De novo assembly of the Aedes aegypti genome using Hi-C yields chromosome-length scaffolds

Construction of the super pan-genome for the genus Actinidia reveals structural variations linked to phenotypic diversity

Kiwifruits, belonging to the genus Actinidia, are acknowledged as one of the most successfully domesticated fruits in the twentieth century. Despite the rich wild resources and diverse phenotypes within this genus, insights into the genomic changes are still limited. Here, we conducted whole-genome sequencing on seven representative materials from highly diversified sections of Actinidia, leading to the assembly and annotation of 14 haplotype genomes with sizes spanning from 602.0 to 699.6 Mb. By compiling these haplotype genomes, we constructed a super pan-genome for the genus. We identified numerous structural variations (SVs, including variations in gene copy number) and highly diverged regions in these genomes. Notably, significant SV variability was observed within the intronic regions of the MED25 and TTG1 genes across different materials, suggesting their potential roles in influencing fruit size and trichome formation. Intriguingly, our findings indicated a high genetic divergence between two haplotype genomes, with one individual, tentatively named Actinidia × leiocacarpae, from sect. Leiocacarpae. This likely hybrid with a heterozygous genome exhibited notable genetic adaptations related to resistance against bacterial canker, particularly through the upregulation of the RPM1 gene, which contains a specific SV, after infection by Pseudomonas syringae pv. actinidiae. In addition, we also discussed the interlineage hybridizations and taxonomic treatments of the genus Actinidia. Overall, the comprehensive pan-genome constructed here, along with our findings, lays a foundation for examining genetic compositions and markers, particularly those related to SVs, to facilitate hybrid breeding aimed at developing desired phenotypes in kiwifruits.

Genome sequence of the wild species, Spinacia tetrandra, including a phased sequence of the extensive sex-linked region, revealing partial degeneration in evolutionary strata with unusual properties

Genetic degeneration is a striking feature of Y chromosomes, often involving losses of many genes carried on the X chromosome. However, the time course of gene losses remains unclear. Sex chromosomes of plants evolved more recently than animals' highly degenerated ones, making them ideal for studying degeneration timing. To investigate Spinacia sex chromosome evolution and the time course of degeneration, we compared genome sequences of cultivated Spinacia oleracea, with a small Y-linked region on Chr4, with its two wild relatives. In spinach and its closest relative Spinacia turkestanica, the Y duplication region (YDR) introduced a male-determining factor into Chr4's low-recombining pericentromeric region. In other words, a turnover event occurred in these species' recent common ancestor. The homologous Chr4 of the more distantly related S. tetrandra has a c. 133 Mb completely sex-linked and partially degenerated region, possibly reflecting the ancestral state. Sequence divergence analysis suggests that two 'evolutionary strata' evolved shortly before the two Spinacia lineages split. Consistent with the turnover hypothesis, the YDR of the other two Spinacia species is not within the S. tetrandra older stratum. We discuss the unexpected findings in S. tetrandra that genetic degeneration, genomic rearrangements, and repetitive sequence density are all greatest in the younger stratum.

Integrative omics reveals mechanisms of biosynthesis and regulation of floral scent in Cymbidium tracyanum

Flower scent is a crucial determiner in pollinator attraction and a significant horticultural trait in ornamental plants. Orchids, which have long been of interest in evolutionary biology and horticulture, exhibit remarkable diversity in floral scent type and intensity. However, the mechanisms underlying floral scent biosynthesis and regulation in orchids remain largely unexplored. In this study, we focus on floral scent in Cymbidium tracyanum, a wild species known for its strong floral fragrance and as a primary breeding parent of commercial Cymbidium hybrids. We present a chromosome-level genome assembly of C. tracyanum, totaling 3.79 Gb in size. Comparative genomic analyses reveal significant expansion of gene families associated with terpenoid biosynthesis and related metabolic pathways in C. tracyanum. Integrative analysis of genomic, volatolomic and transcriptomic data identified terpenoids as the predominant volatile components in the flowers of C. tracyanum. We characterized the spatiotemporal patterns of these volatiles and identified CtTPS genes responsible for volatile terpenoid biosynthesis, validating their catalytic functions in vitro. Dual-luciferase reporter assays, yeast one-hybrid assays and EMSA experiments confirmed that CtTPS2, CtTPS3, and CtTPS8 could be activated by various transcription factors (i.e., CtAP2/ERF1, CtbZIP1, CtMYB2, CtMYB3 and CtAP2/ERF4), thereby regulating the production of corresponding monoterpenes and sesquiterpenes. Our study elucidates the biosynthetic and regulatory mechanisms of floral scent in C. tracyanum, which is of great significance for the breeding of fragrant Cymbidium varieties and understanding the ecological adaptability of orchids. This study also highlights the importance of integrating multi-omics data in deciphering key horticultural traits in orchids.

A natural variation of flavone synthase II gene enhances flavone accumulation and confers drought adaptation in chrysanthemum

Flavones, a key group of flavonoids, play a significant role in plant adaptation to ecological niches and are valuable medicinal resources. However, the genetic basis underlying their contribution to ecological adaptation remains largely unknown. Here, using metabolite-based genome-wide association study, we report that the natural variation of flavone contents in Chrysanthemum indicum, a wild chrysanthemum and medicinal herb, is mainly determined by a recently duplicated flavone synthase II gene CiFNSII-1.2. Enzymatic assays and molecular dynamics simulations reveal that the key amino acid residues 246th and 261th confer the higher enzymatic activity of CiFNSII-1.2 compared with its ancestral form. These residues act as critical modulators, regulating the flexibility of the external entrance and contributing to the enzyme's improved functionality. Transgenic evaluation demonstrate that CiFNSII-1.2 contributes to flavone accumulation and drought adaptation. Our findings provide insights into the biochemical and evolutionary role of flavones in facilitating adaptation to drought-prone habitats in chrysanthemum.

Chromosomal-level genome assembly of solitary bee pollinator Osmia excavata Alfken (Hymenoptera: Megachilidae)

Osmia spp. is a genus of solitary bees that serves as excellent pollinators for various fruit trees and has the potential to enhance pollination services in both agricultural and natural ecosystems. However, the absence of high-quality genomic resources limits our insights into evolutionary biology and ecological adaptations of Osmia. Here, we present a chromosome-level genome of Osmia excavata, using PacBio, Illumina, and Hi-C data. The genome has a total size of 164.35 Mb, with a scaffold N50 of 9.81 Mb, and the majority of contigs (98.50%, 161.88 Mb) are organized into sixteen chromosomes. BUSCO analysis reveals a completeness score of 99.7% (n = 1,367), with 99.6% identified as single-copy BUSCOs and 0.1% as duplicated BUSCOs. The genome contains 13.46% (22.11 Mb) repetitive elements and encodes 11,452 predicted protein-coding genes. This study provides a crucial genomic resource for our understanding of solitary bees' evolution and ecological roles.

Chromosome-level genome assembly of scalloped spiny lobster Panulirus homarus homarus

Lobsters, aquatic organisms of significant economic value, hold an important position in the global aquaculture and fisheries industries. However, due to overfishing and ecological change, the populations of certain lobster species have declined dramatically, prompting conservation efforts in various countries. However, limited genomics research has restricted our capacity to conserve and exploit lobster germplasm resources. Here, we present a chromosome-level reference genome for Panulirus homarus homarus constructed using PacBio long-read sequencing and Hi-C data. The genome assembly size was 2.61 Gb, with a contig N50 of 5.43 Mb, and a scaffold N50 of 36.69 Mb. The assembled sequences were anchored to 73 chromosomes, covering 96.05% of the total genome. A total of 25,580 protein-coding genes were predicted, and 99.98% of the genes were functionally annotated using various protein databases. The high-quality genome assembly provides a valuable resource for studying the biology and evolutionary history of P. h. homarus, and could facilitate sustainable resource management, aquaculture, and conservation of the species.

Chromosome-level genome assembly of Sambus kanssuensis (Coleoptera: Buprestidae)

Sambus kanssuensis Ganglbauer, 1890 (Coleoptera: Buprestidae), distributed in Gansu and Sichuan Provinces of China, is a phytophagous pest that feeds on the toxic plant Buddleja. However, the genomic resources of this beetle remain unknown, which impedes the understanding of its ecological adaptations. Consequently, this study presents a complete, well-assembled, and annotated genome of S. kanssuensis. The assembled results indicate a genome size of 312.42 Mb, comprising 206 scaffolds, with an N50 of 34.04 Mb; 98.68% of the assembly sequences were anchored to 11 chromosomes, including one sex chromosome. The genome contains 12,723 protein-coding genes, of which 11,977 have been annotated. BUSCO analysis revealed that the completeness of the chromosome-level genome is 97.9%. This chromosome-level genome provides valuable data for further investigations into detoxification mechanisms, ecological adaptations, population genetics, and the evolution of Buprestidae.

Chromosome-level genome assemblies of Verpa bohemica and Verpa conica

Verpa, commonly known as "early morel" or "false morel", plays an important ecological role and offers considerable economic and medicinal potential. Despite their significance, research on Verpa species, particularly V. bohemica and V. conica, remains limited. In this study, we assembled high-quality sub-chromosomal genomes of six Verpa strains using Nanopore and Illumina sequencing, with average sizes of 44.38 Mb for V. bohemica and 45.40 Mb for V. conica. Specifically, the assemblies of V. bohemica strain 21108 and V. conica strain 21120 were anchored to 26 and 25 chromosomes with Hi-C technologies, respectively. The consensus quality value (QV) of both V. bohemica and V. conica exceeded 40. In addition, an average of 11,024 and 11,052 protein-coding genes were identified for V. bohemica and V. conica, respectively, with BUSCO completeness scores ranging from 98.71% to 99.24%. Overall, these reported genomes will provide valuable genomic resources for the evolution and ecological roles research of Verpa.

High-quality assembly of the chromosomal genome for Flemingia macrophylla reveals genomic structural characteristics

Flemingia macrophylla, a prominent shrub species within the Fabaceae family, is widely distributed across China and Southeast Asia. In addition to its ecological importance, it possesses notable medicinal value, with its roots traditionally used for treating rheumatism, enhancing blood circulation, and alleviating joint pain. We employed Nanopore sequencing platforms to generate a high-quality reference genome for F. macrophylla, with an assembled genome size of 1.01 Gb and a contig N50 of 59.43 Mb. A total of 33,077 protein-coding genes were predicted, and BUSCO analysis indicated a genome completeness of 99%. Phylogenomic analyses showed that F. macrophylla is most closely related to Cajanus cajan among the sampled taxa, with an estimated divergence time of 13.2-20.0 MYA. Evidence of whole-genome duplication (WGD) events was detected in F. macrophylla, C. cajan, and P. vulgaris, with these species sharing two WGD events. The unique gene families in F. macrophylla are associated with strong resistance to both abiotic and biotic stress, supporting its remarkable ecological adaptability. Furthermore, gene family expansion analysis revealed a significant enrichment of genes related to secondary metabolites biosynthesis, providing a molecular basis for its high medicinal value. In summary, this study provides a foundational genomic resource for F. macrophylla, offering valuable insights into its genetic architecture, evolutionary history, and potential applications in medecine and agriculture. The comprehensive analyses lay the groundwork for future research into the species's medicinal properties and evolutionary biology.

A chromosomal-level genome assembly of Araneus marmoreus Schenkel, 1953 (Araneae: Araneidae)

The marbled orb-weaver spider, Araneus marmoreus (Araneae: Araneidae), is distinguished by its unique inflated, pumpkin-like abdomen. Numerous genome studies have been conducted on Araneidae species, providing insights into their unique biological traits. However, studies on A. marmoreus remain limited, despite its ecological significance and intriguing morphology. The lack of a high-quality reference genome has further hindered in-depth exploration of its evolutionary biology and ecological dynamics. Here, we present a chromosome-level genome assembly for A. marmoreus, generated using a combination of Illumina, PacBio, and Hi-C sequencing technologies. The assembled genome is 2.39 Gb in size, comprising 13 chromosomes, with a scaffold N50 of 181.8 Mb and a contig N50 of 721.3 kb. The assembly achieved a BUSCO completeness score of 97.1% (n = 2,934), including 91.0% complete and single-copy BUSCOs and 6.1% complete and duplicated BUSCOs. Repetitive sequences accounted for 59.25% of the genome, and 23,381 protein-coding genes were annotated. This high-quality genome provides a valuable resource for advancing research into the evolutionary genomics and ecological dynamics of A. marmoreus.

Chromosome-level genome assembly for clubrush (Scirpus × mariqueter) endemic to China

Scirpus × mariqueter (Tang & F.T.Wang) Tatanov, which is endemic to eastern estuaries in China, is a tidal zone-engineering species with great promise for managing greenhouse gases and enhancing ecosystem resilience against invasive species. Although S. mariqueter is widely recognized as a hybrid species derived from Bolboschoenus planiculmis (F. Schmidt) T.V. Egorova and Schoenoplectus triqueter (L.) Palla, its speciation remains highly controversial. The lack of a reference genome is the major cause of this ambiguity. We generated the first chromosome-level genome assembly for S. mariqueter combining PacBio long-reads, Illumina short-reads, and the Hi-C method. The genome assembly consisted of 227.75 Mb (contig N50: 3.89 Mb). We also constructed a haploid karyotype comprising 54 pseudochromosomes. The average size of these pseudochromosomes was small (4.05 Mb). Thirty-two pseudochromosomes were assembled to a telomere to telomere level. Repetitive elements represented approximately 54.12% of the genome. We predicted and annotated 25,239 protein-coding genes. The overall BUSCO score was 95.10%, with notably few duplicated genes (1.70%). This high-quality genome provides critical data for future studies.

The whole genome sequence of Cordyceps cicadae - an edible and potential medicinal fungus

Cordyceps cicadae is an entomopathogenic fungus from the Cordyceps genus and a well-known edible mushroom with a long history of use in Asia. It contains many bioactive compounds beneficial to human health, giving it broad application prospects in medicine. In this study, we generated the complete genome sequence of C. cicadae strain 2-2 using a combination of Illumina, PacBio, and Hi-C sequencing technologies. This comprehensive genome sequence comprises 9 chromosomes, an N50 contig size of 4,798,690 bp, a GC content ratio of 52.65%, a total size of 34.60 Mb, and 8,019 predicted coding genes. Additionally, we conducted functional annotation of the genome, revealing that 63.2% of the genes were enriched in 50 GO terms and 87.8% in 387 KEGG pathways. We also identified 542 enzyme genes, noting that C. cicadae has a greater number of GHs compared to other fungi in the Cordyceps genus. Notably, NR database analysis revealed that 6,441 genes in C. cicadae are similar to those in Cordyceps fumosorosea, suggesting that C. cicadae may serve as a cost-effective alternative to this expensive traditional medicinal fungus. This study presents the first chromosome-level genome of the Cordyceps genus, providing a comprehensive analysis of the genetic composition and functions of C. cicadae and establishing a foundation for advancing research and development of Cordyceps fungi.

Chromosome-scale whole genome assembly and annotation of the Jamaican field cricket Gryllus assimilis

Gryllus assimilis, commonly known as Jamaican field cricket, is an edible insect with significant economic value in sustainable food production. Despite its importance, a high-quality reference genome of G. assimilis has not yet been published. Here, we report a chromosome-level reference genome of G. assimilis based on Oxford Nanopore Technologies (ONT) sequencing, Illumina sequencing, and Hi-C technologies. The assembled genome has a total length of 1.60 Gbp with a scaffold N50 of 102 Mbp, and 96.80% of the nucleotides was assigned to 15 chromosome-scale scaffolds. The assembly completeness was validated using BUSCO, achieving 99.5% completeness against the arthropoda database. We predicted 27,645 protein-coding genes, and 825 Mb repetitive elements were annotated in the reference genome. This reference genome of G. assimilis can provide a basis for the subsequent development of genomic resources, offering insights for future functional genomic studies, comparative genomics, and DNA-informed breeding of this species.

A vetiver-specific terpene synthase VzTPS9 contributes to the high attractiveness of vetiver to rice stem borer

Vetiver (Vetiveria zizanioides) is highly attractive to the rice stem borer (Chilo suppressalis, RSB) and is widely utilized as a trap plant for RSB control in East Asia. However, the underlying mechanism driving this high level of attractiveness remains unclear. In this study, we identified volatiles emitted by vetiver using SPME/GC-MS and found that cedrol constitutes 12.15% of the total volatile profile. Both Y-tube olfactometer and electroantennography assays revealed that cedrol is highly attractive to female RSB moths at a concentration of 200 μg/μL. To investigate the mechanism responsible for the high level of cedrol in vetiver, we sequenced and assembled a chromosome-level genome of vetiver, identifying a vetiver-specific terpene synthase, VzTPS9, which is responsible for the synthesis of cedrol from farnesyl pyrophosphate (FPP). Subsequently, we constructed a transgenic rice line by integrating VzTPS9 into the rice genome. Enzyme assays and gene expression analyses demonstrated that the transgenic rice produced higher levels of cedrol, which were positively correlated with VzTPS9 expression levels, and consequently, with increased attractiveness to female RSB moths. These findings suggest that increased expression of VzTPS9 in vetiver leads to elevated cedrol synthesis, contributing to its enhanced attractiveness to RSB. This work uncovers the molecular mechanism behind vetiver's high attractiveness to RSB and provides valuable insights for developing more effective strategies for utilizing vetiver as a trap plant in RSB control.

Genomic structure of yellow lupin (Lupinus luteus): genome organization, evolution, gene family expansion, metabolites and protein synthesis

Yellow lupin (Lupinus luteus) gives valuable high-quality protein and has good sustainability due to its ability in nitrogen fixation and exudation of organic acids, which reduces the need for chemical-based phosphate fertilization in acid soils. However, the crop needs further improvements to contribute in a major way to sustainable agriculture and food security.In this study, we present the first chromosome-level genome assembly of L. luteus. The results provide insights into its genomic organization, evolution, and functional attributes. Using integrated genomic approaches, we unveil the genetic bases governing its adaptive responses to environmental stress, delineating the intricate interplay among alkaloid biosynthesis, mechanisms of pathogen resistance, and secondary metabolite transporters. Our comparative genomic analysis of closely related species highlights recent speciation events within the Lupinus genus, exposing extensive synteny preservation alongside notable structural alterations, particularly chromosome translocations. Remarkable expansions of gene families implicated in terpene metabolism, stress responses, and conglutin proteins were identified, elucidating the genetic basis of L. luteus' superior nutritional profile and defensive capabilities. Additionally, a diverse array of disease resistance-related (R) genes was uncovered, alongside the characterization of pivotal enzymes governing quinolizidine alkaloid biosynthesis, thus shedding light on the molecular mechanisms underlying "bitterness" in lupin seeds.This comprehensive genomic analysis serves as a valuable resource to improve this species in terms of resilience, yield, and seed protein levels to contribute to food and feed to face the worldwide challenge of sustainable agriculture and food security.

Haplotype-resolved genome assembly provides insights into the genetic basis of green peach aphid resistance in peach

Green peach aphid (GPA) is one of the most destructive pests of peach, threatening both growth and fruit quality. However, the mechanism underlying GPA resistance remains unclear. Here, we performed haplotype-resolved genome assembly of a GPA-resistant cultivar and identified an allele-specific expressed gene, PpNLR1, responsible for the GPA-resistant trait. A genome-wide association study (GWAS) revealed a functional 20-bp insertion or deletion (indel) in the PpNLR1 promoter, which co-segregated with the GPA-resistant trait and directly influenced promoter activity. Furthermore, jasmonate (JA) signaling, activated during GPA infestation, induced the transcription of PpERF109. This transcription factor specifically bound to the "CAAGT" motif within the GWAS-identified 20-bp insertion of the PpNLR1 promoter, resulting in allele-specific expression (ASE). Functional validation of the two alleles (PpNLR1-Hap1 and PpNLR1-Hap2) in both peach and Arabidopsis demonstrated their role in aphid resistance. Additionally, two GPA salivary proteins were identified as effectors, triggering reactive oxygen species (ROS) and activating the peach immune system in conjunction with the PpNLR1 protein. Comparative genomics and phylogenetic analysis indicated that an ∼53.6-kb genomic variation surrounding PpNLR1 underwent negative selection during peach evolution. In conclusion, the JA-mediated PpERF109-PpNLR1 module and GPA effector proteins significantly contribute to GPA resistance in peach. The novel haplotype-resolved genome assembly and identified key genes provide valuable resources for future genomic research and GPA resistance breeding in peach.

Two haplotype-resolved telomere-to-telomere genome assemblies of Xanthoceras sorbifolium

Yellowhorn (Xanthoceras sorbifolium) is widely used in northern China for landscaping, desertification control, and oil production. However, the lack of high-quality genomes has hindered breeding and evolutionary studies. Here, we present the first haplotype-resolved, telomere-to-telomere (T2T) yellowhorn genomes of PBN-43 (white single-flowered) and PBN-126 (white double-flowered) using PacBio HiFi and Hi-C data. These assemblies range from 464.34 Mb to 468.97 Mb and include all centromeres and telomeres. Genome annotation revealed that an average of 67.99% (317.09 Mb) of yellowhorn genomic regions consist of repetitive elements across all haplotypes. The number of protein-coding genes ranges from 35,039 to 35,174 among assemblies, representing an average 50.16% increase over the first published yellowhorn genome. Additionally, 93.90% of the annotated genes have functional annotations. We found yellowhorn experienced an LTR-RT burst during the last 0.45-0.48 Mya. These data provide a resource for investigating genomic variations, phylogenetic relationships, duplication modes, and the distribution of nucleotide-binding leucine-rich repeat (NLR) genes, and support further research into yellowhorn breeding.

Scaffolded and annotated nuclear and organelle genomes of the North American brown alga Saccharina latissima

Increasing the genomic resources of emerging aquaculture crop targets can expedite breeding processes as seen in molecular breeding advances in agriculture. High quality annotated reference genomes are essential to implement this relatively new molecular breeding scheme and benefit research areas such as population genetics, gene discovery, and gene mechanics by providing a tool for standard comparison. The brown macroalga Saccharina latissima (sugar kelp) is an ecologically and economically important kelp that is found in both the northern Pacific and Atlantic Oceans. Cultivation of Saccharina latissima for human consumption has increased significantly this century in both North America and Europe, and its single blade morphology allows for dense seeding practices used in the cultivation of its Asian sister species, Saccharina japonica. While Saccharina latissima has potential as a human food crop, insufficient information from genetic resources has limited molecular breeding in sugar kelp aquaculture. We present scaffolded and annotated Saccharina latissima nuclear and organelle genomes from a female gametophyte collected from Black Ledge, Groton, Connecticut. This Saccharina latissima genome compares well with other published kelp genomes and contains 218 scaffolds with a scaffold N50 of 1.35 Mb, a GC content of 49.84%, and 25,012 predicted genes. We also validated this genome by comparing the synteny and completeness of this Saccharina latissima genome to other kelp genomes. Our team has successfully performed initial genomic selection trials with sugar kelp using a draft version of this genome. This Saccharina latissima genome expands the genetic toolkit for the economically and ecologically important sugar kelp and will be a fundamental resource for future foundational science, breeding, and conservation efforts.

New insights into the cold tolerance of upland switchgrass by integrating a haplotype-resolved genome and multi-omics analysis

BACKGROUND

Switchgrass (Panicum virgatum L.) is a bioenergy and forage crop. Upland switchgrass exhibits superior cold tolerance compared to the lowland ecotype, but the underlying molecular mechanisms remain unclear.

RESULTS

Here, we present a high-quality haplotype-resolved genome of the upland ecotype "Jingji31." We then conduct multi-omics analysis to explore the mechanism underlying its cold tolerance. By comparative transcriptome analysis of the upland and lowland ecotypes, we identify many genes with ecotype-specific differential expression, particularly members of the cold-responsive (COR) gene family, under cold stress. Notably, AFB1, ATL80, HOS10, and STRS2 gene families show opposite expression changes between the two ecotypes. Based on the haplotype-resolved genome of "Jingji31," we detect more cold-induced allele-specific expression genes in the upland ecotype than in the lowland ecotype, and these genes are significantly enriched in the COR gene family. By genome-wide association study, we detect an association signal related to the overwintering rate, which overlaps with a selective sweep region containing a cytochrome P450 gene highly expressed under cold stress. Heterologous overexpression of this gene in rice alleviates leaf chlorosis and wilting under cold stress. We also verify that expression of this gene is suppressed by a structural variation in the promoter region.

CONCLUSIONS

Based on the high-quality haplotype-resolved genome and multi-omics analysis of upland switchgrass, we characterize candidate genes responsible for cold tolerance. This study advances our understanding of plant cold tolerance, which provides crop breeding for improved cold tolerance.

A haplotype-resolved genome assembly and gene expression map of Cushion willow

Salix brachista, commonly known as Cushion willow, is a common component of subnival alpine assemblages and a dioecious or monoecious plant with a creeping stem and numerous lateral branches. Cushion willow takes cuttings more easier and has a specific sex system, making it a suitable system for studying the evolution of plant sex determination, adaptive evolution of alpine plants, and mining stress resistance gene resource that cope with the hostile alpine environment. Therefore, Cushion willow has potential value in genetic improvements for willows used as bioenergy crops, in gardening, and as ornamental plants. However, the genome of Cushion willow still contains some un-assembled repetitive sequences, and there is limited availability of a gene expression atlas, which hinders its potential use for the aforementioned purposes. Here, we updated the genome of Cushion willow to be haplotype-resolved and near telomere-to-telomere, and obtained a high-quality transcriptomic map. Our research provides a potential model species for alpine adaptive research, sex determination evolution studies, and improving willow crops.

The telomere-to-telomere genome assembly and annotation of the rock carp (Procypris rabaudi)

Procypris rabaudi, commonly known as the rock carp, is an endemic economic fish in the middle-upper reaches of the Yangtze River. To enhance the understanding the biology of rack carps, a high-quality reference genome is required in different areas of study. Here, we generated the first telomere-to-telomere genome assembly and annotation of the rock carp, which spans 1.64 Gb with a contig N50 of 32.36 Mb. Hi-C assembly suggested that 99.83% sequences were positioned to 50 pseudo-chromosomes. Notably, 43 chromosomes were assembled without any gap. Through the integration of homologous-based predictions and RNA-sequencing technology, we identified 44,402 protein-coding genes, with 43,663 of them (98.3%) predicted to be functional. Furthermore, our assembled genome achieved 98.1% BUSCO completeness. This work improves the quality of the rock carp genome and provides valuable foundation for the future studies of genomics, biology and the fishery resources breeding.

Chromosome-scale assembly of Artemia tibetiana genome, first aquatic invertebrate genome from Tibet Plateau

Genomic-level studies on the adaptive evolution of animals in the Qinghai-Tibet Plateau have been rapidly increasing. However, most studies are concentrated on vertebrates, and there are few reports on invertebrates. Here, we report the chromosome-level genome assembly for the brine shrimp Artemia tibetiana from Kyêbxang Co, a high-altitude (4620 m above sea level) salt lake on the plateau, based on the combination of Illumina, Nanopore long-reads and Hi-C sequencing data. The assembled genome is 1.69 Gb, and 94.83% of the assembled sequences are anchored to 21 pseudo-chromosomes. Approximately 75% of the genome was identified as repetitive sequences, which is higher than most crustaceans documented so far. A total of 17,988 protein-coding genes were identified, among them 14,388 were functionally annotated. This genomic resource provides the foundation for whole-genome level investigation on the genetic adaptation of Artemia to the harsh conditions in the Qinghai-Tibet Plateau.

Haplotype-resolved genomes provide insights into the origins and functional significance of genome diversity in bivalves

Bivalves are famed for exhibiting vast genetic diversity of poorly understood origins and functional significance. Through comparative genomics, we demonstrate that high genetic diversity in these invertebrates is not directly linked to genome size. Using oysters as a representative clade, we show that despite genome size reduction during evolution, these bivalves maintain remarkable genetic variability. By constructing a haplotype-resolved genome for Crassostrea sikamea, we identify widespread haplotype divergent sequences (HDSs), representing genomic regions unique to each haplotype. We show that HDSs are driven by transposable elements, playing a key role in creating and maintaining genetic diversity during oyster evolution. Comparisons of haplotype-resolved genomes across four bivalve orders uncover diverse HDS origins, highlighting a role in genetic innovation and expression regulation across broad timescales. Further analyses show that, in oysters, haplotype polymorphisms drive gene expression variation, which is likely to promote phenotypic plasticity and adaptation. These findings advance our understanding of the relationships among genome structure, diversity, and adaptability in a highly successful invertebrate group.

The unexplored diversity of rough-seeded lupins provides rich genomic resources and insights into lupin evolution

Lupin crops provide nutritious seeds as an excellent source of dietary protein. However, extensive genomic resources are needed for crop improvement, focusing on key traits such as nutritional value and climate resiliency, to ensure global food security based on sustainable and healthy diets for all. Such resources can be derived either from related lupin species or crop wild relatives, which represent a large and untapped source of genetic variation for crop improvement. Here, we report genome assemblies of the cross-compatible species Lupinus cosentinii (Mediterranean) and its pan-Saharan wild relative L. digitatus, which are well adapted to drought-prone environments and partially domesticated. We show that both species are tetraploids, and their repetitive DNA content differs considerably from that of the main lupin crops L. angustifolius and L. albus. We present the complex evolutionary process within the rough-seeded lupins as a species-based model involving polyploidization and rediploidization. Our data also provide the foundation for a systematic analysis of genomic diversity among lupin species to promote their exploitation for crop improvement and sustainable agriculture.

Chromosome-level genome assembly of the doctor fish (Garra rufa)

Garra rufa, or doctor fish, is a small cyprinid known for its high-temperature tolerance and its use in ichthyotherapy. Recently, this trait has gained interest as a model for human diseases, including infections and cancer xenografts, though limited genomic resources hinder experimental use. In this study, we have generated a high-quality, chromosome-level genome assembly of G. rufa using PacBio HiFi long-read sequencing and Hi-C technology. The genome is 1.38 Gb in size, with 25 chromosomes and a scaffold N50 of 49.3 Mb. Approximately 59% of the genome consists of repetitive elements, while 27,352 protein-coding genes were annotated, with 98.3% being functionally characterized. BUSCO analysis revealed 94.5% and 94.7% completeness for the genome assembly and annotated protein sequences, respectively. Notably, we identified two heat shock transcription factor (HSF) genes, 239 heat shock protein (HSP)-related genes, and 1,036 heat shock elements (HSEs) in regulatory regions. Phylogenetic analysis supports the placement of G. rufa within the Labeoninae subfamily. This genome assembly provides a valuable resource for advancing G. rufa as a model organism.

The expanded Bostrychia moritziana genome unveils evolution in the most diverse and complex order of red algae

Red algae are an ancient eukaryotic lineage that were among the first to evolve multicellularity. Although they share a common origin with modern-day plants and display complex multicellular development, comprehensive genome data from the most highly evolved red algal groups remain scarce. Here, we present a chromosome-level genome assembly of Bostrychia moritziana, a complex red seaweed in the Rhodomelaceae family of the Ceramiales-the largest and most diverse order of red algae. Contrary to the view that red algal genomes are typically small, we report significant genome size expansion in Bostrychia and other Ceramiales, which represents one of at least three independent expansion events in red algal evolution. Our analyses suggest that these expansions do not involve polyploidy or ancient whole-genome duplications, but in Bostrychia rather stem from the proliferation of a single lineage of giant Plavaka DNA transposons. Consistent with its enlarged genome, Bostrychia has an increased gene content shaped by de novo gene emergence and amplified gene families in common with other Ceramiales, providing insight into the genetic adaptations underpinning this successful and species-rich order. Finally, our sex-specific assemblies resolve the UV sex chromosomes in Bostrychia, which feature expanded gene-rich sex-linked regions. Notably, each sex chromosome harbors a three amino acid loop extension homeodomain (TALE-HD) transcription factor orthologous to ancient regulators of haploid-diploid transitions in other multicellular lineages. Together, our findings offer a unique perspective of the genomic adaptations driving red algal diversity and demonstrate how this red seaweed lineage can provide insight into the evolutionary origins and universal principles underpinning complex multicellularity.

Chromatin loops are an ancestral hallmark of the animal regulatory genome

In bilaterian animals, gene regulation is shaped by a combination of linear and spatial regulatory information. Regulatory elements along the genome are integrated into gene regulatory landscapes through chromatin compartmentalization1,2, insulation of neighbouring genomic regions3,4 and chromatin looping that brings together distal cis-regulatory sequences5. However, the evolution of these regulatory features is unknown because the three-dimensional genome architecture of most animal lineages remains unexplored6,7. To trace the evolutionary origins of animal genome regulation, here we characterized the physical organization of the genome in non-bilaterian animals (sponges, ctenophores, placozoans and cnidarians)8,9 and their closest unicellular relatives (ichthyosporeans, filastereans and choanoflagellates)10 by combining high-resolution chromosome conformation capture11,12 with epigenomic marks and gene expression data. Our comparative analysis showed that chromatin looping is a conserved feature of genome architecture in ctenophores, placozoans and cnidarians. These sequence-determined distal contacts involve both promoter-enhancer and promoter-promoter interactions. By contrast, chromatin loops are absent in the unicellular relatives of animals. Our findings indicate that spatial genome regulation emerged early in animal evolution. This evolutionary innovation introduced regulatory complexity, ultimately facilitating the diversification of animal developmental programmes and cell type repertoires.

An annotated near-complete sequence assembly of the Magnaporthe oryzae 70-15 reference genome

Magnaporthe oryzae is a devastating fungal pathogen that causes substantial yield losses in rice and other cereal crops worldwide. A high-quality genome assembly is critical for addressing challenges posed by this pathogen. However, the current widely used MG8 assembly of the M. oryzae strain 70-15 reference genome contains numerous gaps and unresolved repetitive regions. Here, we report a complete 44.82 Mb high-quality nuclear genome and a 35.95 kb circular mitochondrial genome for strain 70-15, generated using deep-coverage PacBio high-fidelity sequencing (HiFi) and high-resolution chromatin conformation capture (Hi-C) data. Notably, we successfully resolved one or both telomere sequences for all seven chromosomes and achieved telomere-to-telomere (T2T) assemblies for chromosomes 2, 3, 4, 6, and 7. Based on this T2T assembly, we predicted 12,100 protein-coding genes and 493 effectors. This high-quality T2T assembly represents a significant advancement in M. oryzae genomics and provides an enhanced reference for studies in genome biology, comparative genomics, and population genetics of this economically important plant pathogen.

Chromosome-level genome assembly of Parotis chlorochroalis (Lepidoptera: Crambidae: Spilomelinae)

Parotis Hübner, 1831 is a genus within the family Crambidae, which is recognized as one of the most diverse families of Lepidoptera. Species within the genus Parotis can be readily distinguished from other closely related genera by their distinctive green or yellow-green body coloration. However, the genus Parotis has received relatively limited research attention, and the scarcity of genome-wide molecular resources has impeded a more comprehensive understanding of its evolution, adaptation, and phylogenetic relationships. This study reports the first genome assembly for Parotis chlorochroalis (Hampson, 1912), generated through PacBio Hi-Fi and Hi-C sequencing technologies. The assembled genome has a size of 456.23 Mb, comprising 31 chromosomes. Approximately 181.82 Mb, which constitutes 39.85% of the genome, has been identified as repetitive sequences. The genome assembly includes 16,299 protein-coding genes, of which 94.82% have been functionally annotated. This chromosome-level genome assembly not only advance understanding of P. chlorochroalis but also has the potential to facilitate genomic studies of other lepidopteran species.

A telomere-to-telomere gap-free assembly integrating multi-omics uncovers the genetic mechanism of fruit quality and important agronomic trait associations in pomegranate

Pomegranate is an important perennial fruit tree distributed worldwide. Reference genomes with gaps and limit gene identification controlling important agronomic traits hinder its functional genomics and genetic improvements. Here, we reported a telomere-to-telomere (T2T) gap-free genome assembly of the distinctive cultivar 'Moshiliu'. The Moshiliu reference genome was assembled into eight chromosomes without gaps, totalling ~366.71 Mb, with 32 158 predicted protein-coding genes. All 16 telomeres and eight centromeres were characterized; combined with FISH analysis, we revealed the atypical telomere units in pomegranate as TTTTAGGG. Furthermore, a total of 16 loci associated with 15 important agronomic traits were identified based on GWAS of 146 accessions. Gene editing and biochemical experiments demonstrated that a 37.2-Kb unique chromosome translocation disrupting the coding domain sequence of PgANS was responsible for anthocyanin-less, knockout of PgANS in pomegranate exhibited a defect in anthocyanin production; a unique repeat expansion in the promoter of PgANR may affected its expression, resulting in black peel; notably, the G → A transversion located at the 166-bp coding domain of PgNST3, which caused a E56K mutation in the PgNST3 protein, closely linked with soft-seed trait. Overexpression of PgNST3A in tomato presented smaller and softer seed coats. The E56K mutation in PgNST3 protein, eliminated the binding ability of PgNST3 to the PgMYB46 promoter, which subsequently affected the thickness of the inner seed coat of soft-seeded pomegranates. Collectively, the validated gap-free genome, the identified genes controlling important traits and the CRISPR-Cas9-mediated gene knockout system all provided invaluable resources for pomegranate precise breeding.

Limited cell-autonomous anticancer mechanisms in long-lived bats

Several bat species live >20-40 years, suggesting that they possess efficient anti-aging and anti-cancer defenses. Here we investigate the requirements for malignant transformation in primary fibroblasts from four bat species Myotis lucifugus, Eptesicus fuscus, Eonycteris spelaea, and Artibeus jamaicensis - spanning the bat evolutionary tree and including the longest-lived genera. We show that bat fibroblasts do not undergo replicative senescence, express active telomerase, and show attenuated SIPs with dampened secretory phenotype. Unexpectedly, unlike other long-lived mammals, bat fibroblasts are readily transformed by two oncogenic "hits": inactivation of p53 or pRb and activation of HRASG12V. Bat fibroblasts exhibit increased TP53 and MDM2 transcripts and elevated p53-dependent apoptosis. M. lucifugus shows a genomic duplication of TP53. We hypothesize that some bat species have evolved enhanced p53 activity as an additional anti-cancer strategy, similar to elephants. Further, the absence of unique cell-autonomous tumor suppressive mechanisms may suggest that in vivo bats may rely on enhanced immunosurveillance.

Haplotype-resolved genome reveals haplotypic variation and the biosynthesis of medicinal ingredients in Areca catechu L

Areca catechu, as a traditional Chinese medicine, contains a high concentration of therapeutic compounds. However, the biosynthesis of these compounds is largely unexplored. We present a haplotype-resolved genome assembly and annotation for A. catechu, with chromosome-level genome sizes of 2.45 Gb (Ac. Hap1) and 2.49 Gb (Ac. Hap2). A comparative analysis of the haplotypes revealed significant divergence, including multiple Mb-level large inversions. Furthermore, A. catechu shared two whole genome duplications with other palm plants and its genome size had increased due to the insertion of transposons within the last 2.5 million years. By integrating transcriptomics and metabolomics, two tandem genes (AcGNMT1 and AcGNMT2) were negatively associated with guvacine and trigonelline in gene-metabolite interaction network. AcGNMT1, AcGNMT2 and their three homologous genes were involved in the conversion of guvacine to arecoline. Further analyses tested the function of AcUGT71CE15, AcUGT74CJ38, AcUGT87EE5 and AcUGT83S982 as glucosyltransferases, and AcUGT78AP14 was identified as a rhamnosyltransferase involved in flavonol glycosylation. Our study provides a high-quality genome of A. catechu, characterizes the arecoline biosynthetic pathway and expands the understanding of the diversity of UDP-glucosyltransferase and UDP-rhamnosyltransferase, offering insights into the potential of A. catechu for the biosynthesis of bioactive compounds.

Four near-complete genome assemblies reveal the landscape and evolution of centromeres in Salicaceae

BACKGROUND

Centromeres play a crucial role in maintaining genomic stability during cell division. They are typically composed of large arrays of tandem satellite repeats, which hinder high-quality assembly and complicate our efforts to understand their evolution across species. Here, we use long-read sequencing to generate near-complete genome assemblies for two Populus and two Salix species belonging to the Salicaceae family and characterize the genetic and epigenetic landscapes of their centromeres.

RESULTS

The results show that only limited satellite repeats are present as centromeric components in these species, while most of them are located outside the centromere but exhibit a homogenized structure similar to that of the Arabidopsis centromeres. Instead, the Salicaceae centromeres are mainly composed of abundant transposable elements, including CRM and ATHILA, while LINE elements are exclusively discovered in the poplar centromeres. Comparative analysis reveals that these centromeric repeats are extensively expanded and interspersed with satellite arrays in a species-specific and chromosome-specific manner, driving rapid turnover of centromeres both in sequence compositions and genomic locations in the Salicaceae.

CONCLUSIONS

Our results highlight the dynamic evolution of diverse centromeric landscapes among closely related species mediated by satellite homogenization and widespread invasions of transposable elements and shed further light on the role of centromere in genome evolution and species diversification.

Chromosome-level genome assembly of the freshwater bivalve Anodonta woodiana

The freshwater bivalve Anodonta (Sinanodonta) woodiana originated in the Yangtze River basin of China and is now widely distributed in Asia, Europe, North America, and Africa. This species has important economic and ecological value. Using Illumina, PacBio, and Hi-C technology, a high-quality chromosome-level genome of A. woodiana was assembled. The genome size was 2.80 Gb, with a contig N50 of 4.01 Mb and a scaffold N50 of 143.34 Mb. In total, 1609 contigs, accounting for 99.57% of the total assembled genome, were anchored into 19 chromosomes. In total, 1.51 Gb repeat sequences were annotated and 44,785 protein-coding genes were predicted. This study is the first to reveal the genome of A. woodiana and the genus Anodonta, which will effectively contribute to investigations of this species' biology, molecular mechanisms in response to environmental stress, and resource management.

Quantifying the influence of genetic context on duplicated mammalian genes

Gene duplication is a fundamental part of evolutionary innovation. While single-gene duplications frequently exhibit asymmetric evolutionary rates between paralogs, the extent to which this applies to multi-gene duplications remains unclear. In this study, we investigate the role of genetic context in shaping evolutionary divergence within multi-gene duplications, leveraging microsynteny to differentiate source and target copies. Using a dataset of 193 mammalian genome assemblies and a bird outgroup, we systematically analyze patterns of sequence divergence between duplicated genes and reference orthologs. We find that target copies, those relocated to new genomic environments, exhibit elevated evolutionary rates compared to source copies in the ancestral location. This asymmetry is influenced by the distance between copies and the size of the target copy. We also demonstrate that the polarization of rate asymmetry in paralogs, the "choice" of the slowly evolving copy, is biased towards collective, block-wise polarization in multi-gene duplications. Our findings highlight the importance of genetic context in modulating post-duplication divergence, where differences in cis-regulatory elements and co-expressed gene clusters between source and target copies may be responsible. This study presents a large-scale test of asymmetric evolution in multi-gene duplications, offering new insight into how genome architecture shapes functional diversification of paralogs.

Integration of De Novo Chromosome-Level Genome and Population Resequencing of Peganum (Nitrariaceae): A Case Study of Speciation and Evolutionary Trajectories in Arid Central Asia

Natural hybridization is a significant driving force in plant evolution and speciation. Understanding the genetic mechanism and dynamic evolutionary trajectories of divergence between species and hybrids remains a central goal in evolutionary biology. Here, we examined the genetic divergence of Peganum and their intermittent and hybrid entities (IHEs) from large-scale sympatric and allopatric regions. We sequenced the genomes of Peganum from the Arid Central Asia (ACA) region and its surrounding areas, discovering that the origin of Peganum could be traced to the Hexi Corridor in eastern Central Asia, where migration led to geographic and environmental isolation, giving rise to new species based on natural selection. Different Peganum species, exhibiting excellent dispersal abilities, migrated to the same regions and underwent hybridization. The descendant species of Peganum inherited and developed adaptive traits from parent species through gene flow and introgression, particularly in DNA repair and wax layer formation, leading to the speciation of the IHEs. This study clarified the transition stages in hybrid speciation and identified the Mixing-Isolation-Mixing cycles (MIM) model as a speciation framework suitable for Peganum, marking the initial identification of this unique evolutionary model in the ACA region.

Gap-free genome assembly and comparative analysis reveal the evolution and lignin degradation mechanisms of Cylindrobasidium torrendii

The Physalacriaceae family comprises numerous saprophytic edible and medicinal fungi with significant ecological and economic importance. However, the lack of high-quality genomic data has hindered systematic studies of this family. Here, we report the chromosome-level genome assembly of Cylindrobasidium torrendii, a species identified in China, using a combination of Illumina, PacBio HiFi, and Hi-C sequencing technologies. The 33.67 Mb genome, featuring a GC content of 52.00 %, demonstrates enhanced continuity and completeness. Phylogenetic analysis based on 1685 single-copy orthologous gene families places C. torrendii in close evolutionary proximity to Armillaria mellea and Gymnopus necrorhizus, with a divergence time of 112.39 Mya. Comparative genomics reveals conserved syntenic blocks between chromosomes of C. torrendii and those of Pleurotus ostreatus and Lentinula edodes. Gene family analysis identified 980 expanded and 487 contracted gene families, with expanded genes significantly enriched in secondary metabolite biosynthesis pathways. CAZyme, P450, and laccase gene family comparisons highlighted the evolutionary dynamics of these gene families in C. torrendii. Transcriptomic analysis under fungal dark stress revealed significant upregulation of genes such as CtoLAC7 and CAZymes (GH and CE families). This study provides a high-quality genomic resource and novel insights into the genetic and functional characteristics of C. torrendii and the Physalacriaceae family.

Telomere-to-telomere gap-free genome assembly provides genetic insight into the triterpenoid saponins biosynthesis in Platycodon grandiflorus

Platycodon grandiflorus has been widely used in Asia as a medicinal herb and food because of its anti-inflammatory and hepatoprotective properties. P. grandiflorus has important clinical value because of the active triterpenoid saponins in its roots. However, the biosynthetic pathway of triterpenoid saponins in P. grandiflorus remains unclear, and the related genes remain unknown. Therefore, in this study, we assembled a high-quality and integrated telomere-to-telomere P. grandiflorus reference genome and combined time-specific transcriptome and metabolome profiling to identify the cytochrome P450s (CYPs) responsible for the hydroxylation processes involved in triterpenoid saponin biosynthesis. Nine chromosomes were assembled without gaps or mismatches, and nine centromeres and 18 telomere regions were identified. This genome eliminated redundant sequences from previous genome versions and incorporated structural variation information. Comparative analysis of the P. grandiflorus genome revealed that P. grandiflorus underwent a core eudicot γ-WGT event. We screened 211 CYPs and found that tandem and proximal duplications may be crucial for the expansion of CYP families. We outlined the proposed hydroxylation steps, likely catalyzed by the CYP716A/72A/749A families, in platycodin biosynthesis and identified three PgCYP716A, seven PgCYP72A, and seven PgCYP749A genes that showed a positive correlation with platycodin biosynthesis. By establishing a T2T assembly genome, transcriptome, and metabolome resource for P. grandiflorus, we provide a foundation for the complete elucidation of the platycodins biosynthetic pathway, which consequently leads to heterologous bioproduction, and serves as a fundamental genetic resource for molecular-assisted breeding and genetic improvement of P. grandiflorus.

In a nutshell: pistachio genome and kernel development

Pistachio is a sustainable nut crop with exceptional climate resilience and nutritional value. However, the molecular processes underlying pistachio nut development and nutritional traits are largely unknown, compounded by limited genomic and molecular resources. To advance pistachios as a future food source and a model system for hard-shelled fruits, we generated a chromosome-scale reference genome of the most widely grown pistachio cultivar (Pistacia vera 'Kerman') and a spatiotemporal study of nut development. We integrated tissue-level physiological data from thousands of nuts over three growing seasons with transcriptomic data encompassing 14 developmental time points of the hull, shell, and kernel to assemble gene modules associated with physiological changes. Our study defined four distinct stages of pistachio nut growth and maturation. We then focused on the kernel to identify transcriptional and metabolic changes in molecular pathways governing nutritional quality, such as the accumulation of unsaturated fatty acids, which are vital for shelf life and dietary value. These findings revealed key candidate conserved regulatory genes, such as PvAP2-WRI1 and PvNFYB-LEC1, likely involved in oil accumulation in kernels. This work yields new knowledge and resources that will inform other woody crops and facilitate further improvement of pistachio as a globally significant, sustainable, and nutritious crop.

Telomere-to-telomere genome and multi-omics analysis of Prunus avium cv. Tieton provides insights into its genomic evolution and flavonoid biosynthesis

The European sweet cherry (Prunus avium) is highly valued for its superior quality, delectable taste, and robust stress resistance, leading to its extensive cultivation in the world. However, the previous incomplete genome assemblies have impeded its evolution and genetic regulation studies. In this study, we generated a Telomere-to-Telomere gap-free genome assembly of P. avium cv. Tieton, using advanced sequencing technologies. The assembled genome comprises eight pseudochromosomes with a genome size of 342.23 Mb and a contig N50 of 40.66 Mb. Comparative genomic analysis identified several unique stress resistance-related genes, possibly associated with the species' environmental adaptation. The integrative analyses of genomics, transcriptomes and metabolomes identified some key structural genes and metabolites crucial to flavonoid biosynthesis of sweet cherry. Our analyses revealed that 85 flavonoid metabolites, which are highly differentially accumulated among five tissues (flesh, stem, leaf, bud, and seed) of cherry. Interestingly, eight abundant flavonoids (Narcissoside, Typhaneoside, Myricetin 3-0-galactoside, Diosmin, Neohesperidin, Liquiritin apioside, 5,6,7-Trimethoxyflavone and Oroxin B) were highly accumulated in cherry flesh tissues. The gene-metabolite correlation analysis revealed that seven genes (HTC8, HTC6, CYP75B1_9, CYP75B1_10, 4CL1, DFR1, and FLS1) significantly regulated flavonoid accumulation in cherry flesh. Additionally, some structural genes (4CL6, PAL3, CYP75A2, F3H1, CYP75B1_8, and CYP75B1_10) were identified in the flavonoid biosynthetic pathway and were highly expressed, aligning with high flavonoid metabolite content in cherry flesh. These identified genes and metabolites are likely pivotal in conferring sweet cherry's stress resistance and high-quality traits. These findings offer deep insights into the mechanisms of genomic evolution and flavonoid biosynthesis, which also lay a solid foundation for further function genomics studies and breeding improvement in cherry.

Rapid Colonisation of Synanthropic Stone Martens in a Highly Urbanised Region: Insights From Temporal and Spatial Analysis

Medium-sized carnivores, including the synanthropic stone marten (Martes foina Erxleben, 1777), have shown remarkable adaptability to urbanised and fragmented landscapes, facilitating their spread across mainland Europe. This study investigates the recolonisation of a highly urbanised region by stone martens within two decades, examining spatial and temporal genome-wide data (using genotyping by sequencing) to reveal colonisation dynamics, sources, and barriers influencing their expansion. Using genotypes from 5536 SNPs across 376 stone martens collected between 1995 and 2013, our findings indicate that stone martens successfully expanded through urban environments, yet dispersal was neither entirely random nor strictly distance-dependent. The initial southeastern stronghold (E1) showed the lowest genetic diversity and limited spatial expansion, while other population sources contributed to recolonisation, highlighting a complex, multi-source expansion. Gene flow in the early stages was largely confined to E1, progressing northward and eventually enabling exchange with a second eastern lineage (E2). Meanwhile, the western lineage displayed higher connectivity, occasionally crossing barriers like motorways. Motorways, however, significantly shaped recolonisation patterns, reducing gene flow, while other elements such as built-up areas, secondary roads or waterways showed an additional though very small effect. Over the study period, genetic patch size increased, indicating longer dispersal distances. Gene flow strengthened within both eastern (E1 and E2) and western populations. Still, the western population diverged into two subclusters (W1 and W2) of which one became more differentiated. This suggests limited genetic homogenisation in the near future. This study provides insights into the genetic and ecological dynamics of carnivore recolonisation in highly fragmented landscapes.

Haplotype-resolved genome of Agastache rugosa (Huo Xiang) provides insight into monoterpenoid biosynthesis and gene cluster evolution

Monoterpenoids are small volatile molecules produced by many plants that have applications in consumer products and healthcare. Plants from the mint family (Lamiaceae) are prodigious producers of monoterpenoids, including a chemotype of Agastache rugosa (Huo Xiang), which produces pulegone and isomenthone. We sequenced, assembled and annotated a haplotype-resolved chromosome-scale genome assembly of A. rugosa with a monoterpene chemotype. This genome assembly revealed that pulegone biosynthesis genes are in a biosynthetic gene cluster, which shares a common origin with the pulegone gene cluster in Schizonepeta tenuifolia. Using phylogenetics and synteny analysis, we describe how the clusters in these two species diverged through inversions and duplications. Using Hi-C analysis, we identified tentative evidence of contact between the pulegone gene cluster and an array of pulegone reductases, with both regions also enriched in retrotransposons. This genome and its analysis add valuable and novel insights to the organization and evolution of terpenoid biosynthesis in Lamiaceae.

The chromosome-level genome of Centella asiatica provides insights into triterpenoid biosynthesis

Centella asiatica is a well-known herbal plant that makes a significant contribution to the treatment of various chronic ailments. Triterpenoid saponins are the main active components extracted from C. asiatica, which have rich pharmacological activity. However, only a few studies have systematically elucidated the molecular mechanism underlying the biosynthesis of triterpenoid saponins in C. asiatica. Here, we report a chromosome-level reference genome of C. asiatica, by using Illumina, PacBio HiFi, and Hi-C technologies. The assembled genome exhibits high quality with a size of 455 Mb and a contig N50 of 36 Mb. A total of 26,479 protein-coding genes were predicted. Comparative genomic analysis revealed that the gene families involved in triterpenoid saponin biosynthesis, including squalene synthase (SS) and farnesyl diphosphate synthase (FPS), rapidly expanded in the C. asiatica genome. In particular, we have discovered two whole-genome duplication events in C. asiatica genomes. A further comprehensive analysis of the metabolome and transcriptome was performed using different tissues of C. asiatica in order to identify the key genes associated with triterpenoid saponin biosynthesis. Consequently, seven enzyme genes were considered to play important roles in triterpenoid biosynthesis. Subsequent functional characterization of CaOSC4 demonstrated that it is responsible for the biosynthesis of three ursane-type triterpenoids in C. asiatica. Our research establishes a genomic data platform that can be employed in the excavation of genes and precision breeding in C. asiatica. Additionally, the results offer new insights into the biosynthesis of triterpenoid saponins.

Chromosome-Level Genome Assembly and Annotation of the Amur Rat Snake Elaphe schrenckii

The Amur rat snake (Elaphe schrenckii), a widely distributed colubrid species in Northeast Asia, plays a critical role in controlling rodent and mouse populations in the wild. Despite its ecological and evolutionary significance, genomic resources for this nonvenomous species have been limited. In this study, we present a high-quality, chromosome-level genome assembly of E. schrenckii, generated by PacBio HiFi long-read sequencing and Hi-C chromatin interaction mapping. The assembled genome size comprises 1.69 Gb, with a scaffold N50 length of 215 Mb. Hi-C scaffolding anchored the genome into 18 chromosomes, including one that represents the conserved Z chromosome of snakes, consistent with karyotypic observations. This assembly enables further gene annotation and analysis of chromosomal synteny patterns. Repetitive elements account for 53.2% of the genome, with long interspersed nuclear element retrotransposons being the predominant class (23.2%). We identified 18,529 protein-coding genes, with 90.6% functionally annotated through homology-based methods. The genome assembly is highly complete, with a BUSCO score of 97.4% (tetrapoda_odb10). This resource provides a foundation for comparative studies of colubrid genome evolution, which also serves as a crucial reference for conservation genomics, particularly for Asian snake populations facing habitat fragmentation.

Chromosomal level genome assembly of medicinal plant Rosa laevigata

Rosa laevigata Michx., an endemic perennial herbaceous plant in China, possesses significant medicinal value in traditional herbal practices. However, the absence of a reference genome has hindered its development and utilization. In this study, we present a chromosome-level de novo genome assembly of two haplotypes (Hap1 and Hap2) of R. laevigata by integration of Hifi long reads, BGI short reads, and Hi-C reads. The assembled Hap1 genome spans 493 Mb, Hap2 genome spans 479 Mb, and both of them were assigned to 7 chromosomes each. The mapping rate of BGI short reads to the two haplotypes genome is approximately 99.26% and 99.23%, and BUSCO assessment reveals that 98.6% and 98.7% of the genes are complete. Furthermore, we predicted 43,480 and 41,251 protein-coding genes in two haplotype genomes, respectively. The chromosome-level genome of R. laevigata enhances the genetic resources available for Rosa species and lays the groundwork for subsequent medicinal development.

Pan-Genome Analysis Reveals Local Adaptation to Climate Driven by Introgression in Oak Species

The genetic base of local adaptation has been extensively studied in natural populations. However, a comprehensive genome-wide perspective on the contribution of structural variants (SVs) and adaptive introgression to local adaptation remains limited. In this study, we performed de novo assembly and annotation of 22 representative accessions of Quercus variabilis, identifying a total of 543,372 SVs. These SVs play crucial roles in shaping genomic structure and influencing gene expression. By analyzing range-wide genomic data, we identified both SNPs and SVs associated with local adaptation in Q. variabilis and Quercus acutissima. Notably, SV-outliers exhibit selection signals that did not overlap with SNP-outliers, indicating that SNP-based analyses may not detect the same candidate genes associated with SV-outliers. Remarkably, 29%-37% of candidate SNPs were located in a 250 kb region on chromosome 9, referred to as Chr9-ERF. This region contains 8 duplicated ethylene-responsive factor (ERF) genes, which may have contributed to local adaptation of Q. variabilis and Q. acutissima. We also found that a considerable number of candidate SNPs were shared between Q. variabilis and Q. acutissima in the Chr9-ERF region, suggesting a pattern of repeated selection. We further demonstrated that advantageous variants in this region were introgressed from western populations of Q. acutissima into Q. variabilis, providing compelling evidence that introgression facilitates local adaptation. This study offers a valuable genomic resource for future studies on oak species and highlights the importance of pan-genome analysis in understating mechanism driving adaptation and evolution.

Chromosome-level genome assembly of the sap beetle Glischrochilus (Librodor) japonius (Coleoptera: Nitidulidae)

Sap beetles are widely distributed in the Holarctic and tropical regions, with diverse feeding habits and strong adaptability. They play important roles in the decay of plants, the spread of fungi and bacteria, and the carbon and nitrogen cycles in agricultural ecosystems. Here, we provide an annotated, chromosome level reference genome assembly for a sap beetle Glischrochilus (Librodor) japonius (Motschulsky, 1857), a member of the family Nitidulidae, assembled using PacBio HiFi and Hi-C data from female specimens. The final assembly has a total size of 789.06 Mb, with 94.91% of the sequence successfully anchored to 10 chromosomes. The scaffold N50 is 77.84 Mb, and BUSCO (endopterygota_odb10 database) completeness is 97.20%. Repetitive elements comprise 54.67% of the genome (431.38 Mb). We identified 1,673 noncoding RNAs and predicted 22,526 protein-coding genes in the genome. This genome will serve as a valuable resource for advancing our understanding of the evolution and ecology of sap beetles, and will facilitate comparative studies of genome structure within the Nitidulidae family.

Evolutionary history of magnoliid genomes and benzylisoquinoline alkaloid biosynthesis

Benzylisoquinoline alkaloids (BIAs) are important metabolites synthesized in early-diverging eudicots and magnoliids, yet the genetic basis of BIA biosynthesis in magnoliids remains unclear. Here, we decode the genomes of two magnoliid species, Saruma henryi and Aristolochia manshuriensis, and reconstruct the ancestral magnoliid karyotype and infer the chromosomal rearrangement history following magnoliid diversification. Metabolomic, transcriptomic, and phylogenetic analyses reveal the intermediate chemical components and genetic basis of BIA biosynthesis in A. manshuriensis. Although the core enzymes involved in BIA synthesis appear to be largely conserved between early-diverging eudicots and magnoliids, the biosynthetic pathways in magnoliids seem to exhibit greater flexibility. Significantly, our investigation of the evolutionary history of BIA biosynthetic genes revealed that almost all were duplicated before the emergence of extant angiosperms, with only early-diverging eudicots and magnoliids preferentially retaining these duplicated genes, thereby enabling the biosynthesis of BIAs in these groups.

Chromosome-level genomes of Arctic and Antarctic mosses: Aulacomnium turgidum and Polytrichastrum alpinum

Bryophytes play a crucial role in the ecosystems of polar regions. These simple plants are among the predominant vegetation types in both Arctic and Antarctic landscapes, where they contribute significantly to biodiversity and ecological stability. Here, we report the chromosome-level genomes of two polar moss species, the Arctic Aulacomnium turgidum and Antarctic Polytrichastrum alpinum. Utilizing a combination of Illumina short reads, Nanopore long reads, and Hi-C data, we assembled genomes of 277.84 Mb for A. turgidum and 498.33 Mb for P. alpinum, respectively. These assemblies were anchored to 11 chromosomes for A. turgidum and 8 chromosomes for P. alpinum. Both species exhibited a sex chromosome with distinct genomic characteristics. Gene annotations revealed 25,999 protein-coding genes in A. turgidum and 28,070 in P. alpinum. The high completeness of the gene space was validated via BUSCO, achieving impressive scores of 98.2% and 98.0%. These high-quality genomes provide critical resources for studying the adaptive evolution and stress tolerance mechanisms of mosses in extreme polar environments.

Chromosome-level genome assembly of Dendrothrips minowai and genomic analysis highlights distinct adaptations to high polyphenols in tea plants

BACKGROUND

Dendrothrips minowai Priesner, a significant pest in tea-producing regions of Asia, particularly China, damages tea plants (Camellia sinensis) by feeding on their tender leaves rich in polyphenols. Seven assembled genomes from the order Thysanoptera are currently available.

RESULTS

This study presents the first chromosome-level genome assembly of D. minowai generated by PacBio Revio, Oxford Nanopore Technologies, MGI, and Hi-C technology. The assembled genome measures 350.11 Mb with 1269 contigs with a contig N50 of 536.34 Kb and a scaffold N50 of 16.86 Mb, organized across 19 chromosomes. A total of 16 730 protein-coding genes were identified, with 92.28% functionally annotated. The phylogenetic analysis reveals that D. minowai diverged approximately 103.2 million years ago, preceding all reported genomes of Thripidae species. Comparative genomic analysis identified 12 expanded and 172 contracted gene families of D. minowai, with expanded gene families linked to host plant metabolite processing and detoxification enzymes. Additionally, oligophagous thrips, D. minowai and Stenchaetothrips biformis, possess fewer chemosensory genes (gustatory receptors, odorant receptors, ionotropic receptors, chemosensory proteins, and odorant binding proteins) and detoxification genes (P450s, carboxyl/cholinesterases, UDP-glycosyltransferases) than polyphagous species (Frankliniella occidentalis and Thrips palmi). Interestingly, D. minowai exhibits an expansion in ABC transporter families, especially ABCG and ABCC, which is likely essential for detoxifying the high polyphenol content in tea plants.

CONCLUSION

This study provides another genome sequence for oligophagous thrips species, which enriches the genomic data for further studies on the evolution, host adaptation, and novel control strategies of thrips. © 2025 Society of Chemical Industry.