Cd Toxicity Research Articles

OsHARBI1-1 enhances cadmium tolerance in yeast through YAP1 mediated modulation of cell wall integrity genes and catalase genes.

Harbinger transposase-derived 1 proteins (HARBI1s) play important roles in plant growth, development, and response to abiotic stress. OsHARBI1-1 has been identified as a gene encoding HARBI1-1 protein in rice and has been shown to be responsive to Cadmium (Cd) stress. However, the function of OsHARBI1-1 protein under heavy metal stress remains unclear. In this study, the function of a novel rice Cd-responsive gene, OsHARBI1-1, under Cd stress was characterized by heterologous expression in yeast. The heterologous expression OsHARBI1-1 conferred yeast with increased tolerance to Cd. In addition, the yeast cells expressing OsHARBI1-1 exhibited enhanced tolerance to Congo red and exhibited an increase in cell wall thickness under Cd stress, suggesting a potential correlation between increased Cd tolerance and cell wall thickness in the transgenic yeast. When OsHARBI1-1 was expressed in ∆yap1 or ∆yap1∆ycf1 yeast mutants, there was no significant difference in the tolerance of transgenic yeast to Cd and Congo red, as well as in cell wall thickness compared to the control. Meanwhile, the expression of cell wall integrity (CWI) genes and catalase genes in transgenic yeast was up-regulated in a YAP1-dependent manner under Cd or Congo red stress. The above facts supported the inference that OsHARBI1-1 may counteract Cd toxicity by enhancing the expression of YAP1, thereby increasing the thickness of the cell wall and activating the expression of catalase genes.

Investigation of Cannabidiol's Protective Effects on Cadmium-Induced Toxicity in Mice.

Current chelation treatments used for cadmium poisoning may cause some serious side effects. Thus, safer novel treatments could be promising for clinical use. This study evaluated the effects of cannabidiol on Cd toxicity. Four groups of 10 mice were formed: Groups I and III were cadmium-free, while groups II and IV received 50 mg/L cadmium in drinking water. Groups III and IV received daily cannabidiol (25 mg/kg) via intragastric gavage. After 30 days, the animals were killed, and blood and tissue samples were collected. Oxidative stress and inflammation markers, including glutathione, catalase, myeloperoxidase, TNF-α, IL-1β and IL-6, were analysed using ELISA. Additionally, histological evaluations of the liver, kidney and testis were performed. Cadmium exposure reduced glutathione and catalase levels in the blood, liver, kidney and testis, while increasing myeloperoxidase. Cannabidiol mitigated these effects on oxidative stress markers. Cannabidiol also reduced the increase in proinflammatory cytokines. Histopathological analysis revealed reduced liver and kidney damage in cannabidiol-treated groups compared to cadmium-only groups. In addition, histopathological evaluation showed CBD had no protective effect on the testicular tissue against Cd toxicity. Our results indicate that cannabidiol protects against some toxic effects of cadmium. If confirmed by future studies, cannabidiol may be proposed as a novel treatment for cadmium toxicity.

Chronic cadmium exposure to minimal-risk doses causes dysfunction of epididymal adipose tissue and metabolic disorders.

Cadmium (Cd) is among the top seven most hazardous environmental contaminants. Minimal risk levels for daily exposure have been established, such as no observable adverse effect level (NOAEL) and lowest observable adverse effect level (LOAEL). Chronic exposure to Cd, at both NOAEL and LOAEL doses, causes toxicity in diverse tissues. However, Cd toxicity in adipose tissue, an endocrine and metabolic organ, remains relatively understudied. We aimed to investigate the potentially toxic effects of chronic Cd exposure (at NOAEL and LOAEL doses) on epidydimal adipose tissue of adult male Wistar rats. Ninety male Wistar rats were divided into three groups (n=30): Control Cd-free, NOAEL, and LOAEL that received CdCl2 in drinking water for 15days to 5months. We evaluated over time zoometry, serum and adipose Cd concentration, redox balance, GLUT4 and Nrf2 expression, histology, leptin, adiponectin, adipose insulin resistance index, free fatty acids, and glucose tolerance. The higher dose group showed a more pronounced and sustained increase in serum and adipose tissue of Cd concentration. Zoometry was similarly affected in both Cd-exposed groups with adipocyte hypertrophy. The redox balance was maintained due to the augmenting of Nrf2 expression. Leptin concentration augmented, while adiponectin diminished. Adipose insulin resistance increased simultaneously to lipolysis and glucose intolerance despite high GLUT4 expression. In conclusion, this study provides strong evidence that chronic Cd exposure, even at minimal risk levels (LOAEL and NOAEL doses), has toxic effects, disrupting the function of epididymal adipose tissue and contributing to metabolic disorders.

Plant-microbiome interactions for enhanced crop production under cadmium stress: A review.

Cadmium (Cd) is a toxic heavy metal that has detrimental effects on agriculture crops and human health. Both natural and anthropogenic processes release Cd into the environment, elevating its contents in soils. Under Cd stress, strong plant-microbiome interactions are important in improving crop production, but a systematic review is still missing. This review demonstrates the importance of microbiomes and their interactions with plants in mitigating Cd toxicity and promoting crop growth. Endogenous and exogenous microbiomes play a role to enhance plant's ability to respond to Cd stress. Specifically, the rhizosphere microbiome, which includes plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi, endosphere microbiome, and phyllosphere microbiome, are involved in Cd accumulation, immobilization, and translocation, and Cd-induced stress management. The mechanisms underlying these plant-microbiome interactions vary depending on the species and varieties of crops, composition and diversity of the microbiome, and level of Cd stress. Among the microbiome-mediated approaches, biosorption, bioprecipitation, and bioaccumulation are promising for Cd remediation in soil. Additionally, the endosphere microbiome, particularly Cd resistant endophytes, reduces Cd toxicity, increases the expression of Cd efflux genes, and enhances crop growth through regulating crops' antioxidant machinery and endogenous hormones. Furthermore, improved agricultural practices modulate the soil and plant microbiomes, thereby reducing Cd stress and increasing crop productivity.

Occurrence and health risk assessment of selected metals in commercially available infant formulas in Jordan.

Infant formulas are the primary source of nutrition for infants and babies when breastfeeding is unavailable, as they are enriched with a variety of macro- and micronutrients to improve their nutritional value and satisfy the different needs of babies. Recently, there has been a rising concern about toxic metal levels in infant formulas, as highlighted by various studies. However, there are currently no sufficient studies focusing on toxic metal levels of infant formulas in Jordan. The current study aims to determine the levels of 25 metals, including Na, Mg, K, Ca, Cr, Fe, Mn, Co, Ni, Cu, Zn, Li, Ti, V, Ga, Sr, Ag, Ba, Bi, Th, U, Al, Cd, In, and Pb, in infant formulas (starter infant formula, follow-on formula, and growing-up formula) using inductively coupled plasma mass spectrometry (ICP-MS) and evaluate their safety and quality. The metal compositions of 37 infant formula samples collected from different Jordanian pharmacies were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after digesting the samples with 9 mL of HNO3 (70 %) and 3 mL of H2O2 (30 %) using the microwave-assisted digestion technique. The possible health risks associated with the exposure to Cd, Pb, Al, and Ni in infant formulas were evaluated using estimated daily intake, target hazard quotient, and hazard index calculations. Also, method validation, including accuracy, precision, limit of detection, and limit of quantification, was performed. The results revealed that follow-on formula (intended for 7-12-month-old babies) had the highest mean concentration of all studied metals, except for zinc, which had the highest mean concentration in starter infant formula (intended for less than 6-month-old babies). Also, 72.97 % and 89.20 % of the tested samples had Pb and Cd levels that exceeded the European permissible limit, respectively. Regarding the estimated daily intake (EDI), babies aged 7-12 months were found to be the most exposed to Cd and Pb toxicity, while babies aged less than 6 months were found to be the most exposed to Ni toxicity. Unfortunately, the overall non-carcinogenic negative adverse effects (hazard index HI) of Cd and Pb for babies aged 7-12 months exceeded the acceptable threshold of 1. Based on the results, the consumption of infant formulas sold in Jordan may pose serious health risks to babies, with Cd and Pb levels in follow-on formulas (posing the highest risk). The source of contamination in infant formulas may be contaminated raw materials, the manufacturing process, packaging, or storage. So, strict regulations ought to be established to safeguard the health of babies.

Green synthesized silicon dioxide nanoparticles (SiO2NPs) ameliorated the cadmium toxicity in melon by regulating antioxidant enzymes activity and stress-related genes expression

Green synthesized nanoparticles (NPs) are an eco-friendly and cost-effective approach to reduce heavy metal stress in plants. Among heavy metals, cadmium (Cd) possesses higher toxicity to the crops and ultimately reduces their growth and yield. The current study aims to evaluate the effectiveness of green synthesized SiO2NPs to reduce toxic effects of Cd in melon (Cucumis melo) by regulating physiological parameters, enhancing antioxidant enzyme activity, and modulating stress-related gene expression. The SiO2NPs were synthesized using Artemisia annua plant extract having spherical shape and size within the range of 40-70 nm and characterized using advanced spectroscopic and analytical techniques. The application of SiO2NPs (75mg/L) significantly improved physiological parameters such as shoot length (SL), root length (RL), leaf fresh weight (LFW), root fresh weight (RFW), leaf dry weight (LDW) and root dry weight (RDW) by 14%, 20%, 15%, 16%, 14%, and 28%, respectively, compared to Cd-stressed plants. Photosynthetic pigments (chlorophyll and carotenoids) showed a notable increase of 15% and 40%, respectively. Furthermore, the activities of antioxidant enzymes such as SOD, POD, CAT, and APX were enhanced by 28.67%, 35.45%, 32.07%, and 42.75%, respectively. In addition, applying SiO2NPs increased the concentration of macronutrients N, P, and K by 33%, 40%, and 37%, respectively, compared to Cd-stressed plants. Moreover, SiO2NPs upregulated the expression of several stress-related genes and reduced Cd accumulation in shoots and roots. This study reveals that green synthesized SiO2NPs effectively reduced the Cd toxicity in melon by improving morphological and physiological parameters, enhancing antioxidant enzyme activity, and regulating the expression of stress-related genes. These findings suggest that green synthesized SiO2NPs could play a crucial role in sustainable agriculture by protecting crops from heavy metal stress.

Physiological and transcriptomic analysis of purple flowering stalks (Brassica campestris var. purpurea) under cadmium stress and exogenous glutathione application.

Glutathione (GSH) has a beneficial effect on the response of plants to cadmium (Cd) stress. The physiological and molecular processes by which glutathione influences Cd tolerance in purple flowering stalks (a Brassica vegetable) remain unclear. The aim of this study was to investigate the role of exogenous GSH in alleviating Cd toxicity in purple flowering stalks. On day 10 of the Cd stress treatment, spraying of GSH resulted in an increase in the net photosynthetic rate by 18.48%; enhanced antioxidant enzyme activities and the endogenous GSH and ascorbic acid contents; reduced the malondialdehyde and proline content 32.45% and 24.65%, respectively; and reduced the Cd content in the roots by 2.93%. On day 5, the transcriptome analysis showed that the application of GSH up-regulated the expression of 27 genes in the photosynthetic pathway. In contrast, GSH application led to the down-regulation of most genes involved in GSH metabolism, sulfur metabolism, and arginine and proline metabolism. These findings will aid future studies of the response of purple flowering stalks to Cd stress.

Salicylic acid confers cadmium tolerance in wheat by regulating photosynthesis, yield and ionic homeostasis

Wheat (Triticum aestivum L.) productivity and quality can be threatened by soil cadmium (Cd) contamination, posing a concern to food security. Salicylic acid (SA) is an endogenously produced signaling molecule that activates the defense system imparting abiotic stress tolerance in plants. Hence, an experiment was conducted to explore the roles of foliar application of SA in ameliorating Cd toxicity in two wheat varieties. The treatments comprised of, a) Cd stress: i) Cd0 = control (No Cd), Cd1 = 500 µM Cd stress at 30 days after sowing (DAS); SA applications: (i) SA0 = control (No SA) (ii) SA1 = 0.5 mM SA at 32 DAS, and c) Wheat varieties: (i) Anaj-17 and (ii) Akbar-19. The experiment was carried out with three replicates in a completely randomized design (CRD). The findings of the study have revealed that Cd stress prominently reduced the plant growth and yield, gaseous exchange attributes, and relative water content of both wheat varieties, and more reduction was observed in Anaj-17 as compared to Akbar-19. Plant height, economic yield, photosynthetic rate, and relative water content were decreased by (9.80 and 8.20%), (12.2 and 6.58%), (20 and 11.32%), and (12.5 and 10%) in Anaj-17 and Akbar-19 respectively. Further, SPAD value and chlorophyll fluorescence decreased under Cd toxicity in both wheat cultivars as compared to non-stress conditions. Contrarily, electrolyte leakage and Cd contents were increased in the plants as compared to the control. However, the foliar applications of SA in Cd-stressed plants significantly improved the plant growth and yield attributes, relative water content, gas exchange attributes, and chlorophyll content in both wheat varieties as compared to control-no SA applied. In addition, chlorophyll fluorescence and nutrient uptake were also improved under SA applications as compared to control. However, SA played an ameliorative role in reducing Cd-toxicity by reducing the electrolyte leakage and Cd uptake by the plants. Among the varieties, Akbar-19 outperformed the Anaj-17 to impart Cd toxicity under SA applications based on plant morphophysiological attributes. Hence, the outcomes of the experiment recommended that the foliar treatment of SA amended the Cd tolerance of wheat varieties by improving plant physiological and biochemical attributes.

Cadmium Pollution Deteriorates the Muscle Quality of Labeo rohita by Altering Its Nutrients and Intestinal Microbiota Diversity.

The detrimental effects of cadmium (Cd), a hazardous heavy metal, on fish have triggered global concerns. While the ecotoxicity of Cd on fish has been investigated, the impact of Cd on muscle quality and its correlation with the gut microbiota in fish remains scarce. To comprehensively uncover Cd effects based on preliminary muscle Cd deposition, relevant studies, and ecological Cd pollution data, we exposed Labeo rohita to Cd under concentrations of 0.00 (control), 0.05, and 0.40mg/L for 30days and assessed fish health, muscle quality, and intestinal bacterial diversity. We observed significant Cd bioaccumulation in the fish muscle and intestine at 0.40mg/L treatment, adversely impacting fish health with lower growth indices, higher mortality, behavioral aberrations, and clinical anomalies. More interestingly, Cd exposure decreased muscle quality by reducing nutrient levels, including fat, protein, iron, zinc, mono and polyunsaturated fatty acids, and increasing free amino acids and saturated fatty acids. Elevated oxidative stress markers, including total superoxide dismutase (T-SOD), catalase (CAT), and hydrogen peroxide (H2O2), were detected in the muscles, indicating degraded quality as a result of damage to cellular structures including proteins, lipids, and DNA. Simultaneously, we found Cd exposure altered fish intestinal microbial diversity, impairing muscle nutrient assimilation, thereby influencing muscle quality. Functional predictions suggested a decrease in pathways related to fermentation and chemoheterotrophy in the exposed groups. Overall, this study highlights how Cd toxicity jeopardizes fish health and deteriorates muscle quality which needs to be addressed for human benefit.

Effect of sludge-based biochar on the stabilization of Cd in soil: experimental and theoretical studies

Soil heavy metal contamination and sludge disposal have become globally environmental issues problems of great concern. Utilizing sludge pyrolysis to produce biochar for remediating heavy metal-contaminated soil is an effective strategy to solve these two environmental problems. In this study, municipal sewage sludge and papermaking sludge were used as feedstock to prepare co-pyrolyzed biochar, which was then applied to reduce the toxicity of Cd in soil. The results indicated that the application of co-pyrolyzed biochar significantly increased soil pH, CEC, and enzyme activity, while decreasing the content of available Cd in the soil. Following the application of 3% co-pyrolyzed biochar, the proportion of acid-soluble Cd in the soil decreased to below 46%, as the biochar facilitated the conversion of leachable acid-soluble Cd to stable oxidizable and residual forms through precipitation and complexation. The DFT computational results indicate that the aromatics in co-pyrolyzed biochar can adsorb Cd ions through cation-π interactions, while carboxyl, hydroxyl, aldehyde, and amide groups can provide more electrons for the adsorption of Cd ions, resulting in stronger adsorption capacities. The study findings provide a feasible solution for the resourceful treatment of sludge and the remediation of heavy metal-contaminated soil.

Blood cadmium levels of children aged 0-6years in China: A national cross-sectional study.

Cd has no known biological function and poses significant health risks in humans. Children are particularly susceptible to Cd toxicity due to their higher absorption rates and weaker biological defenses. However, national blood Cd levels (BCLs) in Chinese children aged 0-6years remain unclear. We employed a multistage stratified cluster sampling method to obtain a representative sample of 30,156 Chinese children aged 0-6years. Venous blood samples were collected under sterile conditions. High-sensitivity quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) was used to analyze Cd levels. The Kruskal-Wallis and the chi-square tests were employed for statistical comparisons. Strict quality control was maintained throughout the study. The geometric mean (GM) BCL among children was 0.146μg/L. Children in eastern and southern China had significantly higher BCLs compared to those in central, western, and northern regions (P<0.001). Rural children showed higher BCLs compared to those in urban areas (P<0.001). Among provinces, children in Hunan and Guangdong had the highest BCLs. We evaluated the BCLs in Chinese children aged 0-6years and reported specific indicators of BCLs across various stratifications. Significant regional variation was observed, particularly between northern and southern regions. These findings prompt further discussion on the spatial distribution of BCLs and the potential underlying causes. Based on our results, we further propose reference values for BCLs in Chinese children and stress the urgent need for enhanced environmental control and remediation in regions where children are exposed to higher BCLs.

Mechanistic Insights into the Effects of Aged Polystyrene Nanoplastics on the Toxicity of Cadmium to Triticum Aestivum.

The widespread concern over nanoplastics (NPs) has prompted extensive research into their environmental impact. Concurrently, the study examined the combined toxicity of PS NPs and cadmium (Cd) on wheat. As indicated by the results of in situ Micro-ATR/FTIR, the aging process of PS NPs (50nm) led to an increase in carbonyl and hydroxyl groups on their surface, enhancing hydrophilicity and consequently, the adsorption capacity for Cd. The toxicity assessment, measured by the impact on wheat leaf and root biomass after 7 d culture, revealed that pristine PS NPs with concentrations of 0-5000mg·kg⁻¹ had a negligible effect on Cd toxicity to wheat leaves. However, aged PS NPs significantly intensified the inhibitory effect on wheat root growth, particularly at low Cd concentrations (≤ 5.0mg·kg⁻¹). This synergistic toxicity between aged PS NPs and Cd is suspected to stem from the increased bioaccumulation of Cd in wheat, likely facilitated by the aged NPs. Thus, the study shed light on the aging behavior of soil surface NPs and its implications for environmental risk assessment.

Multiple biological responses and transcriptome plasticity of the model unicellular eukaryote paramecium for cadmium toxicity aggravated by freshwater acidification.

Cadmium (Cd) pollution is a widespread threat to aquatic life, and ongoing freshwater acidification (FA) can be expected to interact with Cd compounds to disrupt freshwater ecosystems. However, the effects of FA on Cd biotoxicity remain unclear. Herein, the model ciliate Paramecium tetraurelia, a model unicellular eukaryotic organism, was used to explore the response to environmental relevant concentrations of Cd under acidification conditions. We show for the first time that exposure to acidified freshwater accelerated Cd bioaccumulation and enhanced Cd bioavailability in P. tetraurelia, suggesting the synergistic interaction of Cd and FA. The co-exposure greatly reduced the abundance and carbon biomass, altered lysosomal membrane stability, induced oxidative stress, and consumed more ATP in exposed ciliates. Transcriptome plasticity enabled P. tetraurelia to develop a Cd stress-adaptive transcriptional profile (upregulation of transport and detoxification and downregulation of energy metabolism) under acidification. With a concomitant inhibition in energy production, the exposed ciliates might have diverted the energy from growth and cell replication to compensate for the energetic cost from stress response and detoxification. Collectively, acidified freshwater could aggravate Cd toxicity, which, in turn, arouses the response strategy of ciliates to cope with stress, providing a mechanistic understanding of the interaction between freshwater acidification and Cd pollution in the basic trophic level ciliated protozoa in freshwater ecosystems.

Assessment of the interaction of copper and zinc with cadmium to reduce its toxicity in heavy metal-contaminated river basin soils

Copper (Cu) and zinc (Zn) serve a dual purpose by providing essential nutrients to plants and reducing cadmium (Cd) toxicity in the soil–plant system. Using Cu and Zn to alleviate Cd toxicity could be an effective and low-cost method for rehabilitating contaminated soils. Two laboratory incubation experiments were conducted to study the interaction mechanisms between Cd and Cu, and Cd and Zn at different application levels in metal-contaminated Typic Haplaquept soil. In the first experiment, 2 g of soil were placed in wide-mouthed test tubes in duplicate, with four levels of Cd (0, 1, 2, and 5 mg kg−1) and four levels of Cu (0, 5, 10, and 20 mg kg−1) added simultaneously. The second experiment used the same levels of Cd with four levels of Zn (0, 5, 10, and 20 mg kg−1). The samples were kept at 50% field water holding capacity and incubated for 0, 7, 15, 30, and 60 days at room temperature (26 ± 1 °C). The study results showed that increasing doses of Cu or Zn significantly and consistently reduced the extractable Cd and increased the soil Cu or Zn content. Over time, a significant reduction in extractable Cd and Zn and an increase in Cu in the soil were observed. Cd concentrations exhibited a gradual decline of 71.8%, 70.2%, 69.8%, and 73.5% at Cu levels of 0, 5, 10, and 20 mg kg⁻1, and 69.2%, 69.6%, 68.0%, and 70.1% at Zn levels of 0, 5, 10, and 20 mg kg⁻1, respectively, averaging a 71.3% and 69.2% reduction over an incubation period from 0 to 60 days. The interactions of Cd with Cu, Cd with Zn, Cu with days, Zn with days, and Cd with days significantly decreased Cd and Zn and increased Cu contents in the soil. The interactions between Cd and Cu, and Cd and Zn in the soil were antagonistic, demonstrating that applying Cu and Zn to the soil effectively counteracted Cd toxicity, supporting healthy plant growth in Cd-contaminated soil. It can be useful in reducing heavy metal pollution in the soils providing a sustainable and economical approach with ramifications for the environment. Using antagonistic interaction of Cd with essential micronutrients such as Cu and Zn, it contributed to soil restoration, diminished bioavailability of toxic metals and further raised the potential for safer agricultural practices in contaminated locations.

Effects of Cd and Cr stress on physiological and morphological traits of two cultivars of wheat (Triticum aestivum L.) under hydroponic system

&lt;p style="line-height:150%;text-align:justify;"&gt;&lt;span style="font-family:&amp;quot;Times New Roman&amp;quot;,serif;" lang="EN-US"&gt;Hydroponic experiment was conducted to evaluate the single and combine effect of different concentration of Cd (&lt;/span&gt;&lt;span style="color:#212121;font-family:&amp;quot;Times New Roman&amp;quot;,serif;" lang="EN-US"&gt;80 µM, 100 µM&lt;/span&gt;&lt;span style="font-family:&amp;quot;Times New Roman&amp;quot;,serif;" lang="EN-US"&gt;) and Cr&lt;/span&gt;&lt;span style="color:#212121;font-family:&amp;quot;Times New Roman&amp;quot;,serif;" lang="EN-US"&gt; (120 µM, 140 µM)&amp;nbsp;&lt;/span&gt;&lt;span style="font-family:&amp;quot;Times New Roman&amp;quot;,serif;" lang="EN-US"&gt;on the seedlings of two wheat cultivars viz. FA-08 and SH-13 commonly grown in Hazara division of Khyber Pakhtunkhwa- Pakistan. High dose accumulation of Cd and Cr greatly affected the plant height and leaf number. The presence of Cd reduced the accumulation of Cr, whereas the effect of Cr on the accumulation of Cd depends on the concentrations of Cd used. Different treatments of these HMs (heavy metals) greatly fluctuate the total amount of phytochemicals in leaves of wheat seedlings. The application of Cd and Cr separately and in combination increased the total phenolics in all treatments compared to control groups which were tested on the 18&lt;sup&gt;th&lt;/sup&gt; day of treatment. Highest levels of total phenolics were recorded in FA-08 when Cd is used in a concentration of 80µM. Flavonoid content was high in FA-08 at level Cd+Cr:100+140µM. SH-13 also depicted highest antioxidant activity at level Cd:80µM against all treatments&lt;sub&gt;&amp;nbsp;&lt;/sub&gt;as compared to FA-08. Cd and Cr behaved synergistically because the combined toxicity of Cd and Cr was less than Cd or Cr alone. The current study suggests that both wheat cultivars were tolerant to stress of Cd and Cr up to certain limit and high concentration reduced the contents of phytochemicals, this might cause decrease in the wheat yield.&lt;/span&gt;&lt;/p&gt;

Hybrid Pennisetum colonization by Bacillus megaterium BM18-2 labeled with green fluorescent protein (GFP) under Cd stress

Researchers have reported that Bacillus megaterium BM18-2 reduces Cd toxicity in Hybrid Pennisetum, but understanding the interaction between plants and associated endophytes is crucial for understanding phytoremediation strategies under heavy metal stress. The current study aims to monitor the colonization patterns of GFP-labeled endophytic bacteria BM18-2 on Hybrid Pennisetum grass. Additionally, it will monitor Cd’s effect on plant bacterial colonization. Confocal laser scanning microscopy of plant roots infected with gfp tagged BM18-2 revealed that the bacterium colonised root hairs and epidermal cells at the early stage of colonization, and over time, the bacteria penetrated to the internal tissues following their colonization of the stem and leaf. The roots, stems, and leaves of H. Pennisetum grown in Cd-contaminated soil contained a higher number of bacteria than those grown in normal soil. The result of Cd translocation indicated the condensation of heavy metals in the root cells and stem, while no Cd was found in the leaf. The study will also look for the enzymatic activity of bacteria BM18-2 and use Leadmium Green AM dye to track how Cd is taken up and moved through the plant. The enzymatic activity results showed that BM18-2 can produce catalase and amylase, but did not record any cellulase or lipase activity. As a result, the pattern of useful endophytic BM18-2 colonization through H. Pennisetum grass will aid in the application and maintenance of these bacteria in farming, and it presents new opportunities for the development of innovative strategies in the fields of agriculture and biotechnology.

Disentangling the role of selenium in antagonizing the toxicity of arsenic and cadmium.

Cadmium (Cd) and inorganic arsenic (As) compounds are considered to be among the major public health hazards. This is due to both the high intrinsic toxicity of these substances and the often difficult to avoid exposure of the general population through contaminated water and food. One proposed method to reduce the toxic effects of As and Cd on animals and humans is the use of selenium (Se). As discussed in our previous article, laboratory studies show that this micronutrient can have a beneficial effect on the detoxification of As and Cd in the body through the formation of non-toxic complexes with these elements, as well as through the antioxidant effects of selenoproteins. New data that have emerged in recent years allow for a clearer description of the interaction between Se and As and Se and Cd. Human studies show that optimal levels of Se can have a beneficial effect in reducing the toxic effects associated with exposure to As or Cd. However, as Se levels in the body increase, the protective effects of Se may be reversed. Recent laboratory studies confirm the antagonistic effects of medium doses of Se toward Cd and As through the formation of nontoxic complexes, antioxidant, anti-inflammatory effects, and induction of pro-survival pathways in cells. In conclusion, Se has a complex effect on As and Cd toxicity, with both benefits and potential risks, depending on the form of Se and its dose as a supplement or the status (level) of this micronutrient in the body.

Nanosilica and salicylic acid synergistically regulate cadmium toxicity in rice

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 Cd-contaminated soils.

Arbuscular mycorrhizal fungi mitigate cadmium stress in maize.

Soil cadmium (Cd) pollution poses a significant environmental threat, impacting global food security and human health. Recent studies have highlighted the potential of arbuscular mycorrhizal (AM) fungi to protect crops from various heavy metal stresses, including Cd toxicity. To elucidate the tolerance mechanisms of maize in response to Cd toxicity under AM symbiosis, this study used two maize genotypes with contrasting Cd tolerance: Zhengdan958 (Cd-tolerant) and Zhongke11 (Cd-sensitive). Rhizobox experiments were conducted with and without AM inoculation, alongside Cd treatment. The results revealed that Cd stress severely impaired growth and root development in both genotypes. However, AM symbiosis significantly improved plant height, stem diameter, biomass, root morphology, photosynthetic capacity, nutrient uptake, antioxidant enzyme activity, root Cd content, and concentration, while also reducing lipid peroxidation and shoot Cd accumulation in both genotypes. Notably, AM symbiosis had a more pronounced effect on stem diameter (increased 55 %), root dry weight (118 %), root superoxide dismutase (42 %), and peroxidase activity (209 %), as well as shoot translocation factor (77 %) in Zhongke11 compared to Zhengdan958. Overall, AM symbiosis alleviated Cd toxicity in maize through multiple mechanisms, including enhanced photosynthesis, nutrient uptake, antioxidant defenses, and modulation of Cd transport and accumulation. This study provides valuable insights into the potential application of Cd-tolerant maize genotypes and AM symbiosis for managing Cd-contaminated soils.

Chemotaxis of rhizosphere Pseudomonas sp. induced by foliar spraying of lanthanum reduces cadmium uptake by pakchoi.

Foliar application of rare earth micronutrient of lanthanum (La) exhibits great potential in reducing cadmium (Cd) uptake in crops, the underlying mechanisms controlling the interaction between Cd toxicity-relieved crops and soil microbiota are poorly understood. In this study, LaCl3 with the concentrations of 10 and 30μM was sprayed on pakchoi (Brassica chinensis L.) planting on Cd contaminated solution and soil to determine the changes of root metabolites and rhizosphere bacterial communities. Compared to the control, Cd concentration in pakchoi leaves was significantly decreased by 30.9% and 22.6% with the high group under both hydroponic and pot culture by applying 30μM LaCl3. Herein, the concrete evidence is provided that pakchoi plants in response to foliar-spraying La under soil or solution Cd toxicity can promote the root secretion of amino acids, resulting in a strong enrichment of nitrogen-related microorganisms. To probe this linkage, a Pseudomonas representative specie was isolated that had the ability of consuming alanine, the most oversecreted root exudate due to La application. Further results demonstrated that this strain had the capacities for alleviating Cd toxicity and enhancing crop growth by immobilizing Cd and secreting plant-beneficial metabolites. This study reveals a plant-extrudate-microbiome feedback loop for responding to La-relieved Cd toxicity in crops by the chemotaxis of rhizosphere Pseudomonas toward alanine secreted by pakchoi.