Search Results (263)

Background/Objectives: Flower bud morphogenesis is a critical developmental phase during which blueberry transitions from vegetative to reproductive growth, yet the transcriptome dynamics and regulatory networks within buds during this process have not been systematically characterized. Methods: Terminal buds of the rabbiteye blueberry ‘Brightwell’ were sampled at six time points spanning from summer shoot cessation to bud swelling and dormancy entry. RNA sequencing, trend clustering, and Pearson correlation network analyses were performed to identify potentially important genes and regulatory relationships. Results: A total of 26,302 differentially expressed genes were identified, with a major transcriptomic shift at week 15. From four major expression trends, 1050 candidate genes were selected, including 176 flowering-related genes, 770 transcription factors, and 277 hormone-related genes. Photoperiod and vernalization pathway genes (COLs, VRN1, etc.) were predominantly down-regulated, whereas age pathway genes (SPLs) and MADS-box flower development genes (FULs, AP3, PI, and SEP2, etc.) were up-regulated. The floral integrators FT and SOC1 exhibited opposite expression dynamics: SOC1 was highly expressed during the early-to-mid stage, whereas FT peaked at the late stage, with the two showing opposing co-expression and correlation patterns. This suggests stage-specific divergence between the two integrators in coordinating flower bud differentiation and dormancy entry. Multiple hormone pathways (IAA, BR, JA, and SA, etc.) converged independently onto floral regulatory hubs through their biosynthesis/metabolism and signal transduction genes, with numerous transcription factors also involved. Conclusions: These findings provide a comprehensive view of bud transcriptome dynamics and propose a molecular regulatory framework integrating flowering signals, hormones, and transcriptional cascades, offering a theoretical foundation and gene resources for blueberry breeding. Full article

Pollinators, particularly bees, are essential for the reproduction of flowering plants, including ornamentals, and for maintaining ecosystem balance, benefitting gardens by supporting plant health and promoting robust flowering. However, pollinator populations are declining, with pesticide exposure recognized as one of several contributing stressors. Thiamethoxam, a commonly used systemic insecticide in ornamental horticulture (and its toxic metabolite clothianidin), has been found in nectar resources at levels harmful to bees. This study evaluated the impact of different thiamethoxam application rates on pollen contamination in blanket flower (Gaillardia pulchella L.), a popular source of pollen for bee pollinators. Container plants were drench-treated with low (0.30 g/L) and high (0.64 g/L) rates of thiamethoxam during the mature floral bud stage. The results show that thiamethoxam and clothianidin were present in pollen at both application rates. However, only clothianidin levels significantly increased with the application rate (p = 0.0009). When the pesticide concentrations measured in pollen were used to calculate the estimated exposure doses based on pollen consumption, the values exceeded published median lethal doses (LD50) for the common eastern bumble bee (Bombus impatiens Cresson) and buff-tailed bumble bee (Bombus terrestris L.), indicating substantial ecological risk. These findings underscore the potential threat posed to some pollinator species by thiamethoxam-treated ornamentals. Full article

Volatile composition is a core trait that determines the ornamental and application value of Rosa flowers. In the current study, the volatile profiles of freeze-dried Rosa gallica flowers were comprehensively characterized via gas chromatography-mass spectrometry (GC-MS), coupled with heatmap clustering, principal component analysis (PCA), and relative odor activity value (rOAV) determination. A total of 181 volatile compounds were identified, and distinct volatile profiles were observed between flower samples treated with headspace extraction (RG-HS) and solid-phase microextraction (RG-SPME). Alcohols were the dominant volatile class in RG-SPME, whereas aldehydes were abundant in the RG-HS group. In terms of aroma characteristics, RG-SPME presented stronger green, floral, citrus, and fatty odors, while RG-HS exhibited a more pronounced fruity note. Moreover, sulfurous and dairy notes were unique to RG-SPME and RG-HS, respectively. Additionally, 27 volatiles showed rOAV above one, with 2,3-butanedione and trans-citral having the greatest rOAV value of 100, were identified as the potential aroma-active contributors to butter-like and citrus odors in RG-HS and RG-SPME, respectively. These results provide a methodological reference for volatile profiling of R. gallica flowers, and support the selection of appropriate extraction methods for future research and resource utilization. Full article

Objectives: This study aims to provide a theoretical basis for a deeper understanding of the transcriptional regulatory network underlying the formation of Primula forbesii floral scent, and also offers important genetic resources for the molecular improvement of floral scent traits in Primula species. Methods: Using the P. forbesii cultivar ‘Pink violet’ as experimental material, we cloned PfbHLH131 and analyzed its expression pattern. We also validated its function via virus-induced gene silencing (VIGS) and used gas chromatography–mass spectrometry (GC-MS) to analyze changes in floral aroma components in silenced plants. Additionally, we detected the expression levels of key structural genes involved in floral aroma biosynthesis in silenced plants via qRT-PCR to elucidate the regulatory role of PfbHLH131 in the biosynthesis of P. forbesii floral aroma. Results: The cloned PfbHLH131 open reading frame is 922 bp in length, encoding a total of 307 amino acids, and contains a bHLH_AtBPE_like domain characteristic of the bHLH gene family. Quantitative real-time PCR (qRT-PCR) revealed that PfbHLH131 is highly expressed in floral organs, peaking during full bloom. Subcellular localization studies indicated that it is localized to the nucleus. VIGS-mediated transient silencing of PfbHLH131 significantly reduced the release of terpenoid and phenylpropanoid floral odor compounds and suppressed the expression of multiple key structural genes in both synthetic pathways. Conclusions: PfbHLH131 is a positive regulator of scent biosynthesis in P. forbesii. Full article

Gustatory perception in honeybees is a key determinant of foraging decisions and pollen source selection. However, the molecular mechanisms underlying this sensory discrimination remain poorly understood. To investigate these mechanisms during the collection of pollen from different floral sources, this study utilized antennae from worker bees foraging on pear and rapeseed pollen, and non-pollen-foraging workers as controls. Illumina high-throughput transcriptome sequencing was employed to identify differentially expressed genes (DEGs), perform functional annotation, and characterize gustatory receptor (GR) genes. Compared with the control group, 583 DEGs and 516 DEGs were identified in pear-pollen and rapeseed-pollen foragers, respectively, whereas only 73 DEGs were detected between the two pollen-foraging groups. Several DEGs were associated with chemosensory perception, signal transduction, energy metabolism, and immune responses. Notably, genes involved in membrane-associated signaling and stimulus response exhibited differential expression patterns among foraging groups, suggesting adaptive molecular responses to distinct floral resources. Gene Ontology (GO) analysis indicated that DEGs were primarily associated with cellular processes, membrane components, and binding functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment highlighted significant involvement in phagosome, phosphatidylinositol signaling system, oxidative phosphorylation, and extracellular matrix–receptor interaction. Notably, seven GR-related genes were identified in the antennal transcriptome, including five known GR genes and two novel candidates, all with complete open reading frames. Four of these genes featured the canonical seven-transmembrane domain structure of insect GRs. Phylogenetic analysis, in addition to the known sugar receptors AmelGR43a, AmelGR64f, and AmelGR64f-X1, based on GRs from Apis mellifera and Drosophila melanogaster suggested that AmelGR28b, AmelGR10, AmelGR12, and AmelGR13 may belong to the bitter taste receptor family. Quantitative real-time PCR (qRT-PCR) validation demonstrated that the expression patterns of the selected seven DEGs were consistent with the RNA-seq results. This study reveals differential expression patterns and potential functional divergence of gustatory receptor genes in Apis mellifera during pollen collection from different floral sources. It provides important molecular evidence for understanding how honeybees accurately recognize and preferentially forage specific pollen sources via gustatory perception, and offers valuable theoretical and practical insights for honeybee behavioral ecology and crop pollination management. Full article

Successful conservation biological control programs require a good understanding the nutritional ecology of natural enemies to maximize their field efficacy. This study evaluated the effects of non-floral sugar sources on fitness parameters of Mastrus ridens, a specialized parasitoid of the codling moth. In the laboratory, we compared the longevity, parasitism, and reproduction of adult parasitoids exposed to different sugar sources, including Vicia faba extrafloral nectar, honeydew from several hemipteran species, diluted honey (positive control), and no-sugar controls. We also tested the effects of exposing parasitoids to honey for only 24 h. The results showed that sugar availability and source type significantly affected parasitoid performance. Extrafloral nectar was better than mealybug honeydew, with female offspring numbers similar to those exposed to honey, and increased the number of parasitized host larvae by up to 3.5-fold compared to no-sugar conditions. The effects of honeydew effects on male longevity were variable, possibly explained by its composition, and the mode of presentation. Parasitoids with a short exposure to high-quality sugar performed poorly. Our findings indicate that successful conservation and augmentative biological control programs using this species require field provision of high-quality, accessible sugar resources. Full article

Lilac (Syringa oblata Lindl.) is an important eco-economic aromatic shrub in northern China; however, the key volatile organic compounds (VOCs) responsible for its floral aroma and their origin remain largely unexplored. In this study, we conducted an integrated analysis of volatile metabolomics and transcriptomics to elucidate the composition, dynamic changes, and potential regulatory network of VOCs across different floral organs and petal developmental stages. A total of 1440 VOCs were identified in the stamens, pistils, and petals, with petals being the primary contributors to the overall floral aroma. Analysis of different petal developmental stages revealed that the full-bloom stage (S3) is critical for VOCs emission. The floral aroma of S. oblata is primarily composed of terpenoids, alcohols, and aldehydes. By relative odor activity value (rOAV) with multivariate statistical screening, seven key VOCs with high contributions to the floral aroma were identified. Transcriptome analysis identified 69,935 differentially expressed genes (DEGs) across petal developmental stages, which were predominantly enriched in metabolic pathways and the biosynthesis of secondary metabolites. The expression patterns of these DEGs were highly consistent with the accumulation trends of VOCs, increasing at stages S2 and S3 and subsequently declining at stage S4. Integrative analysis of VOCs and gene expression further identified candidate genes significantly correlated with the key aroma volatiles. Specifically, the carotenoid pathway-related genes CYP97A3 and LYC may influence the formation of carotenoid-derived volatiles and floral aroma. Additionally, genes associated with the fatty acid-lipoxygenase pathway, transport-related genes, and transcription factors are potentially involved in the formation and regulation of aldehyde and alcohol volatiles. These findings advance our understanding of the floral aroma formation in S. oblata and provide metabolic basis, candidate gene resources and a theoretical foundation for the genetic improvement of aroma traits and the breeding of new cultivars. Full article

Carex is among the most species-rich genera of angiosperms and plays important ecological roles in wetlands, alpine regions, and temperate ecosystems worldwide. However, research on this genus has long been challenged by pronounced phenotypic plasticity, reduced floral morphology, frequent hybridization, and complex chromosomal evolution. Although recent advances in molecular phylogenetics, comparative genomics, reproductive biology, and ecophysiology have substantially expanded the knowledge of Carex, these findings remain fragmented across disciplines. Here, we synthesize current evidence on Carex taxonomy and phylogeny, genomic and karyotypic evolution, reproductive and life history strategies, abiotic stress responses, ecosystem functions, and bioresource potential within a cross-scale framework. This review emphasizes how genomic architecture, life history variation, and ecophysiological adaptation jointly shape species diversification and ecosystem functioning, while clarifying their implications for habitat restoration and the sustainable use of Carex resources. Finally, we identify key priorities for future research, including improved phylogenomic resolution, comparative functional studies, climate-resilience assessment, and germplasm conservation and sustainable use. Full article

Ning black autumn tea from Jiangxi, China, is often neglected by farmers due to quality decline under hot and arid autumn conditions. In this study, four soil moisture levels (T1–T4, ranging from 32.75% to 18.36%) were established through different sprinkler irrigation frequencies to investigate their effects on tea quality. T2 (27.98% soil moisture) exhibited the highest content of total free amino acids (13.77 mg/g), which was 13.33% higher than that in T4 (12.15 mg/g). Notably, T2 had the highest content of umami amino acids (6.75 mg/g) and the lowest content of bitter amino acids (3.07 mg/g) among all treatments. The total non-esterified catechin content in T2 (18.92 mg/g) was 2.74-fold higher than that in T4 (6.90 mg/g). Among the 55 volatile compounds identified, trans-nerolidol reached its highest odor activity value in T2 (11.77), contributing to a distinctive fruity and floral aroma. Sensory evaluation confirmed that T2 had the highest taste score (89.7), with significantly reduced bitterness and astringency, consistent with its enriched umami amino acids (6.75 mg/g) and lower bitter amino acids (3.07 mg/g). These findings demonstrate that maintaining soil moisture at approximately 28% through moderate sprinkler irrigation effectively balances flavor-related metabolites and improves autumn tea quality, offering a practical strategy to reduce resource waste and increase economic returns. Full article

Bees play crucial ecological, economic, and environmental roles, and research on them increasingly includes a spatial dimension. Geographic Information Systems (GISs) enable the acquisition, storage, analysis, management, and visualization of spatial data. However, GIS applications in bee research have expanded while remaining dispersed across topics, tools, taxa, and methodological approaches. This study provides a comprehensive and updated review of GIS applications in bee research by integrating bibliometric analysis with a structured synthesis of GIS purposes and techniques. A total of 228 publications were analyzed to assess publication trends, co-authorship patterns, keyword themes, study areas, taxonomic coverage, GIS application themes, and methodological tools. GIS was used to select suitable apiary sites, map floral resources, analyze bee behavior, assess diseases and pests, monitor bee products, evaluate urban and landscape contexts, and predict climate change effects. The main GIS-related approaches included multicriteria decision analysis (MCDA), remote sensing, species distribution models (SDMs), spatial interpolation, WebGIS platforms, and emerging machine-learning applications. The review also identified underrepresented taxa, especially wild bees, stingless bees, and other Apis species. Future advances should integrate MCDA with data-driven models, improve floral-resource mapping with remote sensing, and strengthen reproducibility through standardized spatial data and workflows. Full article

Magnolia cavaleriei var. platypetala ‘Tanchun’ is a newly registered flower variety in China, known for its characteristic floral aroma that intensifies toward full bloom. However, the composition of the volatiles of this aromatic flower remains uncharacterized. Here, we compared the volatile organic compound composition of Tanchun through gas chromatography–mass spectrometry and comparative transcriptome sequencing analyses of the stamen (S), pistil (P), and petals (T) during flower development, i.e., the bud (S1), semi-opened (S2), and bloom (S3) stages. We present a first comprehensive profile of 1395 metabolites from Tanchun’s floral organs. Terpenoids (26.2%) constituted the largest chemical group, followed by esters (17.52%), nitrogen compounds (9.83%), hydrocarbons (8.11%), alcohols (7.97%), aldehydes (6.53%), and others. We found that volatile organic compound (VOC) accumulation was both spatiotemporal and stage-specific. The S1 and S2 transition was characterized by scent notes of green, herbal, and waxy aromas, while the S2 and S3 shift exhibited a richer profile of fruity, sweet, and creamy notes, primarily in petals. A comparative VOC and transcriptomic analysis revealed that petals activate pathways for structural expansion and precursor mobilization, stamens enhance lipid and terpenoid metabolism, and pistils maintain a conserved profile. Importantly, the S1 and S2 transition in petals establishes the biochemical foundation by activating acyl-CoA, phenylpropanoid, and terpenoid synthesis pathways, which enables the activation of the butanoate metabolism pathway at S3, leading to the production of ester-rich compounds that define the floral scent. The transition to full bloom involves a shift to energy-efficient volatile biosynthesis, supported by carbohydrate restructuring and phytohormonal regulation. Our results provide the first comprehensive volatilome and transcriptome resource for ‘Tanchun’, revealing a highly efficient, multi-stage strategy for floral fragrance biosynthesis. This work lays a molecular foundation for future horticultural improvement and biotechnological applications in the flavor and fragrance industries. Full article

Zhuyecha (ZYC, Camellia sp.) is a newly discovered special wild tea plant resource in Cangwu County, Wuzhou City, Guangxi Province, China. However, there have been few scientific studies on it. This study investigated its morphological and chemical characteristics. The results revealed that ZYC is an arbor-type, upright plant with lanceolate leaves. The flower has five petals, five sepals, a trifid style, and a glabrous ovary. ZYC exhibited a unique chemical profile distinguished from common tea cultivars. Compared with the control cultivated varieties (Hongyan 12, Fuyun 6, and Yinghong 9), ZYC fresh leaves contained significantly higher contents of theobromine, theophylline, and gallic acid, but considerably lower caffeine and lower total catechins. The principal catechins were epi-form/galloylated catechins EGCG and ECG. Notably, theobromine was the most abundant alkaloid in ZYC, followed by caffeine and theophylline. In ZYC fresh leaves, 15 differential non-volatile metabolites were identified, and 22 key aroma compounds were screened, including linalool, (E)-2-hexenal, hexanal, heptan-2-ol, and β-myrcene, among others. The volatile components were primarily alcohols, aldehydes, and esters, contributing to floral, fruity, and green aroma attributes. This work enhances the understanding of the botanical and phytochemical properties of ZYC and provides scientific guidance for further research and efficient utilization of this natural low-caffeine/high-theobromine tea resource. Full article

Fruit production in many crops depends on pollen transfer by animals, and many self-sterile crops rely on long-distance pollen transfer by animals between different genotypes, i.e., between different cultivars. Foragers such as honeybees may need to visit and carry the pollen of more than one cultivar to be effective pollinators, but we currently have little understanding of how many foragers are carrying more than one cultivar of pollen. We determined the number of cultivars carried by honeybees returning to their hive with pollen at two locations in an orchard of a predominantly self-sterile tree crop, macadamia. The locations were either (i) close to only one macadamia cultivar or (ii) between two macadamia cultivars. We sampled honeybees early in the flowering period, when the floral resource availability was lower, and at peak flowering when the resource availability was higher. We identified the cultivars carried by individual honeybees using a SABER-MassARRAY method that distinguishes cultivar-specific SNPs in pollen DNA. We found that most honeybees carried pollen from only one identified macadamia cultivar, regardless of the hive location and time within the flowering period. Only 15% of the honeybees were carrying pollen from more than one identified macadamia cultivar. This suggests that most honeybee foraging visits to flowers in the orchard were unlikely to have resulted in cross-pollination. Pollenizer trees could be interplanted among the main cultivars in macadamia orchards to increase the number of honeybees carrying cross-pollen and increase their pollination efficiency. Full article

Background/Objectives: Tree peony (Paeonia suffruticosa) has a short flowering period, and its regulatory mechanisms remain poorly understood. These limitations have severely constrained its industrial development. Expansins (EXPs) are key proteins that mediate cell wall loosening associated with petal expansion, yet they remain uncharacterized in tree peony. Methods: This study utilized gene family identification, key gene screening and functional research, as well as regulatory network analysis to reveal the role of the EXP family in the regulation of flower opening. Results: This study presents the first genome-wide identification of 36 PsEXP genes in tree peony, classifying them into four evolutionarily conserved subfamilies (PsEXPA, PsEXPB, PsEXLA, and PsEXLB). Promoter analysis revealed that 28 out of 36 PsEXP promoters contain gibberellin (GA)-responsive elements. Exogenous GA₃ treatment significantly promoted flower opening and upregulated eight PsEXPs, with PsEXPA4-1 showing the highest expression level and promoter GA-responsive element abundance. Subcellular localization confirmed that PsEXPA4-1 was targeted to the cell wall. Overexpression of PsEXPA4-1 in Arabidopsis led to early flowering and enlarged petals, indicating that PsEXPA4-1 had the potential to promote cell expansion, consistent with its proposed role in tree peony flower opening. Mechanistically, we identified a bHLH transcription factor, PsbHLH25, whose expression was induced by GA. Y1H and dual-luciferase assays indicated that PsbHLH25 can bind to the PsEXPA4-1 promoter. Conclusions: This study systematically characterized the EXP gene family in tree peony, revealed PsEXPA4-1 as a key effector downstream of GA promoting flower opening, and discovered PsbHLH25 as a transcriptional activator linking GA signaling to PsEXPA4-1. These findings provided important insights into GA-mediated floral opening and genetic resources for understanding the molecular mechanisms and enabling precise flowering time regulation in tree peony. Full article

Leuconostoc suionicum strain JNUCC 76 (=CH10) was isolated from cherry blossom flowers (Prunus yedoensis) collected on Jeju Island, Republic of Korea, representing a flower-associated strain of L. suionicum. To clarify its taxonomic position and genomic characteristics, whole-genome sequencing was performed using a hybrid PacBio–Illumina approach. The complete genome was assembled into a single circular chromosome of 2.20 Mb with a GC content of 36.8% and high sequencing depth, indicating a high-quality, closed genome assembly. Genome annotation revealed a compact gene repertoire dominated by functions related to carbohydrate transport and metabolism, amino acid utilization, and core cellular processes, consistent with adaptation to plant-derived, sugar-rich environments. Genome-based phylogenomic analyses using average nucleotide identity (ANI), digital DNA–DNA hybridization (dDDH), and Genome BLAST Distance Phylogeny (GBDP) placed strain JNUCC 76 within the species L. suionicum. Genome-based metrics clearly exceeded the accepted species thresholds, supporting the assignment of the strain to L. suionicum. Secondary metabolite gene cluster analysis identified a limited number of low-complexity and precursor-oriented biosynthetic gene clusters, including RiPP-like, type III polyketide synthase, and terpene-precursor clusters, suggesting that the ecological fitness of the strain relies primarily on primary metabolism rather than extensive secondary metabolite production. Overall, this study expands current knowledge of flower-associated Leuconostoc lineages and provides a high-quality genomic framework for future comparative and functional studies. The genomic features of strain JNUCC 76 highlight floral environments as underexplored reservoirs of lactic acid bacteria diversity and support further evaluation of flower-derived Leuconostoc strains as potential postbiotic or fermentation-based resources for cosmetic and related biotechnological applications. Full article