Salinity stress is one of the most detrimental abiotic factors affecting plant development, harming vast swaths of agricultural land worldwide. Silicon is one element that is obviously crucial for the production and health of plants. With the advent of nanotechnology in agricultural sciences, the application of silicon oxide nanoparticles (SiO-NPs) presents a viable strategy to enhance sustainable crop production. The aim of this study was to assess the beneficial effects of SiO-NPs on the morpho-physio-biochemical parameters of rice (Oryza sativa L., variety: DRR Dhan 73) under both normal and saline conditions. To create salt stress during transplanting, 50 mM NaCl was injected through the soil. 200 mM SiO-NPs were sprayed on the leaves 25 days after sowing (DAS). It was evident that salt stress significantly hindered rice growth because of the reductions in shot length (41 %), root length (38 %), shot fresh mass (40 %), root fresh mass (47 %), shoot dry mass (48 %), and root dry mass (39 %), when compared to controls. Together with this growth inhibition, elevated oxidative stress markers including a 78 % increase in malondialdehyde (MDA) and a 67 % increase in hydrogen peroxide (H2O2) indicating enhanced lipid peroxidation were noted. Increasing the chlorophyll content (14 %), photosynthetic rate (11 %), protein levels, total free amino acids (TFAA; 13 %), and total soluble sugars (TSS; 11 %), all help to boost nitrogen (N; 16 %), phosphorous (P; 14 %), potassium (K; 12 %), and vital nutrients. The adverse effects of salt stress were significantly reduced by exogenous application of SiO-NPs. Additionally; SiO-NPs dramatically raised the activity of important antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT), improving the plant's ability to scavenge reactive oxygen species (ROS) and thereby lowering oxidative damage brought on by salt. This study highlights SiO-NPs' potential to develop sustainable farming practices and provides significant new insights into how they enhance plant resilience to salinity, particularly in salt-affected regions worldwide.

Excessive fluorine accumulation poses a significant threat to soil ecology and even human health, yet its impact on soil fauna, especially earthworms, remains poorly understood. This study employed multi-omics and biomarkers to investigate high fluorine-induced biochemical changes that cause tissue damages in Eisenia fetida. The results demonstrated that earthworms exhibited obvious damage with fluorine addition exceeding 200 mg kg(-1), with stress levels escalating as fluorine contents increased. Further analysis of the underlying mechanisms revealed that fluorine could upregulate genes encoding mitochondrial respiratory chain complexes I-III and downregulate those for IV-V, leading to reactive oxygen species (ROS) accumulation despite antioxidant system activation. The resulting ROS interfered with deoxyribonucleoside triphosphate synthesis, prompting homologous recombination as the main DNA repair mechanism. Additionally, fluorine-induced ROS also attacked and disrupted protein and lipid related metabolisms ultimately causing oxidative damages. These cumulative oxidative damages from high fluorine contents subsequently triggered autophagy or apoptosis, resulting in tissue ulceration and epithelial exfoliation. Therefore, high fluorine could threaten earthworms by inducing ROS accumulation and subsequent biomolecule damages.

The global escalation of soil salinization has led to increased water erosion, adversely impacting plant growth and development. Heat shock proteins (HSPs) are highly conserved proteins found across a wide range of organisms. When biological organisms are stimulated by the external environment, they will express themselves in large quantities. HSPs play a pivotal role in mediating plant responses to abiotic stress. This study identified 22 members of the PcHsp20 gene family with complete open reading frames (ORFs) through transcriptomic analysis conducted under Pugionium cornutum salt stress, and evaluated their expression levels. Notably, PcHsp18.1 was significantly upregulated in the leaves of Pugionium cornutum (L.) Gaertn. Based on this, we cloned the PcHsp18.1 gene and determined through subcellular localization that PcHsp18.1 is localized in both the cytoplasm and nuclear membrane. Subsequently, we transformed the PcHsp18.1 gene into Arabidopsis thaliana to investigate its involvement in the response to salt stress. The results indicated that the overexpressing (OE) plants exhibited improved growth conditions, higher seed germination rates, increased root lengths, a greater number of lateral roots, reduced relative conductivity, and elevated relative chlorophyll content compared to the wild-type (WT) plants. These findings suggesting that the transgenic line possesses enhanced salt tolerance. Moreover, the concentrations of malondialdehyde (MDA) and relative conductivity in the overexpressing (OE) plants were significantly lower than those observed in the wild-type (WT) plants, suggesting a reduced extent of damage to their cell membranes. In comparison to the wild type (WT), the transgenic line (OE) exhibited elevated activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with increased proline content, suggesting that the transgenic plants possess enhanced resistance to abiotic stress and a greater capacity for scavenging reactive oxygen species (ROS). Meanwhile, salt treatment resulted in the significant expression of stress-related genes in the transgenic plants. These results indicate that PcHsp18.1 positively regulates salt stress in Arabidopsis.

Salinity is a common environmental stress that disrupts physiological and biochemical processes in plants, inhibiting growth. Silicon is a key element that enhances plant tolerance to such abiotic stresses. This study examined the effects of silicon supplementation on physiological, biochemical, and molecular responses of GF677 and GN15 rootstocks under NaCl-induced salinity stress. The experiment was conducted in a greenhouse using a factorial design with two rootstocks, three NaCl concentrations (0, 50, and 100 mM), and three silicon levels (0, 1, and 2 mM) in a randomized complete block design with three replicates. Salinity significantly reduced growth parameters, including shoot and root fresh and dry weights, RWC, and photosynthetic activity, with GN15 being more sensitive to salt stress than GF677. Silicon supplementation, especially at 2 mM, alleviated NaCl-induced damage, enhancing biomass retention and RWC under moderate and high NaCl levels. Additionally, silicon reduced electrolyte leakage, lipid peroxidation, and hydrogen peroxide accumulation, suggesting a protective role against oxidative stress. Biochemical analyses showed that silicon increased the accumulation of osmolytes such as proline, soluble sugars, glycine betaine, and total soluble protein, particularly in GF677. Silicon also boosted antioxidant enzyme activities, mitigating oxidative damage. In terms of mineral nutrition, silicon reduced Na+ and Cl- accumulation in leaves and roots, with the greatest reduction observed at 2 mM Si. Gene expression analysis indicated that NaCl stress upregulated key salt tolerance genes, including HKT1, AVP1, NHX1, and SOS1, with silicon application further enhancing their expression, particularly in GF677. The highest levels of gene expression were found in plants treated with both NaCl and 2 mM Si, suggesting that silicon improves salt tolerance by modulating gene expression. In conclusion, this study demonstrates the potential of silicon as an effective mitigator of NaCl stress in GF677 and GN15 rootstocks, particularly under moderate to high salinity conditions. Silicon supplementation enhances plant growth, osmotic regulation, reduces oxidative damage, and modulates gene expression for salt tolerance. Further research is needed to assess silicon's effectiveness under soil-based conditions and its applicability to other rootstocks and orchard environments. This study is the first to concurrently evaluate the physiological, biochemical, and molecular responses of GF677 and GN15 rootstocks to silicon application under salt stress conditions.

Tetracycline (TC) antibiotics are one of the class of drugs widely used in clinical practice but also constitute a significant environmental concern. However, the adverse effects of TC on non-target organisms have not been well studied. The aim of this study was to examine the influence of exposure to high levels of TC on thalli of lichens to determine the impact on (1) physiological parameters including integrity of cell membranes, photosynthetic efficiency and viability, (2) oxidative stress response such as membrane lipid peroxidation, and (3) enzymatic antioxidant activities as catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR). Data demonstrated that exposure to tetracycline did not markedly affect the lichen membrane damage as indicated by no change in conductivity. This antibiotic diminished the potential photosystem II efficiency (FV/FM) indicating enhanced susceptibility as evidenced by lower chlorophyll fluorescence and chlorophyll content. The viability of lichens exposed to high concentrations of tetracycline was significantly reduced. The concentrations of thiobarbituric acid reactive substances were markedly elevated with increasing concentrations of antibiotics. At higher TC concentrations, 500 mg/L SOD activity was significantly elevated. In the case of CAT, APX and GR, TC at higher concentrations significantly decreased these enzymic activities. The findings of this study contribute to the knowledge that TC antibiotics exert adverse ecotoxicological effects on lichens at high concentrations and provided a better understanding of the mechanisms underlying toxicity. Data also indicates that lichens may serve as an effective biomonitoring species for TC antibiotic exposure.

This study aimed to evaluate the synergistic effects of zinc sulfate and Pseudomonas spp. in terms of mitigating drought stress in maize (Zea mays L.) by analyzing physiological, biochemical, and morphological responses under field conditions. A two-year (2018-2019) field experiment investigated two irrigation levels (optimal and moderate stress) and twelve treatment combinations of zinc sulfate application methods (without fertilizer, soil, foliar, and seed priming) with zinc-solubilizing bacteria (no bacteria, Pseudomonas fluorescens, and Pseudomonas aeruginosa). Drought stress significantly reduced chlorophyll content, increased oxidative damage, and impaired membrane stability, leading to a 42.4% increase in electrolyte leakage and a 10.9% reduction in leaf area index. However, the combined application of zinc sulfate and P. fluorescens, and P. aeruginosa mitigated these effects, with seed priming showing the most significant improvements. Specifically, seed priming with zinc sulfate and P. fluorescens increased catalase activity by 76% under non-stress conditions and 24% under drought stress. Principal component analysis revealed that treatments combining zinc sulfate and P. fluorescens, and P. aeruginosa were strongly associated with improved chlorophyll content, carotenoid content, and grain yield while also enhancing osmotic adjustment and antioxidant enzyme activity. These findings highlight the potential of the use of zinc sulfate and P. fluorescens as well as P. aeruginosa as sustainable strategies for enhancing maize drought tolerance, mainly through seed priming and soil application methods.

Heavy metals (HMs) contamination is a major issue produced by industrial and mining processes, among other human activities. The capacity of fungi to eliminate HMs from the environment has drawn attention. However, the main process by which fungi protect the environment against the damaging effects of these HMs, such as cadmium (Cd), is still unknown. In this study, some fungi were isolated from HMs-polluted soil. The minimum inhibitory concentrations (MICs) and the tolerance indices of the tested isolates against Cd were evaluated. Moreover, molecular identification of the most tolerant fungal isolates (Aspergillus niger and A. terreus) was done and deposited in the GenBank NCBI database. The results showed that the colony diameter of A. niger and A. terreus was decreased gradually by the increase of Cd concentration. Also, all the tested parameters were influenced by Cd concentration. Lipid peroxidation (MDA content) was progressively increased by 12.95-105.95% (A. niger) and 17.27-85.38% (A. terreus), respectively, from 50 to 200 mg/L. PPO, APX, and POD enzymes were elevated in the presence of Cd, thus illustrating the appearance of an oxidative stress action. Compared to the non-stressed A. niger, the POD and PPO activities were enhanced by 92.00 and 104.24% at 200 mg/L Cd. Also, APX activity was increased by 58.12% at 200 mg/L. Removal efficiency and microbial accumulation capacities of A. niger and A. terreus have also been assessed. Production of succinic and malic acids by A. niger and A. terreus was increased in response to 200 mg/L Cd, in contrast to their controls (Cd-free), as revealed by HPLC analysis. These findings helped us to suggest A. niger and A. terreus as the potential mycoremediation microbes that alleviate Cd contamination. We can learn more about these fungal isolates' resistance mechanisms against different HMs through further studies.

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.

The root-knot nematode (RKN), Meloidogyne javanica, causes severe damage to a wide variety of crops. These nematodes significantly reduce tomato yield globally, causing symptoms such as stunted growth, galls on roots, chlorosis, and wilting, ultimately leading to host death. Classical nematode control methods, such as the application of chemical nematicides, are very effective; however, their use is limited due to conflicts with sustainable agriculture. Therefore, biological methods, are gaining attention as more environmentally friendly options. In the present study, 47 strains of bacteria were isolated from the rhizosphere of RKN-infected plants. The effect of these strains was studied on egg hatching and second stage infective juveniles (J2s) mortality of M. javanica, in vitro. Then, three holes were made in the soil around the roots of non-inoculated and nematode inoculated tomato plants and a suspension of 15 mL of three isolates with the greatest negative effect on hatching and J2s mortality (107 CFU/ml), was poured into the holes. Stenotrophomonas maltophilia CPHE1, Peribacillus frigoritolerans Rhs-L31 and Bacillus cereus Pt0-RL12 improved the vegetative indices of inoculated plants compared to control plants. These strains significantly reduced nematode hatching and significantly increased mortality of nematode J2s; and in greenhouse pot experiments significantly reduced the number of nematode eggs and egg masses, root galls, and nematode reproduction factor. In each case, inoculation with the bacterial strains significantly increased peroxidase and superoxide dismutase activity, and decreased catalase activity in tomato roots infected with M. javanica. The present study indicates the potential of these bacterial strains for biocontrol of M. javanica on tomato.