Small organic compounds (SOCs) are widespread environmental pollutants that pose a significant threat to ecosystem health and human well-being. In this study, the FrmA gene from Escherichia coli was overexpressed alone or in combination with FrmB in Arabidopsis thaliana and their resistance to multiple SOCs was investigated. The transgenic plants exhibited varying degrees of increased tolerance to methanol, formic acid, toluene, and phenol, extending beyond the known role of FrmA in formaldehyde metabolism. Biochemical and histochemical analyses showed reduced oxidative damage, especially in the FrmA/BOE lines, as evidenced by lower malondialdehyde (MDA), H2O2 and O-2(center dot-) levels, indicating improved scavenging of reactive oxygen species (ROS). SOC treatment led to significantly higher levels of glutathione (GSH) and, to a lesser extent, ascorbic acid (AsA) in the transgenic plants than in the wild-types. After methanol exposure, GSH levels increased by 95 % and 72 % in the FrmA/BOE and FrmAOE plants, respectively, while showing no significant increase in the wild-type plants. The transgenic plants also maintained higher GSH:GSSG and AsA:DHA ratios, exhibited upregulated glutathione reductase (GR) and dehydroascorbate reductase (DHAR) activities, and correspondingly increased gene expression. In addition, the photosynthetic parameters of the transgenic plants were less affected by SOC stress, which represents a significant photosynthetic advantage. These results emphasize the potential of genetically engineered plants for phytoremediation and crop improvement, as they exhibit increased tolerance to multiple hazardous SOCs. This research lays the foundation for sustainable approaches to combat pollution and improve plant resilience in the face of escalating environmental problems.

As soil acidification occurs due to industrial and agricultural production processes, it can induce the release of rhizotoxic aluminium ions (Al3+) into the soil, ultimately causing aluminium (Al) stress. Excessive Al content in soil exhibits significant phytotoxicity, inhibiting the growth of roots and stems. In this study, we conducted an investigation into the Al stress tolerance of two apple rootstocks, namely 'YZ3' and 'YZ6', and discovered that 'YZ3' exhibited a superior ability to alleviate the inhibitory effects of Al stress on plant growth. By comparing the transcriptomes of two rootstocks, a differentially expressed gene, MdDUF506, containing an unknown functional (DUF) domain, was identified. Overexpression of MdDUF506 in apple and calli enhances the ability to scavenge reactive oxygen species (ROS), subsequently mitigating the oxidative damage induced by Al stress on plant growth and development. Furthermore, MdDUF506 regulates Al stress tolerance by modulating the expression of genes related to Al stress (MdSTOP1, MdRSL1, MdRSL4, MdGL2, and MdRAE1). MdDUF506 interacts with MdCNR8, positively regulating Al stress tolerance. Taken together, these discoveries offer crucial candidate genes for targeted breeding as well as fresh insights into resistance to Al stress.

Distinguishing the origin of lunar water ice requires in situ isotopic measurements with high sensitivity and robustness under extreme lunar conditions; however, challenges such as uncertain water contents and isotopic fractionation induced by regolith particles restrict isotopic analysis. Herein, we present a miniaturized tunable diode laser absorption spectrometer (TDLAS) developed as the core prototype for the Chang'E-7 Lunar Soil Water Molecule Analyzer (LSWMA). The wavelength range of the instrument is 3659.5-3662.0 cm-1, and the system integrates a Herriott cell for stable multi-isotope (H2 16O, H2 18O, H2 17O, and HD16O) detection and employs regolith samples of known isotopic experiments to quantify adsorption-induced fractionation. Performance evaluations demonstrated a dynamic water detection range of 0.01-2 wt % and isotope precision up to 1.3 parts per thousand for delta D (30.5 s), 0.77 parts per thousand for delta 18O (36 s), and 0.75 parts per thousand for delta 17O (21.5 s) with extended averaging. Repeated injections of three types of standard water revealed a volume-dependent deviation (Delta delta D up to -59.5 parts per thousand) attributed to multilayer adsorption effects, while simulated lunar soil experiments identified additional isotopic fractionation (Delta delta D up to -12.8 parts per thousand) caused by particle binding. These results validate the ability of the spectrometer to resolve subtle isotopic shifts under lunar conditions, providing critical data for distinguishing water origins and advancing future resource utilization strategies.

Aluminum (Al) toxicity is a major limiting factor for plant growth in acidic soils. Melatonin (MT) is involved in plant responses to various environmental stresses. In this study, the role of exogenous MT in alleviating Al toxicity was investigated in soybean (Glycine max L.). The results demonstrated that MT application alleviated Al-induced inhibition of root elongation, reduced Al accumulation in root tips, and mitigated oxidative damage and cell death in root tips. Under Al stress, MT treatment increased the activities of antioxidant enzymes (SOD, CAT, APX, and POD) and the contents of antioxidants (ASA and GSH) in root tips. Furthermore, Al stress significantly enhanced citrate secretion from soybean roots, while MT application further promoted citrate efflux under Al exposure. Under Al stress, MT treatment significantly increased citric acid levels in root tips by upregulating the expression of citrate synthase gene and downregulating the expression of aconitase gene. In addition, MT application significantly increased the expression of citrate transporter genes (GmMATE13 and GmMATE47) in root tips. Taken together, these findings suggest that MT enhances soybean tolerance to Al stress by activating the antioxidant defense system and promoting citrate secretion. This study provides a theoretical foundation for the application of MT to mitigate Al toxicity in plants.

The increasing global temperatures, driven largely by anthropogenic activities, pose a significant threat to crops worldwide, with heat stress (HS) emerging as one of the most severe challenges to agricultural productivity. Among the numerous human-induced pressures threatening terrestrial ecosystems globally, microplastics (MPs) represent one of the most persistent and urgent concerns. This study investigated the effects of heat stress (HS) at 35 degrees C and 40 degrees C (12 h exposure) on wheat (Triticum aestivum) and maize (Zea mays) grown in soil contaminated with polyethylene microplastics (PE-MPs; 0.01%, 0.1%, and 1% w/w), assessing their physiological and biochemical responses. The results indicated a significant (p < 0.05) reduction in plant height, root length, leaf area, chlorophyll content, and biomass of the selected plants due to MPs application. HS alone and in co-exposure with MPs caused damage to plant tissues as shown by significant (p < 0.05) reactive oxygen species (ROS) production, and lipid peroxidation. Under ROS induction, proline and antioxidant enzymes (CAT, POD, SOD) exhibited significantly (p < 0.05) higher levels in combined stress (HS + MPs) than in individual treatments. In conclusion, wheat exhibited higher levels of H2O2 and MDA stress markers indicating increased oxidative stress compared to maize. In contrast, maize showed elevated levels of proline, CAT, POD, and SOD, suggesting greater resistance to environmental stresses than wheat. Our results provide new understandings of sustainable agriculture practices and hold vast promise in addressing the challenges of HS and MP stresses in agricultural soils.

Soil salinization is increasingly recognized as a critical environmental challenge that significantly threatens plant survival and agricultural productivity. To elucidate the mechanism of salt resistance in poplar, physiological and transcriptomic analyses were conducted on 84K poplar (Populus alba x Populus glandulosa) under varying salt concentrations (0, 100, 200 and 300 mM NaCl). As salt levels increased, observable damage to poplar progressively intensified. Differentially expressed genes under salt stress were primarily enriched in photosynthesis, redox activity and glutathione metabolism pathways. Salt stress reduced chlorophyll content and net photosynthetic rate, accompanied by the downregulation of photosynthesis-related genes. NaCl (300 mM) significantly inhibited the photochemical activity of photosystems. The higher photochemical activity under 100 and 200 mM NaCl was attributed to the activated PGR5-cyclic electron flow photoprotective mechanism. However, the NAD(P)H dehydrogenase-like (NDH)-cyclic electron flow was inhibited under all salt levels. Salt stress led to reactive oxygen species accumulation, activating the ASA-GSH cycle and antioxidant enzymes to mitigate oxidative damage. Weighted gene co-expression network analysis showed that five photosynthesis-related hub genes (e.g., FNR and TPI) were down-regulated and nine antioxidant-related hub genes (e.g., GRX, GPX and GST) were up-regulated under salt stress conditions. PagGRXC9 encodes glutaredoxin and was found to be differentially expressed during the salt stress condition. Functional studies showed that overexpressing PagGRXC9 enhanced salt tolerance in yeast, and in poplar, it improved growth, FV/FM, non-photochemical quenching values and resistance to H2O2-induced oxidative stress under salt stress. This study constructed the photosynthetic and antioxidant response network for salt stress in poplar, revealing that PagGRXC9 enhances salt tolerance by reducing photoinhibition and increasing antioxidant capacity. These findings provide valuable insights for breeding salt-tolerant forest trees.

Jadomycin B, produced by the soil bacterium Streptomyces venezuelae ISP5230, induces cytotoxicity in human breast cancer cells in vitro and has antitumoral effects in animal models. In models of multidrugresistant, triple-negative breast cancer, jadomycin B has shown promise as it is not a substrate of ABCB1 and ABCG2 drug efflux transporters. The generation of reactive oxygen species and inhibition of topoisomerases are potential mechanisms of jadomycin B-mediated DNA damage and apoptosis. However, the mechanisms of jadomycin B's anticancer activity have not been fully elucidated. By gradually exposing MDA-MB-231 triple-negative human breast cancer cells to jadomycin B, we hypothesized that resistance could be selected to further understand jadomycin B's pharmacological mechanisms. A 3-fold increase in the jadomycin B IC50 was observed in MDA-MB-231 cells exposed to increasing jadomycin B concentrations (0-3 mu M) over 7 months, herein 231-JB cells. The 231-JB cells were cross-resistant to jadomycin F and S but not to the comparator drugs mitoxantrone, doxorubicin, and SN-38. The 231-JB cells did not have increased mRNA expression of topoisomerase-2 nor ABCB1 and ABCG2. Cyclooxygenase-2 (COX-2) increased by 25-fold, but expression of prostaglandin E2 receptor 4 did not significantly change. Cotreatment with celecoxib (15-45 mu M), a COX-2 inhibitor, resensitized the 231-JB cells to jadomycin B (IC50 1/4 1.41 +/- 0.24 to 0.75 +/- 0.31 mu M vs 2.28 +/- 0.54 with 0 mu M celecoxib). To our knowledge, this work represents the first report of the involvement of COX-2 in jadomycin B activity in vitro, proving to be an exciting new target for the exploration of jadomycin B anticancer activity. Significance Statement: Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin production, is associated with procancer signaling. COX-2, ABCB1, and ABCG2 overexpression are typically correlated in cancer, contributing to chemotherapy resistance. We observed increased COX-2, but not ABCG2 or

Previous research on cadmium (Cd) focused on toxicity, neglecting hormesis and its mechanisms. In this study, pakchoi seedlings exposed to varying soil Cd concentrations (CK, 5, 10, 20, 40 mg/kg) showed an inverted Ushaped growth trend (hormesis characteristics): As Cd concentration increases, biomass exhibited hormesis character (Cd5) and then disappear (Cd40). ROS levels rose in both Cd treatments, with Cd5 being intermediate between CK and Cd40. But Cd5 preserved cellular structure, unlike damaged Cd40, hinting ROS in Cd5 acted as signaling regulators. To clarify ROS controlled subsequent metabolic processes, a multi-omics study was conducted. The results revealed 143 DEGs and 793 DEMs across all Cd treatment. KEGG indicated among all Cd treatments, the functional differences encompass: plant hormone signal transduction and starch and sucrose metabolism. Through further analysis, we found that under the influence of ROS, the expression of IAA synthesis and signaling-related genes was significantly up-regulated, especially under Cd5 treatment. This further facilitated the accumulation of reducing sugars, which provided more energy for plant growth. Our research results demonstrated the signaling pathway involving ROS-IAA-Sugar metabolism, thereby providing a novel theoretical basis for cultivating more heavy metal hyperaccumulator crops and achieving phytoremediation of contaminated soils.

Boron (B) deficiency and copper (Cu) excess are common problems in citrus orchard soils. Citrus sinensis seedlings were exposed to 25 (B25) or 2.5 (B2.5) mu M H3BO3 and 0.5 (Cu0.5) or 350 (Cu350) mu M CuCl3 for 24 weeks. Cu350 upregulated 2210 (1012) genes and 482 (341) metabolites and downregulated 3201 (695) genes and 175 (43) metabolites in roots at B2.5 (B25). Further analysis showed that the B-mediated mitigation of Cu toxicity in roots involved the coordination of the following aspects: (a) enhancing the ability to maintain cell wall and plasma membrane stability and function; (b) lowering the impairment of Cu350 to primary and secondary metabolisms and enhancing their adaptability to Cu350; and (c) alleviating Cu350-induced oxidative stress via the coordination of reactive oxygen species (ROS) and methylglyoxal detoxification systems. Cu350 upregulated the abundances of some saccharides, amino acids and derivatives, phospholipids, secondary metabolites, and vitamins, and the expression of several ROS detoxification-related genes in roots of B2.5-treated seedlings (RB2.5), but these adaptive responses did not prevent RB2.5 from Cu-toxicity (oxidative damage). The study identified some genes, metabolites, and metabolic processes/pathways possibly involved in root Cu tolerance. Additionally, the responses of gene expression and metabolite profiling to Cu-B treatments differed between leaves and roots. Therefore, this study provided novel information for B to reduce Cu toxicity in roots and might contribute to the development of soil amendments targeting Cu excess in citrus and other crops.

Contamination of vegetables with heavy metals and microplastics is a major environmental and human health concern. This study investigated the role of taurine (TAE) in alleviating arsenic (As) and polyvinyl chloride microplastic (MP) toxicity in broccoli plants. The experiment followed a completely randomized design with four replicates per treatment. Plants were grown in soil spiked with MP (200 mg kg-1), As (42.8 mg kg-1), and their combination (As + MP) with or without taurine (TAE; 100 mg L-1) foliar supplementation. Results demonstrated that MP, As, and As + MP toxicity markedly decreased growth, chlorophyll content, photosynthesis, and nutrient uptake in broccoli plants. Exposure to individual or combined MP and As increased oxidative damage, indicated by elevated methylglyoxal (MG), superoxide radical (O2 & sdot;-), hydrogen peroxide (H2O2), hydroxyl radical (& sdot;OH), and malondialdehyde (MDA) levels alongside intensified lipoxygenase (LOX) activity and leaf relative membrane permeability (RMP). Histochemical analyses revealed higher lipid peroxidation, membrane damage as well as increased H2O2 and O2 center dot- levels in the leaves of stressed plants. Micropalstic and As toxicity deteriorated anatomical structures, with diminished leaf and root epidermal thickness, cortex thickness, and vascular bundle area. However, TAE improved the antioxidant enzyme activities, endogenous ascorbate-glutathione pools, hydrogen sulfide and nitric oxide levels that reduced H2O2, O2 & sdot;-, & sdot;OH, RMP, MDA, and activity of LOX. Taurine elevated osmolyte accumulation that protected membrane integrity, resulting in increased leaf relative water content and plant biomass. Plants supplemented with TAE demonstrated improved anatomical structures, resulting in diminished As uptake and its associated phytotoxicity. These findings highlight that TAE improved redox balance, osmoregulation, ion homeostasis, and anatomical structures, augmenting tolerance to As and MP toxicity in broccoli.