Emerging contaminants and climate change are major challenges that soil organisms are facing today. Triclosan (TCS), an antibacterial agent, is widespread and hazardous in terrestrial environments, but there is a lack of information on how its toxicity will change because of climate change. The aim of the study was to evaluate the short-term effects of increased temperature, decreased soil moisture content (drought), and their complex interaction on triclosan-induced biochemical changes in Eisenia fetida (as well as growth and survival). Four different treatments were used in TCS-contaminated soil tests with E. fetida (10-750 mg TCS kg-1): C (21 degrees C + 60 % water holding capacity (WHC)), D (21 degrees C and 30 % WHC), T (25 degrees C + 60 % WHC), and T + D (25 degrees C + 30 % WHC). The more prominent TCS effect on the survival was seen only after two weeks and at the high TCS concentrations, though a negative effect on weight growth was recorded after one week of exposure at all tested TCS concentrations and climate conditions. Under standard (C) conditions, an activated E. fetida antioxidative system effectively reduced the oxidative stress induced by TCS. Changes in the climatic conditions influenced E. fetid a's biochemical response to TCS-induced oxidative stress. Despite the enhanced activity of antioxidant enzymes, the combination of drought (D) and TCS caused significant lipid peroxidation in E. fetida. Under elevated temperature, E. fetida experienced oxidative stress and a considerable rise in lipid peroxidation due to insufficient activation or inhibition of antioxidant enzymes.

Due to the unregulated handling of e-waste, the co-existence of PBDEs and heavy metals in water bodies and soil has been detected with high frequency. However, the combined toxicity for aquatic creatures remains unclear. This study investigated the single and combined stress of BDE3 and copper on the photosynthesis and antioxidant enzyme system of Salvinia natans (L.). The results indicated that there were no negative effects on photosynthetic pigments under single stress of BDE3 or combined stress with copper. However, to deal with oxidative stress, antioxidant defense enzymes, including SOD and CAT, were activated in S. natans. SOD was sensitive in the first stage, while CAT activity was significantly increased until the end of 14 days of incubation. Malondialdehyde content increased significantly, which indicated that excessive reactive oxygen species from pollution of BDE3 or coexistence with copper could not be eliminated. BDE3 concentration in the aqueous phase declined with time, while copper was accumulated over time in S. natans, with BCF increasing to 0.31 +/- 0.073 at the end. Our study indicated that the co-existence of copper could exacerbate the damage caused by BDE3 to S. natans in aqueous environment.

Soil salinity and alkalinity severely suppress plant growth and crop yields. This study compared the effects of neutral and alkaline salt exposure, both individually and mixed, on metal content and morphophysiological responses in halophyte Haloxylon ammodendron. Our results showed that alkaline salt exposure more considerably inhibited the growth and photosynthesis of H. ammodendron than neutral salt exposure. Under neutral salt conditions, Na accumulated significantly, while K and Fe absorption was hindered. In contrast, under alkaline salt stress, Na accumulation was more pronounced, leading to a greater inhibition of K absorption. Additionally, Ca accumulation was promoted, while the transport of Fe, Mg, and Cu from root to shoot was suppressed. Alkaline salt stress also induced more severe osmotic stress, triggering a stronger accumulation of soluble sugars to counteract it. Furthermore, seedlings under alkaline stress showed higher levels of REL, H2O2, and MDA, but lower activities of SOD, POD, CAT, and APX, indicating increased oxidative damage. These findings suggest that H. ammodendron can adapt well to neutral salt stress through efficient antioxidant enzyme systems and osmotic stress regulation. In contrast, alkaline stress severely inhibits the absorption and transport of mineral elements and disrupts the balance of antioxidant enzymes. Besides, the deleterious effects of neutral-alkaline salt mixed stress were significantly less than those of alkaline stress alone, indicating a reciprocal enhancement between neutral and alkaline salt stress was occurred.

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.

Many studies have reported modification in the degree of O3 damage to photosynthesis by elevated CO2 and soil N supply. However, the mechanism underlying the modification is unclear. To clarify the important determinants in the degree of O3 damage to net photosynthetic rate (A) in the leaves of Fagus crenata (Siebold's beech) under elevated CO2 and with different soil N supply, F. crenata seedlings were grown for two growing seasons under combinations of two O3 levels (low concentration at approximately 4 nmol mol-1 and two times the ambient concentration), two CO2 levels (ambient and 700 mu mol mol-1), and three levels of soil N supply (0, 50 and 100 kg N ha- 1 year -1). During the second growing season, we determined A, stomatal conductance for calculating phytotoxic O3 dose (POD), antioxidant concentrations, and antioxidative enzyme activities in the leaves for evaluating O3 detoxification capacity. We calculated the O3-induced reduction in mean A (Delta Amean) during the second growing season using the data reported in our previous study and plotted it against mean daily POD without flux threshold (POD0). There was no significant linear nor non-linear relationship, suggesting that not only POD0 but also O3 detoxification capacity are important determinants of Delta Amean under elevated CO2 and N supply. We found significant negative linear relationships of Delta Amean per unit POD0 (Delta Amean/POD0) with reduced ascorbate concentration in the low O3 treatment, and with percentage of O3-induced change in activity of monodehydroascorbate reductase (MDAR). In addition, the Delta Amean/POD0 was positively and significantly correlated with the activity ratio of ascorbate peroxidase to MDAR. These results suggest that reduced ascorbate pool and its maintenance through the action of MDAR could be important determinants in the degree of O3 damage to net photosynthesis under elevated CO2 and soil N supply.

Allolobophora caliginosa, , an earthworm, was exposed to caffeine (CAF) via artificial soil to evaluate the effects on antioxidant enzymes in animals treated to 0, 10, 20, 40, and 80 mg CAF/kg soil after 7, 14, 28, and 56 d of exposure. There is evidence that antioxidant enzymes protect cells from free radical damage. A high CAF concentration generated changes in the activities of superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxide (POD), but had slight effects on malondialdehyde (MDA) levels after 56 d of exposure. Earthworms' ' MDA levels elevated somewhat after 7, 14, and 28 d. Earthworms treated with CAF were unable to induce the cytotoxic action over a very long period of time (56 d), as three enzymes [polyphenol oxidase (PPO), acetyl cholinesterase (AChE), and cellulose] were significantly inhibited. These data support the notion that oxidative stress plays a role in the response of earthworms to CAF poisoning.