Dibutyl phthalate (DBP) is one of the most widely used phthalate esters (PAEs) that raise increasing ecotoxicological concerns due to their harmful effects on living organisms and ecosystems. Recently, while PAEs pollution in the Yangtze River has attracted significant attention, little research has been conducted on the impact of PAEs stress on S. prenanti, an endemic and valuable species in the Yangtze River. In this study, one control group (C-L) and three experimental groups: T1-L (3 mu g/L), T2-L (30 mu g/L), and T3-L (300 mu g/L) were established with reference to the DBP concentration in the environment. For the first time, we investigated the effects of DBP stress on the liver of S. prenanti using histomorphological, physiological, and biochemical indexes, as well as a joint multi-omics analysis. The results revealed that compared to the C-L group, liver structural damage and stress were not significant in the environmental concentration group (T1-L) and the number of differential genes and differential metabolites were lower. However, as DBP stress concentration increased, the liver damage became severe, with significant vacuolation and hemolysis observed in the T2-L and T3-L groups. The TUNEL assay revealed a significant increase in the number of apoptotic cells along with a notable rise in differential genes and metabolites in the T2-L and T3-L groups. Oxidative stress markers (T-AOC, SOD, CAT, and GSH-PX) were also significantly higher in the T2-L and T3-L groups. RNA-Seq analysis showed that the protein processing in the endoplasmic reticulum pathway was most significantly-enriched differential gene pathway shared by both C-L vs T2-L and C-L vs T3-L, with most of the genes in this pathway showing significant up-regulation. This suggests that the protein processing in the endoplasmic reticulum pathway may play a key role in protecting the liver from injuries caused by high DBP stress. Interestingly, C XI, C XII, C XIII, C XIV and C XV in the chemical carcinogenesis-reactive oxygen species pathway were significantly down-regulated in the T2-L and T3-L groups based on combined transcriptomic and metabolomic analyses, suggesting that DBP causes liver injury by disrupting mitochondria. This comprehensive histomorphometric and multi-omics study demonstrated that the current DBP concentration in the habitat of S. prenanti in the upper reaches of the Yangtze River temporarily causes less liver damage. However, with increasing of DBP concentration, DBP could still cause serious liver damage to S. prenanti. This study provides a new mechanistic understanding of the liver response mechanism of S. prenanti under different concentrations of DBP stress and offers basic data for the ecological protection of the Yangtze River.

Mitigating the co-existence of environmental stresses on crop plants necessitates the development of integrated, eco-friendly, and sustainable approaches to alleviate plant stress responses. This study represents the first attempt to mitigate the toxic impact of prevalent pollutant (salinity) and an emergent plastic manufacturing pollutants (bisphenol A, BPA) using the polyamine (cadaverine).Tomato plants, treated with or without cadaverine, were subjected to NaCl salinity (120 mM), BPA (375 mg kg(-1) soil), and their combinations compared to non-stressed control plants examining morphological, physiological, metabolic, and molecular responses. After 10 days of transplanting, tomato plants under combined stress were unable to survive without cadaverine application. However, cadaverine spraying mitigated the damaging effects of both single and combined stresses under short- and long-term exposure, enabling stressed plants to endure the conditions and complete their life cycles. Cadaverine efficiently restrained the reduction in chlorophylls, carotenoids, and cytosolutes under applied stresses compared to the stressed plants. Cadaverine also increased alpha-tocopherol content (by 171 and 53 %) and enhanced the activity of polyphenol oxidase (by 26 and 32 %), glutathione s-transferases (by 18 and 39 %), superoxide dismutase (by 23 and 46 %), and phenylalanine ammonia-lyase (by 9 and 25 %), under BPA and salinity stress, respectively. Thus, cadaverine ameliorated the oxidative and nitrosative burst induced by BPA or salinity, respectively by declining hydroxyl radical (by 28 % and 20 %), superoxide anion (by 73 % and 74 %), nitric oxide (by 60 and 65 %), lipid peroxidation (by 35 % and 54 %), and lipoxygenase activity (by 74 and 68 %). Moreover, cadaverine enhanced the expression of defence-related genes, including polyphenol oxidase, tubulin, and thaumatin-like protein, and reduced the uptake of BPA in the tomato's roots while promoting its metabolism in leaves and fruits. This ensured the safety of the harvested fruits. By mitigating stress, improving plant resilience, and limiting pollutant accumulation, cadaverine presents significant potential for sustainable agricultural practices and food safety. These findings offer valuable insights into the role of cadaverine in managing abiotic stress and safeguarding crop health in environmentally challenging conditions.

Apart from directly affecting the growth and development of crops, Cd in the soil can easily enter the human body through the food chain and pose a threat to human health. Therefore, understanding the toxicity of Cd to specific crops and the molecular mechanisms of their response to Cd is essential. In this study, hydroponic experiments were utilized to study the response of foxtail millet to Cd stress through phenotypic investigation, enzyme activity determination, ultrastructure, ionome, transcriptome and metabolome. With the increase in cadmium concentration, both the growth and photosynthetic capacity of foxtail millet seedlings are severely inhibited. The ultrastructure of cells is damaged, cells are deformed, chloroplasts swell and disappear, and cell walls thicken. Cd stress affects the absorption, transport, and redistribution of beneficial metal ions in the seedlings. Multi-omics analysis reveals the crucial roles of glycolysis, glutathione metabolism and phenylpropanoid and lignin biosynthesis pathways in Cd detoxification via energy metabolism, the antioxidant system and cell wall changes. Finally, a schematic diagram of foxtail millet in response to Cd stress was we preliminarily drew. This work provides a basic framework for further revealing the molecular mechanism of Cd tolerance in foxtail millet.

Zinc (Zn), an essential nutrient element, exhibits hormesis in plants-beneficial at low doses but toxic at high concentrations. To understand the molecular mechanisms underlying this hormetic response with low-dose stimulation and high-dose inhibition in wheat, we conducted transcriptomic analysis under different Zn treatments. Low Zn concentration (50 mu M) promoted plant growth by maintaining chlorophyll content, enhancing MAPK signaling, phytohormone signaling, glutathione metabolism, nitrogen metabolism, and cell wall polysaccharide biosynthesis. High Zn concentration (500 mu M) induced ultrastructural damage and suppressed photosynthesis, chlorophyll metabolism, and secondary metabolisms, while upregulating glutathione metabolism. Molecular docking revealed that hydrogen bonds between Zn and antioxidant enzymes facilitated reactive oxygen species scavenging. Notably, exogenous glutathione (GSH) application enhanced wheat tolerance to Zn stress by strengthening the antioxidant defense system and improving photosynthetic capacity. Our findings elucidate the underlying mechanisms of Zn hormesis in wheat and demonstrate the application potential of glutathione in mitigating Zn toxicity, providing strategies for managing Zn-contaminated soils.

Saline-alkaline stress is a common problem in Akebia trifoliata cultivation. In this study, the enhancing effects of 5-azacytidine (5-AzaC) on the resistance of A. trifoliata to saline-alkaline stress and the underlying mechanisms were investigated. Plant height, stem diameter, biomass, root length, fresh weight of root, and root/shoot ratio of 6-month-old A. trifoliata seedlings were measured after saline-alkaline stress with or without 5-AzaC treatment. Moreover, the contents of photosynthetic pigments, malondialdehyde (MDA), H2O2, sodium, soluble sugar, and proline; activities of superoxide dismutase, peroxidase (POD), and catalase (CAT); and anatomical structures of root, stem, and leaf were assessed. Furthermore, comparative transcriptome sequencing was performed. The results demonstrated that growth and development of A. trifoliata were severely inhibited under saline-alkaline stress, suggesting that the seedlings were exposed to severe oxidative and osmotic stresses. Treatment with exogenous 5-AzaC could significantly relieve the symptoms of saline-alkaline stress in A. trifoliata. Under saline-alkaline stress, 5-AzaC could increase the stem diameter, biomass, root length, fresh weight of root, and root/shoot ratio and minimize damages to the anatomical structure. Moreover, absorption of Na+ was reduced; ionic balance was maintained; POD and CAT activities were significantly improved; proline and soluble sugar contents increased, and H2O2 and MDA contents decreased. Transcriptome analysis revealed that 5-AzaC functioned via regulating KEGG pathways such as plant hormone signal transduction, phenylpropanoid biosynthesis, photosynthesis, amino sugar and nucleotide sugar metabolism, and glutathione metabolism under saline-alkaline stress. Particularly, enhanced expression of genes from the auxin pathway in plant hormone signal transduction; the lignin synthetic pathway in phenylpropanoid biosynthesis; and photosystem II, photosystem I, photosynthetic electron transport, and F-type ATP pathway in photosynthesis may be related to 5-AzaC-induced saline-alkaline resistance. The results provided theoretical references for A. trifoliata cultivation in saline-alkaline soil and application of 5-AzaC to improve saline-alkaline tolerance in plants.

A cutting-edge smart nano-hybrid technology, offering potential benefits for plants, has recently been developed to address the pervasive issue of heavy metal pollution. This study explored the potential of this technology in mitigating chromium (Cr) stress in rapeseed using a nano-based system that integrates 100 mu M hydrogen sulphide (H2S) and 50 mu M manganese nanoparticles (Mn-NPs). This strategy reveals Cr-stress tolerance mechanisms through physiological assessments and transcriptome data analysis. The results demonstrated that Cr stress substantially inhibited rapeseed growth while increasing oxidative damage markers (MDA and ROS levels). Conversely, Mn-NP and H2S co-treatment significantly mitigated these effects, as shown by: (1) restored growth metrics, (2) improved photosynthetic performance and membrane integrity, (3) optimized Mn/H2S homeostasis, and (4) reduced tissue Cr accumulation. The reduction in Cr content was attributed to enhanced Cr-detoxification mechanisms, driven by the upregulation of enzymatic antioxidant activities, like superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase. Transcriptomic profiling revealed marked upregulation of genes involved in core metabolic processes, including photosynthetic pathways, carbon assimilation, secondary metabolite biosynthesis, inositol/phosphatidylinositol signalling systems, and stress-response networks. Under Cr stress, Mn-NP and H2S co-treated rapeseed plants displayed enhanced tolerance, highlighting the crucial role of these signalling agents in activating Cr-defence mechanisms. Our findings demonstrate that the integration of nanotechnology and gasotransmitter signalling molecule H2S presents a novel strategy for enhancing heavy metal tolerance and plant productivity in contaminated soils.

Soil salinization threatens sustainable agriculture, necessitating innovative restoration strategies. Suaeda salsa (L.) Pall., a halophyte with exceptional salt tolerance and vivid pigmentation, serves as an ideal model for salinity adaptation. This study integrates physiological and transcriptomic analyses to reveal how high salinity (400 mmolL(-)1 NaCl) upregulates 4,5-DOPA dioxygenase after 30 days of salt stress, promoting betacyanin accumulation to mitigate oxidative damage. Compared to the control, betacyanin content in the 200 mmolL(-)1 and 400 mmolL(-)1 NaCl groups increased to 1.975-fold and 3.675-fold, respectively, while chlorophyll a content decreased by 45.78% and 69.88%, chlorophyll b by 11.45% and 28.24%, and total chlorophyll by 30.28% and 53.06%. This trade-off in pigment allocation highlights the plant's adaptive strategy under salinity stress. The photosynthetic characteristics of S. salsa confirm that its photoprotective mechanisms are significantly enhanced under 400 mmolL(-)1 NaCl. At the molecular level, betacyanin biosynthesis alleviates oxidative stress, while transcriptional regulation of photosystem I (PSI) and photosystem II (PSII) genes-such as PsbY, PsaO, PsbM, and PsbW-partially restores photosynthetic activity. Stabilization of the electron transport chain by upregulated genes like PetA and PetH further enhances photosynthetic resilience. These findings highlight the synergy between betacyanin production and photosynthetic regulation in enhancing salinity resilience, providing insights for soil restoration and salt-tolerant crop breeding.

Perchlorate (ClO4 -) is a type of novel persistent inorganic pollutant that has gained increasing attention because of its high solubility, poor degradability, and widespread distribution. However, the impacts of perchlorate on aquatic autotrophs such cyanobacterium are still unclear. Herein, Synechocystis sp. PCC6803 (Synechocystis) was used to investigate the response mechanisms of perchlorate on cyanobacterium by integrating physiological and transcriptome analyses. Physiological results showed that perchlorate mainly damaged the photosystem of Synechocystis, and the inhibition degree of photosystem II (PSII) was severer than that of photosystem I (PSI). When the exposed cells were moved to a clean medium, the photosynthetic activities were slightly repaired but still lower than in the control group, indicating irreversible damage. Furthermore, perchlorate also destroyed the cellular ultrastructure and induced oxidative stress in Synechocystis. The antioxidant glutathione (GSH) content and the superoxide dismutase (SOD) enzyme activity were enhanced to scavenge harmful reactive oxygen (ROS) in Synechocystis. Transcriptome analysis revealed that the genes associated with photosynthesis and electron transport were significantly regulated. For instance, most genes related to PSI (e.g., psaf, psaf) and the electron transport chain were upregulated, whereas most genes related to PSII (e.g., psbA3, psbD1, psbB, and psbC) were downregulated. Additionally, perchlorate also induced the expression of genes related to the antioxidant system (sod2, gpx, gst, katG, and gshB) to reduce oxidative damage. Overall, this study is the first to investigate the impacts and mechanisms of cyanobacterium under perchlorate stress, which is conducive to assessing the risk of perchlorate in aquatic environments. (c) 2024 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Juglans sigillata, an endemic species in China, serves as a vital local economic resource. Aluminum (Al) stress caused by soil acidification can potentially threaten the growth of J. sigillata. This study aimed to elucidate the mechanism of the alleviation of Al stress by silicon (Si) in J. sigillata. The results showed that Si could reduce the Al accumulation of walnut and improve root growth under Al stress. Si also increased peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities and soluble sugar and proline contents, reduced malonaldehyde (MDA) and H2O2 contents and the O2- production rate, and maintained the homeostasis of cells. Transcriptome analysis revealed significant up-regulation of genes encoding plant hormones (ABA, IAA, and CTK) and photosystem II components (PsbO, PsbQ, PsbW, and PsbY). Under Al stress conditions, the application of exogenous Si notably enhanced the expression of genes associated with heavy metal transport (CAX, PAA, ABC, HMA, NRAMP, and ZIP). Comprehensive transcriptome and metabolomics analysis showed that Si regulated secondary metabolite metabolism via the phenylalanine, galactose, and tryptophan pathway, altered cell wall composition, increased energy supply, and reduced auxin synthesis in root tip transition zones to alleviate Al toxicity of J. sigillata. In summary, the application of Si significantly alleviated Al-induced damage in J. sigillata.

BackgroundSalt stress is considered to be one of the major abiotic stresses influencing rice growth and productivity. To improve rice crop productivity in saline soils, it is essential to choose a suitable variety for mitigating salt stress and gain a deep understanding of the underlying mechanisms. The current study explored the salt tolerance mechanism of wild rice 'HD96-1 (salt resistive)' and conventional rice 'IR29 (salt sensitive)' by evaluating morph-physiological, transcriptomic, and metabolomic approaches.ResultsPhysiological data indicated that HD96-1 had higher chlorophyll content, higher photosynthetic efficiency, more stable Na+/K+, less H2O2, and lower electrolyte leakage under salt stress compared with IR29. Transcriptomic and metabolomic data showed that the expression of NHXs in IR29 was significantly down-regulated under salt stress, leading to a large accumulation of Na+ in the cytoplasm, and that the expression of CHLH, PORA, and PORB was significantly down-regulated, inhibiting chlorophyll synthesis. HD96-1 maintained the balance of Na+ and K+ by increasing the expression of NHX4, and there was no significant change in the expression of genes related to chlorophyll synthesis, which made HD96-1 more resistant to salt stress than IR29. In addition, HD96-1 inhibited the excessive synthesis of hydrogen peroxide (H2O2) and alleviated oxidative damage by significantly down-regulating the expression of ACX4 under salt stress. HD96-1 promoted the accumulation of isoleucine by up-regulating genes of branched-chain amino acid aminotransferase 2 and branched-chain amino acid aminotransferase 4 and might promote the synthesis of raffinose and stachyose by up-regulating the expression of the gene for galactitol synthase 2, which, in turn, maintained a stable osmotic pressure and relieved osmotic stress. We also found that IR29 and HD96-1 alleviated the inhibition of photosynthesis by salt stress by down-regulating the expression of light-harvesting chromophore protein complex (LHCH II)-related genes and reducing the excessive accumulation of glucose metabolites, respectively. In addition, HD96-1 enhances salt tolerance by regulating C2H2 and bHLH153 transcription factors.ConclusionUnder salt stress, HD96-1 maintained ionic balance and photosynthetic efficiency by up-regulating the expression of NHX4 gene and reducing the overaccumulation of glucose metabolites, respectively, and mitigated osmotic stress and oxidative stress by down-regulating the expression of ACX4 and promoting the accumulation of isoleucine, respectively, thereby enhancing the adaptability to salt stress. IR29 maintained photosynthetic efficiency under salt stress by down-regulating the expression of light-harvesting chromophore protein complex (LHCH II)-related genes, thereby enhancing adaptation to salt stress.