The Pfam protein families database

GEDG: gene expression database of grape

BACKGROUND

Grapes are one of the oldest cultivated fruit species in the world, known for their high nutritional value. Grapes and grape products, including wine, are significant to many economies worldwide. Both abiotic and biotic stresses significantly impact the growth and reproduction of grapevines. RNA-Seq is a key tool for studying gene expression patterns under various conditions, such as stress responses, growth and developmental stages. In order to optimise the utilisation of these data for comprehensive research and analysis, and to enhance accessibility for users, we have developed a comprehensive database that provides gene expression profiles and traits in grapes.

DESCRIPTION

We have developed the gene expression database for grapes (GEDG), an online resource that encompasses data on 9 types of abiotic (including heat, cold, hormones, light, climate, nitrogen, frozen) and biotic (disease and pests) stresses and different developmental stages. A total of 32 datasets were related to stress, 20 to growth and development, and one to chromosomal ploidy. The primary objective of GEDG is to expand and utilize transcriptome data to better understand stress responses in grapes. GEDG is the comprehensive database to integrate transcriptome and traits on grape.

CONCLUSION

The Gene Expression Database of Grape (GEDG) was created to serve as a free resource platform for researchers, offering a comprehensive collection of genetic expression profiles for grape varieties based on RNA-seq data. The database is available at https://www.gedg-vitis.cn/index.html .

Diet outperforms microbial transplant to drive microbiome recovery in mice

A high-fat, low-fibre Western-style diet (WD) induces microbiome dysbiosis characterized by reduced taxonomic diversity and metabolic breadth1,2, which in turn increases risk for a wide array of metabolic3-5, immune6 and systemic pathologies. Recent work has established that WD can impair microbiome resilience to acute perturbations such as antibiotic treatment7,8, although little is known about the mechanism of impairment and the specific consequences for the host of prolonged post-antibiotic dysbiosis. Here we characterize the trajectory by which the gut microbiome recovers its taxonomic and functional profile after antibiotic treatment in mice on regular chow (RC) or WD, and find that only mice on RC undergo a rapid successional process of recovery. Metabolic modelling indicates that a RC diet promotes the development of syntrophic cross-feeding interactions, whereas in mice on WD, a dominant taxon monopolizes readily available resources without releasing syntrophic byproducts. Intervention experiments reveal that an appropriate dietary resource environment is both necessary and sufficient for rapid and robust microbiome recovery, whereas microbial transplant is neither. Furthermore, prolonged post-antibiotic dysbiosis in mice on WD renders them susceptible to infection by the intestinal pathogen Salmonella enterica serovar Typhimurium. Our data challenge widespread enthusiasm for faecal microbiota transplant (FMT) as a strategy to address dysbiosis, and demonstrate that specific dietary interventions are, at a minimum, an essential prerequisite for effective FMT, and may afford a safer, more natural and less invasive alternative.

Faecal metagenomes of great tits and blue tits provide insights into host, diet, pathogens and microbial biodiversity

Background. The vertebrate gut microbiome plays crucial roles in host health and disease. However, there is limited information on the microbiomes of wild birds, most of which is restricted to barcode sequences. We therefore explored the use of shotgun metagenomics on the faecal microbiomes of two wild bird species widely used as model organisms in ecological studies: the great tit (Parus major) and the Eurasian blue tit (Cyanistes caeruleus). Results. Short-read sequencing of five faecal samples generated a metagenomic dataset, revealing substantial variation in composition between samples. Reference-based profiling with Kraken2 identified key differences in the ratios of reads assigned to host, diet and microbes. Some samples showed high abundance of potential pathogens, including siadenoviruses, coccidian parasites and the antimicrobial-resistant bacterial species Serratia fonticola. From metagenome assemblies, we obtained complete mitochondrial genomes from the host species and from Isospora spp., while metagenome-assembled genomes documented new prokaryotic species. Conclusions. Here, we have shown the utility of shotgun metagenomics in uncovering microbial diversity beyond what is possible with 16S rRNA gene sequencing. These findings provide a foundation for future hypothesis testing and microbiome manipulation to improve fitness in wild bird populations. The study also highlights the potential role of wild birds in the dissemination of antimicrobial resistance.

B3 Superfamily in Cucumber (Cucumis sativus L.): Identification, Evolution, Expression Patterns, and Function in Glandular Trichome Development

The B3 transcription factor superfamily, crucial for plant growth and stress adaptation, remains poorly characterized in cucumber (Cucumis sativus), a globally important vegetable crop. Here, we conducted the first genome-wide identification of 52 B3 superfamily genes in cucumber, classifying them into LAV, ARF, RAV, and REM subfamilies through integrated phylogenetic and structural analyses. These genes exhibited conserved B3 domains with lineage-specific motif architectures and diverse exon-intron organizations, particularly within the structurally divergent REM subfamily. Collinearity analysis revealed segmental duplication as a key driver of family expansion, notably between syntenic REM clusters on chromosomes 2 (CsREM5-7) and 6 (CsREM18-20). Promoter cis-element profiling identified enrichment in hormone-responsive and stress adaptation motifs, suggesting functional diversification in signaling pathways. Furthermore, tissue-specific expression divergence was observed across 10 organs, with ARF members displaying broad regulatory roles and REM genes showing apical meristem enrichment. Strikingly, CsRAV8 exhibited glandular trichome-specific expression, a novel finding, given Arabidopsis RAVs' lack of trichome-related functions. Spatial validation via in situ hybridization localized CsRAV8 transcripts to trichome glandular head cells. Functional investigation using virus-induced gene silencing (VIGS) demonstrated that CsRAV8 suppression caused significant glandular trichome shriveling, implicating its role in maintaining glandular cavity integrity. This study provides the first comprehensive genomic inventory of B3 transcription factors in cucumber, providing evolutionary insights and functional frameworks for future functional genomics studies.

Genomes of the Caribbean reef-building corals Colpophyllia natans, Dendrogyra cylindrus, and Siderastrea siderea

Coral populations worldwide are declining rapidly due to elevated ocean temperatures and other human impacts. The Caribbean harbors a high number of threatened, endangered, and critically endangered coral species compared with reefs of the larger Indo-Pacific. The reef corals of the Caribbean are also long diverged from their Pacific counterparts and may have evolved different survival strategies. Most genomic resources have been developed for Pacific coral species which may impede our ability to study the changes in genetic composition of Caribbean reef communities in response to global change. To help fill the gap in genomic resources, we used PacBio HiFi sequencing to generate the first genome assemblies for 3 Caribbean reef-building corals, Colpophyllia natans, Dendrogyra cylindrus, and Siderastrea siderea. We also explore the genomic novelties that shape scleractinian genomes. Notably, we find abundant gene duplications of all classes (e.g. tandem and segmental), especially in S. siderea. This species has one of the largest genomes of any scleractinian coral (822 Mb) which seems to be driven by repetitive content and gene family expansion and diversification. As the genome size of S. siderea was double the size expected of stony corals, we also evaluated the possibility of an ancient whole-genome duplication using Ks tests and found no evidence of such an event in the species. By presenting these genome assemblies, we hope to develop a better understanding of coral evolution as a whole and to enable researchers to further investigate the population genetics and diversity of these 3 species.

PLM-ATG: Identification of Autophagy Proteins by Integrating Protein Language Model Embeddings with PSSM-Based Features

Autophagy critically regulates cellular development while maintaining pathophysiological homeostasis. Since the autophagic process is tightly regulated by the coordination of autophagy-related proteins (ATGs), precise identification of these proteins is essential. Although current computational approaches have addressed experimental recognition's costly and time-consuming challenges, they still have room for improvement since handcrafted features inadequately capture the intricate patterns and relationships hidden in sequences. In this study, we propose PLM-ATG, a novel computational model that integrates support vector machines with the fusion of protein language model (PLM) embeddings and position-specific scoring matrix (PSSM)-based features for the ATG identification. First, we extracted sequence-based features and PSSM-based features as the inputs of six classifiers to establish baseline models. Among these, the combination of the SVM classifier and the AADP-PSSM feature set achieved the best prediction accuracy. Second, two popular PLM embeddings, i.e., ESM-2 and ProtT5, were fused with the AADP-PSSM features to further improve the prediction of ATGs. Third, we selected the optimal feature subset from the combination of the ESM-2 embeddings and AADP-PSSM features to train the final SVM model. The proposed PLM-ATG achieved an accuracy of 99.5% and an MCC of 0.990, which are nearly 5% and 0.1 higher than those of the state-of-the-art model EnsembleDL-ATG, respectively.

Coevolving residues distant from the ligand binding site are involved in GAF domain function

Ligand binding to GAF domains regulates the activity of associated catalytic domains in various proteins, such as the cGMP-hydrolyzing catalytic domain of phosphodiesterase 5 (PDE5) activated by cGMP binding to GAFa domain. However, the specific residues involved and the mechanism of GAF domain function remain unclear. Here, we combine computational and experimental approaches to demonstrate that two highly coevolving residues, L267 and F295, distant from the ligand binding site, play a critical role in GAF domain allostery. Statistical Coupling Analysis (SCA) of GAF domain sequences identified these residues, and molecular dynamics (MD) simulations of both apo and holo forms of wild-type and mutant (L267A, F295A) PDE5 GAFa domains revealed significant changes in structural dynamics and cGMP interaction. Mutational incorporation into a Bioluminescence Resonance Energy Transfer (BRET)-based biosensors, which detects ligand-induced conformational changes, showed altered GAF domain conformation and increased EC50 for cGMP-induced conformational changes. Similar effects were observed in full-length PDE5 and the GAF domain fluorescent protein, miRFP670nano3. Structural analysis of conformers observed in MD simulations suggested a mechanism by which these coevolving residues influence GAF domain allostery. Our findings provide insight into the role of distant residues in GAF domain function and may enhance understanding of allostery in proteins.

Transcriptomic analysis reveals molecular phenological changes during the flower-to-fruit transition in Vanilla planifolia Andrews (Orchidaceae)

BACKGROUND

The transition from flower to fruit, encompassing flower formation to fruit maturation, has been extensively studied in model plants such as Arabidopsis thaliana. However, the Orchidaceae family, including Vanilla planifolia, exhibits a unique phenomenon known as post-pollination syndrome (PPS), where pollination initiates ovule development but often leads to premature ovary drop. This phenomenon significantly impacts the yield and stability of V. planifolia crops. Understanding the molecular mechanisms underlying PPS is essential for improving crop production. This study explores transcriptomic and histological variations to identify key molecular and phenological changes in the ovary during the flower-to-fruit transition in V. planifolia.

RESULTS

The flower-to-fruit transition in Vanilla planifolia involves dynamic changes in gene expression and phenotypic events, which can be categorized into four distinct stages: (1) Pre-pollination: Ovary differentiation is characterized by the enrichment of nitrogen metabolism and photoperiod-responsive pathways. The upregulation of VpVRN5-like and VpNAC14-like suggests their roles in photoperiod-induced flowering and ovarian tissue differentiation in response to nitrate availability. (2) Pollination: Key events include nucellar filament branching and the functional enrichment of pathways associated with growth and responses to light intensity. The upregulation of VpMBS1-like indicates its involvement in regulating and adapting to high light conditions. (3) Post-pollination: This stage is marked by embryo sac formation and pollen tube elongation, with enrichment in auxin response pathways. The upregulation of VpIAA6-like and VpRALF27-like suggests their roles in auxin signaling during ovule development. (4) Fertilization: Seed development is associated with the enrichment of abiotic stress response pathways and carbohydrate transport. The upregulation of VpAAE3-like, VpPR1-like, and VpSWET12-like suggests functions in stress responses and sucrose transport, potentially linked to fungal interactions or symbiosis.

CONCLUSIONS

This study characterizes the molecular and phenological changes occurring during the flower-to-fruit transition in V. planifolia by integrating transcriptomic analysis with anatomical data on post-pollination syndrome. Based on functional predictions, this approach provides valuable insights into the mechanisms governing this transition in plants exhibiting PPS and identifies candidate genes for future experimental validation in V. planifolia.

CLINICAL TRIAL NUMBER

Not applicable.

A geological timescale for bacterial evolution and oxygen adaptation

Microbial life has dominated Earth's history but left a sparse fossil record, greatly hindering our understanding of evolution in deep time. However, bacterial metabolism has left signatures in the geochemical record, most conspicuously the Great Oxidation Event (GOE). We combine machine learning and phylogenetic reconciliation to infer ancestral bacterial transitions to aerobic lifestyles, linking them to the GOE to calibrate the bacterial time tree. Extant bacterial phyla trace their diversity to the Archaean and Proterozoic, and bacterial families prior to the Phanerozoic. We infer that most bacterial phyla were ancestrally anaerobic and adopted aerobic lifestyles after the GOE. However, in the cyanobacterial ancestor, aerobic metabolism likely predated the GOE, which may have facilitated the evolution of oxygenic photosynthesis.

Unraveling the diversity of protein-carbohydrate interfaces: Insights from a multi-scale study

Protein-carbohydrate interactions play a crucial role in numerous fundamental biological processes. Thus, description and comparison of the carbohydrate binding site (CBS) architecture is of great importance for understanding of the underlying biological mechanisms. However, traditional approaches for carbohydrate-binding protein analysis and annotation rely primarily on the sequence-based methods applied to specific protein classes. The recently released DIONYSUS database aims to fill this gap by providing tools for CBS comparison at different levels: both in terms of protein properties and classification, as well as in terms of atomistic CBS organization. In the current study, we explore DIONYSUS content using a combination of the suggested approaches in order to evaluate the diversity of the currently resolved non-covalent protein-carbohydrate interfaces at different scales. Notably, our analysis reveals evolutionary convergence of CBS in proteins with distinct folds and coming from organisms across different kingdoms of life. Furthermore, we demonstrate that a CBS structure based approach has the potential to facilitate functional annotation for the proteins with missing information in the existing databases. In particular, it provides reliable information for numerous carbohydrate-binding proteins from rapidly evolving organisms, whose analysis is particularly challenging for classical sequence-based methods.

Chromosome-Level Genome Assembly of the Loach Goby Rhyacichthys aspro Offers Insights Into Gobioidei Evolution

The percomorph fish clade Gobioidei is a suborder that comprises over 2200 species distributed in nearly all aquatic habitats. To understand the genetics underlying their species diversification, we sequenced and annotated the genome of the loach goby, Rhyacichthys aspro, an early-diverging group, and compared it with nine additional Gobioidei species. Within Gobioidei, the loach goby possesses the smallest genome at 594 Mb, and a rise in species diversity from early-diverging to more recently diverged lineages is mirrored by enlarged genomes and a higher presence of transposable elements (TEs), particularly DNA transposons. These DNA transposons are enriched in genic and regulatory regions and their copy number increase is strongly correlated with substitution rate, suggesting that DNA repair after transposon excision/insertion leads to nearby mutations. Consequently, the proliferation of DNA transposons might be the crucial driver of Gobioidei diversification and adaptability. The loach goby genome also points to mechanisms of ecological adaptation. It contains relatively few genes for lateral line development but an overrepresentation of synaptic function genes, with genes putatively under selection linked to synapse organisation and calcium signalling, implicating a sensory system distinct from other Gobioidei species. We also see an overabundance of genes involved in neurocranium development and renal function, adaptations likely connected to its flat morphology suited for strong currents and an amphidromous life cycle. Comparative analyses with hill-stream loaches and the European eel reveal convergent adaptations in body shape and saltwater balance. These findings shed new light on the loach goby's survival mechanisms and the broader evolutionary trends within Gobioidei.

Comparative pangenomics of Streptococcus pneumoniae from Malawi: uncovering genetic variability and pathogenicity

Streptococcus pneumoniae is a significant cause of bacterial infections, including pneumonia, meningitis and septicemia, primarily affecting children, the elderly and immunocompromised individuals. This study aimed to elucidate the serotype and lineage distribution and molecular mechanisms underlying pneumococcal invasiveness through a comprehensive pangenomic analysis of 1416 isolates from Malawi. Our analysis comprised 810 isolates from asymptomatic carriers and 606 isolates from patients with bacteraemia or meningitis. We identified 58 serotypes, with serotypes 1, 5 and 12F exhibiting significantly higher prevalence among patients. These serotypes likely exhibit reduced nasopharyngeal colonization and demonstrate rapid dissemination to sterile sites. Notably, these serotypes form a distinct lineage with distinct genomic characteristics, including the absence of V-type ATP synthase. The pangenome analysis revealed two highly conserved surface protein complexes, F-type ATP synthase and SecA1-SecY, which deserve further investigation as potential targets for novel therapeutic interventions.

Structural assembly of the PAS domain drives the catalytic activation of metazoan PASK

PAS domains are ubiquitous sensory modules that transduce environmental signals into cellular responses through tandem PAS folds and PAS-associated C-terminal (PAC) motifs. While this conserved architecture underpins their regulatory roles, here we uncover a structural divergence in the metazoan PAS domain-regulated kinase (PASK). By integrating evolutionary-scale domain mapping with deep learning-based structural models, we identified two PAS domains in PASK, namely PAS-B and PAS-C, in addition to the previously known PAS-A domain. Unlike canonical PAS domains, the PAS fold and PAC motif in the PAS-C domain are spatially segregated by an unstructured linker, yet a functional PAS module is assembled through intramolecular interactions. We demonstrate that this assembly is nutrient responsive and serves to remodel the quaternary structure of PASK that positions the PAS-A domain near the kinase activation loop. This nutrient-sensitive spatial arrangement stabilizes the activation loop, enabling catalytic activation of PASK. These findings revealed an alternative mode of regulatory control in PAS sensory proteins, where the structural assembly of PAS domains links environmental sensing to enzymatic activity. By demonstrating that PAS domains integrate signals through dynamic structural rearrangements, this study broadens the understanding of their functional and regulatory roles and highlights potential opportunities for targeting PAS domain-mediated pathways in therapeutic applications.

Genome-wide identification of the NAC family genes of adzuki bean and their roles in rust resistance through jasmonic acid signaling

BACKGROUND

Adzuki bean (Vigna angularis) rust, caused by the fungus Uromyces vignae, is an important disease affecting adzuki bean yield and quality. Previously, several NAC transcription factors (TFs) were induced by rust infection in a resistant adzuki bean variety, suggesting that NAC TF members may play important roles in rust resistance.

RESULTS

To further explore the functions of NAC TFs in rust resistance and to provide a reference for resistant varietal breeding, 101 NAC TFs were identified from the adzuki bean genome. The synteny analysis revealed 25 pairs of VaNACs in the genome, which exhibited whole-genome/segmental duplication. Based on the phylogenetic relationships and conserved motif characteristics, the NAC TFs of V. angularis can be divided into 16 subfamilies. Previous transcriptome data showed that nine VaNACs are significantly induced by rust infection. Here, a cis-acting element analysis of these nine genes revealed that most contain hormone responsive elements, such as abscisic acid and methyl jasmonate (MeJA). The expression levels of these nine VaNACs were dynamically regulated in response to exogenous MeJA treatment, as revealed by quantitative real-time PCR analysis. Among them, seven VaNACs exhibited significantly upregulated expression, peaking at 12 h post treatment (hpt) and remaining significantly higher than that of the untreated control group for 48 hpt. These results suggest that these VaNACs are responsive to MeJA signaling and may play roles in the early and sustained transcriptional regulation of stress-related pathways. The exogenous MeJA decreased rust severity on adzuki bean leaves by 45.68%. Additionally, the expression levels of these nine genes in adzuki bean leaves in response to rust infection after pretreatment with MeJA were investigated. The expression of VaNAC002 rapidly peaked at 24 h post inoculation (hpi) and remained significantly higher than the control from 120 to 192 hpi. Subsequently, transient overexpression of VaNAC002 significantly enhanced the resistance of tobacco to Botrytis cinerea, indicating that VaNAC002 positively regulates plant disease resistance.

CONCLUSION

These findings suggest that adzuki bean NAC family members may play important roles in disease resistance through JA signaling, with VaNAC002 having a positive regulatory role in plant immunity.

Genome-wide analysis and functional validation of the cotton FAH gene family for salt stress

BACKGROUND

Fatty acid hydroxylases (FAHs) are a family of enzymes that includes fatty acid hydroxylases, carotenoid hydroxylases, and sterol desaturases. Fatty acids are highly important for plants. They are the main source of energy storage and the main component of the cell membrane. Saturated fatty acids can be divided into two categories: saturated fatty acids and unsaturated fatty acids. FAHs play a pivotal role in enhancing plant salt tolerance by modulating fatty acid metabolic pathways, thereby improving cell membrane stability and antioxidant capacity.

RESULTS

In this study, we identified a total of 129 FAH gene family members in four cotton species, namely, Gossypium hirsutum, Gossypium darwinii, Gossypium arboreum, and Gossypium raimondii. The FAH genes were divided into five subgroups via evolutionary analysis. FAH genes located in the same subgroup presented similar gene structures and a consistent distribution of conserved motifs through the analysis of evolutionary trees, gene structures, and conserved motifs. Chromosomal localization analysis of the FAH gene family revealed that it has undergone chromosomal segment duplication events. Analysis of cis-acting elements suggested that the FAH gene may be involved in regulating biotic and abiotic stresses, plant growth and development, signaling pathways, and other physiological processes. The RT‒qPCR results revealed significant differences in the expression levels of FAH gene family members under salt stress conditions compared with those in the control group. Additionally, we successfully silenced Gohir.A03G045300 through VIGS experiments, and the results indicated that the silenced plants were more sensitive to salt stress than the control plants were. This suggests that Gohir.A03G045300 may be involved in the response of cotton to salt stress.

CONCLUSIONS

A total of 129 FAH genes were identified in four Gossypium species through bioinformatics analysis. Gene silencing of FAH members in G. hirsutum revealed that the FAH gene family plays a crucial role in the response of cotton to salt stress.

Revealing Genomic Traits and Evolutionary Insights of Oryza officinalis from Southern China Through Genome Assembly and Transcriptome Analysis

Wild rice, as the ancestor of cultivated rice, has accumulated a wide range of beneficial traits through prolonged natural selection and evolution. Oryza officinalis, belonging to the CC genome, differs significantly from the AA genome. In this study, we utilized second- and third-generation sequencing, along with Hi-C technology, to assemble the genome of MT10 (O. officinalis). The assembled genome is 552.58 Mb, with contigs and scaffold N50 values of 40.04 and 44.48 Mb, respectively, and 96.73% of the sequences anchored to 12 chromosomes. A total of 33,813 genes were annotated, and repetitive sequences account for 54.24% of the MT10 genome. The number of unique genes in MT10 exceeds that in the O. officinalis genome from Thailand, and their divergence time is estimated at 1.6 million years ago. The MT10 genome exhibits fewer expanded gene families compared to contracted ones, with the expanded families predominantly associated with disease and pest resistance. Comparative genomic analysis of MT10 and Nipponbare reveals sequence variations in biotic and abiotic resistance-related genes. In particular, the presence of R genes and cystatin gene families in MT10 may contribute to its unique insect resistance. Transcriptome analyses indicate that flavonoid biosynthesis and MAPK-related genes are expressed in response to brown planthopper infestation. This study represents the first chromosome-level genome assembly of MT10, providing a reference sequence for the efficient cloning of beneficial genes from O. officinalis, which holds significant potential for the genetic improvement of cultivated rice.

DRAMMA: a multifaceted machine learning approach for novel antimicrobial resistance gene detection in metagenomic data

BACKGROUND

Antibiotics are essential for medical procedures, food security, and public health. However, ill-advised usage leads to increased pathogen resistance to antimicrobial substances, posing a threat of fatal infections and limiting the benefits of antibiotics. Therefore, early detection of antimicrobial resistance genes (ARGs), especially in pathogens, is crucial for human health. Most computational methods for ARG detection rely on homology to a predefined gene database and therefore are limited in their ability to discover novel genes.

RESULTS

We introduce DRAMMA, a machine learning method for predicting new ARGs with no sequence similarity to known ARGs or any annotated gene. DRAMMA utilizes various features, including protein properties, genomic context, and evolutionary patterns. The model demonstrated robust predictive performance both in cross-validation and an external validation set annotated by an empirical ARG database. Analyses of the high-ranking model-generated candidates revealed a significant enrichment of candidates within the Bacteroidetes/Chlorobi and Betaproteobacteria taxonomic groups.

CONCLUSIONS

DRAMMA enables rapid ARG identification for global-scale genomic and metagenomic samples, thus holding promise for the discovery of novel ARGs that lack sequence similarity to any known resistance genes. Further, our model has the potential to facilitate early detection of specific ARGs, potentially influencing the selection of antibiotics administered to patients. Video Abstract.

Deep transcriptome and metabolome analysis to dissect untapped spatial dynamics of specialized metabolism in Saussurea costus (Falc.) Lipsch

Saussurea costus (Falc.) is an endangered medicinal plant possessing diverse phytochemical compounds with clinical significance and used to treat numerous human ailments. Despite the source of enriched phytochemicals, molecular insights into spatialized metabolism are poorly understood in S. costus. This study investigated the dynamics of organ-specific secondary metabolite biosynthesis using deep transcriptome sequencing and high-throughput UHPLC-QTOF based untargeted metabolomic profiling. A de novo assembly from quality reads fetched 59,725 transcripts with structural (53.02%) and functional (66.13%) annotations of non-redundant transcripts. Of the 7,683 predicted gene families, 3,211 were categorized as 'single gene families'. Interestingly, out of the 4,664 core gene families within the Asterids, 4,560 families were captured in S. costus. Organ-specific differential gene expression analysis revealed significant variations between leaves vs. stems (23,102 transcripts), leaves vs. roots (30,590 transcripts), and roots vs. stems (21,759 transcripts). Like-wise, putative metabolites (PMs) were recorded with significant differences in leaves vs. roots (250 PMs), leaves vs. stem (350 PMs), and roots vs. stem (107 PMs). The integrative transcriptomic and metabolomic analysis identified organ-specific differences in the accumulation of important metabolites, including secologanin, menthofuran, taraxerol, lupeol, acetyleugenol, scopoletin, costunolide, and dehydrocostus lactone. Furthermore, a global gene co-expression network (GCN) identified putative regulators controlling the expression of key target genes of secondary metabolite pathways including terpenoid, phenylpropanoid, and flavonoid. The comprehensive functionally relevant genomic resource created here provides beneficial insights for upscaling targeted metabolite biosynthesis through genetic engineering, and for expediting association mapping efforts to elucidate the casual genetic elements controlling specific bioactive metabolites.

Genomic characterization and antifungal properties of Paenibacillus polymyxa YF, a promising biocontrol agent against Fusarium oxysporum pathogen of codonopsis root rot

Root rot, a destructive soil-borne disease, poses a significant threat to a wide range of economically important crops. Codonopsis, a high-value medicine plant, is particularly susceptible to substantial production losses caused by Fusarium oxysporum-induced root rot. In this study, we identified a promising biocontrol agent for codonopsis root rot, Paenibacillus polymyxa YF. In vitro assay demonstrated that the strain YF exhibited a 70.69% inhibition rate against F. oxysporum and broad-spectrum antifungal activities against the selected six postharvest pathogens. Additionally, the strain YF demonstrated significant plant growth-promoting properties. Subsequent in vivo inoculation assays revealed that the strain YF effectively mitigated disease symptoms of F. oxysporum-induced root rot in codonopsis, even achieving a complete disease prevention efficacy rate of 100%. Our findings further elucidated that the robust biocontrol capacity of the strain YF against F. oxysporum is mediated through multiple mechanisms, including inhibition of fusaric acid secretion, downregulation of virulence-associated genes in F. oxysporum, and the production of multiple hydrolytic enzymes. Genomic analysis showed that the strain YF has a 5.62-Mb single circular chromosome with 5,138 protein-coding genes. Comprehensive genome mining of the strain YF also identified numerous genes and gene clusters involved in bio-fertilization, resistance inducers synthesis, plant colonization, biofilm formation, and antimicrobial activity. These findings provide insights into the biocontrol mechanisms of the strain YF and offer substantial potential for its further exploration and application in crop production.

Molecular Mechanisms of Gene Expression Regulation in Response to Heat Stress in Hemerocallis fulva

Hemerocallis fulva is one of the three major flowers in the world; its flower type and color are very rich, with high ornamental value and economic value. Heat stress severely limits the cultivation and geographical distribution of H. fulva. Genetic resources and their underlying molecular mechanisms constitute the cornerstone of contemporary breeding technologies. However, research on the response of H. fulva to heat stress remains relatively scant. In this study, we used the heat-resistant 'Dan Yang' variety and heat-sensitive 'Nuo Mi Lu' variety with phenotypic expression as experimental materials to determine the changes in substance and gene expression levels, and used bioinformatics technology to study the molecular mechanisms and gene resource mining of H. fulva in response to heat stress. We identified several thousand differentially expressed genes (DEGs) in different comparison groups. At the same time, 1850 shared DEGs were identified in two H. fulva genotypes responding to heat stress. The dynamic cutting algorithm was used to cluster the genes, and 23 gene co-expression modules were obtained. The MEorangered, MElightpink, and MEmagenta modules were significantly correlated with physiological and biochemical traits. We identified ten key genes closely related to the response of H. fulva to heat stress, including plant-pathogen interactions, plant hormone signal transduction, oxidative transduction phosphorylation, and the plant hormone signal transduction pathway. This study not only analyzes the molecular mechanism of H. fulva response to heat stress, but also provides genetic resources for breeding H. fulva heat tolerance.

Genome-resolved adaptation strategies of Rhodobacterales to changing conditions in the Chesapeake and Delaware Bays

The abundant and metabolically versatile aquatic bacterial order, Rhodobacterales, influences marine biogeochemical cycles. We assessed Rhodobacterales metagenome-assembled genome (MAG) abundance, estimated growth rates, and potential and expressed functions in the Chesapeake and Delaware Bays, two important US estuaries. Phylogenomics of draft and draft/closed Rhodobacterales genomes from this study and others placed 46 nearly complete MAGs from these bays into 11 genera, many were not well characterized. Their abundances varied between the bays and were influenced by temperature, salinity, and silicate and phosphate concentrations. Rhodobacterales genera possessed unique and shared genes for transporters, photoheterotrophy, complex carbon degradation, nitrogen, and sulfur metabolism reflecting their seasonal differences in abundance and activity. Planktomarina genomospecies were more ubiquitous than the more niche specialists, HIMB11, CPC320, LFER01, and MED-G52. Their estimated growth rates were correlated to various factors including phosphate and silicate concentrations, cell density, and light. Metatranscriptomic analysis of four abundant genomospecies commonly revealed that aerobic anoxygenic photoheterotrophy-associated transcripts were highly abundant at night. These Rhodobacterales also differentially expressed genes for CO oxidation and nutrient transport and use between different environmental conditions. Phosphate concentrations and light penetration in the Chesapeake Bay likely contributed to higher estimated growth rates of HIMB11 and LFER01, respectively, in summer where they maintained higher ribosome concentrations and prevented physiological gene expression constraints by downregulating transporter genes compared to the Delaware Bay. Our study highlights the spatial and temporal shifts in estuarine Rhodobacterales within and between these bays reflected through their abundance, unique metabolisms, estimated growth rates, and activity changes.

IMPORTANCE

In the complex web of global biogeochemical nutrient cycling, the Rhodobacterales emerge as key players, exerting a profound influence through their abundance and dynamic activity. While previous studies have primarily investigated these organisms within marine ecosystems, this study delves into their roles within estuarine environments using a combination of metagenomic and metatranscriptomic analyses. We uncovered a range of Rhodobacterales genera, from generalists to specialists, each exhibiting distinct abundance patterns and gene expression profiles. This diversity equips them with the capacity to thrive amidst the varying environmental conditions encountered within dynamic estuarine habitats. Crucially, our findings illuminate the adaptable nature of estuarine Rhodobacterales, revealing their various energy production pathways and diverse resource management, especially during phytoplankton or algal blooms. Whether adopting a free-living or particle-attached existence, these organisms demonstrate remarkable flexibility in their metabolic strategies, underscoring their pivotal role in driving ecosystem dynamics within estuarine ecosystems.

Learning maximally spanning representations improves protein function annotation

Automated protein function annotation is a fundamental problem in computational biology, crucial for understanding the functional roles of proteins in biological processes, with broad implications in medicine and biotechnology. A persistent challenge in this problem is the imbalanced, long-tail distribution of available function annotations: a small set of well-studied function classes account for most annotated proteins, while many other classes have few annotated proteins, often due to investigative bias, experimental limitations, or intrinsic biases in protein evolution. As a result, existing machine learning models for protein function prediction tend to only optimize the prediction accuracy for well-studied function classes overrepresented in the training data, leading to poor accuracy for understudied functions. In this work, we develop MSRep, a novel deep learning-based protein function annotation framework designed to address this imbalance issue and improve annotation accuracy. MSRep is inspired by an intriguing phenomenon, called neural collapse (NC), commonly observed in high-accuracy deep neural networks used for classification tasks, where hidden representations in the final layer collapse to class-specific mean embeddings, while maintaining maximal inter-class separation. Given that NC consistently emerges across diverse architectures and tasks for high-accuracy models, we hypothesize that inducing NC structure in models trained on imbalanced data can enhance both prediction accuracy and generalizability. To achieve this, MSRep refines a pre-trained protein language model to produce NC-like representations by optimizing an NC-inspired loss function, which ensures that minority functions are equally represented in the embedding space as majority functions, in contrast to conventional classification methods whose embedding spaces are dominated by overrepresented classes. In evaluations across four protein function annotation tasks on the prediction of Enzyme Commission numbers, Gene3D codes, Pfam families, and Gene Ontology terms, MSRep demonstrates superior predictive performance for both well- and underrepresented classes, outperforming several state-of-the-art annotation tools. We anticipate that MSRep will enhance the annotation of understudied functions and novel, uncharacterized proteins, advancing future protein function studies and accelerating the discovery of new functional proteins. The source code of MSRep is available at https://github.com/luo-group/MSRep.

Microbial drivers of biogeochemical cycles in deep sediments of the Kathiawar Peninsula Gulfs of India

Deep marine sediments are rich in microbial diversity, which holds metabolic repertoire to modulate biogeochemical cycles on a global scale. We undertook the environmental microbiome inhabiting the Gulf of Kathiawar Peninsula as a model system to understand the potential involvement of the deep marine sediment microbial community and as a cohort in the carbon, nitrogen, and sulfur biogeochemical cycles. These gulfs are characterized by dynamic tidal variations, diverse sediment textures, and nutrient-rich waters, driven by coastal processes and the interaction between natural coastal dynamics and anthropogenic inputs that shape its microbial community diversity. Our findings suggest that carbon fixation was carried out by Gamma-proteobacteria with CBB cycle-related genes or by microbial participants with Wood-Ljungdahl pathway-related genes. Microbial communities involved in nitrogen metabolism were observed to be rich and diverse, and most microbial communities potentially contribute to the nitrogen cycle via processing nitrogen oxides. Bacteria belonging to the KSB1 phylum were also found to fix nitrogen. The sulfur cycle was spread throughout, with Verrucomicrobiota phylum being a major contributor. The varying napAB genes, significantly lower in the Gulf of Kutch compared to the Gulf of Cambay and the Arabian Sea, mediated nitrate reduction. Dynamics between these pathways were mutually exclusive, and organic carbon oxidation was widespread across the microbial community. Finally, the proteobacteria phylum was highly versatile and conceivably contributed to biogeochemical flux with exceptionally high abundance and the ability to form metabolic networks to survive. The work highlights the importance of critical zones and microbial diversity therein, which needs further exploration.

Adaptive Defense Mechanism During Flowering Period of Rhododendron decorum Revealed by Comparative Transcriptomic Analysis

Rhododendron decorum, a widely distributed Rhododendron species in southwestern China, is recognized not only for its significant ornamental value but also as a culinary resource for local tribes. However, the defense mechanisms underlying the ecological adaptations of R. decorum remain to be elucidated. In this study, we conducted comparative transcriptomic analyses of various organs (corolla, androecium/gynoecium and leaves) of R. decorum collected from two distinct two regions. Approximately 186.98 Gb of clean data were generated from three organs of R. decorum across these regions. Through de novo assembly, a total of 92,025 unigenes were obtained and nearly half of them (43,515 unigenes) were successfully annotated. Enrichment analysis of differentially expressed genes (DEGs) within three comparative groups of different organs (HQI/LFI, HQO/LFO and HQL/LFL, respectively) revealed that the distribution of R. decorum in the Heqing region exhibited an increased requirement for plant immunity, including resistance to diseases, insects, and herbivores across various plant organs. Conversely, R. decorum in the Lijiang region showed a greater reliance on environmental factors, such as cold tolerance, aromatic compounds production, and the attraction of pollinating insects. Notably, the validation of 21 pivotal genes identified from significantly regulated enrichment pathways across different organs showed functional consistency in the KEGG enrichment analysis among different organs in these two regions. The functional disparities observed in the transcriptome of R. decorum across distinct regions provide valuable insight into the understanding of its adaptive defense mechanism.

Multi-omics analysis reveals key regulatory defense pathways in Ruppia sinensis in response to water salinity fluctuations

Seagrasses maintain cellular water balance by regulating ion concentrations and accumulating organic osmolytes, enabling them to survive in the fluctuating salinity of intertidal environments. However, the molecular mechanisms underlying seagrass responses to salinity changes remain relatively understudied. To address this, we conducted a multi-omics analysis of Ruppia sinensis under low, moderate, and high salinity conditions to uncover the mechanisms behind its adaptation to salinity fluctuations. Our research revealed that the transition from low to high salinity significantly altered the physiological characteristics of R. sinensis. Simultaneously, the species enhanced its ability to cope with and adapt to salinity fluctuations by increasing antioxidant enzyme activity. Integration of multi-omics data further indicated that under high salinity conditions, R. sinensis synthesizes more flavonoids to bolster its adaptive capacity. Additionally, the phenylpropanoid metabolic pathway appears to play a crucial role in the response of R. sinensis to changes in water salinity.

Distinct interspecies thermal resistance strategies exhibited by euplanktonic, tychoplanktonic and benthic diatoms under marine heatwaves

Extreme climate events, such as marine heatwaves (MHWs), are expected to occur more frequently and intensely in the future, resulting in a substantial impact on marine life. The way that diatoms respond to MHWs may have crucial effects on global primary production and biogeochemical cycles. Euplanktonic diatoms appear to benefit from MHWs directly, but this phenomenon needs an explanation. As concerns tychoplanktonic and benthic diatoms, no studies have been addressed on their thermal response strategies. To address this, we investigated the responses and underlying mechanisms of three typical growth forms of diatoms, Pseudo-nitzschia multiseries (euplanktonic), Paralia guyana (tychoplanktonic) and Navicula avium (benthic), under heat stress by combining a growth experiment with transcriptomic analysis. Our results showed that the physiological responses of diatoms to MHWs and underlying molecular mechanisms are largely related to their growth forms. The euplanktonic diatom was first depressed, but then had a distinct increase in the growth rate accompanied by inducing zeatin and unsaturated fatty acid biosynthesis and repressing substance assimilation and energy metabolism. Contrarily, the benthic diatom showed elevated substance and energy demands for macromolecules accumulation by reducing cell division and increasing photosynthesis and nitrogen assimilation. The tychoplanktonic diatom exhibited higher physiological plasticity to maintain growth and cellular homeostasis. Our results indicate the increased rate of cell division in euplanktonic diatoms under heat stress is likely an emergency response strategy promoting diatom dispersal for survival, but at the cost of disturbances of metabolic balance.

Developing a microfluidic-based epicPCR reveals diverse potential hosts of the mcrA gene in marine cold seep

Anaerobic methanotrophic (ANME) microbes play a crucial role in the bioprocess of anaerobic oxidation of methane (AOM). However, due to their unculturable status, their diversity is poorly understood. In this study, we established a microfluidics-based epicPCR (Emulsion, Paired Isolation, and Concatenation PCR) to fuse the 16S rRNA gene and mcrA gene to reveal the diversity of ANME microbes (mcrA gene hosts) in three sampling push-cores from the marine cold seep. A total of 3725 16S amplicon sequence variants (ASVs) of the mcrA gene hosts were detected, and classified into 78 genera across 23 phyla. Across all samples, the dominant phyla with high relative abundance (>10%) were the well-known Euryarchaeota, and some bacterial phyla such as Campylobacterota, Proteobacteria, and Chloroflexi; however, the specificity of these associations was not verified. In addition, the compositions of the mcrA gene hosts were significantly different in different layers, where the archaeal hosts increased with the depths of sediments, indicating the carriers of AOM were divergent in depth. Furthermore, the consensus phylogenetic trees of the mcrA gene and the 16S rRNA gene showed congruence in archaea not in bacteria, suggesting the horizontal transfer of the mcrA gene may occur among host members. Finally, some bacterial metagenomes were found to contain the mcrA gene as well as other genes that encode enzymes in the AOM pathway, which prospectively propose the existence of ANME bacteria. This study describes improvements for a potential method for studying the diversity of uncultured functional microbes and broadens our understanding of the diversity of ANMEs.

Hairpin in a haystack: In silico identification and characterization of plant-conserved microRNA in Rafflesiaceae

Rafflesiaceae is a family of endangered plants whose members are solely parasitic to the tropical grape vine Tetrastigma (Vitaceae). Currently, the genetics of their crosstalk with the host remains unexplored. In this study, we use homology-based in silico approaches to characterize micro-RNAs (miRNAs) expressed by Sapria himalayana and Rafflesia cantleyi from published omics data. Derived from secondary structures or hairpins, miRNAs are small regulators of gene expression. We found that some plant-conserved miRNA still exists in Rafflesiaceae. Out of 9 highly conserved miRNA families in plants, 7 families (156/157, 159/319, 160, 165/166, 171, 172, 390) were identified with a total of 22 variants across Rafflesiaceae. Some miRNAs were missing endogenous targets and may have evolved to target host miRNA, though this requires experimental verification. Rafflesiaceae miRNA promoters are mostly inducible by ethylene that mediates stress response in the host but could be perceived by the parasites as a signal for growth. This study provides evidence that certain miRNAs with ancient origins in land plants still exist in Rafflesiaceae, though some may have been coopted by parasites to target host genes.

Novel adaptive immune systems in pristine Antarctic soils

Antarctic environments are dominated by microorganisms, which are vulnerable to viral infection. Although several studies have investigated the phylogenetic repertoire of bacteria and viruses in these poly-extreme environments with freezing temperatures, high ultra violet irradiation levels, low moisture availability and hyper-oligotrophy, the evolutionary mechanisms governing microbial immunity remain poorly understood. Using genome-resolved metagenomics, we test the hypothesis that Antarctic poly-extreme high-latitude microbiomes harbour diverse adaptive immune systems. Our analysis reveals the prevalence of prophages in bacterial genomes (Bacteroidota and Verrucomicrobiota), suggesting the significance of lysogenic infection strategies in Antarctic soils. Furthermore, we demonstrate the presence of diverse CRISPR-Cas arrays, including Class 1 arrays (Types I-B, I-C, and I-E), alongside systems exhibiting novel gene architecture among their effector cas genes. Notably, a Class 2 system featuring type V variants lacks CRISPR arrays, encodes Cas1 and Cas2 adaptation module genes. Phylogenetic analysis of Cas12 effector proteins hints at divergent evolutionary histories compared to classified type V effectors and indicates that TnpB is likely the ancestor of Cas12 nucleases. Our findings suggest substantial novelty in Antarctic cas sequences, likely driven by strong selective pressures. These results underscore the role of viral infection as a key evolutionary driver shaping polar microbiomes.

Biomolecular Interaction of Carnosine and Anti-TB Drug: Preparation of Functional Biopeptide-Based Nanocomposites and Characterization through In Vitro and In Silico Investigations

Host-directed therapies (HDTs) resolve excessive inflammation during tuberculosis (TB) disease, which leads to irreversible lung tissue damage. The peptide-based nanostructures possess intrinsic anti-inflammatory and antioxidant properties among HDTs. Native carnosine, a natural dipeptide with superior self-organization and functionalities, was chosen for nanoformulation. In the present work, multiscale self-assembly approaches of carnosine were developed using a solvent-mediated process (hexafluoro-2-propanol) and further linked with first-line anti-TB drugs. The organofluorine compound in a solvent is attributed to the self-assembling process with heteroatom acceptors in carnosine. In the carnosine-anti-TB drug nanocomposite, the functional moieties represent the involvement of hydrogen bonding and the electrostatic force of attraction. The minimum inhibitory concentration of carnosine-anti-TB drug composites represents an antimycobacterial effect on par with standard drugs. The silicon findings complemented the in vitro results through quantum chemical simulations, elucidating the respective binding pockets between putative Mtb drug targets and carnosine-anti-TB composites. These findings confirmed that the carnosine and anti-TB drug nanocomposites prepared through a solvent-mediated process act as a rational design for functional nanodelivery systems for sustainable TB therapeutics.

Genome architecture of the allotetraploid wild grass Aegilops ventricosa reveals its evolutionary history and contributions to wheat improvement

The allotetraploid wild grass Aegilops ventricosa (2n = 4x = 28, genome DvDvNvNv) has been recognized as an important germplasm resource for wheat improvement owing to its ability to tolerate biotic stresses. In particular, the 2NvS segment from Ae. ventricosa, as a stable and effective resistance source, has contributed greatly to wheat improvement. The 2NvS/2AS translocation is a prevalent chromosomal translocation between common wheat and wild relatives, ranking just behind the 1B/1R translocation in importance for modern wheat breeding. Here, we assembled a high-quality chromosome-level reference genome of Ae. ventricosa RM271 with a total length of 8.67 Gb. Phylogenomic analyses revealed that the progenitor of the Dv subgenome of Ae. ventricosa is Ae. tauschii ssp. tauschii (genome DD); by contrast, the progenitor of the D subgenome of bread wheat (Triticum aestivum L.) is Ae. tauschii ssp. strangulata (genome DD). The oldest polyploidization time of Ae. ventricosa occurred ∼0.7 mya. The Dv subgenome of Ae. ventricosa is less conserved than the D subgenome of bread wheat. Construction of a graph-based pangenome of 2AS/6NvL (originally known as 2NvS) segments from Ae. ventricosa and other genomes in the Triticeae enabled us to identify candidate resistance genes sourced from Ae. ventricosa. We identified 12 nonredundant introgressed segments from the Dv and Nv subgenomes using a large winter wheat collection representing the full diversity of the European wheat genetic pool, and 29.40% of European wheat varieties inherit at least one of these segments. The high-quality RM271 reference genome will provide a basis for cloning key genes, including the Yr17-Lr37-Sr38-Cre5 resistance gene cluster in Ae. ventricosa, and facilitate the full use of elite wild genetic resources to accelerate wheat improvement.

Comprehensive genome annotation of the model ciliate Tetrahymena thermophila by in-depth epigenetic and transcriptomic profiling

The ciliate Tetrahymena thermophila is a well-established unicellular model eukaryote, contributing significantly to foundational biological discoveries. Despite its acknowledged importance, current studies on Tetrahymena biology face challenges due to gene annotation inaccuracy, particularly the notable absence of untranslated regions (UTRs). To comprehensively annotate the Tetrahymena macronuclear genome, we collected extensive transcriptomic data spanning various cell stages. To ascertain transcript orientation and transcription start/end sites, we incorporated data on epigenetic marks displaying enrichment towards the 5' end of gene bodies, including H3 lysine 4 tri-methylation (H3K4me3), histone variant H2A.Z, nucleosome positioning and N6-methyldeoxyadenine (6mA). Cap-seq data was subsequently applied to validate the accuracy of identified transcription start sites. Additionally, we integrated Nanopore direct RNA sequencing (DRS), strand-specific RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) data. Using a newly developed bioinformatic pipeline, coupled with manual curation and experimental validation, our work yielded substantial improvements to the current gene models, including the addition of 2,481 new genes, updates to 23,936 existing genes, and the incorporation of 8,339 alternatively spliced isoforms. Furthermore, novel UTR information was annotated for 26,687 high-confidence genes. Intriguingly, 20% of protein-coding genes were identified to have natural antisense transcripts characterized by high diversity in alternative splicing, thus offering insights into understanding transcriptional regulation. Our work will enhance the utility of Tetrahymena as a robust genetic toolkit for advancing biological research, and provides a promising framework for genome annotation in other eukaryotes.

Genome-Wide Identification and Functional Characterization of SKP1-like Gene Family Reveal Its Involvement in Response to Stress in Cotton

SKP1 constitutes the Skp1-Cullin-F-box ubiquitin E3 ligase (SCF), which plays a role in plant growth and development and biotic and abiotic stress in ubiquitination. However, the response of the SKP1-like gene family to abiotic and biotic stresses in cotton has not been well characterized. In this study, a total of 72 SKP1-like genes with the conserved domain of SKP1 were identified in four Gossypium species. Synteny and collinearity analyses revealed that segmental duplication played a major role in the expansion of the cotton SKP1-like gene family. All SKP1-like proteins were classified into three different subfamilies via phylogenetic analysis. Furthermore, we focused on a comprehensive analysis of SKP1-like genes in G. hirsutum. The cis-acting elements in the promoter site of the GhSKP1-like genes predict their involvement in multiple hormonal and defense stress responses. The expression patterns results indicated that 16 GhSKP1-like genes were expressed in response to biotic or abiotic stresses. To further validate the role of the GhSKP1-like genes in salt stress, four GhSKP1-like genes were randomly selected for gene silencing via VIGS. The results showed that the silencing of GhSKP1-like_7A resulted in the inhibition of plant growth under salt stress, suggesting that GhSKP1-like_7A was involved in the response to salt stress. In addition, yeast two-hybrid results revealed that GhSKP1-like proteins have different abilities to interact with F-box proteins. These results provide valuable information for elucidating the evolutionary relationships of the SKP1-like gene family and aiding further studies on the function of SKP1-like genes in cotton.

A fully phased, chromosome-scale genome of sugar beet line FC309 enables the discovery of Fusarium yellows resistance QTL

Sugar beet (Beta vulgaris L.) is a global source of table sugar and animal fodder. Here we report a highly contiguous, haplotype phased genome assembly and annotation for sugar beet line FC309. Both assembled haplomes for FC309 represent the largest and most contiguous assembled beet genomes reported to date, as well as gene annotations sets that capture over 1,500 additional protein-coding loci compared to prior beet genome annotations. These new genomic resources were used to identify novel quantitative trait loci (QTL) for Fusarium yellows resistance from the FC309 genetic background using an F2 mapping-by-sequencing approach. The highest QTL signals were detected on Chromosome 3, spanning approximately 10Mbp in both haplomes. A parallel transcriptome profiling experiment identified candidate genes within the Chromosome 3 QTL with plausible roles in disease response, including NBS-LRR genes with expression trends supporting a role in resistance. Investigation of genetic variants in these candidate genes found 1 major disease-resistance protein containing high-effect variants of interest. Collectively, the genomic resources for FC309 presented here are foundational tools for comparative genomics, mapping other traits in the FC309 background, and as a reference genome for other beet studies due to its contiguity, completeness, and high-quality gene annotations.

Genome-wide identification and gene expression pattern analysis of the glycoside hydrolase family 1 in Fagopyrum tataricum

BACKGROUND

The β-glucosidases (BGLU) of glycoside hydrolase family 1 hydrolyze the glycosidic bond to release β-D-glucose and related ligands, which are widely involved in important physiological processes in plants. Genome-wide analysis of the BGLU genes in the model crops Arabidopsis thaliana and Oryza sativa revealed that they are functionally diverse. In contrast, the BGLU gene family in Tartary buckwheat remains unclear.

RESULTS

This study identified the FtBGLU gene family based on Tartary buckwheat genomic data and analyzed the biological function of the FtBGLU gene using bioinformatics methods and the expression pattern of the gene using fluorescence quantitative PCR. The results showed that 39 BGLU genes were identified in Tartary buckwheat, which were classified into 10 subfamilies and one unclassified group. They were unevenly distributed on 10 chromosomes, and seven tandem duplication events involving 19 FtBGLU genes were observed, which mainly occurred in subfamily II. Their physicochemical properties are highly variable; however, they have relatively conserved exon-intron structures and high sequence homology in the subfamily, and most of the FtBGLUs contain conserved motifs, among which the expression products FtBGLU1, FtBGLU17, FtBGLU19, FtBGLU21, FtBGLU22, and FtBGLU28 have no β-glucosidase activity. Additionally, we analyzed the tissue expression specificity of 10 FtBGLU genes during Tartary buckwheat growth and development and their expression patterns under adversity stress and hormone treatments. Revealing the important role of the BGLU gene family in Tartary buckwheat growth and development, as well as its response to adversity, provides strong support for further analysis of its regulatory mechanisms and functional applications. A total of 39 FtBGLU genes were identified. Bioinformatics analysis of the gene structure, evolutionary relationship, and expression pattern of the Fagopyrum tataricum BGLU gene family establishes a foundation for a better understanding and future research on the Tartary buckwheat BGLU gene family.

Genome-wide identification, characterization and expression profiles of FORMIN gene family in cotton (Gossypium Raimondii L.)

BACKGROUND

Gossypium raimondii serves as a widely used genomic model cotton species. Its genetic influence to enhance fiber quality and ability to adapt to challenging environments both contribute to increasing cotton production. The formins are a large protein family that predominately consists of FH1 and FH2 domains. The presence of the formin domains highly regulates the actin and microtubule filament in the cytoskeleton dynamics confronting various abiotic stresses such as drought, salinity, and cold temperatures.

RESULTS

In this study, 26 formin genes were analyzed and characterized in G. raimondii and mostly were found in the nucleus and chloroplast. According to the evolutionary phylogenetic relationship, GrFH were dispersed and classified into seven different groups and shared an ancestry relationship with MtFH. The GrFH gene structure prediction revealed diverse intron-exon arrangements between groups. The FH2 conserved domain was found in all the GrFH distributed on 12 different chromosomes. Moreover, 11 pairs of GrFH transpired segmental duplication. Among them, GrFH4-GrFH7 evolved 35 million years ago (MYA) according to the evolutionary divergence time. Besides, 57 cis-acting regulatory elements (CAREs) motifs were found to play a potential role in plant growth, development, and in response to various abiotic stresses, including cold stress. The GrFH genes mostly exhibited biological processes resulting in the regulation of actin polymerization. The ERF, GATA, MYB, and LBD, major transcription factors (TFs) families in GrFH, regulated expression in abiotic stress specifically salt as well as defense against certain pathogens. The microRNA of GrFH unveiled the regulatory mechanism to regulate their gene expression in abiotic stresses such as salt and cold. One of the most economic aspects of cotton (G.raimondii) is the production of lint due to its use in manufacturing fabrics and other industrial applications. The expression profiles of GrFH in different tissues particularly during the conversion from ovule to fiber (lint), and the increased levels (up-regulation) of GrFH4, GrFH6, GrFH12, GrFH14, and GrFH26 under cold conditions, along with GrFH19 and GrFH26 in response to salt stress, indicated their potential involvement in combating these environmental challenges. Moreover, these stress-tolerant GrFH linked to cytoskeleton dynamics are essential in producing high-quality lint.

CONCLUSIONS

The findings from this study can contribute to elucidating the evolutionary and functional characterizations of formin genes and deciphering their potential role in abiotic stress such as cold and salt as well as in the future implications in wet lab.

Identification of the Wnt signal peptide that directs secretion on extracellular vesicles

Wnt proteins are hydrophobic glycoproteins that are nevertheless capable of long-range signaling. We found that Wnt7a is secreted long distance on the surface of extracellular vesicles (EVs) following muscle injury. We defined a signal peptide region in Wnts required for secretion on EVs, termed exosome-binding peptide (EBP). Addition of EBP to an unrelated protein directed secretion on EVs. Palmitoylation and the signal peptide were not required for Wnt7a-EV secretion. Coatomer was identified as the EV-binding protein for the EBP. Analysis of cocrystal structures, binding thermodynamics, and mutagenesis found that a dilysine motif mediates EBP binding to coatomer with a conserved function across the Wnt family. We showed that EBP is required for Wnt7a bioactivity when expressed in vivo during regeneration. Overall, our study has elucidated the structural basis and singularity of Wnt secretion on EVs, alternatively to canonical secretion, opening avenues for innovative therapeutic targeting strategies and systemic protein delivery.

Genetic Analysis of the Peach SnRK1β3 Subunit and Its Function in Transgenic Tomato Plants

BACKGROUND/OBJECTIVES

The sucrose non-fermentation-related kinase 1 (SnRK1) protein complex in plants plays an important role in energy metabolism, anabolism, growth, and stress resistance. SnRK1 is a heterotrimeric complex. The SnRK1 complex is mainly composed of α, β, βγ, and γ subunits. Studies on plant SnRK1 have primarily focused on the functional α subunit, with the β regulatory subunit remaining relatively unexplored. The present study aimed to elucidate the evolutionary relationship, structural prediction, and interaction with the core α subunit of peach SnRK1β3 (PpSnRK1) subunit.

METHODS

Bioinformatics analysis of PpSnRK1 was performed through software and website. We produced transgenic tomato plants overexpressing PpSnRK1 (OEPpSnRK1). Transcriptome analysis was performed on OEPpSnRK1 tomatoes. We mainly tested the growth index and drought resistance of transgenic tomato plants.

RESULTS

The results showed that PpSnRK1 has a 354 bp encoded protein sequence (cds), which is mainly located in the nucleus and cell membrane. Phylogenetic tree analysis showed that PpSnRK1β3 has similar domains to other woody plants. Transcriptome analysis of OEPpSnRK1β3 showed that PpSnRK1β3 is widely involved in biosynthetic and metabolic processes. Functional analyses of these transgenic plants revealed prolonged growth periods, enhanced growth potential, improved photosynthetic activity, and superior drought stress tolerance.

CONCLUSIONS

The study findings provide insight into the function of the PpSnRK1 subunit and its potential role in regulating plant growth and drought responses. This comprehensive analysis of PpSnRK1 will contribute to further enhancing our understanding of the plant SnRK1 protein complex.

Dominance of recombinant DWV genomes with changing viral landscapes as revealed in national US honey bee and varroa mite survey

Honey bees are essential pollinators for global agriculture. The viromes of US commercial apiaries and their ectoparasitic mites are poorly characterized at a strain level and there is a need to integrate genomics into pathogen surveillance. We sequenced RNA viromes from 383 adult bees and 173 mites pooled samples from 11 major US beekeeping hubs in 2021, assembling 45 complete and 1702 partial genomes. Protein sequence similarity networks and recombinant genome identification revealed a new viral landscape. Sinaivirus (n = 312), Iflavirus sacbroodi (n = 280), and Iflavirus aladeformis (DWV, n = 135) genomes were common. Recombinant DWV genomes with high nucleotide identity were widespread, and DWV type A master variants were rare, with an indication that RT-PCR surveillance may over-detect type A due to the prevalence of recombinant DWV genomes. Future work should use genomic strategies to avoid misidentification of common honey bee virus genomes and their impact on colony health.

Grapevine pangenome facilitates trait genetics and genomic breeding

Grapevine breeding is hindered by a limited understanding of the genetic basis of complex agronomic traits. This study constructs a graph-based pangenome reference (Grapepan v.1.0) from 18 newly generated phased telomere-to-telomere assemblies and 11 published assemblies. Using Grapepan v.1.0, we build a variation map with 9,105,787 short variations and 236,449 structural variations (SVs) from the resequencing data of 466 grapevine cultivars. Integrating SVs into a genome-wide association study, we map 148 quantitative trait loci for 29 agronomic traits (50.7% newly identified), with 12 traits significantly contributed by SVs. The estimated heritability improves by 22.78% on average when including SVs. We discovered quantitative trait locus regions under divergent artificial selection in metabolism and berry development between wine and table grapes, respectively. Moreover, significant genetic correlations were detected among the 29 traits. Under a polygenic model, we conducted genomic predictions for each trait. In general, our study facilitates the breeding of superior cultivars via the genomic selection of multiple traits.

Genome-wide analysis reveals the contributors to fast molecular evolution of the Chinese hook snout carp (Opsariichthys bidens)

Variations in molecular evolutionary rate have been widely investigated among lineages and genes. However, it remains an open question whether fast rate of molecular evolution is driven by natural selection or random drift, and how the fast rate is linked to metabolic rate. Additionally, previous studies on fast molecular evolution have been largely restricted to concatenated matrix of genes or a few specifically selected genes, but less is known for individual genes at the genome-wide level. Here we addressed these questions using more than 5000 single-copy orthologous (SCO) genes through comparative genomic and phylogenetic analyses among fishes, with a special focus on a newly-sequenced clupeocephalan fish the Chinese hook snout carp Opsariichthys bidens. We showed O. bidens displays significantly higher mean substitution rate and more fast-evolving SCO genes (2172 genes) than most fishes studied here. The rapidly evolving genes are enriched in highly conserved and very basic functions such as translation and ribosome that are critical for biological fitness. We further revealed that ∼25 % of these fast-evolving genes exhibit a constant increase of substitution rate from the common ancestor down to the present, suggesting a neglected but important contribution from ancestral states. Model fitting showed that ∼85 % of fast-evolving genes exclusive to O. bidens and related species follow the adaptive evolutionary model rather than random-drift model, and 7.6 % of fast-evolving genes identified in O. bidens have experienced positive selection, both indicating the reflection of adaptive selection. Finally, metabolic rate was observed to be linked with substitution rate in a gene-specific manner. Overall, our findings reveal fast molecular evolution of SCO genes at genome-wide level in O. bidens, and uncover the evolutionary and ecological contributors to it.

Genome-wide identification and expression analysis of the WRKY gene family reveal essential roles in abiotic stress responses and polysaccharides and flavonoids biosynthesis in Platostoma palustre (Blume) A. J. Paton

BACKGROUND

Platostoma palustre (Blume) A. J. Paton is an economic crop with medicinal and edible properties. WRKY transcription factors are widely involved in the growth and development, response to adversity stress, and hormone transduction of plants. The identification of the WRKY gene family has been completed in many plants, however, it has not yet been identified and analyzed at the genome-wide level in P. palustre.

RESULTS

In this study, we identified 133 PpWRKY gene family members (PpWRKYs) at the whole genome level of P. palustre, which were unevenly distributed on 15 chromosomes. Based on their protein structure and phylogenetic characteristics, the 133 PpWRKYs were divided into 3 subgroups. Segmental duplication events might play a crucial role in the expansion of the PpWRKY gene family. Through the transcriptome expression data analysis, the expression profiles of PpWRKY genes under Cd, red light, salt, and drought stresses were analyzed in this study, suggesting that WRKY transcription factors may play a crucial role in responding to different abiotic stresses in P. palustre. Notably, PpWRKY92 exhibited simultaneous responses to Cd, light intensity, salt, and drought stresses. Additionally, PpWRKY21, 75, 90, 52, 124, 39, 115, 122, 20, and 76 demonstrated a strong correlation with both monosaccharides and flavonoids. Taken together, PpWRKY20, 39, 75, 76, 90, 92, 115, 122, and 124 were found to be associated with the abiotic stress response and polysaccharides and flavonoids biosynthesis in P. palustre, except the low-expressed PpWRKY21 and 52.

CONCLUSION

The present study laid the foundation for the abiotic stress response and metabolite regulation of this gene family in P. palustre.

Chromosome-level genome assemblies and genetic maps reveal heterochiasmy and macrosynteny in endangered Atlantic Acropora

BACKGROUND

Over their evolutionary history, corals have adapted to sea level rise and increasing ocean temperatures, however, it is unclear how quickly they may respond to rapid change. Genome structure and genetic diversity contained within may highlight their adaptive potential.

RESULTS

We present chromosome-scale genome assemblies and linkage maps of the critically endangered Atlantic acroporids, Acropora palmata and A. cervicornis. Both assemblies and linkage maps were resolved into 14 chromosomes with their gene content and colinearity. Repeats and chromosome arrangements were largely preserved between the species. The family Acroporidae and the genus Acropora exhibited many phylogenetically significant gene family expansions. Macrosynteny decreased with phylogenetic distance. Nevertheless, scleractinians shared six of the 21 cnidarian ancestral linkage groups as well as numerous fission and fusion events compared to other distantly related cnidarians. Genetic linkage maps were constructed from one A. palmata family and 16 A. cervicornis families using a genotyping array. The consensus maps span 1,013.42 cM and 927.36 cM for A. palmata and A. cervicornis, respectively. Both species exhibited high genome-wide recombination rates (3.04 to 3.53 cM/Mb) and pronounced sex-based differences, known as heterochiasmy, with 2 to 2.5X higher recombination rates estimated in the female maps.

CONCLUSIONS

Together, the chromosome-scale assemblies and genetic maps we present here are the first detailed look at the genomic landscapes of the critically endangered Atlantic acroporids. These data sets revealed that adaptive capacity of Atlantic acroporids is not limited by their recombination rates. The sister species maintain macrosynteny with few genes with high sequence divergence that may act as reproductive barriers between them. In the Atlantic Acropora, hybridization between the two sister species yields an F1 hybrid with limited fertility despite the high levels of macrosynteny and gene colinearity of their genomes. Together, these resources now enable genome-wide association studies and discovery of quantitative trait loci, two tools that can aid in the conservation of these species.

Comparative and Spatial Transcriptome Analysis of Rhododendron decorum Franch. During the Flowering Period and Revelation of the Plant Defense Mechanism

BACKGROUND

Rhododendron is a globally distributed and extensive genus, comprising over 1000 species. In the southwestern mountains of China, there exists a remarkable diversity of Rhododendron, with Yunnan Province alone harboring more than 600 species. R. decorum Franch. has long been utilized by local communities for its medicinal and edible properties. However, the transcriptional regulation function, medicinal properties, and edibility characteristics of R. decorum Franch. currently lack a solid theoretical basis.

METHODS

Total RNA was extracted from leaves, corollas and androecium/gynoecium of R. decorum Franch. in Heqing county, followed by the construction of cDNA libraries and the de novo assembly of transcriptomes.

RESULTS

A total of 63,050 unigenes were extracted from the flowers and leaf organs of R. decorum Franch. Among these unigenes, 43,517 were predicted to be coding sequences, with 32,690 being effectively annotated. Differential gene expression enrichment was observed among different organs within their respective transcriptomes; notably floral organs exhibited significant defense against plant diseases along with signal transduction functions. Furthermore, during the flower harvesting period, all floral organs exhibited gene enrichment pathways associated with carbohydrate metabolism. Additionally, the stamen and pistil displayed flavonoid metabolism pathways, suggesting their potential applications as functional food or medicine.

CONCLUSIONS

Our results shed light on plant-pathogen defense mechanisms and the molecular bias of flavonoids biosynthesis on flower organs during the flowering period, which might help to understand the consumption of R. decorum Franch. corollas by the Bai nationality of Heqing county.

Genome-wide and functional analysis of late embryogenesis abundant (LEA) genes during dormancy and sprouting periods of kernel consumption apricots (P. armeniaca L. × P. sibirica L.)

Late embryogenesis abundant (LEA) proteins play a crucial role in protecting cells from stress, making them potential contributors to abiotic stress tolerance. This study focuses on apricot (P. armeniaca L. × P. sibirica L.), where a comprehensive genome-wide analysis identified 54 LEA genes, categorized into eight subgroups based on phylogenetic relationships. Synteny analysis revealed 14 collinear blocks containing LEA genes between P. armeniaca × P. sibirica and Arabidopsis thaliana, with an additional 9 collinear blocks identified between P. armeniaca × P. sibirica and poplar. Examination of gene structure and conserved motifs indicated that these subgroups exhibit consistent exon-intron patterns and shared motifs. The expansion and duplication of LEA genes in P. armeniaca × P. sibirica were driven by whole-genome duplication (WGD), segmental duplication, and tandem duplication events. Expression analysis, utilizing RNA-seq data and quantitative real-time RT-PCR (qRT-PCR), indicated induction of PasLEA2-20, PasLEA3-2, PasLEA6-1, Pasdehydrin-3, and Pasdehydrin-5 in flower buds during dormancy and sprouting phases. Coexpression network analysis linked LEA genes with 15 cold-resistance genes. Remarkably, during the four developmental stages of flower buds in P. armeniaca × P. sibirica - physiological dormancy, ecological dormancy, sprouting period, and germination stage - the expression patterns of all PasLEAs coexpressed with cold stress-related genes remained consistent. Protein-protein interaction networks, established using Arabidopsis orthologs, emphasized connections between PasLEA proteins and cold resistance pathways. Overexpression of certain LEA genes in yeast and Arabidopsis conferred advantages under cold stress, including increased pod length, reduced bolting time and flowering time, improved survival and seed setting rates, elevated proline accumulation, and enhanced antioxidative enzymatic activities. Furthermore, these overexpressed plants exhibited upregulation of genes related to flower development and cold resistance. The Y1H assay confirmed that PasGBF4 and PasDOF3.5 act as upstream regulatory factors by binding to the promoter region of PasLEA3-2. PasDOF2.4, PasDnaJ2, and PasAP2 were also found to bind to the promoter of Pasdehydrin-3, regulating the expression levels of downstream genes. This comprehensive study explores the evolutionary relationships among PasLEA genes, protein interactions, and functional analyses during various stages of dormancy and sprouting in P. armeniaca × P. sibirica. It offers potential targets for enhancing cold resistance and manipulating flower bud dormancy in this apricot hybrid.

Protein Involved in Tip Elongation (PITE) regulates root hair growth in rice

Polar tip growth in plants occurs only in root hairs and pollen tubes. In particular, root hair growth is considered very important in the growth of plants, as it is critical for water and nutrient absorption. Polar tip growth is regulated by various factors, including plant hormones such as abscisic acid (ABA) and gibberellin (GA) and cell wall modifications. We aimed to elucidate the effects and mechanisms on tip growth of a novel gene containing the domain of unknown function (DUF) 3511. We found that Protein Involved in Tip Elongation (PITE) is involved in root hair development in rice (Oryza sativa L.). PITE protein was observed in the plasma membrane and cytoplasm of root hairs. Pite mutants generated by the CRISPR/Cas9 system showed a shorter root hair phenotype compared to the wild type. Through RNA sequencing and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis, we found that the expression of genes that affect cell wall rigidity and GA metabolism-related genes were differently regulated in pite mutants. PITE could interact with acyl transferase and haloacid dehalogenase-like hydrolase (HAD9) in the nucleus and cytoplasm. Our study suggests that PITEs containing the DUF3511 domain regulate root hair growth in rice by mediating the expression of genes that can regulate cell wall rigidity or cause changes in GA metabolism through interactors such as HAD9.

Exploring structural diversity across the protein universe with The Encyclopedia of Domains

The AlphaFold Protein Structure Database (AFDB) contains more than 214 million predicted protein structures composed of domains, which are independently folding units found in multiple structural and functional contexts. Identifying domains can enable many functional and evolutionary analyses but has remained challenging because of the sheer scale of the data. Using deep learning methods, we have detected and classified every domain in the AFDB, producing The Encyclopedia of Domains. We detected nearly 365 million domains, over 100 million more than can be found by sequence methods, covering more than 1 million taxa. Reassuringly, 77% of the nonredundant domains are similar to known superfamilies, greatly expanding representation of their domain space. We uncovered more than 10,000 new structural interactions between superfamilies and thousands of new folds across the fold space continuum.

The coral Oculina patagonica holobiont and its response to confinement, temperature, and Vibrio infections

BACKGROUND

Extensive research on the diversity and functional roles of the microorganisms associated with reef-building corals has been promoted as a consequence of the rapid global decline of coral reefs attributed to climate change. Several studies have highlighted the importance of coral-associated algae (Symbiodinium) and bacteria and their potential roles in promoting coral host fitness and survival. However, the complex coral holobiont extends beyond these components to encompass other entities such as protists, fungi, and viruses. While each constituent has been individually investigated in corals, a comprehensive understanding of their collective roles is imperative for a holistic comprehension of coral health and resilience.

RESULTS

The metagenomic analysis of the microbiome of the coral Oculina patagonica has revealed that fungi of the genera Aspergillus, Fusarium, and Rhizofagus together with the prokaryotic genera Streptomyces, Pseudomonas, and Bacillus were abundant members of the coral holobiont. This study also assessed changes in microeukaryotic, prokaryotic, and viral communities under three stress conditions: aquaria confinement, heat stress, and Vibrio infections. In general, stress conditions led to an increase in Rhodobacteraceae, Flavobacteraceae, and Vibrionaceae families, accompanied by a decrease in Streptomycetaceae. Concurrently, there was a significant decline in both the abundance and richness of microeukaryotic species and a reduction in genes associated with antimicrobial compound production by the coral itself, as well as by Symbiodinium and fungi.

CONCLUSION

Our findings suggest that the interplay between microeukaryotic and prokaryotic components of the coral holobiont may be disrupted by stress conditions, such as confinement, increase of seawater temperature, or Vibrio infection, leading to a dysbiosis in the global microbial community that may increase coral susceptibility to diseases. Further, microeukaryotic community seems to exert influence on the prokaryotic community dynamics, possibly through predation or the production of secondary metabolites with anti-bacterial activity. Video Abstract.

Novel cellular functions of Cys2-His2 zinc finger proteins in anthracnose development and dissemination on pepper fruits by Colletotrichum scovillei

Colletotrichum species are notorious for causing anthracnose on many fruits, leading to significant economic losses worldwide. As a model, we functionally characterized cys2-his2 (C2H2) zinc finger proteins (CsCZFs) in Colletotrichum scovillei, a major causal agent of pepper fruit anthracnose in many countries. In all, 62 CsCZFs were identified by in silico genomic analysis. Twelve were selected based on their expression profiles to generate targeted deletion mutants for functional investigation. ΔCsczf1 markedly reduced conidiation and constitutive expression of CsCZF1 partially recovered conidiation in an asexual reproduction-defective mutant, ΔCshox2. Deletion of CsCZF12, orthologous to the calcineurin-responsive transcription factor Crz1, impaired autophagy in C. scovillei. ΔCsczf9 was defective in surface recognition, appressorium formation, and suppression of host defenses. CsCZF9 was identified as an essential and novel regulator under the control of the mitogen-activated protein kinase (CsPMK1) in an early step of appressorium development in C. scovillei. This study provides novel insights into CsCZF-mediated regulation of differentiation and pathogenicity in C. scovillei, contributing to understanding the regulatory mechanisms governing fruit anthracnose epidemics.IMPORTANCEThe phytopathogenic fungus Colletotrichum scovillei is known to cause serious anthracnose on chili pepper. However, the molecular mechanism underlying anthracnose caused by this fungus remains largely unknown. Here, we systematically analyzed the functional roles of cys2-his2 zinc finger proteins (CsCZFs) in the dissemination and pathogenic development of this fungus. Our results showed that CsCZF1 plays an important role in conidiation and constitutive expression of CsCZF1 restored conidiation in an asexual reproduction-defective mutant, ΔCshox2. The CsCZF9, a novel target of the mitogen-activated protein kinase (CsPMK1), is essential for surface recognition to allow appressorium formation and suppression of host defenses in C. scovillei. The CsCZF12, orthologous to the calcineurin-responsive transcription factor Crz1, is involved in the autophagy of C. scovillei. Our findings reveal a comprehensive mechanism underlying CsCZF-mediated regulation of differentiation and pathogenicity of C. scovillei, which contributes to the understanding of fruit anthracnose epidemics and the development of novel strategies for disease management.

A combination of joint linkage and genome-wide association study reveals putative candidate genes associated with resistance to northern corn leaf blight in tropical maize

Northern corn leaf blight (NCLB), caused by Setosphaeria turcica, is a major fungal disease affecting maize production in sub-Saharan Africa. Utilizing host plant resistance to mitigate yield losses associated with NCLB can serve as a cost-effective strategy. In this study, we conducted a high-resolution genome-wide association study (GWAS) in an association mapping panel and linkage mapping with three doubled haploid (DH) and three F3 populations of tropical maize. These populations were phenotyped for NCLB resistance across six hotspot environments in Kenya. Across environments and genotypes, NCLB scores ranged from 2.12 to 5.17 (on a scale of 1-9). NCLB disease severity scores exhibited significant genotypic variance and moderate-to-high heritability. From the six biparental populations, 23 quantitative trait loci (QTLs) were identified, each explaining between 2.7% and 15.8% of the observed phenotypic variance. Collectively, the detected QTLs explained 34.28%, 51.37%, 41.12%, 12.46%, 12.11%, and 14.66% of the total phenotypic variance in DH populations 1, 2, and 3 and F3 populations 4, 5, and 6, respectively. GWAS, using 337,110 high-quality single nucleotide polymorphisms (SNPs), identified 15 marker-trait associations and several putative candidate genes linked to NCLB resistance in maize. Joint linkage association mapping (JLAM) identified 37 QTLs for NCLB resistance. Using linkage mapping, JLAM, and GWAS, several QTLs were identified within the genomic region spanning 4 to 15 Mbp on chromosome 2. This genomic region represents a promising target for enhancing NCLB resistance via marker-assisted breeding. Genome-wide predictions revealed moderate correlations with mean values of 0.45, 0.44, 0.55, and 0.42 for within GWAS panel, DH pop1, DH pop2, and DH pop3, respectively. Prediction by incorporating marker-by-environment interactions did not show much improvement. Overall, our findings indicate that NCLB resistance is quantitative in nature and is controlled by few major-effect and many minor-effect QTLs. We conclude that genomic regions consistently detected across mapping approaches and populations should be prioritized for improving NCLB resistance, while genome-wide prediction results can help incorporate both major- and minor-effect genes. This study contributes to a deeper understanding of the genetic and molecular mechanisms driving maize resistance to NCLB.