Search Results (244)

Zinc (Zn) deficiency poses a major global health challenge, and wheat grains generally contain low Zn concentrations. In this study, the wheat cultivar ‘Zhongmai 175’ was identified as zinc-efficient. Hydroponic experiments demonstrated that Zn deficiency induced the secretion of oxalic acid and malic acid in root exudates and significantly increased total root length in ‘Zhongmai 175’. To elucidate the underlying regulatory mechanisms, transcriptome profiling via RNA sequencing was conducted under Zn-deficient conditions. A total of 2287 and 1935 differentially expressed genes (DEGs) were identified in roots and shoots, respectively. Gene Ontology enrichment analysis revealed that these DEGs were primarily associated with Zn ion transport, homeostasis, transmembrane transport, and hormone signaling. Key DEGs belonged to gene families including VIT, NAS, DMAS, ZIP, tDT, HMA, and NAAT. KEGG pathway analysis indicated that phenylpropanoid biosynthesis, particularly lignin synthesis genes, was significantly downregulated in Zn-deficient roots. In shoots, cysteine and methionine metabolism, along with plant hormone signal transduction, were the most enriched pathways. Notably, most DEGs in shoots were associated with the biosynthesis of phytosiderophores (MAs, NA) and ethylene. Overall, genes involved in Zn ion transport, phytosiderophore biosynthesis, dicarboxylate transport, and ethylene biosynthesis appear to play central roles in wheat’s adaptive response to Zn deficiency. These findings provide a valuable foundation for understanding the molecular basis of Zn efficiency in wheat and for breeding Zn-enriched varieties. Full article

The functional role of MAPKK genes in potato (Solanum tuberosum L.) under high-temperature stress remains unexplored, despite their critical importance in stress signaling and yield protection. We characterized StMAPKK1, a novel group D MAPKK localized to plasma membrane/cytoplasm. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed cultivar-specific upregulation in potato (‘Atlantic’ and ‘Desiree’) leaves under heat stress (25 °C, 30 °C, and 35 °C). Transgenic lines overexpressing (OE) StMAPKK1 exhibited elevated antioxidant enzyme activity, including ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), mitigating oxidative damage. Increased proline and chlorophyll accumulation and reduced oxidative stress markers, hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), indicate improved cellular redox homeostasis. The upregulation of key antioxidant and heat stress-responsive genes (StAPX, StCAT1/2, StPOD12/47, StFeSOD2/3, StMnSOD, StCuZnSOD1/2, StHSFA3 and StHSP20/70/90) strengthened the enzymatic defense system, enhanced thermotolerance, and improved photosynthetic efficiency, with significant improvements in net photosynthetic rate (Pn), transpiration rate (E), and stomatal conductance (Gs) under heat stress (35 °C) in StMAPKK1-OE plants. Superior growth and biomass (plant height, plant and its root fresh and dry weights, and tuber yield) accumulation, confirming the positive role of StMAPKK1 in thermotolerance. Conversely, RNA interference (RNAi)-mediated suppression of StMAPKK1 led to a reduction in enzymatic activity, proline content, and chlorophyll levels, exacerbating oxidative stress. Downregulation of antioxidant-related genes impaired ROS scavenging capacity and declines in photosynthetic efficiency, growth, and biomass, accompanied by elevated H₂O₂ and MDA accumulation, highlighting the essential role of StMAPKK1 in heat stress adaptation. These findings highlight StMAPKK1’s potential as a key genetic target for breeding heat-tolerant potato varieties, offering a foundation for improving crop resilience in warming climates. Full article

Micronutrient deficiencies adversely affect human health and pose a significant global threat. Enhancing the accumulation of micronutrients in the edible parts of crops through genetic breeding is a promising strategy to mitigate micronutrient deficiencies in humans. FW2.2-like (FWL) genes play crucial roles in regulating heavy metal homeostasis in plants. We previously obtained two allelic mutants for each of the rice OsFWL1 (osfwl1a and osfwl1b) and OsFWL2 (osfwl2a and osfwl2b) genes. In this study, we showed that disruption of either OsFWL1 or OsFWL2 significantly enhanced the accumulation of metallic micronutrients in brown rice. Compared with that in the wild type, the iron (Fe) concentration in brown rice was higher in the osfwl1a (+166.7%), osfwl1b (+24.3%), and osfwl2a (+99.2%) mutants; the manganese (Mn) concentration was elevated in all four mutants (+25.1% to 35.6%); the copper (Cu) concentration increased in osfwl2a (+31.0%) and osfwl2b (+29.0%); and the zinc (Zn) concentration increased in osfwl2a (+10.2%). Additionally, disruption of OsFWL1 or OsFWL2 affected the homeostasis of metallic micronutrients in seedlings. Transcriptome analysis suggested that OsFWL1 and OsFWL2 might regulate cell wall polysaccharide metabolism and the expression of heavy metal transporter genes. Protein interaction analysis revealed that OsFWL1 interacted with OsFWL2 on the cell membrane. These findings suggest that OsFWL1 and OsFWL2 can serve as genetic biofortification tools to increase the concentrations of metallic micronutrients in rice grains. Full article

This study aimed to compare the contents of copper (Cu), zinc (Zn), magnesium (Mg), and iron (Fe) in healthy liver tissue from deceased liver donors (DGs), in cirrhotic tissue from patients without (CIR) or with hepatocellular carcinoma (CIR-HCC) and in HCC tissue from the latter patients. Liver tissue samples were obtained from cirrhotic liver transplant recipients, with (n = 14) and without HCC (n = 14), and from DGs (n = 18). In patients with HCC, both cirrhotic and tumor tissue was collected. The tissue metal content was measured using atomic absorption spectrometry. The Cu content of DG tissue was significantly lower than that of CIR-HCC and HCC tissue but not CIR tissue. The tissue Zn and Mg contents were significantly higher in DG tissue than in CIR, CIR-HCC, and HCC tissues. No difference was observed for Fe. The Cu/Zn ratio progressively increased in DG, CIR, CIR-HCC, and HCC tissues. The increased Cu content in cirrhotic and tumor tissue of HCC patients and the fact that the latter had the highest value for the Cu/Zn ratio indirectly suggest the potential role of these metals in hepatocarcinogenesis. These findings support a pathophysiological basis for further experimental studies to investigate the potential therapeutic implications of pharmacological agents targeting metal homeostasis in this malignancy. Full article

The interactive effects between nano-silicon dioxide (n-SiO₂) and elevated CO₂ (eCO₂; 645 ppm) on soybean physiology, nitrogen fixation, and nutrient dynamics under climate stress remain underexplored. This study elucidates their combined effects under ambient (aCO₂; 410 ppm) and eCO₂ conditions. eCO₂ + n-SiO₂ synergistically enhanced shoot length (30%), total chlorophyll (112.15%), and photosynthetic rate (103.23%), alongside improved stomatal conductance and intercellular CO₂ (17.19%), optimizing carbon assimilation. Nodulation efficiency increased, with nodule number and biomass rising by 48.3% and 53.6%, respectively, under eCO₂ + n-SiO₂ versus aCO₂. N-assimilation enzymes (nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase) surged by 38.5–52.1%, enhancing nitrogen metabolism. Concurrently, phytohormones (16–21%) and antioxidant activities (15–22%) increased, reducing oxidative markers (18–22%), and bolstering stress resilience. Nutrient homeostasis improved, with P, K, Mg, Cu, Fe, Zn, and Mn elevating in roots (13–41%) and shoots (13–17%), except shoot Fe and Zn. These findings demonstrate that n-SiO₂ potentiates eCO₂-driven benefits, amplifying photosynthetic efficiency, nitrogen fixation, and stress adaptation through enhanced biochemical and nutrient regulation. This synergy underscores n-SiO₂ role in optimizing crop performance under future CO₂-rich climates, advocating nano-fertilizers as sustainable tools for climate-resilient agriculture. Full article

Superoxide dismutases (SODs) maintain redox homeostasis through the catalytic dismutation of superoxide anions, thereby affording protection to organisms against oxidative damage. The SOD family, encompassing Cu/Zn-SOD, Mn-SOD, Fe-SOD, and Ni-SOD, exhibits structural diversity and constitutes a multilevel antioxidant defense system with discrete subcellular localizations. Beyond their antioxidant functions, SODs also function as immunomodulatory proteins, regulating the maturation, proliferation, and differentiation of immune cells. They further fulfill a crucial role in host responses to parasitic infections. The current review synthesizes and critically evaluates extant research to comprehensively delineate the molecular architecture of SODs, their intricate post-translational modification (PTM) networks, and their dual regulatory mechanisms at the interface of immunomodulation and pathological processes. This review establishes a critical framework for elucidating the biological significance of redox homeostasis maintenance. Full article

Plants dynamically regulate ions in the tree to defend against abiotic stresses such as drought and saline-alkali, However, it is not clear how ‘Junzao’ jujube regulates ions to maintain a normal life cycle under saline-alkali stress. Therefore, in this study, the roots of 10-year old steer jujube trees were watered using a saline and alkaline gradient solution simulating the main salt (NaCl) and alkali (NaHCO₃) of Aral with NaCl:NaHCO₃ = 3:1 gradient of 0, 60, 180, and 300 mM, and three jujube trees with uniform growth were taken as samples in each treatment plot, and the ion contents of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and carbon (C) in each organ of the fruit at the dot red period (S1) and full-red period (S2) were determined, in order to elucidate the relationship between physiological adaptation mechanisms of saline-alkali tolerance and the characteristics of mineral nutrient uptake and utilisation in jujube fruit. The results showed that under saline-alkali stress, Na was stored in large quantities in the roots, Ca and Mg in the perennial branches at S1, Na and Fe in the leaves at S2, and K, Mg and Mn in the perennial branches. There was no significant difference in the distribution of C content in various organs of ‘Junzao’. Compared with CK (0 mM), under salinity stress, the K content in the leaves was significantly reduced at S1 and S2, and the K/Na ratios remained > 1.0. At S2, under medium and high concentrations of saline-alkali stress (180–300 mM), the K/Na is less than 1, and the ionic homeostasis was disrupted, and the leaves die and fall off, and the Na is excreted from the body. The selective transport coefficients SK/Na, SCa/Na and SMg/Na from root to leaf showed a downward trend at S1, but still maintained positive transport capacity. At S2, this stage is close to leaf fall, the nutrient transport coefficient is less than 1, and a large amount of nutrients are returned to the perennial branches and roots occurred. These results indicated that the mechanism of nutrient regulation and salt tolerance in jujube trees was different at different growth stages. Full article

Lead (Pb) is a pervasive neurotoxicant with well-documented detrimental effects on the central nervous system, particularly in vulnerable populations such as children. Despite historical recognition of its toxicity, Pb exposure remains a significant public health concern due to its environmental persistence, historical industrial use, and ongoing applications in modern technologies. This review focuses on the mechanisms by which Pb disrupts glutamatergic signaling, a critical pathway for learning, memory, and synaptic plasticity. Pb’s interference with glutamate receptors (ionotropic NMDA and AMPA, as well as metabotropic receptors), transporters (EAATs, VGLUTs, and SNATs), and metabolic pathways (glutamate–glutamine cycle, TCA cycle, and glutathione synthesis) are detailed. By mimicking divalent cations like Ca²⁺ and Zn²⁺, Pb²⁺ disrupts calcium homeostasis, exacerbates excitotoxicity, and induces oxidative stress, ultimately impairing neuronal communication and synaptic function. These molecular disruptions manifest cognitive deficits, behavioral abnormalities, and increased susceptibility to neurodevelopmental and neurodegenerative disorders. Understanding Pb’s impact on glutamatergic neurotransmission offers critical insights into its neurotoxic profile and highlights the importance of addressing its effects on neural function. Full article

Zinc (Zn) is a crucial trace element in vertebrates, fulfilling a range of physiological functions, whose metabolism and homeostasis are manipulated by Zn transporter proteins. SUMOylation, a reversible post-translational modification (PTM), extensively participates in various biological processes in the body, yet its underlying mechanism in regulating Zn transporters remains unexplored. Our findings indicate that high dietary Zn substantially elevated intestinal Zn content and modulated the expression profiles of Zn transporter-related genes and proteins, including ZIP8 transporter. In addition, high Zn diet tended to inhibit the SUMOylation modification and upregulate deSUMOylation modification in the intestine and intestinal epithelial cells. Furthermore, we found that the ZIP8 protein undergoes SUMOylation modification; UBC9 upregulated but SENP1 and Zn downregulated the SUMOylation level of ZIP8, and the K24 and K222 positions are the primary SUMOylation modification sites of ZIP8 protein in yellow catfish. Mechanistically, SENP1 modulates the deSUMOylation modification of ZIP8 by sensing Zn-induced oxidative stress. In summary, for the first time, we have uncovered a unique regulatory mechanism of ZIP8 mediated by SUMOylation modification in vertebrates and demonstrate that SENP1 is capable of sensing oxidative stress to reduce the SUMOylation modification of ZIP8 at K24 and K222 sites. Full article

This study evaluated the response of two willow varieties, Salix × smithiana Willd. and Salix viminalis L. var. Gigantea, to selected heavy metals and elevated soil salinity, simulating complex environmental conditions during phytoremediation. Plants propagated from stem cuttings were cultivated in pots under field conditions in soil artificially contaminated with a mixture of Cd, Ni, Cu, Zn, and Pb salts at two concentration levels representing lower and higher guideline thresholds. Sodium chloride was added to induce salinity stress. S. × smithiana exhibited enhanced growth under combined metal and salinity stress, suggesting efficient tolerance mechanisms. This was reflected in elevated relative water content (RWC) and increased accumulation of Zn and Cd in shoots. In contrast, Gigantea showed growth inhibition and primarily sequestered metals in roots, indicating a stress-avoidance strategy and reduced metal translocation. While salinity alone negatively affected both varieties, its combination with metals mitigated growth reduction in S. × smithiana, possibly due to improved ion homeostasis or cross-tolerance. Zn and Cd displayed the highest bioconcentration and mobility. Based on bioconcentration factor (BCF) and translocation factor (TF), S. × smithiana appears suitable for phytoextraction, whereas S. viminalis var. Gigantea appears suitable for phytostabilization. These results support species-specific approaches to phytoremediation in multi-contaminant environments. Full article

Phytochelatins (PCs) are well-characterized for their role in detoxifying non-essential metals like cadmium (Cd), but their role in zinc (Zn) homeostasis remains underexplored. In this study, we investigated the role of the Nicotiana tabacum phytochelatin synthase 1 (NtPCS1) in counteracting Zn toxicity in plants. qRT-PCR data showed that the transcript level of the NtPCS1 gene was upregulated by ZnSO₄, leading to increased PC production in the wild-type tobacco plants. Functional complementation assays in Arabidopsis thaliana revealed that overexpression of NtPCS1 rescued the Zn hypersensitivity of the Atpcs1 mutant, with the N-terminal region being indispensable for Zn tolerance. In addition, transgenic tobacco plants overexpressing NtPCS1 (PCS1 lines) exhibited superior root elongation under ZnSO₄ stress compared to the wild-type plants, particularly when supplemented with glutathione (GSH). The observed phenotypic advantage is attributed to NtPCS1-mediated overproduction of PCs, which facilitated Zn chelation and enabled cellular detoxification. These findings highlight the important role of NtPCS1 in Zn tolerance via GSH-linked PCs synthesis, offering insights into PCS-mediated Zn detoxification and a genetic strategy for developing Zn-resistant plants. Full article

Eucalypts are a diverse group of Myrtaceae native to Australia and adapted to a wide range of edaphoclimatic conditions, including variation in phosphorus (P) soil availability. While Corymbia and Eucalyptus species have evolved in P-poor soils, they still respond to P additions. Nutrient ratios have been used to study nutritional imbalances in plants, as they relate to nutrient homeostasis within cells and ultimately productivity. This study investigated the effects of providing adequate (normal) and high doses of phosphorus (P) on nutrient ratios in leaves and stems of Eucalyptus and Corymbia species. High soil P may happen due to high natural soil concentration and over-fertilization. These species were pre-selected from a 22-eucalypt species screening, based on their responses—either positive, negative, or neutral—to increased dry mass at high soil P compared to normal P. Two species, Corymbia citriodora and C. maculata, which showed increased dry mass under high P levels, exhibited enhanced shoot growth and improvements in parameters related to photosystem efficiency. Except for Zn, which has an antagonistic relationship with P, the concentrations of other nutrients known to exhibit either antagonism or synergism with P were not significantly altered in the leaves and stems. As a result, there were no notable changes in the ratios with high P data compared to those with normal P data. Ratios calculated among K, Ca, Mg, Fe, and Mn data also remained unchanged. However, a principal component analysis, which was performed with all nutrient ratios, effectively separated the normal P and high P treatments and distinguished between species belonging to the genera Corymbia and Eucalyptus. The validity of such nutrient ratios is discussed, and it is suggested that they may not be applicable in studies involving high nutrient doses, which may also be true for other nutrients. Additionally, using ratios under unbalanced field fertilization may lead to an incorrect nutritional interpretation. Full article

Aegilops tauschii, a monocotyledonous annual grass, recognized as a pivotal progenitor of modern wheat (Triticum aestivum L.), serves as the D-genome donor in hexaploid wheat. This diploid species (2n = 2x = 14, DD) harbors a substantial reservoir of genetic diversity, particularly in terms of biotic and abiotic stress resistance traits. The extensive allelic variation present in its genome has been increasingly utilized for wheat genetic enhancement, particularly through introgression breeding programs aimed at improving yield potential and stress resilience. Heavy metal ATPases (HMAs), which belong to the P-type ATPase superfamily and are also known as P1B-type ATPases, play a crucial role in transporting heavy metals and maintaining metal ion homeostasis in plant cells. HMAs have been extensively studied in model plants like Arabidopsis thaliana and rice. However, this family has not been reported in A. tauschii. Here, we conducted the genome-wide identification and bioinformatics analysis of the AetHMA gene family in A. tauschii, resulting in the discovery of a total of nine AetHMA members. Among AetHMA genes, six pairs are large-block duplication genes, which mainly occur among the four genes of AetHMA2, AetHMA4, AetHMA8, and AetHMA9. Additionally, there is one pair that consists of tandem duplication genes (AetHMA6: AetHMA7). All AetHMAs can be classified into six groups (I–VI), which are further divided into two branches: the copper subclasses and the zinc subclasses. Initially, A. tauschii was grown in a 1/2 Hoagland nutrient solution and subsequently exposed to four heavy metals: zinc (Zn), copper (Cu), manganese (Mn), and cadmium (Cd). Following this treatment, the expression profiles of nine AetHMA genes were assessed. The results indicated that, under zinc and manganese stress, the HMA family members exhibited enhanced expression in the leaves, whereas the expression of most members in the roots was downregulated. In the roots, except for AetHMA2, AetHMA5, and AetHMA8, the expression levels of other members were upregulated in response to Cd exposure. Furthermore, AetHMA4 diminishes the tolerance of yeast to Mn by increasing the absorption of Mn, while AetHMA8 increases the tolerance of yeast to Cd by reducing the absorption of Cd. This study provides experimental data regarding the function of the AetHMA gene in the transport, regulation, and detoxification of heavy metal elements in A. tauschii. Full article

Obesity arises from a complex interplay of genetic and environmental factors. Even among individuals with the same genetic predisposition, diet-induced obesity (DIO) exhibits varying degrees of susceptibility, which are categorized as DIO and diet-induced obesity resistance (DR). The hypothalamus plays a pivotal role in regulating energy homeostasis. This study performed a comparative hypothalamic proteomic analysis in DIO and DR rats to identify differentially expressed proteins (DEPs) associated with alterations in body weight. Male Sprague Dawley rats were fed either a standard chow diet or a high-fat diet for 12 weeks. DIO rats exhibited the most rapid weight gain compared to both the control and DR rats. Despite consuming similar caloric intake, DR rats exhibited less weight gain relative to DIO rats. Proteomic analysis revealed 31 DEPs in the hypothalamus of DR rats compared to DIO rats (with a false discovery rate (FDR) < 1%). Notably, 14 proteins were upregulated and 17 proteins were downregulated in DR rats. Gene ontology analysis revealed an enrichment of ion-binding proteins, such as those binding to Fe²⁺, Zn²⁺, Ca²⁺, and Se, as well as proteins involved in neuronal activity and function, potentially enhancing neuronal development and cognition in DR rats. The DEPs pathway analysis via the Kyoto Encyclopedia of Genes and Genomes (KEGG) implicated starch and sucrose metabolism, antigen processing and presentation, and the regulation of inflammatory mediator affecting TRP channels. Western blotting confirmed the proteomic findings for TRPV4, CaMKV, RSBN1, and BASP1, which were consistent with those obtained from Tandem Mass tag (TMT) proteomic analysis. In conclusion, our study highlights the hypothalamic proteome as a critical determinant in the susceptibility to DIO and provides novel targets for obesity prevention and treatment. Full article

Brassinosteroids (BRs) are crucial plant hormones that play a significant role in regulating various physiological processes, including micronutrient homeostasis. This review delves into the complex roles of BRs in the uptake, distribution, and utilization of essential micronutrients such as iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), and boron (B). BRs influence the expression of key transporter genes responsible for the absorption and internal distribution of these micronutrients. For iron, BRs enhance the expression of genes related to iron reduction and transport, improve root architecture, and strengthen stress tolerance mechanisms. Regarding zinc, BRs regulate the expression of zinc transporters and support root development, thereby optimizing zinc uptake. Manganese homeostasis is managed through the BR-mediated regulation of manganese transporter genes and chlorophyll production, essential for photosynthesis. For copper, BRs influence the expression of copper transporters and maintain copper-dependent enzyme activities crucial for metabolic functions. Finally, BRs contribute to boron homeostasis by regulating its metabolism, which is vital for cell wall integrity and overall plant development. This review synthesizes recent findings on the mechanistic pathways through which BRs affect micronutrient homeostasis and discusses their implications for enhancing plant nutrition and stress resilience. Understanding these interactions offers valuable insights into strategies for improving micronutrient efficiency in crops, which is essential for sustainable agriculture. This comprehensive analysis highlights the significance of BRs in micronutrient management and provides a framework for future research aimed at optimizing nutrient use and boosting plant productivity. Full article