedlings to Cd and Pb stress by applying 50 mg/L Cd, 100 mg/L Pb, and a combination of 50 mg/L Cd + 100 mg/L Pb. The goal was to understand how these heavy metals impact the growth, antioxidant systems, and secondary metabolic pathways in tomato seedlings. The results showed that compared with the control, Cd + Pb stress significantly increased the content of soluble sugar by 37.40% and 33.46% on days 5 and 15, respectively, and the content of proline by 77.91% to 93.91% during the entire period in tomato seedlings. It also elevated electrical leakage by 110.52% on day 15, maintained the levels of malondialdehyde close to the control, enhanced the activities of superoxide dismutase by 33.32% on day 10 and 11.22% on day 15, peroxidase by 42.15% on day 10, and catalase by 90.78% on day 10. Additionally, it reduced the contents of hydrogen peroxide by 15.47% to 29.64% and the rate of formation of superoxide anions by 26.34% to 53.47% during the entire period of treatment. The transcriptomic analysis revealed a significant differential expression of the genes involved in pathways, such as phenylalanine, glutathione, arginine and proline, and nitrogen metabolism. These genes included PALs, HDCs, GGCT, ODC1, LAPs, SMS, and SAMDC. Notably, transcription factors, such as ERF109, ARF9, GRF3, GRF4, GRF7, and GRF9, were also significantly regulated. The study concluded that Cd and Pb stress enhanced the osmoregulatory and antioxidant defense systems in tomato seedlings, which may contribute to their tolerance to heavy metal stress. Future research could explore the application of these findings to develop strategies to improve the resistance of plants to contamination with heavy metals.

Soil organic carbon (SOC) rapidly accumulates during ecosystem primary succession in glacier foreland. This makes it an ideal model for studying soil carbon sequestration and stabilization, which are urgently needed to mitigate climate change. Here, we investigated SOC dynamics in the Kuoqionggangri glacier foreland on the Tibetan Plateau. The study area along a deglaciation chronosequence of 170-year comprising three ecosystem succession stages, including barren ground, herb steppe, and legume steppe. We quantified amino sugars, lignin phenols, and relative expression of genes associated with carbon degradation to assess the contributions of microbial and plant residues to SOC, and used FT-ICR mass spectroscopy to analyze the composition of dissolved organic matter. We found that herbal plant colonization increased SOC by enhancing ecosystem gross primary productivity, while subsequent legumes development decreased SOC, due to increased ecosystem respiration from labile organic carbon inputs. Plant residues were a greater contributor to SOC than microbial residues in the vegetated soils, but they were susceptible to microbial degradation compared to the more persistent and continuously accumulating microbial residues. Our findings revealed the organic carbon accumulation and stabilization process in early soil development, which provides mechanism insights into carbon sequestration during ecosystem restoration under climate change.