Al Toxicity Research Articles

Alteration of aluminum tolerance mediated by insertion of same transposable element at different sites in the upstream region of HvAACT1 in Japanese barley accessions

ABSTRACT Aluminum (Al) toxicity is a major limiting factor for crop production in acid soils. Barley is highly sensitive to Al, so the genetic improvement of its Al tolerance is required. However, useful breeding materials and genetic factors for improving its tolerance are remain largely unclear. Here, we compared the Al tolerance of ‘Minorimugi’ and ‘Fibersnow,’ both six-rowed hulled barley cultivars grown mainly in northern Japan, using relative root length (RRL) as an index, and found that Minorimugi had higher tolerance. Quantitative trait locus (QTL) analysis using recombinant inbred lines (RILs) derived from the two cultivars detected a major QTL at the HvAACT1 (Al-ACTIVATED CITRATE TRANSPORTER 1) locus that explained approximately 36% of the variance. The PCR amplification analysis revealed a 1-kb transposable element (TE) insertion at −1.9 kb in the upstream region of HvAACT1 in Minorimugi that enhances HvAACT1 expression. The TE has the same nucleotide sequence as one previously found at −4.8 kb in the upstream region of HvAACT1 in ‘Murasakimochi,’ which is an Al tolerant cultivar. In the Japanese barley population, the Murasakimochi-type HvAACT1 upstream allele is shared mainly among barley accessions developed in the Shikoku area, while the Minorimugi-type allele is shared mainly among accessions developed in the Hokuriku and Nagano area. This geographic difference indicates that both alleles are shared among different subpopulations in Japanese barley, which may be advantageous for growth in acid soils. Our results provide information about a new allele of the HvAACT1 upstream region and potential breeding materials for improving the Al tolerance of barley.

Characterization of SgALMT genes reveals the function of SgALMT2 in conferring aluminum tolerance in Stylosanthes guianensis through the mediation of malate exudation

Aluminum (Al) toxicity is the major constraint on plant growth and productivity in acidic soils. An adaptive mechanism to enhance Al tolerance in plants is mediated malate exudation from roots through the involvement of ALMT (Al-activated malate transporter) channels. The underlying Al tolerance mechanisms of stylo (Stylosanthes guianensis), an important tropical legume that exhibits superior Al tolerance, remain largely unknown, and knowledge of the potential contribution of ALMT genes to Al detoxification in stylo is limited. In this study, stylo root growth was inhibited by Al toxicity, accompanied by increases in malate and citrate exudation from roots. A total of 11 ALMT genes were subsequently identified in the stylo genome and named SgALMT1 to SgALMT11. Diverse responses to metal stresses were observed for these SgALMT genes in stylo roots. Among them, the expressions of 6 out of the 11 SgALMTs were upregulated by Al toxicity. SgALMT2, a root-specific and Al-activated gene, was selected for functional characterization. Subcellular localization analysis revealed that the SgALMT2 protein is localized to the plasma membrane. The function of SgALMT2 in mediating malate release was confirmed by analysis of the malate exudation rate from transgenic composite stylo plants overexpressing SgALMT2. Furthermore, overexpression of SgALMT2 led to increased root growth in transgenic stylo plants treated with Al through decreased Al accumulation in roots. Taken together, the results of this study suggest that malate secretion mediated by SgALMT2 contributes to the ability of stylo to cope with Al toxicity.

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 (2mM) on attenuating Al toxicity (0, 10, 15 and 20mgL-1, as Al2(SO4)3·18H2O) in sugarcane seedlings. After 45days, 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.

Ability of Nutrient Management and Molecular Physiology Advancements to Overcome Abiotic Stress: A Study on Sub-Saharan African Crops

Abiotic stress is a major cause of the declining crop yield worldwide, especially in tropical agricultural areas. Meeting the global food demand has become a serious challenge, especially in tropical areas, because of soil acidity, Al and Fe toxicity, drought and heat stress, and climate change. In this article, we reviewed several research and review papers from Google Scholar to list the different solutions available for the mitigation of abiotic stress, especially in tropical regions where several major crops, such as maize, sorghum, wheat, rice, soybean, and millet, are affected by abiotic stress and fertilizer input. In particular, Sub-Saharan Africa (SSA) has been affected by the low use of fertilizers owing to their high cost. Therefore, soil and plant researchers and farmers have developed many techniques to mitigate the effects of stress and improve the crop yield based on the agroecological zone and crop type. Nutrient management using chemical fertilizers alone or in combination with organic crops is a strategy recommended to cope with abiotic stress and increase the crop yield, particularly in developing countries. Notably, integrated soil fertility management has been effective in semi-arid areas under drought and heat stress and in subhumid and humid areas with high soil acidity and Fe toxicity in Africa. Recent advances in the molecular physiology of various crops considered a staple food in SSA have facilitated the breeding of transgenic tolerant plants with high yield. However, the feasibility and implementation of this technique in the African continent and most tropical developing countries are major issues that can be solved via adequate subsidies and support to farmers. This review can aid in the development of novel strategies to decrease hunger and food insecurity in SSA.

Evaluation of Different Agricultural Limes for Bread Wheat and Fababean Production in Acid Soil of West Shewa Zone, Ethiopia

The application of lime is believed to enhance soil health status through improving soil pH, base saturation and reduces Al and Mn toxicities. Liming effects depend on the source, composition, purity and fineness of the lime. The performance of three liming materials and one control treatment was evaluated in a field trial, further evaluation and validation was done at three districts on different farmers’ sites during 2023 main cropping season. The liming materials included calcitic lime, hydrated lime, and quick lime. The treatments laid out in randomized complete block design. The results of the study showed that all tested lime materials (calcitic lime, hydrated lime, and quick lime) improved yield and agronomic performance of wheat, barley and fababean in comparably. This implies that hydrated limes can serve as an alternative agricultural lime to ameliorate soil acidity. Hence, these liming materials can be used as agricultural lime material and the result is confirmed through validation across locations on different testing crops (wheat, barley and Faba bean). So, it is recommended that liming materials which can be easily accessed for the farmers is recommended because of there is no significant difference among liming material tested.

Ameliorative role of diets fortified with Artocarpus altilis in a Drosophila melanogaster model of aluminum chloride-induced neurotoxicity

Backgrounds: Artocarpus altilis (breadfruit) belongs to the family Moraceae. Artocarpus altilis possesses antioxidative, anti-inflammatory, and anti-proliferative properties. Aluminum (Al) is extensively utilized for consumer products, cooking utensils, pharmaceuticals, and industries. Indication for the neurotoxicity of Al is investigated in various studies, notwithstanding the precise mechanisms of Al toxicity are yet to be fully elucidated, and, which requires novel therapy. In this study, we determined the ameliorative role of Artocarpus altilis on aluminum chloride-induced neurotoxicity in Drosophila melanogaster.MethodsVarying concentration of the extract were used to formulate diets for 6 groups of flies. Group 1 contained basal diet, group 2 contained basal diet and aluminium chloride (AlCl3), group 3 contained basal diet + 0.1% unseeded breadfruit (UBF), group 4 contained basal diet + 1% unseeded breadfruit, group 5 and 6 contained basal diet + AlCl3 + 0.1% and 1% unseeded breadfruit. Assays such as acetylcholinesterase activity, malondialdehyde (MDA) concentration level, catalase activity, and superoxide dismutase (SOD) activity were carried out after 7 days of exposure respectively.ResultsThe results showed low activity of acetylcholinesterase activity and MDA level and high catalase and SOD activity in the pretreated and post-treated flies with Artocarpus altilis compared to the normal and negative control respectively.ConclusionsTaken together, Artocarpus altilis is a promising prophylactic, antiacetylcholinesterase, and antioxidant plant in the prevention, management and treatment of neurodegenerative diseases.Graphical

A synthetic microbial community used as a bioinoculant can overcome rice production constraints in acid soils.

A customised synthetic microbial community (SynCom) composed of carefully selected rhizosphere-competent bacterial strains improved rice growth, yield and resistance to soil acidity and Al toxicity.

Physiological Mechanism through Which Al Toxicity Inhibits Peanut Root Growth.

Al (Aluminum) poisoning is a significant limitation to crop yield in acid soil. However, the physiological process involved in the peanut root response to Al poisoning has not been clarified yet and requires further research. In order to investigate the influence of Al toxicity stress on peanut roots, this study employed various methods, including root phenotype analysis, scanning of the root, measuring the physical response indices of the root, measurement of the hormone level in the root, and quantitative PCR (qPCR). This research aimed to explore the physiological mechanism underlying the reaction of peanut roots to Al toxicity. The findings revealed that Al poisoning inhibits the development of peanut roots, resulting in reduced biomass, length, surface area, and volume. Al also significantly affects antioxidant oxidase activity and proline and malondialdehyde contents in peanut roots. Furthermore, Al toxicity led to increased accumulations of Al and Fe in peanut roots, while the contents of zinc (Zn), cuprum (Cu), manganese (Mn), kalium (K), magnesium (Mg), and calcium (Ca) decreased. The hormone content and related gene expression in peanut roots also exhibited significant changes. High concentrations of Al trigger cellular defense mechanisms, resulting in differentially expressed antioxidase genes and enhanced activity of antioxidases to eliminate excessive ROS (reactive oxygen species). Additionally, the differential expression of hormone-related genes in a high-Al environment affects plant hormones, ultimately leading to various negative effects, for example, decreased biomass of roots and hindered root development. The purpose of this study was to explore the physiological response mechanism of peanut roots subjected to aluminum toxicity stress, and the findings of this research will provide a basis for cultivating Al-resistant peanut varieties.

Comparative Liming Power of Chicken Manure and Selected Dolomitic Sources on an Acidic High Altitude Burundi Surface Soil

A research initiative was set up to evaluate the comparative liming power of locally available dolomitic products and chicken manure, using an amaranth (Amaranthus viridis L.) test crop. The soil used was acidic, of low % base saturation and risks of Al toxicity, deficient in available P, exchangeable Mg, Ca and K. The experimental setup was a completely randomized design with 11 treatments and 3 replicates which included: a control treatment (equivalent to 100 kg DAP/ha), 4 mineral amendments (Moso Lime, Moso Ground Dolomite, Bubanza Ground Dolomite and Busiga Ground Dolomite) applied at equivalents of 1 T/ha and 2 T/ha, and chicken manure applied at equivalent of 10 and 20 T/ha. The study duration was three months withthree test crop harvests at one-month interval. Monthly measured plant growth and production parameters were plant height, root length, shoot length, root biomass, shoot biomass and their summation (total biomass). Soil pH, available P and exchangeable acidity (Al3++ H+) were assessed at the start and the completion of the pot study. Obtained results could be summarized as follows: (i) the highest available P accumulation was associated with the equivalent of 20 T/ha of chicken manure; (ii) application of equivalents 20 T/ha of chicken manure, 2 T/ha Moso Ground Dolomite and 2 T/ha Moso Lime increased soil pH by 0.2 to 0.5 pH-unitsand reduced exchangeable acdity ; (ii) DAP fertilized treatment was characterised by the lowest pH value and the highest Al3+and H+exchangeable acidity, illustrating the acidifying effect of this NH4+-bearing fertilizer; (iv) amarant growth (root and height) and biomass (root + shoot) production were highest with 20 T/ha chicken manure, 2 T/ha Moso Ground Dolomite and 2 T/haMoso lime. Application rate was only statisticallt detectable for Moso Ground Dolomite (+ 162 %) and chicken manure (+ 182 %). Overall, 20 T/ha chicken manure showed the highest and most stable amaranth root + shoot biomass yields, demonstrating its potential residual effect, which should be evaluated and confirmed under field conditions.

Memory impairment induced by aluminum nanoparticles is associated with hippocampal IL-1 and IBA-1 upregulation in mice

ABSTRACT Objectives Increasing evidence indicates a link between aluminum (Al) intake and Alzheimer’s disease (AD). The main entry of Al into the human body is through oral route, and in the digestive tract, under the influence of the pH change, Al can be transformed into Al nanoparticles (Al-NP). However, studies related to the effect of Al-NP on the brain are limited and need further investigation. Neuro-inflammation is considered as one of the principal features of AD. Microglial activation and expression of the inflammatory cytokine IL-1β (interleukin-1β) in the brain have been used as hallmarks of brain inflammation. Therefore, in the present study, the hippocampal levels of ionized calcium-binding adaptor molecule 1 (IBA-1), as the marker of microglia activation, and IL-1β were assessed. Methods Adult male NMRI mice were treated with Al-NP (5 or 10 mg/kg) for 5 days. A novel object recognition (NOR) test was used to assess memory. Following cognitive assessments, the hippocampal tissues were isolated to analyze the levels of IL-1β and IBA-1 as well as beta actin proteins using western blot technique. Results Al-NP in both doses of 5 and 10 mg/kg impaired NOR memory in mice. In addition, Al-NP increased IL-1β and IBA-1 in the hippocampus. Discussion These findings indicate that the memory impairing effect of Al-NP coincides with hippocampal inflammation. According to the proposed relationship between AD and Al toxicity, this study can increase the knowledge about the toxic effects of Al-NP and highlight the need to limit the use of this nanoparticle.

Aluminium stress-induced modulation of root gravitropism in pea (Pisum sativum) via auxin signalling

Aluminium (Al) toxicity stands out as a primary cause of crop failure in acidic soils. The root gravity setpoint angle (GSA), one of the important traits of the root system architecture (RSA), plays a pivotal role in enabling plants to adapt to abiotic stress. This study explored the correlation between GSA and Al stress using hydroponic culture with pea (Pisum sativum) plants. The findings revealed that under Al stress, GSA increased in newly developed lateral roots. Notably, this response remained consistent regardless of the treatment duration, extending for at least 3 days during the experiment. Furthermore, exposure to Al led to a reduction in both the size and quantity of starch granules, pivotal components linked to gravity perception. The accumulation of auxin in root transition zone increased. This variation was mirrored in the expression of genes linked to granule formation and auxin efflux, particularly those in the PIN-formed family. This developmental framework suggested a unique role for the root gravitropic response that hinges on starch granules and auxin transport, acting as mediators in the modulation of GSA under Al stress. Exogenous application of indole-3-acetic acid (IAA) and the auxin efflux inhibitor N-1-naphthylphthalamic acid (NPA) had an impact on the root gravitropic response to Al stress. The outcomes indicate that Al stress inhibited polar auxin transport and starch granule formation, the two processes crucial for gravitropism. This impairment led to an elevation in GSA and a reconfiguration of RSA. This study introduces a novel perspective on how plant roots react to Al toxicity, culminating in RSA modification in the context of acidic soil with elevated Al concentrations.

Lime microdosing: A new liming strategy for increased productivity in acid soils

AbstractDespite the effectiveness of the fertilizer microdosing technique, lime microdosing (LMD) to alleviate the negative impacts of soil acidity has not been comprehensively assessed. In a 3‐year study at four sites across three countries (one in the United States, two in Ghana, and one in Burkina Faso), we evaluated the effectiveness of the microdosing technique for lime application to alleviate the adverse effects of soil acidity in cropping systems, using corn (Zea mays L.) as the study crop. LMD was evaluated at four lime application rates, including 5%, 10%, 25%, and 50% of the calculated lime‐requirement rate (LR), which was compared to the traditional lime broadcasting strategy using 75% and 100% LR. Averaged across all experimental sites for the duration of the study, LMD with 25% LR resulted in similar grain yield, and nitrogen, phosphorus, and potassium recovery efficiency as those of the traditional lime broadcast techniques with 100% LR, but significantly greater than those of the lime broadcast techniques with 75% LR. Postharvest rhizosphere aluminum saturation percentage of the LMD with 25% LR was similar to that of the traditional lime broadcast techniques with 100% LR. However, LMD with lime application rates lower than 25% LR was not agronomically effective. The combined results suggest that LMD could be an efficient liming technique, and that with this technique, as little lime material as 25% LR could be used to mitigate the negative impacts of Al toxicity associated with soil acidity. Nevertheless, economic analyses are required to determine the profitability of utilizing the LMD technique to mitigate the negative impacts of soil acidity on crop production relative to the traditional lime‐broadcast approach.

Autophagy confers aluminum tolerance by enhancing the antioxidant capacity and promoting oxidized protein degradation in wheat (Triticum aestivum.) roots

Aluminum (Al) usually disturbs redox homeostasis and causes irreversible oxidative damage to biomolecules in plants, efficiently removing damaged and toxic macromolecules is essential to Al tolerance. Here, we investigated the role of autophagy, a conserved cellular degradation pathway, in plant Al tolerance using two wheat genotypes with different Al sensitivity. Compared to the sensitive genotype, Al significantly upregulated the expression of autophagy-related genes (ATGs) and enhanced the formation of autophagosomes. Reinforcing autophagy by rapamycin substantially alleviated the inhibition of root growth by Al stress, accompanied by low levels of reactive oxygen species (ROS) accumulation and oxidative damage in wheat roots; whereas inhibition of autophagy by 3-methyladenine (3-MA) aggravated the adverse impacts of Al toxicity. Further experiments showed that Al significantly triggered the accumulation of oxidized proteins, particularly in the sensitive genotype. The content of Al-induced oxidized proteins was reduced by rapamycin but further increased by 3-MA in wheat roots. Wheat plants treated with the inhibitor of vacuole H+-ATPase, concanamycin A, were more sensitive to Al stress and accumulated higher levels of oxidatively-damaged proteins compared to Al treatment. These results reveal that autophagy-mediated redox homeostasis and the clearance of oxidatively damaged proteins play a crucial role in plant's tolerance to Al stress.

Two-for-one: root microbiota orchestrates both soil pH and plant nutrition

Aluminum (Al) toxicity is a crucial limiting factor for crop growth in acid soils. Recently, Liu et al. demonstrated that the root microbiota of rice modulates the responses to Al toxicity and phosphorus limitation, offering intriguing insights into microbiome function and opening new research opportunities.

Inheritance of aluminium tolerance in sunflower (Helianthus annuus L.)

In acidic soil, aluminium (Al) toxicity is one of the foremost restraining factors which inhibit crop performance. Breeding for Al tolerance seems to be a vital approach for enhancing productivity of field crops including sunflower in acidic soil regions. In order to understand the inheritance pattern, tolerant genotypes NDLR-06 and EC601861 were crossed with susceptible genotypes MR-06 and RHA-298. P1, P2, F1, F2 and backcross populations were raised in nutrient solution and classified as tolerant/susceptible by observing root re-growth after staining with eriochrome cyanine R. Dominance nature of Al tolerance over susceptible was confirmed by the responses of F1’s which were similar to the tolerant parents. The segregation ratio for Al tolerance vs. susceptible in the F2 and backcross generations were 3:1 and 1:1, respectively. These outcomes indicated that inheritance of Al tolerance is governed by single dominant gene which can be transferred easily to desirable genotypes via backcross breedingmethod. This is the first report on inheritance of Al tolerance in sunflower.

Mutator-like transposable element 9A interacts with metacaspase 1 and modulates the incidence of Al-induced programmed cell death in peanut.

The toxicity of aluminum (Al) in acidic soil inhibits plant root development and reduces crop yields. In the plant response to Al toxicity, the initiation of programmed cell death (PCD) appears to be an important mechanism for the elimination of Al-damaged cells to ensure plant survival. In a previous study, the type I metacaspase AhMC1 was found to regulate the Al stress response and to be essential for Al-induced PCD. However, the mechanism by which AhMC1 is altered in the peanut response to Al stress remained unclear. Here, we show that a nuclear protein, mutator-like transposable element 9A (AhMULE9A), directly interacts with AhMC1 in vitro and in vivo. This interaction occurs in the nucleus in peanut and is weakened during Al stress. Furthermore, a conserved C2HC zinc finger domain of AhMULE9A (residues 735-751) was shown to be required for its interaction with AhMC1. Overexpression of AhMULE9A in Arabidopsis and peanut strongly inhibited root growth with a loss of root cell viability under Al treatment. Conversely, knock down of AhMULE9A in peanut significantly reduced Al uptake and Al inhibition of root growth, and alleviated the occurrence of typical hallmarks of Al-induced PCD. These findings provide novel insight into the regulation of Al-induced PCD.

Biochar and Silicon for Sustainable Agriculture in Acid Soil- Nutrient Dynamics and Maize Production: A Review

The central part of the country in the world classified Maize as their staple and essential crop, but this crop cannot cultivate appropriately in acidic soil. Thus, biochar, silicon and phosphorus observation can act as an agent to improve the growth of Maize in acidic soil. Additionally, biochar, well known for its alkaline properties, can reduce soil acidification and, at the same time, improve crop production. This low pH condition was caused by aluminium, manganese and low of phosphorus. Thus, silicon and Phosphorus can improve crop productivity. Using biochar as a soil amendment raises the pH value, alone or in combination. Maize (Zea mays L.) and the acidity of the soil are much related to the application of biochar combined with silicon and Phosphorus. Biochar simply can reduce exchangeable soil acidity, but when combined with silicon and Phosphorus, it can have a greater influence on reducing soil Al toxicity. The importance of biochar with different rates combined with silicon and Phosphorus to increase the pH of soil is still an inconsistent result by various studies. This review summarizes the properties of biochar, silicon and phosphorus and provides the scientific reference for its application to archive high yield of Maize and reduce the acidification effect on soil.

Physiological and Transcriptomic Analysis Reveals That Melatonin Alleviates Aluminum Toxicity in Alfalfa (Medicago sativa L.).

Aluminum (Al) toxicity is the most common factor limiting the growth of alfalfa in acidic soil conditions. Melatonin (MT), a significant pleiotropic molecule present in both plants and animals, has shown promise in mitigating Al toxicity in various plant species. This study aims to elucidate the underlying mechanism by which melatonin alleviates Al toxicity in alfalfa through a combined physiological and transcriptomic analysis. The results reveal that the addition of 5 μM melatonin significantly increased alfalfa root length by 48% and fresh weight by 45.4% compared to aluminum treatment alone. Moreover, the 5 μM melatonin application partially restored the enlarged and irregular cell shape induced by aluminum treatment, resulting in a relatively compact arrangement of alfalfa root cells. Moreover, MT application reduces Al accumulation in alfalfa roots and shoots by 28.6% and 27.6%, respectively. Additionally, MT plays a crucial role in scavenging Al-induced excess H2O2 by enhancing the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), consequently reducing malondialdehyde (MDA) levels. More interestingly, the RNA-seq results reveal that MT application significantly upregulates the expression of xyloglucan endotransglucosylase/hydrolase (XTH) and carbon metabolism-related genes, including those involved in the glycolysis process, as well as sucrose and starch metabolism, suggesting that MT application may mitigate Al toxicity by facilitating the binding of Al to the cell walls, thereby reducing intracellular Al accumulation, and improving respiration and the content of sucrose and trehalose. Taken together, our study demonstrates that MT alleviates Al toxicity in alfalfa by reducing Al accumulation and restoring redox homeostasis. These RNA-seq results suggest that the alleviation of Al toxicity by MT may occur through its influence on cell wall composition and carbon metabolism. This research advances our understanding of the mechanisms underlying MT's effectiveness in mitigating Al toxicity, providing a clear direction for our future investigations into the underlying mechanisms by which MT alleviates Al toxicity in alfalfa.

Evaluation of Lentilactobacillus parafarraginis A6-2 strain for aluminum removal and anti-inflammatory effects: implications for alleviating Al toxicity.

To assess the effectiveness of Lentilactobacillus parafarraginis A6-2 cell lysate for the removal of aluminum (Al), which induces neurotoxicity, and its protective effect at cellular level. The cell lysate of the selected L. parafarraginis A6-2 strain demonstrated superior Al removal compared to live or dead cells. The Al removal efficiency of L. parafarraginis A6-2 cell lysate increased with decreasing pH and increasing temperature, primarily through adsorption onto peptidoglycan. Neurotoxicity mitigation potential of L. parafarraginis A6-2 was evaluated using C6 glioma cells. C6 cells exposed with increasing concentration of Al led to elevated toxicity and inflammation, which were gradually alleviated upon treatment with L. parafarraginis A6-2. Moreover, Al-induced oxidative stress in C6 cells showed a concentration-dependent reduction upon treatment with L. parafarraginis A6-2. This study demonstrated that L. parafarraginis A6-2 strain, particularly in its lysate form, exhibited enhanced capability for Al removal. Furthermore, it effectively mitigated Al-induced toxicity, inflammation, and oxidative stress.

Identification of the ALMT gene family in the potato (Solanum tuberosum L.) and analysis of the function of StALMT6/10 in response to aluminum toxicity.

Aluminum (Al)-activated malate transporters (ALMTs) play an important role in the response to Al toxicity, maintenance of ion homeostasis balance, mineral nutrient distribution, and fruit quality development in plants. However, the function of the StALMT gene family in potato remains unknown. In this study, 14 StALMT genes were identified from the potato genome, unevenly distributed on seven different chromosomes. Collinearity and synteny analyses of ALMT genes showed that potatoes had 6 and 22 orthologous gene pairs with Arabidopsis and tomatoes, respectively, and more than one syntenic gene pair was identified for some StALMT gene family members. Real-time quantitative polymerase chain reaction (qPCR) results showed differential expression levels of StALMT gene family members in different tissues of the potato. Interestingly, StALMT1, StALMT6, StALMT8, StALMT10, and StALMT12 had higher expression in the root of the potato cultivar Qingshu No. 9. After being subjected to Al3+ stress for 24 h, the expression of StALMT6 and StALMT10 in roots was evidently increased, displaying their decisive role in Al3+ toxicity. In addition, overexpression of StALMT6 and StALMT10 in Arabidopsis enhanced its tolerance to Al toxicity. These results indicate that StALMT6 and StALMT10 impart Al3+ resistance in the potato, establishing the foundation for further studies of the biological functions of these genes.