Search Results (263)

Fungi regularly occur on spacecrafts, posing a serious risk to humans and equipment. In this study, we characterized how the model organism Aspergillus nidulans responds to low-intensity, short-duration proton irradiation designed to simulate a solar particle event, a common stress factor in space. The oxidative stress-sensitive ∆atfA mutant exhibited a lower survival rate than the wild-type strain. Pretreatment of the wild-type strain with menadione sodium bisulfite (MSB), which activates oxidative stress defense mechanisms, increased tolerance to proton beam radiation. These data are consistent with the idea that oxidative defense contributes to cellular responses to ionizing radiation. Unexpectedly, the applied radiation decreased the tolerance to MSB. To understand this unusual behavior, we compared the transcriptomes of the irradiated and non-irradiated mycelia. As expected, proton beam irradiation upregulated many genes involved in DNA repair but downregulated a large number of antioxidant enzyme genes. The downregulation of three key antioxidant genes—prxA (thioredoxin peroxidase), trxB (thioredoxin reductase), and gsh1 (γ-glutamylcysteine synthase)—was further confirmed by RT-qPCR analysis. One possible explanation is that, due to the rapid elimination of reactive oxygen species generated by water radiolysis, the effects of radiolysis-derived electrons could transiently dominate redox signaling. This shift may interfere with redox sensing in the fungus, resulting in reduced antioxidant gene expression and increased sensitivity to oxidative stress. Oxidative stress sensitivity caused by proton radiation may be the Achilles heel of cells that can survive this stress. Full article

Although the diterpenoid alkaloids of Aconitum carmichaelii Debx. have long been a research focus in phytochemistry and pharmacology, systematic studies on the growth and development of its daughter roots remain limited, yet this process critically determines the yield and quality of the medicinal material. This study utilized the Jiangyou-derived daughter root of A. carmichaelii as experimental material. Quantitative real-time polymerase chain reaction (qRT-PCR) and total lignin quantification demonstrated that both the expression level of AcPRX12 and total lignin relative content were consistently higher in the non-swollen (PB) parts than in the swollen (P) parts of the daughter roots. The complete cDNA sequence of the AcPRX12 (with a full length of 1357 bp and encoding 350 amino acids) was obtained by rapid amplification of cDNA ends (RACE). Bioinformatics analysis identified AcPRX12 as an extracellular class III peroxidase containing a secretory peroxidase domain, and further predicted its strong binding affinity for syringaldazine, an S-type lignin monomer analog. In addition, the heterologous expression of AcPRX12 in Arabidopsis thaliana resulted in a significant increase in lignin content, which inhibited plant growth, as evidenced by shorter roots, thinner stems, smaller leaves, and shorter siliques. Collectively, these results support a model in which AcPRX12 promotes lignin biosynthesis to modulate daughter root development, ultimately shaping its distinctive tapered morphology. In conclusion, our findings propose a lignin-mediated regulatory mechanism for daughter root development controlled by AcPRX12, offering a key gene resource and a theoretical basis for understanding its morphogenesis. Full article

Wheat is one of the world’s most important crops, cultivated across diverse ecogeographic zones on more than ~245 million hectares annually. Classified by vernalization requirement into spring, facultative, or winter types, the latter typically achieves higher yields due to its extended growing season, reaching ~18 t ha⁻¹ and 9–10 t ha⁻¹ as a national average for Western European countries such as Germany, France, and England, compared with the global average of barely above 3 t ha⁻¹. Despite this potential, winter wheat is largely confined to regions with relatively mild winters, while vast temperate zones with extremely cold winters rely on spring wheat. Breeding has traditionally targeted the vernalization–C-repeat Binding Factor (VRN–CBF) pathway, which confers tolerance to moderately severe winters but is insufficient for extreme cold, implying the need for additional layers of adaptive mechanisms. Using multiple genotypic datasets, we identified genomic regions underlying low-temperature tolerance. Genome- and chromosome-wide scans revealed strong differentiation on chromosome 5A (526–703 Mb), overlapping the VRN–CBF loci. SNP-level FST analysis between spring and winter cultivars highlighted the VRN-A1 (586–588 Mb) region and a locus spanning 549 and 559 Mb on chromosome 6A. Further comparisons between winter accessions adapted to extreme cold (≤−12 °C) and mild winters (>0 °C) revealed a differentiated region on chromosome 3B (561–564 Mb) harbouring two key genes conferring CBF-independent cold tolerance, TRAESCS3B02G351100 and TRAESCS3B02G354000, encoding diacylglycerol kinase1 (DGK1) and peroxidase 56 (PRX56), respectively. These findings underscore alternative pathways in shaping cold adaptation, highlighting the need to broaden breeding strategies for extreme environments. We further detected a pronounced haplotype divergence between Chinese and U.S. winter cultivars reflecting distinct breeding trajectories; notably, China, where ~90% of wheat production is of the winter type, achieves national yields >5 t ha⁻¹, compared with ~3 t ha⁻¹ in the United States, where over 70% of production is winter wheat. This contrast suggests that the haplotypes enriched in Chinese winter cultivars could represent valuable resources for enhancing winter wheat performance in other regions with comparable environments. Full article

In this study, a targeted SSR (Simple Sequence Repeat) marker resource was developed based on genes and protein families associated with pathogen- and pest-related defense–resistance mechanisms in Camellia sinensis. Forty-one genes and protein families reported to show upregulation, increased expression, or functional validation under disease and pest stress were selected, and the corresponding 195 loci were mapped onto the Camellia sinensis cv. Shuchazao genome. SSR screening within gene bodies and gene-flanking regions (±5 kb) identified 5197 SSR loci. Putative QTL hotspot regions were defined using locus-based sliding-window analysis, Z-score calculations, and permutation tests, yielding 633 SSRs filtered at the 99% and 95% significance thresholds. Proteome-wide scans based on conserved amino acid motifs identified multiple loci within the WRKY, NAC, LRR, PRX, and CHI families, and Random Forest analysis was used to prioritize SSRs within these families. Finally, 386 SSR primer sets were designed and evaluated by in silico PCR across six tea genomes. Of these, 245 primers produced amplicons in more than one genome, and 124 exhibited polymorphic information content values greater than 0.500. Overall, the developed SSR panels represent a biologically contextualized and experimentally transferable marker resource targeting defense–resistance-associated genic and gene-proximal regions. Full article

Background: Pneumococcal diseases remain a global threat due to the serotype-specific limitations of polysaccharide vaccines. This study evaluated a recombinant protein-based pneumococcal vaccine (PBPV) combining three PspA variants (PRX1/Family1Clade2, P3296/Family2/Clade3, P5668/Family2/Clade4) and detoxified pneumolysin (PlyLD). PspA targets conserved surface epitopes to block immune evasion and achieve broad coverage, while PlyLD neutralizes pore-forming toxins and enhances adaptive immunity. Methods: We evaluated the safety and immunogenicity of the PBPV in animal models. Acute toxicity studies were conducted by administering a single intramuscular injection to ICR mice, whereas chronic toxicity and immunogenicity studies were performed in cynomolgus monkeys via repeated intramuscular injections, with an equal number of male and female animals in both groups. Immune responses were assessed using ELISA, multiplexed opsonophagocytic killing assays (MOPAs), and neutralizing antibody assays. Results: Acute toxicity studies in ICR mice showed no signs of abnormal toxicity or irritation at one-dose levels. In the chronic toxicity study, cynomolgus monkeys received repeated intramuscular injections once every 3 weeks for a total of four administrations, at doses of one dose/monkey and five doses/monkey, followed by a 4-week recovery period. No significant systemic toxic reactions were observed, and the safe dose was determined to be five doses/monkey. In the immunogenicity study of monkey serum, both low-dose and high-dose groups demonstrated significant increases in antigen-specific IgG titers against each component; opsonophagocytic killing activity against pneumococcal strains from Clades 2, 3, and 4 from PspA Families 1 and 2; and neutralization antibody titers against pneumolysin post-vaccination. Conclusions: The recombinant protein-based pneumococcal vaccine exhibited a favorable safety profile and potent immunogenicity in animal models, indicating promise for broad protection against pneumococcal disease. These findings support the further development of PBPVs as a viable alternative to conventional polysaccharide-based vaccines. Full article

Salinity is a major constraint that compromises safflower performance by disrupting redox balance and metabolic homeostasis. Although hormonal mechanisms for improving plant resilience to abiotic stresses have been reported, the mechanistic role of gibberellic acid (GA₃)-induced regulation of safflower tolerance to salinity remains unclear. This study aimed to investigate the impact of exogenous GA₃ application under normal and saline conditions to evaluate its effects on growth, physiology, redox regulation, and flavonoid biosynthesis in safflower. Using phenotypic, physiological, biochemical, and gene expression analysis, it is suggested that GA₃ significantly alleviates salt stress by integrating antioxidant defense and flavonoid biosynthesis. The results of phenotypic and physiological assessments showed that GA₃ at 400 mg/L GA₃ in safflower seedlings suggests enhanced vegetative growth and photosynthetic performance. Under salt stress, GA₃ significantly alleviated oxidative damage by reducing H₂O₂, ${\mathrm{O}}_2^{-}$, and malondialdehyde (MDA) levels, while enhancing osmoprotective compounds such as proline, soluble sugars, proteins, and chlorophyll. GA₃ also significantly increased the activity of antioxidant enzymes (SOD, POD, CAT, APX, GST, DHAR, and Prx), accompanied by the transcriptional upregulation of their corresponding genes, indicating GA₃-mediated regulation of redox homeostasis at both biochemical and molecular levels. In parallel, GA₃ enhanced the accumulation of major flavonoids, particularly hydroxy safflor yellow A (HSYA), with strong induction of key HSYA biosynthetic genes (CtF6H, CtCGT, Ct2OGD1), whereas salinity alone suppressed their expression. In contrast, the quercetin branch displayed a regulatory bottleneck at CtF3H, which remained suppressed under all treatments, although upstream genes were GA₃-responsive. Together, these findings demonstrate that GA₃ enhances salinity tolerance in safflower by simultaneously activating antioxidant defenses and stimulating flavonoid biosynthesis, providing mechanistic insight with practical implications for developing salt-resilient safflower varieties. Full article

Astragalus membranaceus is a model of traditional ‘homologous nature of medicine and food’. Its stems and leaves have been proven to have a variety of biological activities. In this study, high-throughput sequencing technology was used to sequence transcriptomics and metabolomics A. membranaceus stems and leaves at different growth stages (flowerless stage, flower bud stage, flowering stage, green fruit stage, mature fruit staged, and withering stage), and a regulation analysis was conducted on its differentially expressed genes and differentially accumulated metabolites. The results showed that five hub genes, PAL, CHI, AMIE, CAD, and PRX, were found to play a central regulatory role in flavonoid biosynthesis. The combined analysis of transcriptomics and metabolomics constructed a flavonoid metabolic regulatory network during the growth and development of A. membranaceus stems and leaves. At the same time, based on the significant antioxidant activity of isoquercitrin, three genes that may be related to isoquercitrin biosynthesis were screened, namely IF7MAT, FG3, and UGT78D2. The results of this study provide insights into the biosynthesis and comprehensive development and utilization of flavonoids in A. membranaceus. Full article

Typical 2-Cys peroxiredoxins (2-Cys Prxs, AhpC/Prx1 subfamily) are ubiquitous thiol peroxidases that efficiently reduce H₂O₂ and other hydroperoxides via a reactive peroxidatic Cys (C_P). Under elevated hydroperoxide levels, C_P can be hyperoxidized to sulfinic (C_P-SO₂H) or sulfonic (C_P-SO₃H) acids, leading to enzyme inactivation. Notably, eukaryotic 2-Cys Prxs are orders of magnitude more sensitive to hyperoxidation (sensitive Prxs) by H₂O₂ than their bacterial counterparts (robust Prxs). Sensitivity to hyperoxidation also correlates with the catalytic triad composition: enzymes containing threonine (Thr-Prx) are more prone to hyperoxidation by H₂O₂ than those with serine (Ser-Prx). While hyperoxidation is reversed in eukaryotes by an enzyme (sulfiredoxin), it is generally considered irreversible in bacteria. Here, we compared the hyperoxidation susceptibility of three typical 2-Cys Prxs: human Prx2 (Thr-Prx, sensitive), P. aeruginosa (Thr-Prx, robust) and S. epidermidis (Ser-Prx, robust) to lipid hydroperoxides derived from linoleic acid, containing one or two peroxide moieties per molecule. Employing structural analysis, molecular simulations and kinetic assays, we found that lipid peroxides proved to be potent hyperoxidizing agents for all 2-Cys Prx tested, inactivating the enzymes up to 10,000 times faster than H₂O₂. These results may have implications for understanding bacterial oxidative stress responses and antimicrobial resistance. Full article

Lenticel spots (fruit dots) on pear peel strongly influence consumer preference and market price, yet the regulatory networks underlying their lignin/cellulose deposition remain elusive. Here, we integrated electron microscopy, metabolomics, and RNA-seq across three developmental stages (30, 40, and 60 d after full bloom, DAFB) in the pear cultivar ‘Dangshansuli’ (SL) and its bud-sport ‘Dangshanxisu’ (XS). XS exhibited fewer lenticel spots and lower lignin, cellulose, and hemicellulose contents than SL, with the critical onset of lignin and cellulose accumulation detected between 40 and 60 DAFB. Metabolome-wide analysis detected five differentially accumulated lignin monomers, while transcriptome profiling revealed 79 differentially expressed genes (padj ≤ 0.05, |log₂FC| ≥ 1) enriched in phenylpropanoid and cellulose-synthase pathways. Weighted gene co-expression network analysis (WGCNA) uncovered two modules (|r| > 0.8, p < 0.05) positively correlated with lignin and cellulose content, harboring 11 structural genes (4CL, F5H, CCR, COMT, PRX/POD and CESA isoforms) and five transcription-factor families (MYB, NAC, AP2/ERF, WRKY, bHLH). RT-qPCR validated the coordinated down-regulation of these genes in XS relative to SL. Our results decipher the gene–metabolite circuitry driving lenticel lignification in pear, providing molecular targets for breeding peel-perfect cultivars and for cultural practices that minimize superficial blemishes. Full article

Seed germination is crucial for seedling establishment and is regulated by precise reactive oxygen species (ROS) signaling. Class III peroxidases (PRXs), which are plant-specific enzymes, play crucial roles in plant growth, development, and responses to abiotic stress by maintaining ROS homeostasis. However, members of the PRX gene family in tomato, particularly their functions in modulating seed germination, remain poorly understood. In this study, 102 tomato PRXs (SlPRXs) were identified, and they were classified into five groups based on phylogenic analysis. Chromosomal localization revealed that these SlPRX genes are unevenly distributed across 12 tomato chromosomes, with chromosome 02 harboring the highest densities. Gene structure analysis revealed that SlPRXs contain 1 to 10 exons, and SlPRX4 possesses the most exons. All SlPRX proteins possess the characteristic peroxidase domain and share conserved structural motifs. Collinearity analysis suggested that segmental duplications might be the main contributor to the expansion of the SlPRX family. Promoter analysis revealed numerous cis-acting elements related to abiotic/biotic stress responses, phytohormones, and growth and development. Notably, seed germination-related elements such as CARE and RY element were identified in some SlPRXs. Enzymatic and electrophoresis assays indicated that PRX activity increased with seed germination. Moreover, SHAM, the inhibitor of PRX, exerted an inhibitory effect on tomato seed germination. Transcriptome data revealed stage-specific induction of SlPRXs during germination, with distinct expression peaks between 0 and 96 h post imbibition. These findings were further validated by qRT-PCR of the selected SlPRX genes. Overall, the findings enhance our understanding of SlPRX family members in tomato and highlight their potential for improving seed germination. This study also provides valuable genetic resources and potential molecular markers for breeding tomato varieties with improved germination vigor and stress resilience. Full article

Anti-lipopolysaccharide factors (ALFs) are an important molecular category within the antimicrobial peptide family. They play a crucial role in resisting pathogen infections and are of importance in the innate immune system of shrimp. A novel ALF-like gene was identified from L. vannamei in this study. Its expression profile was investigated after WSSV infection. Results demonstrated that the mRNA transcription level of the ALF-like gene was significantly upregulated in hemocytes, hepatopancreas, gills, and intestines of L. vannamei. When the mRNA transcription level of the ALF-like gene was inhibited, the expression levels of key WSSV genes (VP 28 and IE 1) were significantly upregulated, accompanied by a decrease in shrimp survival rate. Meanwhile, the expression of genes involved in the apoptotic pathway (Lv-Caspase 3, Lv-Caspase 8, and Lv-Bcl 2) and antioxidant enzyme pathway (Lv-GST, Lv-CAT, Lv-Prx, Lv-GPX, and Lv-SOD) was also significantly increased. Flow cytometry further revealed that the hemocyte apoptosis rate induced by WSSV infection was reduced when the transcription level of the target gene was inhibited. These results indicate that the Lv-ALF-like gene plays an important regulatory role in the resistance of L. vannamei to WSSV infection, and studying the function of this gene is of great significance for disease prevention and control of shrimp. Full article

Paroxetine (PRX) is a common antidepressant, also frequently used by pregnant women to treat depression and anxiety associated with pregnancy; thus, we should increase warnings about its intake. The increased presence of paroxetine in the environment raises concerns about unintended exposure to it, with consequences for embryonic development. However, the effect of PRX on early embryonic development, particularly on the embryonic brain, is still poorly studied, so this study aimed to investigate its toxicological profile on embryonated eggs of Danio rerio. Embryos of D. rerio were exposed to 1, 10, and 100 μg/L of PRX using the ZFET test. The results showed that exposure to PRX does not interfere with embryonic development but causes adverse effects in larvae, including heartbeats and an inflammatory state, with production of ROS and apoptotic cells on their head. Finally, the immunofluorescence assay for the biomarker acetylcholinesterase showed a decrease in its activity in exposed groups. Therefore, paroxetine is able to reach the nervous system during embryonic development with negative consequences. Full article

Calvarial suture skeletal stem cells (Su-SSCs) are a distinct stem cell population for craniofacial bone formation by intramembranous ossification, compared to long bone periosteal SSCs (LB-PSSCs) with endochondral (osteochondrogenic) ossification. However, whether SSC intrinsic or extrinsic factors affect their differentiation process has not been well elucidated. Here, using an inducible Prx1-CreER-EGFP^+/−;Rosa26-tdTomato mouse model, we observed that endogenous Prx1⁺ Su-SSCs and their orthotopic transplantation into calvarial injury do not form cartilage intermediates at the injury sites, while the transplantation of Prx1⁺ LB-PSSCs into LB injury induces osteochondrogenic differentiation, respectively. However, the heterotopic transplantation of Prx1⁺ Su-SSCs (Su-SSCs into LB injury) showed some surprising findings that the transplanted Su-SSCs acquire new chondrocyte differentiation properties at the LB injury sites, although the heterotopic-transplanted Prx1⁺ LB-PSSCs maintained their endochondral ossification properties at the calvarial injury sites. Further, a comparative single-cell transcriptomic analysis of LB-PSSCs and Su-SSCs revealed that Su-SSCs express a higher set of anti-chondrogenic genes, such as Wnt5b, Twist1 while LB-PSSCs highly express chondrogenic Hoxa-9, Hoxc-9, Hoxa-10, Hoxc-10, and Comp genes. We also found that the heterotopic transplantation of LB-PSSCs into calvarial injury enhances bone healing in vivo. Taken together, these findings suggest that LB-PSSCs have high regenerative capability with invariable endochondral ossification even after the heterotopic transplantation but Su-SSCs are more flexible and regulated by the local bone environment. The transplantation of periosteal SSCs will be a promising method for large craniofacial bone defects. Full article

Drought is one of the major abiotic stresses threatening maize production globally. Under drought stress, maize plants produce excessive reactive oxygen species (ROS), leading to oxidative damage. The apoplast, as the site of substance and signal exchange between plant cells and the external environment, is an important location for the production of ROS under drought stress. Elucidating the ROS scavenging mechanisms in the apoplast is crucial for understanding plant stress responses. However, there is still a lack of research on the ROS scavenging enzymes in maize apoplast and their mediated signaling pathways. We verified that maize peroxidase Prx25 (ZmPrx25) is localized in the apoplast, it scan scavenge hydrogen peroxide (H₂O₂), and we systematically investigated the responses of the apoplastic ZmPrx25-ROS system to osmotic stress. ROS accumulate in the apoplast of maize mesocotyl in response to osmotic stress and transmit the external osmotic stress signals from the apoplast to the inner cellular compartments. The expression of ZmPrx25 is highly upregulated in the meristematic regions of maize seedlings under osmotic and oxidative stress. Overexpression of ZmPrx25 in Arabidopsis promoted seed germination and plant growth, significantly enhancing tolerance to osmotic and oxidative stress. This study provides a new perspective on the role of Prx25 in scavenging ROS under drought stress. Full article

Anemia has been a growing concern for the pediatric population in sub-Saharan Africa. Emerging risk factors for anemia under five years of age in low-income countries are multifaceted, including infectious diseases, nutritional deficiencies, hidden hunger, and various economic determinants, and its health burdens include childhood stunting and reduced cognitive function diminished school performance in children. However, the influence of climatic factors, particularly ambient temperatures, on pediatric anemia remains understudied. In this population-based study, we assess the region-specific associations between pediatric anemia and ambient temperatures in 43 countries in Africa from 2000 to 2019. Using generalized linear regression models (upon adjusting for covariates), we found that the risk of temperatures on pediatric anemia varies across four African regions, whereby the Central and Southern African regions have a positive association between pediatric anemia and ambient temperatures, and Western and Eastern regions are negatively affected. The study aims to provide evidence to stakeholders to curtail the onset of pediatric anemia in high-risk African regions to set up key interventions based on the sustainability goals set by the World Health Organization. Full article