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At least 19 recordsLinked to original sources

PubMed2026

Uncovering molecular regulatory networks of low-temperature stress response in Trachinotus ovatus via integrated transcriptome and metabolome analyses.

Golden pompano (Trachinotus ovatus) is one of the most economically important marine fish species in China. It is susceptible to low-temperature stress, which significantly challenges its production and supply. Nevertheless, study on the regulatory mechanisms underlying low-temperature stress responses in golden pompano remains limited. Here, we firstly performed a time-series transcriptome analysis to reconstruct dynamic response patterns under low-temperature stress in golden pompano. Transcriptome profiling identified common differentially expressed genes (DEGs), including fos, hlf, and hmgb1, as well as condition-specific DEGs across distinct low-temperature stress groups. Based on cluster analysis, all DEGs were classified into five distinct expression patterns, reflecting diversified regulation of expression in golden pompano during low-temperature stress. Furthermore, condition-specific regulatory modules were explored via weighted gene co-expression network analysis (WGCNA), highlighting that the two module hub genes, serbf2 and lipc, might respond to low-temperature stress by regulating the lipid catabolic process. Subsequently, untargeted metabolomic analysis revealed that glycerophospholipid metabolism was a significantly enriched common pathway, highlighting its crucial role in mediating the response to low-temperature stress. Finally, by integrating transcriptomic and metabolomic analyses, a gene-metabolite interaction network associated with glycerophospholipid metabolism under low-temperature stress was established. These findings underscore the significance of multiple candidate genes and glycerophospholipid metabolism in golden pompano's response to low-temperature stress, thereby laying a solid molecular foundation for the development of low-temperature-tolerant fish strains.

Animals↗

PubMed2026

A novel urease-producing strain effectively induces cadmium biomineralization under low-temperature stress.

Microbially induced carbonate precipitation (MICP) has been widely used to immobilize Cadmium (Cd) in contaminated soils in mining-affected regions. However, its remediation efficacy under low-temperature stress, as well as the nucleation process that regulates Cd biomineralization via carbonate precipitation by psychrophilic bacteria, has yet to be investigated. Here, we isolated Pseudomonas sp. J-6, a novel urease-producing strain from tailings in high-altitude cold regions, exhibiting unparalleled cold adaptability at 5 °C and achieving 95.85 % Cd removal efficiency by MICP at 10 °C. Furthermore, the coprecipitation process of Ca1-xCdxCO3 was clarified through the continuous observation of the precipitates after the low-temperature MICP reaction. The crystal morphology transitioned from loose vaterite in the early stage to a dense square-block morphology in the middle stage. Cd2+ progressively shifted from a surface-bound state to lattice incorporation, ultimately resulting in the formation of stable Cd-substituted calcite crystals. In this process, low temperatures led to the formation of larger, highly ordered Cd-substituted calcite crystals, thereby strengthening Cd sequestration and its long-term stability. In addition, under low-temperature stress, Pseudomonas sp. J-6 induced MICP reaction decreased the bioavailable Cd in alpine slag soil by 44.85 % and enhanced physical properties. In the freeze-thaw cycles, the remediation efficiency remained stable. This study clarified the biomineralization potential in high-altitude cryogenic environments and the nucleation process of Cd biomineralization by psychrophilic bacteria-induced carbonate precipitation, filling a critical research gap in its application under extreme conditions and highlighting its promise for sustainable remediation of heavy metal pollution under low-temperature stress.

Cadmium↗

PubMed2026

Human m6A demethylase FTO modulates the flowering time of tomato plants under low-temperature stress.

N6-methyladenosine (m6A) RNA modification plays an important role in plant development and environmental stress responses. However, whether m6A demethylation modulates flowering under low-temperature (LT) stress in tomatoes remains unclear. Here, we investigated whether ectopic expression of FTO, a well-characterized human m6A demethylase, influences flowering and post-transcriptional behaviour in tomato (Solanum lycopersicum) under LT conditions. Flowering of transgenic tomato plants expressing FTO was analyzed under LT and normal conditions (NC), and the impacts of FTO on transcripts-specific m6A level, mRNA stability and splicing efficiency of flowering-related genes were evaluated using RT-qPCR, LC-MS/MS, m6A-IP-qPCR, and RNA decay and splicing analyses. FTO-expressing plants exhibited accelerated flowering specifically under LT, whereas no significant differences were observed under normal growth conditions. This phenotype was accompanied by increased expression of positive floral regulators (SlMC, SlFCA, and SlJ2) and decreased expression of negative regulators (SlSVP, SlSP, and SlTMF) under LT conditions. Notably, these expression changes were associated with altered mRNA stability, with positive regulators showing increased stability and negative regulators showing reduced stability under LT conditions. m6A-IP-qPCR analysis indicated reduced m6A enrichment in these selected transcripts in FTO-expressing plants. In addition to effects on mRNA stability, FTO expression was associated with changes in the splicing efficiency of SlMC transcripts. Collectively, our findings indicate that human FTO functions as an mRNA m6A demethylase in tomatoes and is associated with altered RNA regulatory processes under LT conditions. These findings suggest that m6A-mediated post-transcriptional regulation contributes to stress-induced flowering plasticity under LT conditions, rather than direct activation of canonical flowering pathways.

Abiotic stress↗

PubMed2026

Identification of aquaporin (AQP) genes in the noble scallop Chlamys nobilis and characterization of their expression under low-temperature stress.

Aquaporins (AQPs) are transmembrane channel proteins essential for water homeostasis and cellular stress responses. In marine bivalves, their roles in cold tolerance remain poorly understood despite frequent winter mortality events in aquaculture. Here, we identified nine AQP genes in the genome of the economically important noble scallop Chlamys nobilis. Phylogenetic analysis revealed strong conservation with other bivalve AQPs, and structural features, including conserved NPA motifs and ar/R selectivity filters, support their canonical water/glycerol transport functions. Tissue-specific expression profiling showed predominant enrichment in osmoregulatory tissues (gills, intestine) and gonads. Under both chronic and acute low-temperature stress from 23 °C to 9 °C, most CnAQP genes exhibited transient upregulation followed by suppression. Notably, CnAQP4 displayed sustained upregulation, implicating it as a key mediator of long-term cold adaptation. Promoter analysis further revealed abundant cis-elements linked to growth and development as well as immune regulation. Our findings provide the first comprehensive characterization of the AQP family in C. nobilis, highlighting its critical role in maintaining cellular integrity during cold stress and offering molecular targets for selective breeding of cold-tolerant scallop strains.

Animals↗

PubMed2025

The SlWRKY39-SlZF61 module synergistically regulates SlGSTU42 to enhance low-temperature tolerance in tomato.

Low-temperature stress affects plant growth, and WRKY transcription factors alleviate such damage by regulating downstream genes. This study found that tomato SlWRKY39 significantly responds to low temperatures: its overexpression enhances seedling low-temperature tolerance by promoting ROS scavenging, while knockout exacerbates ROS accumulation and increases sensitivity to low temperatures. Transcriptome analysis indicated induction of glutathione metabolic pathway genes in slwrky39 plants under low-temperature stress. Y1H, EMSA, and Dual-LUC experiments confirmed that SlWRKY39 specifically binds to and activates the SlGSTU42 promoter; silencing SlGSTU42 attenuated the low-temperature tolerance conferred by SlWRKY39 overexpression, verifying that SlWRKY39 improves low-temperature tolerance via direct regulation of SlGSTU42. Additionally, SlZF61 interacts with SlWRKY39, enhancing its regulatory effect on SlGSTU42. SlZF61 overexpression strengthens low-temperature tolerance, while knockout increases sensitivity to low temperatures. In summary, under low-temperature stress, SlWRKY39 and SlZF61 are upregulated expression in tomato; SlWRKY39 binds to the SlGSTU42 promoter, and SlZF61 interacts with SlWRKY39 to form a protein complex, enhancing this binding. They synergistically activate SlGSTU42 transcription, thereby improving seedling low-temperature tolerance by scavenging ROS. This coordinated regulatory mechanism provides a new theoretical basis and practical insights for enhancing tomato low-temperature tolerance and ensuring stable production under low-temperature stress conditions.

Solanum lycopersicum↗

PubMed2025

Construction of cDNA library of Dalbergia odorifera induced by low temperature stress and screening of low temperature tolerant genes.

To systematically analyze the gene function of Dalbergia odorifera, the seedlings of D. odorifera were treated with low-temperature stress for 6 h. Total RNA was extracted from a mixture of seedling roots, stems, and leaves, and a low-temperature-induced D. odorifera yeast cDNA expression library was constructed. The library volume was 1.032 × 108 CFU, and the PCR (Polymerase Chain Reaction) identification of the library bacterial fluid showed that the amplification was around 1000 bp, with a single randomly distributed band, indicating that the library had been recombinantly inserted into the pYES2 vector. The GO (Gene Ontology) analysis showed that the library genes were mainly involved in metabolic and stress signaling pathways. The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis showed that the genes were primarily related to energy and metabolic pathways. Twenty-one genes were screened or obtained at -20°C for low-temperature tolerance. In addition, the organ expression profiles of the candidate genes were analyzed based on RNA-seq data, and the expression profiles of the candidate genes under low-temperature stress were also examined. The construction of the yeast library provides genetic resources for the analysis of the mechanism of low-temperature tolerance of D. odorifera, which is important for comprehending and utilizing the genetic resources of D. odorifera.

Gene Library↗

PubMed2026

Integrative analysis of transcriptome and chromatin accessibility reveals promoter-proximal regulation and identifies candidate ABC transporters associated with cold stress responses in maize.

BACKGROUND: Low-temperature stress is a formidable environmental constraint that severely limits the growth and productivity of maize (Zea mays L.), particularly during the highly vulnerable early seedling stage. While cold tolerance is a critical agronomic objective, the integrated transcriptional and epigenetic regulatory mechanisms that govern this trait remain largely elusive. Characterizing these coordinated molecular networks is fundamental to the genetic enhancement of cold resilience in maize. METHODS: Using two maize inbred lines contrasting in chilling response (ZHB12 tolerant, B73 sensitive), we performed integrative time‑course RNA‑seq and ATAC‑seq to thoroughly and systematically characterize the precise dynamic interplay between gene expression and chromatin accessibility under cold stress conditions at the seedling stage. RESULTS: Physiological assessments confirmed that ZHB12 possesses superior cold tolerance, manifested by significantly attenuated electrolyte leakage and reduced foliar damage compared to B73. Transcriptomic profiling revealed a massive, time-dependent divergence in gene expression between the two genotypes, with a major regulatory transition identified at 24 h of cold exposure. Functional enrichment analysis demonstrated that ZHB12 preferentially activates a robust defense repertoire, including Photosystem II electron transport, diterpenoid biosynthesis, and ATP biosynthetic pathways. Notably, multiple ATP-binding cassette (ABC) transporter genes were coordinately upregulated under chilling, suggesting their potential involvement in cellular homeostasis. ATAC-seq analysis indicated that cold stress is associated with chromatin remodeling in ZHB12, with increased accessibility observed in proximal promoter regions. Integrative analysis identified a core set of dual-responsive genes, in which increased promoter accessibility coincided with transcriptional upregulation. These genes were predominantly enriched in transporter activity and transcriptional regulation, suggesting potential epigenetic link to the superior stress response of ZHB12. CONCLUSION: Our findings reveal extensive transcriptional and chromatin accessibility changes in ZHB12 under cold stress. The observed associations between promoter accessibility and gene activation, particularly in genes involved in transport processes, highlight candidate regulators potentially contributing to cold tolerance. This study provides a molecular framework and identifies high-value candidate genes that may inform future efforts in breeding cold-tolerant maize, pending functional validation.

Zea mays↗

PubMed2026

Identification of Freezing-Responsive microRNAs and Their Targets in Chinese Jujube by Small RNA and Degradome Sequencing.

The jujube tree fruit remains a primary fruit in northern China, yet its geographical distribution and yield are significantly constrained by freezing stress during winter. Numerous studies have highlighted the pivotal regulatory function of microRNAs (miRNAs) in plant responses to low-temperature stress. Nevertheless, the specific miRNAs involved in the response to low temperatures and their associated gene networks in Ziziphus jujuba Mill are not well understood. In this investigation, we utilized high-throughput sequencing to analyze small RNA libraries from branches subjected to temperatures of 4 °C and -30 °C. Our analysis identified a total of 342 miRNAs, comprising 123 known miRNAs and 219 novel miRNAs. The differential expression analysis revealed that under low-temperature conditions, 177 miRNAs underwent significant changes. Among them, specific upregulation of miR319 in the less cold-resistant variety and miR6483 in sensitive variety was observed. By employing degradome sequencing, we identified a total of 1551 target genes corresponding to 3059 unique miRNA target interaction pairs involving 299 miRNAs. Functional analysis using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways indicated that these target genes are primarily associated with transcriptional regulation, metabolic pathways, and genetic information processing. Through a comprehensive analysis, we pinpointed 11 genes corresponding to 9 miRNAs that are implicated in jujube tree cold stress, and 7 target genes of 7 miRNAs were confirmed by 5'-RACE analysis. These miRNAs are likely to exert crucial regulatory functions in the context of jujube tree cold stress. This study is the first to systematically identify miRNAs and their target genes in the response of Ziziphus jujuba Mill to low-temperature stress, which provides important resources for in-depth analysis of the molecular mechanism of jujube tree cold resistance and for cold-resistant breeding.

Ziziphus↗

PubMed2025

Genome-Wide Analysis of the AT-Hook Gene Family in Malus sieversii and Functional Characterization of MsAHL13.

AT-hook motif nuclear-localized (AHL) proteins are pivotal in plant growth, development, and stress responses. Nevertheless, there is limited research on AHL proteins in Malus sieversii. Our study identified 25 AHL genes from the M. sieversii genome, named MsAHL1-MsAHL25. The encoded protein sequences had lengths ranging from 195 to 554 amino acids, molecular weights from 19.17 to 58.53 kDa, and isoelectric points from 4.67 to 10.09. Chromosomal mapping revealed that these 25 genes were unevenly distributed across 10 chromosomes. Collinearity analysis of AHL genes in M. sieversii implied that gene loss might have occurred during its evolution. The phylogenetic tree classified the AHL proteins of M. sieversii into two subfamilies, showing a close relationship with multiple proteins of M. domestica. Promoter analysis indicated that the AHL genes in M. sieversii harbored numerous stress- and hormone-responsive elements, suggesting their potential role in various stress responses. qRT-PCR analysis of six representative MsAHLs under biotic and abiotic stresses demonstrated that the expression of MsAHL13, MsAHL15, and MsAHL17 was significantly upregulated under salt, drought, and cold stresses, while MsAHL01 expression was inhibited under low-temperature stress. All six MsAHLs were induced by the pathogen Valsa mali. Subcellular localization analysis of the specifically expressed protein MsAHL13 showed its nuclear location. Furthermore, luciferase and yeast two-hybrid assays confirmed the in vitro physical interaction between the MsAHL13 and MsMYB1 proteins. This research offers an important theoretical basis for further exploration of the functional mechanisms of this gene family in responding to environmental stresses.

Malus sieversii↗

PubMed2026

Genome-wide identification of WOX transcription factors and functional characterization of WOX4 and WOX13 involved in cold stress response in Malus baccata.

INTRODUCTION: Cold stress is a major abiotic threat to apple production. Malus baccata has exceptional cold hardiness and is widely used as a superior cold-resistant rootstock. The WUSCHEL-related homeobox (WOX) transcription factor family regulates plant growth, development and stress adaptation, whereas the functions of WOX genes in cold tolerance of M. baccata remain elusive. METHODS: In the present work, 19 MbWOX family members were identified and characterized at the genome-wide level. Evolutionary analysis, cis-element prediction, transcriptome profiling and real-time quantitative PCR (RT-qPCR) were performed to screen core cold-responsive genes. Overexpression vectors were constructed and transformed into Arabidopsis seedlings for functional verification. RESULTS: Evolutionary analysis revealed that segmental duplication drove the expansion of the MbWOX family, and these genes contained a variety of stress-responsive cis-elements. Combined transcriptome and RT-qPCR analyses confirmed that MbWOX4 and MbWOX13 were core cold-responsive genes with distinct expression patterns. The two genes participated in cold signal transduction by interacting with different transcription factor networks. Functional tests revealed that MbWOX4 and MbWOX13 isoforms differentially modulated seedling cold tolerance under low-temperature stress.

Malus baccata↗

PubMed2026

Genome-wide identification and evolutionary analysis of the ERF-VII gene family in the tea plant (Camellia sinensis) and functional characterization of CsRAP2.2 in response to cold stress.

The ERF-VII gene family, a critical branch of the AP2/ERF superfamily, is central to plant stress adaptation. However, its evolutionary history and function in tea plant (Camellia sinensis) remain unclear. Here, we performed integrated evolutionary, genomic, and functional analyses of ERF-VII genes across 14 plant lineages and 20 tea plant cultivars. The phylogenetic analysis revealed that ERF-VII proteins originated after vascular plant divergence, coinciding with the emergence of the N-terminal MCGGA/I motif linked to the oxygen-dependent N-degron pathway. Gymnosperms retained few conserved members, whereas angiosperms exhibited lineage-specific expansion-extensive in monocots via whole-genome duplication, moderate in eudicots with functional diversification. Pan-genome analysis across 20 tea plant cultivars further revealed varietal differences in ERF-VII gene distribution. Transcriptome profiling via the Tea Plant Information Archive identified CsRAP2.2 as a cold-inducible ERF-VII member with sustained expression under low-temperature stress. Functional assays demonstrated that silencing CsRAP2.2 reduced cold tolerance, while overexpression in tea leaves and heterologous expression in Arabidopsis thaliana enhanced cold tolerance by maintaining photosystem II efficiency, reducing membrane lipid peroxidation, and improving antioxidant capacity. Weighted gene co-expression network analysis positioned CsRAP2.2 as a regulatory hub integrating cold, hormone, and oxygen-sensing pathways. These results clarify the evolutionary trajectory of ERF-VII genes and establish CsRAP2.2 as a core cold-tolerance regulator in tea plant. These findings may inform future breeding of cold-resilient tea cultivars.

Camellia sinensis↗

PubMed2026

Genome-wide identification and cold-stress-responsive expression analysis of the NOX gene family in Cucumis melo.

NADPH oxidases (NOXs) are crucial enzymes for reactive oxygen species (ROS) generation in plants and play vital roles in growth, development, and stress responses. To elucidate the sequence characteristics of the NOX gene family and its low-temperature response patterns in melon (Cucumis melo L.), this study conducted genome-wide identification and expression profiling of NOX family members using bioinformatics analysis, RNA-seq transcriptome sequencing, and real-time quantitative PCR (RT-qPCR). The results revealed that eight NOX members were identified in the melon genome, distributed across six chromosomes. All members harbored conserved domains including Ferric_reductase, FAD_binding_8, NAD_binding_6, and NADPH_Ox, and the encoded proteins were generally basic and hydrophilic. Phylogenetic analysis classified the NOX proteins into five subgroups. Synteny analysis indicated the presence of only one pair of intraspecific duplicated genes in melon, which was under purifying selection. The promoter regions contained multiple hormone- and stress-responsive cis-acting elements, with CmNOX2 and CmNOX4 harboring low-temperature responsive elements. Following treatment at 4℃ for 24 h and 48 h, leaf relative electrolyte leakage (REL) increased from 28.33% to 42.67% and 52.67%, respectively; transcriptome analysis identified 5,633 and 6,882 differentially expressed genes (DEGs), respectively. Cold-responsive genes exhibited significant differential expression, with SLAC1 and CPK19 showing sustained upregulation. RT-qPCR results demonstrated that the expression of CmNOX2, CmNOX5, CmNOX6, and CmNOX7 was significantly downregulated after low-temperature treatment, whereas CmNOX4 expression was significantly upregulated at 48 h. Integrating promoter elements and expression characteristics, CmNOX4 may represent an important candidate gene involved in melon low-temperature response. This study systematically characterized the structure, evolution, and expression patterns of the melon NOX gene family, identified candidate genes responsive to low temperature, and provides a reference for further investigation into the mechanisms underlying melon cold adaptation.

Cucumis melo↗

PubMed2025

Integrated agronomy of pea (Pisum sativum L.): a review on cultivation, harvesting, and storage for sustainable agriculture.

Peas (Pisum sativum L.) are a cornerstone of sustainable agriculture, yet their potential is limited by fragmented agronomic practices. This review provides an integrated synthesis of advancements across cultivation, mechanized harvesting, and post-harvest storage. Key findings reveal that optimal growth conditions and nanotechnology interventions can significantly enhance abiotic stress tolerance. Mechanized harvesting innovations reduce yield losses by up to 40%, but smallholder adoption and terrain compatibility remain critical challenges. Effective post-harvest strategies, including low-temperature storage and hermetic bags, are crucial for preserving quality. Despite progress, systemic barriers persist. Future research must prioritize interdisciplinary solutions-combining genomics, precision engineering, and farmer training-to unlock the full potential of peas as a keystone crop for sustainable food systems.

climate resilience↗

PubMed2025

Cross-species phenotypic profiling uncovers functional determinants of bacterial cold shock adaptation.

Temperature shifts impose broad physiological stress, requiring precise and dynamic regulatory programs to restore cellular homeostasis. While the heat shock response is well characterized, the mechanisms underlying cold shock response (CSR) remain less understood. To identify genes critical for cold adaptation, we applied transposon sequencing (Tn-seq) to monitor mutant fitness across the full course of CSR and sustained low-temperature growth in two mesophilic bacteria, Escherichia coli and Bacillus subtilis. In B. subtilis, phenotypic profiling revealed a temporally structured program: membrane fluidity and cell wall remodeling were most critical in the early stage of CSR, whereas post-transcriptional regulation became essential during late-stage recovery to reprogram gene expression and restore growth. Cross-species comparison uncovered both conserved and species-specific mechanisms, with RNA metabolism and ribosome/translation regulators playing broad roles. Specifically, we identified a conserved synergy between two ribosomal RNA methyltransferases, RsmA and RsmH, in promoting cold adaptation. In B. subtilis, mutants lacking these enzymes exhibited significant delay in translation recovery following cold-induced global inhibition. Together, these findings provide a comparative, systems-level view of bacterial cold adaptation and establish a framework for exploring stress responses in pathogens and extremophiles.

Cell envelope↗

PubMed2026

Mining the sHSP20 (small heat-shock protein) gene family in finger millet (Eleusine coracana (L.) Gaertn.): structural, evolutionary and predicted abiotic-stress-responsive insights.

Small heat-shock proteins (sHSPs, the HSP20 family) are ATP-independent molecular chaperones that hold partially unfolded substrates and protect the proteome during heat and other abiotic stresses; every member is defined by a conserved α-crystallin domain (ACD). Finger millet (Eleusine coracana) is a climate-resilient, calcium-rich allotetraploid cereal of the semi-arid tropics whose HSP20 repertoire had not been catalogued. The present study is an entirely computational (in silico) analysis of the chromosome-scale reference genome of finger millet (NCBI GenBank assembly GCA_032690845.1, cultivar KNE 796-S). Mining the predicted proteome with the ACD profile (Pfam PF00011) and confirming every candidate by NCBI CD-search recovered 76 non-redundant ACD-bearing HSP20 genes (EcHSP20-1-EcHSP20-76). Based on phylogeny and TargetP-predicted localization, the members were classified into ten subfamilies: seven cytosolic/nuclear classes (C-I to C-VII, 60 members) together with chloroplastic (11), mitochondrial (3) and endoplasmic-reticulum (2) groups. The proteins ranged from 110 to 355 amino acids (12.1-39.2 kDa) with theoretical pI of 4.85-9.69. The 76 loci were distributed over 14 of the 18 chromosomes and were conspicuously absent from chromosomes 8 A, 8B, 9 A and 9B, with pronounced clustering on chromosomes 1, 2, 3 and 6. Duplication analysis detected 149 paralogous pairs (49 homoeologous, 80 segmental/dispersed and 18 tandem); 147 of 148 pairs for which substitution rates could be calculated returned Ka/Ks < 1 (mean 0.20), indicating strong purifying selection consistent with retention after whole-genome/allopolyploid duplication. Promoter analysis (PlantCARE) revealed enrichment of abscisic-acid-responsive (ABRE), MYB/MYC drought-related, STRE, DRE, low-temperature (LTR) and methyl-jasmonate/salicylic-acid elements, whereas canonical heat-shock elements (HSE) were not recovered. Expression profiling against a public drought transcriptome (SRP081350) showed that about half of the genes (39 of 76) are transcribed in leaf tissue, the expressed fraction being dominated by the cytosolic class C-I. This first finger-millet HSP20 catalogue provides a verified, reproducible framework and nominates computationally predicted candidate genes for future functional work on thermotolerance in cereals.

Allotetraploid↗

PubMed1978

Microporous glassy fillers for dental composites.

A microporous filler giving greatly improved finish ability, systemic nontoxic X-ray opacification, low thermal expansion (27.2 x 10(-6)/degrees C), and satisfactory translucencies has been developed for dental composite resin restorations. These fillers are prepared from frits obtained by the low-temperature calcination of gelled inorganic sols followed by a pulsed high-temperature treatment. Composites prepared from these fillers are within the range of commercial products with regard to strength and setting contraction.

Chemical Phenomena↗

PubMed2025

The chloroplast 16S rRNA dimethyltransferase BrPFC1 is required for Brassica rapa development under chilling stress.

Chloroplast ribosomal RNA (Ch-rRNA) methylation is critical for plant development and response to low temperatures. Several Ch-rRNA methyltransferases and their catalytic modes, as well as biological relevance, have been reported in model plant species. However, Ch-rRNA methyltransferases and their functional significance remain poorly characterized in crops, including leafy vegetables such as Chinese cabbage. In this study, we screened an EMS-mutagenized Chinese cabbage population and identified a yellow inner leaf (yif) mutant. This mutant develops yellowing inner leaves with reduced chlorophyll accumulation and ultrastructure-impaired chloroplasts under low-temperature conditions. Genetic analysis revealed a premature termination mutation in BrPFC1, encoding the chloroplast-localized 16S rRNA dimethyltransferase. The BrPFC1 mutation (yif) disrupts the dimethylation of 16S rRNA. The cold-sensitive phenotype of the yif mutant can be explained by temperature-dependent defects in the maturation and assembly of chloroplast ribosomes at 4°C. Through integrated analysis of chloroplast and nuclear transcriptomes coupled with translational profiling at 25°C and 4°C, we established that low temperature preferentially upregulates transcripts encoding nuclear-derived ribosomal proteins, while defective 16S rRNA specifically compromises the translational efficiency of chloroplast-encoded photosynthetic complex and ribosomal protein at 4°C. These findings establish rRNA modification by BrPFC1 as a critical regulatory layer for optimizing chloroplast translational efficiency at 4°C, providing mechanistic insights into post-translational adaptation strategies in Chinese cabbage.

Chloroplasts↗

PubMed2026

Physiological sub-typing of cold and freezing injury in Triticum turgidum subspecies with bioinformatic and expression characterization of glutathione reductase.

BACKGROUND: This study examined how different subspecies of Triticum turgidum (T. durum, T. polonicum, T. turanicum) respond to cold and freezing, assessing their water status, stress responses, and antioxidant system, with particular focus on the structure and function of glutathione reductase (TtGR). METHODS: TtGR genes were first identified from the T. turgidum genome using publicly available genomic resources such as Ensembl Plants. Promoter regions (~2 kb upstream) were analyzed to identify cis-regulatory elements using PlantCARE. Gene classification was performed based on predicted subcellular localization and conserved domain features. Plants were subjected to cold acclimation and freezing treatments, and physiological, biochemical, and enzymatic parameters were measured. RESULTS: Bioinformatics analyses identified four TtGR genes in the T. turgidum genome. The genes in two groups: cytosolic (Class I) and chloroplastic (Class II). Gene structure analysis showed a conserved exon-intron organization, while motif analysis confirmed the presence of Nicotinamide Adenine Dinucleotide Phosphate (NADPH)-binding and redox-active domains across all TtGR proteins. Several regulatory sequences in the promoters are involved in cold (DRE), abscisic acid (ABRE), and stress (STRE) responses, indicating that TtGR genes are dynamically regulated in response to environmental changes. Physiological analyses showed that freezing treatment reduces leaf water content in all genotypes, leading to turgor loss, hydrogen peroxide (H2O2) accumulation, and increased malondealdehyte (MDA) levels. However, tolerance mechanisms addressing water stress and membrane damage differ among genotypes. At the biochemical level, activation of the antioxidant defense system occurs in all genotypes. T. turanicum displays strong defense by significantly increasing enzyme activities, ensuring that the ascorbate-glutathione cycle continues under stress. By contrast, T. polonicum, although showing increased overall enzyme activities, experiences a dramatic drop in glutathione reductase (GR) activity at freezing temperatures, which restricts reduced glutathione (GSH) regeneration and creates a functional bottleneck in the antioxidant cycle. T. durum fails to sustain enzyme activities over the stress period, leading to an intermediate-sensitive response. Thus, whereas T. turanicum effectively maintains antioxidant function during freezing, T. polonicum and T. durum exhibit less efficient stress responses, either through enzymatic bottlenecks or a lack of sustained defense. CONCLUSIONS: One of the most striking findings of this study is the observed dissociation between TtGR gene expression levels and enzyme activities. Low temperature limits the link between transcription and enzyme function. The primary determinant of low-temperature tolerance in T. turgidum subspecies is the sustainability of GR enzyme activity and GSH regeneration under freezing conditions.

Triticum↗