Cadmium (Cd) contamination in soil poses a significant environmental threat, reducing crop yields and compromising food safety. This study investigates the potential of selenium nanoparticles (Se-NPs) synthesized using wheat extract to mitigate Cd toxicity, reduce Cd uptake and mobility, and recover grain nutrient composition in wheat (Triticum aestivum L.). A pot experiment was conducted following a completely randomized design (CRD) with three replications. Treatments included control, four Se-NPs concentrations (10, 25, 50, and 100 ppm), four Cd stress levels (25, 50, 75, and 100 ppm), and their combined interactions. Various physiological, biochemical, and agronomic parameters were analyzed to assess the mitigation potential of Se-NPs against Cd toxicity in wheat. Se-NPs (36.77 nm) were characterized using FTIR, confirming functional groups for stabilization, XRD verifying crystallinity and size via the Scherrer Equation, SEM revealing spherical morphology, and EDX confirming selenium as the predominant element with minor trace elements. Under 50 ppm Cd stress, Se-NPs at 25 ppm reduced days to anthesis by 8.16 % and mitigated a 45.13 % decrease in plant height. Grain yield, which declined by 90.86 % under Cd stress, was restored by 90.86 % with 10 ppm Se-NPs. Additionally, Se-NPs improved thousand kernel weight by 32.71 %, counteracting a 25.92 % reduction due to Cd stress. Antioxidant enzyme activities, including SOD and CAT, increased by up to 333.79 % in roots with Se-NP treatment, while oxidative stress markers decreased by 28 %. Moreover, Se-NPs effectively mitigated Cd uptake and reduced its mobility within the plant. Grain protein content improved by 16.89 %, and carbohydrate levels were maintained at 4.61 % despite Cd exposure. These findings indicate that Se-NPs enhance crop resilience, supporting sustainable food production in Cd-contaminated environments.
Cadmium (Cd) is a pervasive phytotoxic metal which deteriorates soil quality, affecting crops and creating adverse effects on the environment, food safety, and human health. Cd in soil poses negative effects on plants at the physiological, structural, and molecular level. Application of silicon (Si) can reduce Cd accumulation by suppressing Cd uptake in plants, while spermidine (Spd) alleviates Cd toxicity through improved antioxidant capacity. However, their combined effects on antioxidant system and endogenous polyamines (PAs) level in Cd-stressed plants and the underlying antioxidative defense mechanism are poorly understood. Salix matsudana Koidz. is a fast-growing tree species with high Cd tolerance, making it potentially suitable for phytoremediation. Here, the S. matsudana seedings were subjected to 50 mu M Cd stress with or without addition of 1.5 mM sodium silicate and 0.1 mM Spd. Following that, the non-enzymatic/enzymatic antioxidants, stressed-related genes and endogenous PAs levels were determined. The results showed that Cd stress suppressed the growth traits of S. matsudana while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) accumulation in the leaves, which also showed heightened Cd levels. However, exogenous application of Si and Spd increased activities of antioxidative enzymes and ameliorated the Cd-induced oxidative damage. Moreover, combined treatment with Si and Spd showed higher glutathione (GSH) and GSH/GSSH (oxidized glutathione) ratio compared to their individual applications. The results provided sufficient evidence regarding the synergistic effect of Si and Spd in the amelioration of Cd-induced oxidative stress in S. matsudana seedlings.
Cadmium (Cd) toxicity negatively impacts plant health and productivity. Nanosilica (SiO2NPs) and salicylic acid (SA) enhance plant performance and alleviate heavy metals stress. Yet, their combined effects against Cd-toxicity in rice remained less-explored. Thus, a hydroponic study investigated the individual and combined effects of SiO2NPs and SA on Cd-stress mitigation in rice at physio-biochemical, cellular, and molecular levels. Results indicated that Cd-alone treatment caused a significant reduction in rice growth and biomass and photosynthetic efficiency, which was associated with oxidative damage caused by enhanced Cd-accumulation in plant tissues. Cd-induction also potentiated its phytotoxicity by triggering enzymatic antioxidants against the extra production of reactive oxygen species (ROS). The addition of SiO2NPs and/or SA markedly minimized the Cd-induced toxicity by reducing Cd-bioaccumulation (42-56%), protecting photosynthetic efficiency, which were directly correlated with seedling biomass and restored cellular structures (leaf ultrastructure and surface morphology). The combined application of SiO2NPs and SA was more effective in activating antioxidant enzymes, phytohormones biosynthesis, and reducing oxidative damages caused by Cd than sole application. This was evident in the decreased production of ROS, malondialdehyde contents (29-37%), and recovered membrane stability. Moreover, SiO2NPs and/or SA relieved Cd-bioaccumulation (41-56%) by downregulating the Cd-related transporter genes (OsNramp1, OsNramp5, OsHMA2, and OsHMA3). Altogether, the cellular Cd-accumulation, photosynthesis, antioxidant defense, and phytohormones against oxidative stress can be ideal markers for cultivating rice in Cdcontaminated soils.
Cadmium (Cd) contamination in agricultural soils and its accumulation in plant organs have become a global issue due to its harmful effects on human health. The in-situ stabilizing technique, which involves using organic amendments, is commonly employed for removing Cd from agricultural soils. Thus, the current study investigated the effect of vermicompost (VC) on soil properties and plant physio-biochemical attributes, leaf ultrastructure analysis, antioxidant defense mechanisms, and grain yields of two different fragrant rice cultivars, Xiangyaxiangzhan (XGZ) and Meixiangzhan-2 (MXZ-2), under Cd-stress conditions. The results showed that Cd toxicity deteriorates soil quality, the plant's photosynthetic apparatus, and the plant's antioxidant defense mechanism. Moreover, under Cd stress, both cultivars produced significantly lower (p < 0.05) rice grain yields compared to non-Cd stress conditions. However, the VC application alleviated the Cd toxicity and improved soil qualitative traits, such as soil organic carbon, available nitrogen, total nitrogen, phosphorus, and potassium. Similarly, VC amendments improved leaf physiological activity, photosynthetic apparatus function, antioxidant enzyme activities and its related gene expression under Cd stress These enhancements led to increased grain yields of both fragrant under Cd toxicity. The addition of VC mitigated the adverse effects of Cd on the leaf chloroplast structure by reducing Cd uptake and accumulation in tissues. This helped prevent Cd-induced peroxidation damage to leaf membrane lipids by increasing the activities of antioxidant enzymes such as ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD). On average across the growth stages, the Pos-Cd + VC3 treatment increased SOD, APX, CAT, and POD activities by122.2 and 112.5%, 118.6, and 120.6%, 44.6 and 40.6%, and 38.6 and 33.2% in MXZ-2 and XGZ, respectively, compared to the plants treated with Pos-Cd treated alone. Enhancements in leaf physiological activity and plant antioxidant enzyme activity strengthen the plant's antioxidant defense mechanism against Cd toxicity. In addition, correlation analysis showed a strong relationship between the leaf net photosynthetic rate and soil chemical attributes, suggesting that improved soil fertility enhances leaf physiological activity and boosts rice grain yields. Of the treatments, Pos-Cd + VC3 proved to be the most effective treatment in terms of enhancing soil health and achieving high fragrant rice yields. Thus, the outcomes of this study show that the addition of VC in Cd-contaminated soils could be useful for sustainable rice production and safe utilization of Cd-polluted soil.
Cadmium (Cd) hazard is a serious limitation to plants, soils and environments. Cd-toxicity causes stunted growth, chlorosis, necrosis, and plant yield loss. Thus, ecofriendly strategies with understanding of molecular mechanisms of Cd-tolerance in plants is highly demandable. The Cd-toxicity caused plant growth retardation, leaf chlorosis and cellular damages, where the glutathione (GSH) enhanced plant fitness and Cd-toxicity in Brassica through Cd accumulation and antioxidant defense. A high-throughput proteome approach screened 4947 proteins, wherein 370 were differently abundant, 164 were upregulated and 206 were downregulated. These proteins involved in energy and carbohydrate metabolism, CO2 2 assimilation and photosynthesis, signal transduction and protein metabolism, antioxidant defense response, heavy metal detoxification, cytoskeleton and cell wall structure, and plant development in Brassica. . Interestingly, several key proteins including glutathione Stransferase F9 (A0A078GBY1), ATP sulfurylase 2 (A0A078GW82), cystine lyase CORI3 (A0A078FC13), ferredoxin-dependent glutamate synthase 1 (A0A078HXC0), glutaredoxin-C5 (A0A078ILU9), glutaredoxin-C2 (A0A078HHH4) actively involved in antioxidant defense and sulfur assimilation-mediated Cd detoxification process confirmed by their interactome analyses. These candidate proteins shared common gene networks associated with plant fitness, Cd-detoxification and tolerance in Brassica. . The proteome insights may encourage breeders for enhancing multi-omics assisted Cd-tolerance in Brassica, and GSH-mediated hazard free oil seed crop production for global food security.