Ethanolic Extract of Xylopia aethiopica Attenuated Aluminum-Induced Ovarian Toxicity in Adult Female Wistar Rats.

OBJECTIVE: Aluminum is a widely used metal in homes and industries. Xylopia aethiopica is an important medicinal plant with antioxidant properties. The objective of this study is to investigate the ameliorative potential of Xylopia aethiopica on aluminum-induced ovarian toxicity in Wistar rat. METHODS: Twenty-five rats were randomized into five groups with five rats per group. Group 1 received only distilled water; Group 2: received 150mg/kg of aluminum chloride; Group 3: received 150mg/kg aluminum chloride with 100/kg Xylopia aethiopica seed extracts; Group 4: received 150mg/kg aluminum chloride with 50 mg/kg Xylopia aethiopica seed extracts, and Group 5: received 150mg/kg aluminum chloride with 50mg/Kg zinc sulphate. For twenty-one days, all administrations were done orally. The rats were then sacrificed following chloroform anesthesia. The ovaries were harvested for histological examination. RESULTS: The data were analyzed on IBM SPSS software version 21 and the differences in mean values were considered significant at p<0.05. Xylopia aethiopica extracts significantly (p<0.05) reversed the detrimental effects of aluminum chloride on luteinizing hormone, follicle stimulating hormone, progesterone and estradiol. The histological analysis of the ovaries showed a significant improvement in rats treated with Xylopia aethiopica extract and zinc sulphate. However, Xylopia aethiopica was more effective in a dose-dependent manner. CONCLUSIONS: This study suggests that Xylopia aethiopica has ameliorative potential on aluminum-induced toxicity in the ovaries of adult female Wistar Rats.

Silicon attenuates aluminum toxicity in sugarcane plants by modifying growth, roots morphoanatomy, photosynthetic pigments, and gas exchange parameters.

Aluminum (Al) inhibits growth and limits plant productivity in acidic soils. An important strategy to increase Al tolerance is the use of silicon (Si) nutrition. Thus, the aim of this study was to evaluate the interactive role of Si in increasing the growth, physiological and morphoanatomy responses of sugarcane plants under Al toxicity. A 4 × 2 factorial scheme in a completely randomized design was used to study the impact of Si (2 mM) on attenuating Al toxicity (0, 10, 15 and 20 mg L-1, as Al2(SO4)3·18H2O) in sugarcane seedlings. After 45 days, Al toxicity affected sugarcane growth by increasing Al uptake and accumulation, modifying root growth, thickness, and morphoanatomy, and decreasing pigment content, gas exchange parameters, and the number of adaxial and abaxial stomata. However, Si attenuated Al toxicity in the sugarcane seedlings by limiting Al uptake and transport to the shoots, causing positive changes in root morphoanatomy, higher pigment content, improving gas exchange parameters, thereby increased growth. Furthermore, cultivar 'CTC9003' showed beneficial impacts from Si supplementation than 'CTC9002', especially under Al toxicity. The findings of this study suggest that Si plays a notable role in improving anatomical and physiological aspects, particularly the growth of sugarcane seedlings under Al toxicity.

Chrysin bonded to ß-d-glucose tetraacetate enhances its protective effects against the neurotoxicity induced by aluminum in Swiss mice.

OBJECTIVES: To evaluate whether the glycosylation of chrysin (CHR) enhances its protective effects against aluminum-induced neurotoxicity. METHODS: To compare the antioxidant, anticholinesterase, and behavioral effects of CHR with its glycosylated form (CHR bonded to ß-d-glucose tetraacetate, denoted as LQFM280), we employed an integrated approach using both in vitro (SH-SY5Y cells) and in vivo (aluminum-induced neurotoxicity in Swiss mice) models. KEY FINDINGS: LQFM280 demonstrated higher antioxidant activity than CHR in both models. Specifically, LQFM280 exhibited the ability to exert antioxidant effects in the cytoplasm of SH-SY5Y cells, indicating its competence in traversing neuronal membranes. Remarkably, LQFM280 proved more effective than CHR in recovering memory loss and counteracting neuronal death in the aluminum chloride mice model, suggesting its increased bioavailability at the brain level. CONCLUSIONS: The glycosylation of CHR with ß-d-glucose tetraacetate amplifies its neuroprotective effects, positioning LQFM280 as a promising lead compound for safeguarding against neurodegenerative processes involving oxidative stress.

Transcriptome-based strategies for identifying aluminum tolerance genes in popcorn (Zea mays L. var. everta).

Aluminum (Al) toxicity limits crop production worldwide. Although studies have identified genes associated with Al tolerance in crops, a large amount of data remains unexplored using other strategies. Here, we searched for single substitutions and InDels across differentially expressed genes (DEGs), linked DEGs to Al-tolerance QTLs reported in the literature for common maize, and investigated the alternative splicing regulated by Al3+ toxicity. We found 929 substitutions between DEGs in Al-tolerant and 464 in Al-sensitive inbred lines, of which 165 and 80 were non-synonymous, respectively. Only 12 NS variants had deleterious predicted effect on protein function in Al-tolerant and 13 in Al-sensitive. Moreover, 378 DEGs were mapped in Al-QTL regions for the Al-tolerant and 213 for the Al-sensitive. Furthermore, Al stress is primarily regulated at the transcriptional level in popcorn. Important genes identified, such as HDT1, SWEET4a, GSTs, SAD9, PIP2-2, CASP-like 5, and AGP, may benefit molecular assisted popcorn breeding or be useful in biotechnological approaches. These findings offer insights into the mechanisms of Al tolerance in popcorn and provide a 'hypothesis-free' strategy for identifying and prioritizing candidate genes that could be used to develop molecular markers or cultivars resilient to acidic soils.

Nuclear and morpho-histopathological alterations in Astyanax altiparanae exposed to effluent from the process of anodizing aluminum.

Aluminum is a metal widely used from household utensils to civil construction. Anodizing aluminum is a procedure to form a thick layer of aluminum oxide on the surface in order to confer greater resistance to the material. This process generates an effluent with acidic pH and a high concentration of sulfate. Alternatives for the treatment of this effluent involve the use of the chemical precipitation technique, which can be used with salts of barium chloride (BaCl2), calcium chloride (CaCl2), and aluminum hydroxide with commercial limestone (Cc/Al (OH)3). The objective of this study was to evaluate the toxicity of effluents on Astyanax altiparanae (Lambari), by means of somatic, genetic, morphological, and histological markers after 24 and 96 h of exposure. After measuring the biometric data of the animals and the weight of the liver, we found that the condition factor (K) of individuals exposed to the effluent CaCl2 showed a slight reduction in growth after 96 h while the hepatosomatic index (HSI) remained unchanged for all effluents in both sampling times. The micronucleus test with erythrocytes indicated that the raw effluent (E2) induced nuclear changes after 24 h; however, this effect did not persist after 96 h of exposure. Branchial arches were collected and according to Bernet's index for histopathology, all effluents except Cc/Al (OH)3, induced significant changes in the gills. In accordance with the index of Poleksic and Mitrovic-Tutundzic, CaCl2 was the only effluent to compromise branchial operation. The branchial morphology investigated by SEM showed that the raw effluent (E1) induced injuries and compromised gill functions. This study reinforces the importance of biological tests for the assessment and validation of physical chemicals used and effluent treatment techniques as well as the development and application of biological parameters before the wastewater release, whether in a raw state or a treated one.

Silicon as an attenuator of the toxic effects of aluminum in Schinus terebinthifolius plants.

Aluminum (Al) is highly toxic to plants, since it causes stress and inhibits plant growth. Silicon (Si) is known to mitigate the stress caused by Al in several plant species. Thus, the current study aims to investigate the soothing effects of Si on morphophysiological and photosynthetic variables, and the attributes associated with oxidative stress in Schinus terebinthifolius plants exposed to Al. Treatments have followed a completely randomized design, with three repetitions based on the following Al/Si combinations (in mM): Treatment 1: 0 Al + 0 Si; Treatment 2: 0 Al + 2.5 Si; Treatment 3: 1.85 Al + 0 Si; Treatment 4: 1.85 Al + 2.5 Si; Treatment 5: 3.71 Al + 0 Si; Treatment 6: 3.71 Al + 2.5 Si. Each sampling unit consisted of a tray with 15 plants, totaling forty-five per treatment. Shoot and root morphological variables, photosynthetic variables, photosynthetic pigments, hydrogen peroxide concentration, lipid peroxidation (MDA), guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzymes, and non-enzymatic antioxidant such as Ascorbic acid (AsA) and non-protein thiol (NPSH) concentration were assessed. Root growth inhibition followed by changes in root morphological variables have negatively affected root and shoot biomass production in plants only subjected to Al. However, adding 2.5 mM Si to the treatment has mitigated the toxic effects caused by 1.85 mM of aluminum on S. terebinthifolius plants.

Clinical Outcomes of the Deleterious Effects of Aluminum on Neuro-Cognition, Inflammation, and Health: A Review.

Introduction: In the scenario of metal toxicity, aluminum (Al) stands out as a ubiquitous type of metal that can be combined with other elements and form different compounds. Al is widely used daily as an adjuvant in vaccines, antacids, food additives (as components of AI-containing food additives), skin care products, cosmetics, and kitchenware, and can be an element or contaminant present in our daily life. Objective: To present a review of the main deleterious effects of Al on human health. Methods: The search was carried out from September 2022 to February 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using scientific articles from 2012 to 2023. The quality of the studies was based on the GRADE instrument, and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusions: A total of 115 files were search returned. Further, 95 articles were evaluated, and 44 were included in this review. Based on the results, measuring Al's relevance to health is essential in medicine. Several studies have demonstrated clinical outcomes and metabolic alterations with Al exposure. The tolerable weekly intake established by the European Food Safety Authority (EFSA) of 1 mg Al/kg body weight can be achieved through dietary exposure alone. Proven neurotoxicity in humans is the critical adverse effect of Al. A carcinogenic effect of Al has not been proven so far. Preventive medicine advocates that exposure to Al should be kept as low as possible. Chelating agents, such as calcium disodium ethylene diamine tetraacetic acid and deferoxamine, are options for acute poisoning, and monomethysilanetriol supplementation may be a long-term strategy with chelation potential. Further studies are needed to assess the impacts of Al on human health.

Molecular network of the oil palm root response to aluminum stress.

BACKGROUND: The solubilization of aluminum ions (Al3+) that results from soil acidity (pH < 5.5) is a limiting factor in oil palm yield. Al can be uptaken by the plant roots affecting DNA replication and cell division and triggering root morphological alterations, nutrient and water deprivation. In different oil palm-producing countries, oil palm is planted in acidic soils, representing a challenge for achieving high productivity. Several studies have reported the morphological, physiological, and biochemical oil palm mechanisms in response to Al-stress. However, the molecular mechanisms are just partially understood. RESULTS: Differential gene expression and network analysis of four contrasting oil palm genotypes (IRHO 7001, CTR 3-0-12, CR 10-0-2, and CD 19 - 12) exposed to Al-stress helped to identify a set of genes and modules involved in oil palm early response to the metal. Networks including the ABA-independent transcription factors DREB1F and NAC and the calcium sensor Calmodulin-like (CML) that could induce the expression of internal detoxifying enzymes GRXC1, PER15, ROMT, ZSS1, BBI, and HS1 against Al-stress were identified. Also, some gene networks pinpoint the role of secondary metabolites like polyphenols, sesquiterpenoids, and antimicrobial components in reducing oxidative stress in oil palm seedlings. STOP1 expression could be the first step of the induction of common Al-response genes as an external detoxification mechanism mediated by ABA-dependent pathways. CONCLUSIONS: Twelve hub genes were validated in this study, supporting the reliability of the experimental design and network analysis. Differential expression analysis and systems biology approaches provide a better understanding of the molecular network mechanisms of the response to aluminum stress in oil palm roots. These findings settled a basis for further functional characterization of candidate genes associated with Al-stress in oil palm.

Absence of aluminium compromises root integrity, reduces leaf hydration and Rubisco performance in Qualea grandiflora, an Al-accumulating species.

Aluminium (Al) is toxic to most plants. Nevertheless, some species accumulate Al without showing toxicity symptoms. Previous studies have evidenced Al in chloroplasts of Al-accumulating species from the Cerrado vegetation in South America. We ask whether Al increases carbon assimilation through enhanced apparent efficiency of Rubisco. Seedlings of the Al-accumulator Qualea grandiflora (Vochysiaceae) were grown in nutrient solution with 0, 740, and 1480 µm Al. Growth parameters, relative leaf water content, Al concentration in organs, gas exchange and apparent carboxylation efficiency (measured from A/Ci curves) were evaluated for 60 days. Plants without Al showed no root growth, necrotic roots, low gas exchange rates, and decreased apparent carboxylation efficiency. Al-treated plants, however, showed new white roots and increased root biomass leading to higher leaf hydration, and apparent carboxylation efficiency was higher in these plants. Increased Al available in the nutrient solution increased Al accumulation in plant organs. Absence of Al compromised root integrity in Q. grandiflora, thus limiting leaf hydration. No positive direct effect of Al on Rubisco was evidenced in Al-treated plants.

Tolerance mechanisms to aluminum in popcorn inbred lines involving aluminum compartmentalization and ascorbate-glutathione redox pathway.

MAIN CONCLUSION: Inbred line 11-133 of popcorn showed the lowest apoplast Al and total Al concentrations and Al-lumogallion complex, associated with a more efficient antioxidant system, mainly due to glutathione metabolism. Popcorn (Zea mays L. var. everta) is largely intended for human consumption. About 40% of the world's arable soils are acidic. In soils acidic, aluminum (Al) ionizes producing the trivalent cation, which is highly toxic to plants. Hence, this work aimed to: (1) evaluate the Al toxicity sites and its effect on the structure of the root tips, (2) quantify Al concentrations in the apoplast and symplast of the roots, and (3) to elucidate the modulation on the activity of antioxidant enzymes and metabolites of the ascorbate-glutathione cycle in two popcorn inbred lines (ILs) 11-133 and 11-60, classified as tolerant and sensitive to this metal, respectively. Aluminum toxicity did not affect the shoot growth; however, there was a yellowing of the oldest leaf blade only in 11-60. The better performance of 11-133 is related to lower apoplastic and total Al concentrations and Al accumulation in the root associated with a lower fluorescence of Al-lumogallion complex at the root tip, indicating the presence of mechanisms of chelation with this metal. Consequently, this IL showed less change in root morphoanatomy and lower reactive oxygen species and malondialdehyde content, which are associated with a more efficient enzymatic and non-enzymatic system, mainly due to the higher content of the glutathione metabolite and the higher activities of superoxide dismutase, monodehydroascorbate reductase, dehydroascorbate reductase, γ-glutamylcysteine synthetase, and glutathione peroxidase enzymes. Thus, these findings illustrated above indicate how internal mechanisms of detoxification respond to Al in popcorn, which can be used as tolerance biomarkers.

Global Scientific Research Landscape on Aluminum Toxicology.

This study aimed to identify the landscape of current aluminum toxicity based on knowledge mapping of the 100 most-cited articles on toxicological aspects of aluminum in biological organisms. The research was searched in the Web of Science Core Collection (WoS-CC) with publications between 1945 and 2022. Data regarding authorship, title, journal, year of publication, citation count, country, keywords, study design, and research hotspots were extracted and all elected articles were analyzed. Our results showed that among the articles selected, literature review and in vivo studies were the most common study designs. The USA and England were found as the countries with most publications. Alzheimer's disease (AD), aluminum, and neurotoxicity were found as the most frequent keywords. The articles most cited in world literature suggested that aluminum exposure is associated with Alzheimer's disease, Parkinson's disease (PD), dialysis encephalopathy, amyotrophic lateral sclerosis, neurodegeneration changes, cognitive impairment, such as bone damage, oxidative alterations, and cytotoxicity.

Tolerance of cultivars and clonal selections of peach rootstocks to excess aluminum / Tolerância de cultivares e seleções clonais de porta-enxertos de pessegueiro ao excesso de alumínio

Forms of aluminum (Al) present in the solution of tropical and subtropical soils can cause toxicity in rootstocks and peach cultivars, impairing growth and productivity. This can be minimized by growing Al-tolerant rootstocks and cultivars. However, this is not sufficiently known, especially because plant breeding programs do not always consider tolerance as a selection variable for genetic materials. The study aimed to (a) select cultivars and clonal selections of Al-tolerant peach rootstocks, (b) identify variables that confer Al tolerance for use in genetic improvement programs, and (c) propose critical levels (NC) and ranges of toxicity (TF) of Al in relation to morphological variables of the root system. The experimental design was completely randomized, comprising a factorial of 13 (cultivars and clonal selections) x 2 (with and without Al) with three replications. Own-rooted 'BRS Mandinho' peach seedlings (without rootstock) and grafted seedlings of 'BRS Mandinho' on different cultivars and clonal rootstock selections were cultivated in a hydroponic system, composing two levels for the Al factor (absence and presence at 100 mg L−1). The morphological variables of the canopy and root system, Al accumulation in tissues, translocation factor, and the critical level (NC) and toxicity range (TF) of Al in the roots were evaluated. Rootstocks FB-SM-09-43, JB-ESM-09-13, SAS-SAU-09-71, SS-CHI-09-40, 'Sharpe' and VEH-GRA-09-55 were tolerant at high Al concentrations. The NC of Al in the roots in relation to the root surface area of peach rootstocks was 1400 mg Al kg−1, and the FT was between 1200 and 1500 mg Al kg−1.(AU)

Formas de alumínio (Al) presentes na solução de solos tropicais e subtropicais podem causar toxicidade em porta-enxertos e cultivares de pessegueiro, prejudicando o crescimento e a produtividade. Isso pode ser minimizado pelo cultivo de porta-enxertos e cultivares tolerantes ao Al. Porém, isso não é suficientemente conhecido, principalmente porque os programas de melhoramento vegetal nem sempre consideram a tolerância como uma variável de seleção de materiais genéticos. O estudo teve como objetivo (a) selecionar cultivares e seleções clonais de porta-enxertos de pessegueiro tolerantes ao Al, (b) identificar variáveis que confiram tolerância ao Al para uso em programas de melhoramento genético e (c) propor níveis críticos (NC) e faixas de toxicidade (FT) do Al em relação às variáveis morfológicas do sistema radicular. O delineamento experimental foi inteiramente casualizado, compreendendo fatorial 13 (cultivares e seleções clonais) x 2 (com e sem Al) com três repetições. Mudas de pessegueiro 'BRS Mandinho' autoenraizadas (sem porta-enxerto) e mudas enxertadas de 'BRS Mandinho' em diferentes cultivares e seleções de porta-enxertos clonais foram cultivadas em sistema hidropônico, compondo dois níveis para o fator Al (ausência e presença a 100 mg L−1). Foram avaliadas as variáveis morfológicas da parte aérea e do sistema radicular, acúmulo de Al nos tecidos, fator de translocação, NC e FT do Al nas raízes. Os porta-enxertos FB-SM-09-43, JB-ESM-09-13, SAS-SAU-09-71, SS-CHI-09-40, 'Sharpe' e VEH-GRA-09-55 foram tolerantes a altas concentrações de Al. O NC do Al nas raízes em relação à área radicular dos porta-enxertos de pessegueiro foi de 1400 mg Al kg−1, e o FT ficou entre 1200 e 1500 mg Al kg−1.(AU)

Silicon as an attenuator of the toxic effects of aluminum in Schinus terebinthifolius plants / Silício como atenuador dos efeitos tóxicos do alumínio em plantas de Schinus terebinthifolius

Aluminum (Al) is highly toxic to plants, since it causes stress and inhibits plant growth. Silicon (Si) is known to mitigate the stress caused by Al in several plant species. Thus, the current study aims to investigate the soothing effects of Si on morphophysiological and photosynthetic variables, and the attributes associated with oxidative stress in Schinus terebinthifolius plants exposed to Al. Treatments have followed a completely randomized design, with three repetitions based on the following Al/Si combinations (in mM): Treatment 1: 0 Al + 0 Si; Treatment 2: 0 Al + 2.5 Si; Treatment 3: 1.85 Al + 0 Si; Treatment 4: 1.85 Al + 2.5 Si; Treatment 5: 3.71 Al + 0 Si; Treatment 6: 3.71 Al + 2.5 Si. Each sampling unit consisted of a tray with 15 plants, totaling forty-five per treatment. Shoot and root morphological variables, photosynthetic variables, photosynthetic pigments, hydrogen peroxide concentration, lipid peroxidation (MDA), guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzymes, and non-enzymatic antioxidant such as Ascorbic acid (AsA) and non-protein thiol (NPSH) concentration were assessed. Root growth inhibition followed by changes in root morphological variables have negatively affected root and shoot biomass production in plants only subjected to Al. However, adding 2.5 mM Si to the treatment has mitigated the toxic effects caused by 1.85 mM of aluminum on S. terebinthifolius plants.

O alumínio (Al) é altamente tóxico para as plantas, pois causa estresse e inibe o crescimento vegetal. O silício (Si) é conhecido por atenuar o estresse causado pelo Al em diversas espécies vegetais. Assim, o presente estudo tem como objetivo investigar os efeitos suavizantes do Si sobre variáveis morfofisiológicas e fotossintéticas, e os atributos associados ao estresse oxidativo em plantas de Schinus terebinthifolius expostas ao Al. Os tratamentos seguiram um delineamento inteiramente casualizado, com três repetições baseadas nas seguintes combinações Al/Si (em mM): Tratamento 1: 0 Al + 0 Si; Tratamento 2: 0 Al + 2,5 Si; Tratamento 3: 1,85 Al + 0 Si; Tratamento 4: 1,85 Al + 2,5 Si; Tratamento 5: 3,71 Al + 0 Si; Tratamento 6: 3,71 Al + 2,5 Si. Cada unidade amostral constou de uma bandeja com 15 plantas, totalizando quarenta e cinco plantas por tratamento. Variáveis morfológicas da parte aérea e da raiz, variáveis fotossintéticas, pigmentos fotossintéticos, concentração de peróxido de hidrogênio, peroxidação lipídica (MDA), enzimas guaiacol peroxidase (POD) e superóxido dismutase (SOD) e antioxidantes não enzimáticos como ácido ascórbico (AsA) e grupos tiós não protéicos (NPSH) foram avaliadas. A inibição do crescimento radicular seguida de alterações nas variáveis morfológicas radiculares afetaram negativamente a produção de biomassa radicular e aérea em plantas submetidas apenas ao Al. No entanto, a adição de 2,5 mM de Si ao tratamento atenuou os efeitos tóxicos causados por 1,85 mM de alumínio em plantas de S. terebinthifolius.

The effect of aluminum treatment on metabolism in oil palm seedlings

Due to rainfall and high temperatures, the Amazonian soil undergoes changes in its source material and leaching of base cations. This results in deep, infertile, and acidic soil. Aluminum present in acidic soil impairs plant growth and development by inhibiting root formation, enzymatic reactions, absorption, transport, and nutrient utilization. This study aimed to evaluate the effects of aluminum dosage on the metabolism of the oil palm Elaeis guineensis Jacq. The study was conducted in a greenhouse at the Federal Rural University of Amazonia. The experimental design was randomized, with five replications, in which dosages of 0, 10, 20, 30, and 40 mg L-1 aluminum chloride (AlCl3.6H2O) were administered. Electrolyte leakage, nitrate, nitrate reductase, free ammonium, soluble amino acids, proline content, and soluble proteins were analyzed in the leaves and roots of the oil palm. The highest concentration of aluminum was found in the roots. AlCl3 treatment at 40 mg L-1 increased electrolyte leakage, nitrate, ammonium, and proline concentrations in the roots, and amino acid concentrations in both the leaves and roots. Furthermore, a decrease in nitrate reductase enzyme activity was observed in the roots. This study demonstrates that the oil palm has mechanisms of tolerance to aluminum toxicity.

Interactions between Environmental Factors and Glutathione S-Transferase (GST) Genes with Respect to Detectable Blood Aluminum Concentrations in Jamaican Children.

Aluminum (Al) is a metallic toxicant at high concentrations following natural or unnatural exposures. Dietary intake is considered as the main source of aluminum exposure in children. We used data from 366 typically developing (TD) children (ages 2−8 years) who participated as controls in an age- and sex-matched case−control study in Jamaica. We investigated additive and interactive associations among environmental factors and children's genotypes for glutathione S-transferase (GST) genes (GSTT1, GSTM1, GSTP1), in relation to having a detectable blood aluminum concentration (BAlC) of >5.0 µg/L, using multivariable logistic regression models. Findings from interactive models revealed that the odds of having a detectable BAlC was significantly higher among children who ate string beans (p ≤ 0.01), whereas about 40% lower odds of having a detectable BAlC was observed in children with higher parental education level, (p = 0.02). A significant interaction between consumption of saltwater fish and GSTP1 in relation to having a detectable BAlC using either co-dominant or dominant genetic models (overall interaction p = 0.02 for both models) indicated that consumption of saltwater fish was associated with higher odds of having a detectable BAlC only among children with the GSTP1 Ile105Val Ile/Ile genotype using either co-dominant or dominant models [OR (95% CI) = 2.73 (1.07, 6.96), p = 0.04; and OR (95% CI) = 2.74 (1.08, 6.99), p = 0.03]. Since this is the first study from Jamaica that reports such findings, replication in other populations is warranted.

Global Proteomic Profile of Aluminum-Induced Hippocampal Impairments in Rats: Are Low Doses of Aluminum Really Safe?

Hippocampus is the brain area where aluminum (Al) accumulates in abundance and is widely associated with learning and memory. In the present study, we evaluate behavioral, tissue, and proteomic changes in the hippocampus of Wistar rats caused by exposure to doses that mimic human consumption of aluminum chloride (AlCl3) in urban areas. For this, male Wistar rats were divided into two groups: Control (distilled water) and AlCl3 (8.3 mg/kg/day), both groups were exposed orally for 60 days. After the Al exposure protocol, cognitive functions were assessed by the Water maze test, followed by a collection for analysis of the global proteomic profile of the hippocampus by mass spectrometry. Aside from proteomic analysis, we performed a histological analysis of the hippocampus, to the determination of cell body density by cresyl violet staining in Cornu Ammonis fields (CA) 1 and 3, and hilus regions. Our results indicated that exposure to low doses of aluminum chloride triggered a decreased cognitive performance in learning and memory, being associated with the deregulation of proteins expression, mainly those related to the regulation of the cytoskeleton, cellular metabolism, mitochondrial activity, redox regulation, nervous system regulation, and synaptic signaling, reduced cell body density in CA1, CA3, and hilus.

Amelioration of aluminum phytotoxicity in Solanum lycopersicum by co-inoculation of plant growth promoting Kosakonia radicincitans strain CABV2 and Streptomyces corchorusii strain CASL5.

Aluminum (Al) toxicity is the main constraint for crop cultivation in acidic soils. In this study, Al-tolerant rhizobacteria Kosakonia radicincitans (CABV2) and actinobacteria Streptomyces corchorusii (CASL5) were isolated from Beta vulgaris rhizosphere in acidic soil. Both isolates displayed high tolerance to Al (10 mM), produce siderophores, indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate and solubilize phosphate. Co-inoculation of CABV2 and CASL5 strains were significantly increased the root length (312.90%), shoot length (183.19%), fresh weight (224.82%), dry weight (309.25%) and photosynthetic pigments (chlorophyll a 279.69%, chlorophyll b 188.23% and carotenoids 158.20%) of Solanum lycopersicum plants under 300 mg Al kg-1 soil conditions as compared to uninoculated Al stressed plants. Similarly, the co-inoculation treated plants subjected to Al stress condition enhanced the uptake of essential nutrients (N 229%, P 252%, K 115%, Fe 185%, Mg 345% and Ca 202%) by plants as compared to Al stressed uninoculated plants. Under Al stress (300 mg Al kg-1 soil), co-inoculation significantly decreased malondialdehyde content (66%), and increased catalase (83%), superoxide dismutase (82%), peroxidase (89%) activities and root exudates (organic acids 6.44-12.36 fold) in S. lycopersicum as compared to uninoculated plants, indicating that the CABV2 and CASL5 strains were reduced Al-induced oxidative stress. Moreover, co-inoculation significantly reduced Al accumulation in the root (89%), stem (95%) and leaves (94%) of S. lycopersicum under Al stress at 300 mg Al kg-1 soil, compared to the uninoculated plants. This is the first report of K. radicincitans strain CABV2 and S. corchorusii strain CASL5 potentially reducing Al uptake in S. lycopersicum.

A long and stressful day: Photoperiod shapes aluminium tolerance in plants.

Aluminium (Al), a limiting factor for crop productivity in acidic soils (pH ≤ 5.5), imposes drastic constraints for food safety in developing countries. The major mechanisms that allow plants to cope with Al involve manipulations of organic acids metabolism and DNA-checkpoints. When assumed individually both approaches have been insufficient to overcome Al toxicity. On analysing the centre of origin of most cultivated plants, we hypothesised that day-length seems to be a pivotal agent modulating Al tolerance across distinct plant species. We observed that with increasing distance from the Equator, Al tolerance decreases, suggesting a relationship with the photoperiod. We verified that long-day (LD) species are generally more Al-sensitive than short-day (SD) species, whereas genetic conversion of tomato for SD growth habit boosts Al tolerance. Reduced Al tolerance correlates with DNA-checkpoint activation under LD. Furthermore, DNA-checkpoint-related genes are under positive selection in Arabidopsis accessions from regions with shorter days, suggesting that photoperiod act as a selective barrier for Al tolerance. A diel regulation and genetic diversity affect Al tolerance, suggesting that day-length orchestrates Al tolerance. Altogether, photoperiodic control of Al tolerance might contribute to solving the historical obstacle that imposes barriers for developing countries to reach a sustainable agriculture.

Root exudation of oxalic acid in Lotus corniculatus in response to aluminum toxicity

The objective of this research was to identify the existence of root exudation of organic acid in Lotus corniculatus germplasms subjected to toxic aluminum (Al) levels and investigate the effect of this mechanism on the Al content in the root tissue and in morphological parameters of plant development. Two experiments were performed in nutrient solution to evaluate the Al accumulation and exudation of organic acids, using cultivars INIA Draco and São Gabriel and genotypes UFRGS and UF-T2. The plants were cultivated in Al-free solution, which was applied on the 45th day in half of the pots of each genotype. Root exudation was highly correlated with the reduced accumulation of Al in the root tissue (r2 = 0.75 at 72 h). Genotype UF-T2, selected for Al tolerance, extruded 80% more oxalic acid in the presence of Al compared with the other germplasms, indicating that this mechanism is involved with Al tolerance in L. corniculatus. This experiment showed strong evidence that L. corniculatus exhibits Type I tolerance, in which anionic channels are rapidly activated by Al exposure. Exudation of oxalic acid is likely a crucial mechanism that allows the maintenance of L. corniculatus growth when exposed to toxic Al conditions, and this characteristic should be used to identify tolerant genotypes in the future.(AU)