Search Results (92)

Strigolactones (SLs), as a class of novel plant hormones, play important roles in the regulation of plant branching. However, their function in branch development of wintersweet remains unclear. In this study, a gene involved in SLs biosynthesis, CpD27, was identified and isolated from wintersweet. The sequence characteristics, expression patterns, subcellular localization, and functional analysis through heterologous expression in Arabidopsis thaliana were investigated. Multiple sequence alignment showed that CpD27 contains the conserved D27 protein domain DUF4033. Quantitative real-time PCR analysis revealed that CpD27 is expressed in various vegetative organs of wintersweet, with the highest expression in leaves, followed by axillary buds. It is also expressed in all floral organs, with the highest expression level in the outer petals. CpD27 expression is induced by hormones (ABA and ACC) and low temperature (4 °C). Subcellular localization analysis indicated that CpD27 is localized in the chloroplasts of Arabidopsis. Heterologous expression of CpD27 in Arabidopsis delayed bolting. The number of both rosette branches and cauline branches in transgenic plants was reduced compared with wild-type plants. In addition, the expression of AtBRC1 was significantly upregulated in transgenic lines, suggesting that CpD27 has a function similar to that of its homolog in Arabidopsis. Overall, these results indicate that CpD27 plays a conserved role in the SLs-mediated branching pathway, which regulates branch development in wintersweet. This study provides a molecular and theoretical basis for further understanding branch development in wintersweet. Full article

Domain of unknown function (DUF) proteins play important roles in plant responses to biotic and abiotic stresses. DUF4228 proteins, as members of the DUF superfamily, are widely present in plants and exert significant functions under various stress conditions. Sugarcane is an important economic and energy crop in China. However, the role of DUF4228 family members in sugarcane has not been reported. In this study, 126 ScDUF4228 genes were identified for the first time in the genome of the modern cultivar XTT22 and systematically named based on their chromosomal locations (ScDUF4228-1 to ScDUF4228-126). These genes are located on 7 chromosomes of the XTT22 genome, exhibiting an overall uneven distribution. Phylogenetic analysis revealed that the 126 ScDUF4228 proteins can be divided into 9 groups (I–IX). Gene structure analysis indicated that most ScDUF4228 family members lack introns or contain only 1–2 introns, and all members possess a complete DUF4228 domain. Ka/Ks analysis demonstrated that the family as a whole has undergone purifying selection (Ka/Ks < 1), indicating high functional conservation during evolution. Cross-species collinearity analysis showed significant species-specific expansion of the DUF4228 gene family in the Poaceae (particularly in sugarcane and its close relatives), a phenomenon not prominently observed in dicotyledons. Analysis of tissue expression patterns, developmental stages, and diurnal rhythms revealed that the spatiotemporal expression profiles of the 126 ScDUF4228 family members vary, suggesting they may function individually or synergistically during different developmental periods in sugarcane. Yeast medium assay depicted that three members of the ScDUF4228 (ScDUF4228-7, ScDUF4228-18, ScDUF4228-23) family had significant resistance potential under drought stresses. Furthermore, transcriptome analysis after drought treatment showed that ScDUF4228-23 exhibited the most significant upregulation, suggesting it may be a key gene in sugarcane’s response to drought. These results suggest that the DUF4228 gene family has undergone dramatic expansion in sugarcane and may play a crucial regulatory role in drought stress responses. This study provides the necessary molecular foundation for further exploring the functions of ScDUF4228 family members. Full article

We investigate the nonlinear dynamics of a linearly coupled van der Pol–Duffing system using numerical continuation, time-domain simulations, stochastic analysis, and analog circuit experiments. The model exhibits a rich variety of dynamical regimes, including periodic oscillations, period-doubling cascades, and chaotic attractors arising from the interplay between self-excitation and nonlinear stiffness. Numerical continuation is employed to reconstruct the bifurcation structure, enabling the identification of equilibrium branches, periodic solutions, and their stability in parameter space. The time-domain numerical results reveal the mechanisms governing transitions between regular and chaotic dynamics. To assess robustness under realistic conditions, intrinsic stochastic perturbations are introduced, showing that increasing noise intensity progressively erodes fine periodic structures, while larger dynamical domains remain comparatively robust. Experimental results obtained from an analog circuit implementation confirm the main dynamical regimes predicted numerically. Overall, the combined computational and experimental approach provides a systematic characterization of the system’s bifurcation structure and its robustness to noise. The results support the concept of chaos-based sensing and are consistent with previous findings in chaotic bioimpedance detection, indicating that maximum sensitivity occurs near regions of high bifurcation complexity, where small parameter variations induce significant qualitative changes in the system dynamics. Full article

Low temperature critically influences cellular metabolism by impairing processes such as membrane fluidity, enzyme activity, and protein folding. However, the comprehensive genetic landscape and regulatory mechanisms governing cold acclimation remain poorly understood. Here, we performed high-throughput, pooled genetic screening in the model alga Chlamydomonas reinhardtii (C. reinhardtii) to identify genes essential for cold acclimation. Our screening revealed numerous candidate genes implicated not only in early cold response pathways but also in core cellular processes, including DNA dynamics, protein homeostasis, metabolic regulation, and substrate transport. Notably, we identified a member of the RUS (ROOT UVB SENSITIVE) family, encoding a conserved DUF647 domain protein, designated CrRUS1. CRISPR-generated rus1 mutant alleles in C. reinhardtii display a phenotype consistent with our screening: the mutants did not exhibit any visible growth defects, but show severe growth defects at low temperature. Interestingly, the cold-induced phenotypic changes in rus1 can be reversed by dark conditions, suggesting that CrRUS1 likely promotes cold acclimation in C. reinhardtii through a light-dependent pathway. Our work provides novel genetic resources and mechanistic insights into cold acclimation in C. reinhardtii, with potential translational relevance for enhancing cold tolerance in crop species. Full article

A nonlinear ultrasonic time-domain identification method based on chaos sensitivity was proposed in this study. The Duffing chaotic system was introduced into the weak second harmonic identification to realize early detection and quantitative evaluation of fatigue damage in U71Mn steel. First, to ensure the reliability of nonlinear ultrasonic testing, a probe-pressure monitoring device was designed. Through pressure-stability experiments, 16 N was determined as the optimal pressure, which effectively suppresses contact nonlinearity interference and ensures coupling stability. Subsequently, the Duffing chaos detection system was established. The signal-system frequency-matching problem was resolved through time-scale transformation. Simultaneously, the issue of unknown initial phases was resolved using phase traversal compensation. Based on the chaotic system’s sensitivity to specific frequency signals and immunity to noise, the amplitudes of the fundamental wave and second harmonics in the target signals were quantified to calculate the nonlinear coefficient. Experimental results demonstrate that the proposed method can extract these amplitudes directly in the time domain, thereby effectively overcoming the spectral leakage inherent in traditional frequency-domain methods. The nonlinear coefficient of U71Mn steel exhibits a “double-peak” characteristic as fatigue damage increases. Specifically, the first peak appears at approximately 50% of fatigue life, while the second occurs at approximately 80%. This phenomenon is closely correlated with the distinct stages of internal fatigue crack propagation, reflecting a complex damage-evolution mechanism. This study not only provides a novel method for the precise extraction of weak nonlinear signals but also establishes a critical theoretical and experimental foundation for accurate fatigue life prediction for U71Mn rail steel. Full article

The Domains of Unknown Functions 1664 (DUF1664) genes are a class of genes with unknown functions, and their roles in abiotic stresses responses have not yet been reported. Using the hidden Markov model (HMM) profile of DUF1664 (PF07889) obtained from the Pfam database, along with Arabidopsis thaliana DUF1664 family protein sequences as reference, and verifying complete DUF1664 domains with the NCBI CD-Search online tool, seven DUF1664 family members were identified in the peanut (Arachis hypogaea) genome, designated as AhDUF1664-1A through AhDUF1664-4. Promoter analysis revealed that cis-acting elements in AhDUF1664 genes are associated with growth and development, stress responses, and plant hormone signaling, and these genes exhibit relatively conserved motifs. Functional validation showed that ectopic expression of AhDUF1664-1A enhanced tolerance to salt and drought stresses in Arabidopsis thaliana by modulating the expression of ABA signaling-related genes. Our findings identify the AhDUF1664 gene family in peanut and provide a basis for further investigation into the biological functions of these genes. Full article

Goji, a plant unique to China, is recognized for its dual use as both a food and a medicine and is rich in various nutrients. However, long-term asexual propagation often leads to cultivar degeneration and viral accumulation, which severely impact its yield, quality, and disease resistance. Homozygous seeds can stably produce offspring with uniform traits. Haploid breeding technology, which involves doubling the chromosomes of haploid plants to obtain homozygous diploids, can significantly accelerate the breeding process. The DMP (Domain of Unknown Function 679 Membrane Protein) family is a plant-specific family of membrane proteins involved in various biological functions, including physiological processes, reproductive development, and senescence. Concurrently, loss-of-function of the DMP gene impedes the proper integration of the paternal genome following fertilization. Consequently, the embryo develops with exclusively maternal chromosomes, a mechanism that underlies the induction of haploids. In this study, we conducted a genome-wide identification of the DMP gene family in goji, analyzing the physicochemical properties, chromosomal locations, cis-acting elements, phylogenetic relationships, sequence characteristics, expression patterns, and subcellular localization of its members. The objective was to identify DMP genes capable of inducing haploid production in goji berry for future breeding applications. The results revealed a total of 11 DMP family members in the goji berry genome, distributed across seven chromosomes. The proteins encoded by these members contain 136 to 237 amino acids, with molecular weights ranging from 15,267.96 to 26,141.01 Da and isoelectric points (pI) ranging from 5.14 to 9.32. The LbDMPs were found to contain numerous cis-acting elements that play roles in plant responses to abiotic stresses and various phytohormones. Notably, LbDMP1 and LbDMP11, which contain the typical DUF679 domain, are predominantly expressed in pollen, suggesting their involvement in the reproductive process of goji berry. They were therefore identified as candidate genes for haploid induction. Subcellular localization analysis demonstrated that LbDMP1 is localized to the plasma membrane, while LbDMP11 is localized to membrane systems such as the endoplasmic reticulum. This research provides a fundamental basis for further exploration of the functional roles of the DMP gene family in goji berry and offers valuable genetic resources for haploid induction in its breeding programs. Full article

Maize (Zea mays L.) originated in tropical and subtropical regions. During its growth and development, cold stress severely threatens seedling survival rates and final yield by inducing oxidative stress, compromising cell membrane integrity, and causing “physiological drought.” The Domain of Unknown Function 966 (DUF966) gene family comprises a class of regulatory factors containing conserved domains of undetermined function. Although they are considered to be extensively involved in plant growth, development, and stress response, their specific roles within the maize cold-tolerance regulatory network remain to be explored. In this study, 10 ZmDUF966 family members were identified via genome-wide analysis, and their phylogenetic relationships, gene structures, conserved motifs, chromosomal localizations, and cis-acting elements were systematically analyzed. The results indicate that the ZmDUF966 family is highly conserved among Poaceae species, and its promoters are enriched with stress-responsive elements such as LTR and ABRE. The core gene, ZmDUF966-10, was significantly up-regulated (approximately 35-fold at 48 h, p < 0.05) as validated by RT-qPCR under cold stress and is post-transcriptionally regulated by conserved miRNAs such as zma-miR159. Further yeast two-hybrid experiments revealed a preliminary physical interaction between the ZmDUF966-10 protein and an ABA/WDS-induced protein, suggesting its potential involvement in ABA-mediated stress signaling, though functional validation remains to be conducted. In conclusion, this study identifies ZmDUF966-10 as a promising candidate gene that responds to cold signals through multi-level regulatory networks, providing a valuable gene resource for further functional characterization and potential application in cold-tolerant maize improvement. Full article

Cuticular proteins (CPs)—key components of the insect exoskeleton—not only regulate development but also serve as structural barriers that enhance resistance against environmental stressors. This study identified CP gene families in Apis mellifera and analyzed their expression patterns during the worker capped brood development stages from mature larva to pre-eclosion. Using a comprehensive genome-wide bioinformatic approach, we identified 85 CP genes in A. mellifera which comprise six families: CPR (n = 43), CPAPs (n = 27), CPF (n = 2), Tweedle (n = 2), CPLCP (n = 8) and Apidermin (n = 3). Analysis of CP gene evolutionary relationship revealed that each CP family forms a distinct, relatively independent clade. Domain and motif analyses confirmed that all CPR members harbor a conserved Chitin_Bind_4 domain, consistent with CPR family structures in other taxa. Additionally, CPAP members possess one or three Chitin-binding Peritrophin-A domain (CBM_14), CPF members possess a conserved Pupal cuticle protein C1 domain (Cuticle_3), and Tweedle members contain a conserved domain of unknown function (DUF243). In addition, the analysis found no conserved domain within the CPLCP and Apidermin families. RNA-seq data revealed dynamic expression patterns of AmCPs during pupal development, with each gene family displaying a relatively characteristic temporal profile. Quantitative PCR validation of eight highly expressed CPR genes at 9 days post-capping confirmed the RNA-seq results. This work provides a comprehensive bioinformatic characterization and transcriptional analysis of CP genes in A. mellifera, offering a foundation for future functional studies on cuticle formation and identifying candidate genes potentially involved in cuticle development in honeybees. This work relies on transcriptomic data and in silico analyses. All proposed biological roles are hypothetical and require experimental validation. Full article

Membrane lipid remodeling plays a pivotal role in regulating plant growth, reproductive development, and adaptive responses to environmental stress. However, several lipid-modifying enzymes remain uncharacterized in Arabidopsis thaliana. Here, we provide the first comprehensive in silico functional characterization of the unannotated gene AT5G35460, integrating domain architecture, AlphaFold-supported structural validation, and phylogenetic, expression, and regulatory analyses. Domain architecture and conserved DUF2838 signatures, together with transmembrane topology and validation using AlphaFold-predicted structural data, support its identity as a glycerophosphocholine acyltransferase (GPCAT1). Phylogenetic reconstruction showed that GPCAT1 clustered closely with its orthologs of major angiosperms, suggesting deep evolutionary preservation. Expression profiling revealed over a tenfold higher transcript abundance in mature pollen, detected 6–8 times more than during leaf senescence, indicating strong developmental control. Co-expression network analysis revealed links to the lipid metabolism genes (CDS2, LACS8, and SBH1) as well as factors involved in response to stress, indicating that AT5G35460 may act at the level of phosphatidylcholine remodeling, membrane resistance and stress response. Analysis of the promoter sequences showed AACTAAA, ABRE and G-box elements (pollen-specific, ABA-responsive and stress-inducible motif respectively), suggesting appropriate transcriptional regulation consistent with its expression profile. As a whole, the findings revealed that AT5G35460 is an unexplored membrane-localized acyltransferase involved in lipid maintenance during reproductive development and environmental responses. This study serves as a basis for subsequent functional characterization and identifies AT5G35460 as a potential target for modifying pollen viability, senescence kinetics and stress tolerance in plants. Full article

The Neuroblastoma Breakpoint Family (NBPF) consists of 23 genes, 9 of which are pseudogenes, and is characterized by extensive duplication events and species-specific diversification in Homo sapiens, as well as by the presence of a unique protein domain known as Olduvai (also referred to as DUF1220 or the NBPF domain). Previous studies have attempted to define subfamilies based on the presence of HLS triplet domains; however, this classification has become increasingly unclear with the identification of additional NBPF members. The family remains poorly understood, and the functions of many genes are still unknown, although several have been hypothesized to play key roles in cell proliferation and developmental processes, particularly in neural and skeletal tissues. In this study, we systematically analyzed all available data on the NBPF gene family using the PRISMA-S methodology to infer the biological functions in which these genes may be involved. We also generated multiple phylogenetic trees to support the creation of coherent subfamilies and to correlate the origin of each subfamily with homologous genes in our last common ancestor with the Pan genus, providing what we believe to be one of the most comprehensive phylogenetic reconstructions including all currently annotated NBPF members. Through comparative genomic and phylogenetic analyses, we propose that the NBPF may have originated from a duplication of the PDE4DIP gene, with NBPF26 representing the ancestral member from which the remaining NBPF genes diverged via lineage-specific segmental duplications. In this systematic review and comparative genomic study, we present the first integrative synthesis of our knowledge of the NBPF, encompassing its evolutionary origins, structural dynamics, expression across tissues, and clinical associations. Full article

The Domain of Unknown Function 506 (DUF506) family, part of the PD-(D/E)XK nuclease superfamily, has been shown to play a vital role in plant development and responses to abiotic stresses. However, the function of the DUF506 family in cultivated peanuts remains unknown. This study identified 23 AhDUF506 genes using bioinformatics approaches; these genes are spread across 15 chromosomes and grouped into 4 subfamilies. Additionally, by analyzing gene structure, upstream cis-acting elements, and transcriptional expression changes of AhDUF506 genes in different tissues and under various stress conditions, their expression levels and response mechanisms to abiotic stresses were examined. In mature tissues, the expression levels of seven AhDUF506 genes in flowers were significantly higher than those in other tissues. Under abiotic stress, their expression levels were all up-regulated in the roots of peanut plant seedlings. These findings provide an important foundation for a deeper understanding of the molecular characteristics of the DUF506 family in Arachis hypogaea (peanut), supporting future research on the functional characterization of its genes. Full article

DNA-protecting proteins (Dps) are crucial for safeguarding chromosomal DNA in starved cells during the stationary phase under stressful conditions. In previous research, the two Dps proteins in Deinococcus geothermalis, Dgeo_0257 (Dps3) and Dgeo_0281 (Dps1), were found to complement each other in protecting DNA from oxidative damage. This study investigates the physiological changes and transposition of insertion sequences (ISs) in a double-knockout (DK) mutant lacking both dps genes. Comparisons between the wild-type and mutant strains revealed significant phenotypic differences in viability under oxidative stress conditions induced by hydrogen peroxide and ferrous ions, particularly during the stationary phase. Notably, oxidative stress triggered the transposition of the IS families IS701 and IS5, with IS66 being transposed exclusively in the DK mutant into a gene encoding phytoene desaturase. Transcriptomic analysis using RNA-seq revealed substantial fold changes in gene expression across the genome. For example, the dgeo_1459–1460 gene cluster, which encodes a DUF421 domain-containing protein and a hypothetical protein, was highly upregulated under both oxidative and non-oxidative conditions. Interestingly, catalase, encoded by a single gene in D. geothermalis, was upregulated in the DK mutant during the stationary phase, with expression levels exceeding those observed in the single dps gene-deficient mutants. Conversely, a prominent downregulation of the Fur family regulator was detected. These findings highlight the growth phase-dependent physiological adaptation of the dps-DK mutant and reveal a novel IS transposition event of the ISBst12 group involving the IS66 family. Therefore, this study provides new observations into the influence of DNA-protective protein deficiency on oxidative stress responses and IS transposition in D. geothermalis, as well as the regulatory mechanisms of the catalase induction pathway, raising the need for further investigation into the role of OxyR. Full article

Nucleotide-binding site-leucine-rich repeat (NLR) proteins are key intracellular immune receptors in plants. Integrated domains (IDs) can occasionally be fused with NLRs, contributing to their functional diversity. However, the diversity and evolutionary patterns of NLR-IDs across angiosperms remain poorly understood. In this study, we analyzed 305 angiosperm genomes and found that the proportion of NLR genes containing IDs (NLR-ID genes) ranges from 0% to 38.3%, with an average of 10.6%. A total of 1226 unique IDs were identified, some of which are widely distributed, while others are specific to particular taxa. Notably, 415 of these IDs are homologous to plant proteins targeted by pathogen effectors, suggesting their role as candidate decoys. Comparative analysis of NLR-IDs in two subfamilies—TIR-NLR (TNL) and CC-NLR (CNL)—revealed that TNL genes have a significantly higher frequency of IDs, with the C-JID and DUF3542 domains being most prevalent. N-terminal fusion of the DUF3542 domain in CNL genes correlates with the loss of the MADA motif. Our findings expand the understanding of NLR-ID diversity and provide insights into the dynamic evolution of NLR protein architecture in angiosperms. Full article

The spotted-leaf mutant, characterized by spontaneous lesion formation resembling pathogen-induced hypersensitive cell death, serves as an ideal model for studying the molecular mechanisms behind rice (Oryza sativa) disease resistance and programmed cell death, as these plants display hypersensitive responses that mimic those triggered by pathogen infection. In this study, we generated a knockout line using CRISPR/Cas9 technology in homologous mutant HM113-induced calli. LOC_Os07g30510 encodes a cysteine-rich receptor kinase with a DUF26 domain, consisting of 688 amino acids. HM113 was localized to the cytosol and expressed in most rice tissues at various growth stages. A single nucleotide substitution from A to T was observed at the 847th base of LOC_Os07g30510, causing an amino acid change from serine to cysteine. Our results demonstrated that the A847T mutation was responsible for the spotted-leaf phenotype in the HM113 mutant through gene editing technology, as new frameshift mutations were introduced upstream of the A847T site in the HM113 gene. The mutation phenotype of HM113 was eliminated and resistance to bacterial blight was also lost, indicating that it is a gain-of-function gene. Full article