PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Populus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2026

A Leucine-Rich Repeat Receptor-Like Protein Associated with a QTL for Septoria Stem Canker in Populus trichocarpa × Populus deltoides Hybrid Poplar.

The fungal plant pathogen Sphaerulina musiva (Ascomycota) causes Septoria stem canker, the most economically damaging disease of Populus plantations in North America, yet the genetic determinants of host resistance remain uncharacterized in hybrid poplar. Using an inoculation experiment with the 52-124 pseudo-backcross family of Populus trichocarpa × Populus deltoides (TD × D) hybrid poplar, a single significant QTL was identified on Chromosome 16 (LOD = 4.93) associated with both stem canker count and disease severity score. Transcriptomic analysis of two resistant and two susceptible genotypes across a 72-hour infection time course identified a single differentially expressed gene within the QTL candidate gene window: Podel.16G125900, a putative leucine-rich repeat receptor-like protein (LRR-RLP) with homology to receptor-like protein 33 in Arabidopsis thaliana. Podel.16G125900 is located 3001 bp (0.019 cM) upstream of the QTL peak and showed a strong infection-induced upregulation in susceptible genotype 852 (log2 fold-change = 20.47) and higher baseline expression in resistant genotypes relative to susceptible genotypes across all infection time points, consistent with a resistance mechanism in which expression level contributes to the degree of resistance conferred. Two P. trichocarpa homologs were not differentially expressed and differ substantially in sequence content, suggesting the resistance function is specific to the resistant P. deltoides lineage. These findings identify Podel.16G125900 as a strong candidate gene underlying quantitative resistance mechanisms modulating Septoria stem canker resistance in the 52-124 family of TD × D hybrid poplar and provide a target for future functional validation and marker-assisted resistance breeding.

Disease Resistance↗
PubMed2026

Genus-Wide Pan-Genome Analysis of Populus bZIP Transcription Factors with Reanalysis of Public Salt-Stress Transcriptomes.

Basic leucine zipper (bZIP) transcription factors regulate plant development and stress responses, but their genus-wide diversity in Populus remains unclear. We analyzed 19 Populus genomes and retained 1764 bZIP proteins, including 21 independent new loci and four annotation corrections. Of these, 1762 were assigned to 79 orthologous gene groups (OGGs), comprising 43 core, 20 soft-core, 15 shell and one cloud OGG, of which 59 showed copy-number variation. Phylogenetic analysis assigned 74 representative pangenes to 13 subfamilies, with five remaining unclassified and motif patterns differing among subfamilies. Whole-genome duplication (WGD)/segmental duplication accounted for 81.0% of OGG-assigned proteins and contributed predominantly to the conserved component. Although 72.2% of bZIP proteins overlapped a transposable element within the gene body or 2-kb flanks, this proportion was modestly lower than in matched non-bZIP genes, and copy-number-variable OGGs showed no greater TE coverage than invariant OGGs. Among retained homologous comparisons, 97.6% had Ka/Ks ≤ 1, supporting predominant purifying selection. Across the heterogeneous public salt-stress RNA-seq datasets analyzed, no OGG showed a significant, directionally concordant response in at least two Populus taxa. These results reveal a conserved bZIP framework shaped mainly by ancient duplication alongside variable genomic contexts and transcriptional responses.

Populus↗
PubMed2026

Benchmarking Assembly-Free K-mer Methods for Species Identification in Complex Plant Groups: A Case Study in Populus.

Species identification in taxonomically complex plant groups is frequently limited by the inadequacy of organellar markers, whose phylogenetic signal is disrupted by cytonuclear discordance and chloroplast capture. Using the taxonomically complex genus Populus as a model, we evaluated an assembly-free k-mer workflow against a curated SNP reference benchmark. Whole-genome resequencing data from 235 Populus individuals were curated to a 202-individual, 34-species reference dataset in which all retained species are strictly monophyletic in a genome-wide SNP analysis. Independent maximum likelihood analyses further confirmed that the 31 non-hybrid backbone species each maintained high-support monophyly, while taxa of documented reticulate origin showed placement patterns consistent with their reticulate histories. ABBA-BABA D-statistics detected widespread residual allele sharing within the backbone, though the strongest signals did not correspond to the species pairs responsible for the few k-mer identification failures. Against this benchmark, complete plastomes showed limited resolution, recovering only 3.0% species monophyly and 71.1% nearest-neighbor assignment. The optimized k-mer workflow, operating directly on raw reads without assembly or alignment, recovered 91.2% species monophyly, 99.0% nearest-neighbor assignment, and 98.0% group-average assignment. K-mer length was the primary accuracy-controlling parameter, with k = 31 falling within a stable accuracy plateau. Distance-based metrics reached near-saturation at 0.2× sequencing depth, indicating that low-coverage genome skimming can support scalable nuclear genome-based identification with standard computational resources. K-mer distance heatmaps also flagged unusual genomic affinities in hybrid-origin and outlier samples, providing a rapid screen for subsequent population genomic analyses. These results support assembly-free k-mer distances as an efficient tool for reference-based species identification and sample screening in complex plant groups, with residual limitations concentrated near recently diverged species boundaries. Model-based phylogenomic, coalescent, and network analyses remain necessary for resolving deeper species relationships and detailed introgression histories.

Populus↗
PubMed2026

Genome-wide association study and KASP development for growth and leaf traits in Populus deltoides.

BACKGROUND: Populus deltoides is a valuable timber species of considerable importance in the study of forest genetic breeding. However, its genetic improvement continues to rely predominantly on conventional selection and hybridization strategies hampered by long breeding cycles and limited efficiency. RESULTS: A total of 209 P. deltoides accessions were genotyped using a 60K SNP (Single nucleotide polymorphism) liquid array. Following quality control, 46,031 high-quality SNPs were screened and analyzed alongside 15 phenotypic traits in a genome-wide association study (GWAS), which identified 219 SNPs significantly associated with the traits. After further screening and annotation, a final set of 57 target SNPs and 77 candidate genes was obtained. Using kompetitive allele-specific PCR (KASP) assays, we successfully developed 48 polymorphic KASP markers. Of these, 25 markers exhibited significant phenotypic differences (p&#x2009;<&#x2009;0.05) across genotype groups. CONCLUSIONS: These 25 KASP markers can serve as reliable and practical tools for phenotype-assisted selection, providing efficient molecular resources for accelerating genetic improvement and marker-assisted breeding in poplar.

Populus↗
PubMed2025

Resistance of Populus davidiana&#x2009;&#xd7;&#x2009;P. bolleana overexpressing cinnamoyl-CoA reductase gene to Lymantria dispar larvae.

Lignin is a crucial defense phytochemical against phytophagous insects. Cinnamoyl-CoA reductase (CCR) is a key enzyme in lignin biosynthesis. In this study, transgenic Populus davidiana&#x2009;&#xd7;&#x2009;P. bolleana overexpressing the PdbCCR gene were generated via Agrobacterium-mediated transformation. Successful integration of PdbCCR into the poplar genome was confirmed by PCR amplification and quantitative reverse transcription PCR (qRT-PCR). The lignin content in the transgenic poplar leaves was significantly higher than that in the wild poplar, and after L. dispar larvae fed on the transgenic poplar, the CCR activity was clearly induced. The L. dispar larvae grew slowly after feeding on transgenic poplar and the laccase, cellulase and three detoxifying enzymes were induced compared with larvae after feeding on wild-type poplar. The bioassay further revealed that transgenic poplar plants overexpressing PdbCCR showed a high level of resistance to L. dispar larvae. These results confirmed that PdbCCR is a candidate gene for breeding insect resistant poplar.

Populus↗
PubMed2025

Dynamic Rhizodeposition in the Woody Perennial Populus trichocarpa.

Plants undergo physiological and metabolic changes that release specific molecules into the surrounding soil, a process collectively known as rhizodeposition. These compounds play crucial roles in plant-microbe-soil interactions, such as supporting plant development and resilience in changing environments. Under nutrient-limited conditions, these plant-derived compounds modify the rhizosphere environment, mobilizing otherwise inaccessible nutrients and recruiting stress-adaptive microbial communities that support stress resilience. Currently, the chemical diversity of rhizodeposition has yet to be fully realized but is expected to be a complex mixture that includes soluble organic compounds excreted from root cells, along with products of root cell turnover, sloughed-off root cap and border cells, and mucilage. Here, we developed a methodological and conceptual framework for an in-depth measurement of rhizodeposition through critical advancements in untargeted metabolomics. This approach provided foundational insights into the dynamic changes in rhizodeposition for the woody perennial Populus trichocarpa and rhizodeposit profiles varying by genotype, time, location, and environment. More broadly, this study provides a framework that will help formulate the next steps to effectively study rhizodeposition.

Populus↗
PubMed2025

Haplotype-resolved telomere-to-telomere genome assembly of Populus lasiocarpa unveils retrotransposon-driven centromere evolution.

Centromeres, essential for chromosome segregation, exhibit remarkable evolutionary dynamism in sequence composition and structural organization. Here, we report the first haplotype-resolved, telomere-to-telomere genome assembly of Populus lasiocarpa (PLAS) and precisely map all 38 functional centromeres through CENH3 ChIP-Seq. Unlike classical satellite-rich centromeres in model plants, PLAS centromeres lack abundant satellite arrays but are dominated by retrotransposons, particularly RLG and RIL elements, which form intricate nested TE arrays within the functional centromeric regions, disrupting their structural integrity and driving their evolution. Comparative analysis with P. trichocarpa reveals a conserved retrotransposon-dominated architecture, despite minimal sequence conservation. We propose a cyclic model of centromere evolution in which autonomous retrotransposons destabilize functional centromeres through epigenetic erosion, triggering neocentromere formation at pericentromeric sites enriched in transposable elements (TEs) and tandem repeats (TRs). These neocentromeres either succumb to recurrent retrotransposon invasions or stabilize through KARMA-mediated TR expansion, ultimately giving rise to satellite-rich centromeres. Our work redefines centromeres as dynamic, epigenetically plastic domains shaped by retrotransposon-TR antagonism, challenging the satellite-centric paradigm and offering novel insights into plant genome evolution.

Retroelements↗
PubMed2026

PtoeIF5A1: A Pleiotropic Regulator of Development, PCD, and Salt Tolerance in Populus tomentosa.

Eukaryotic translation initiation factor 5A (eIF5A) is a highly conserved protein family unique to eukaryotes, yet its functional characterization in woody plants remains limited. In this study, we identified four eIF5A genes (PtoeIF5A1-PtoeIF5A4) from the genome of Populus tomentosa, a fast-growing tree species indigenous to China, and characterized their expression patterns and functional roles through bioinformatics analysis, quantitative real-time PCR, stable overexpression in Arabidopsis thaliana, and transient expression in Nicotiana benthamiana leaves. Our results demonstrated that all PtoeIF5A proteins contain a conserved OB-fold domain and multiple phosphorylation sites, with PtoeIF5A1 showing predominant expression in roots and secondary xylem. Functional assays revealed that PtoeIF5A1 overexpression accelerated inflorescence stem elongation and early flowering in Arabidopsis, induced visible chlorosis and programmed cell death (PCD) in tobacco leaves, and significantly enhanced salt tolerance under NaCl treatment. Collectively, these findings establish PtoeIF5A1 in poplar as a pleiotropic regulator integrating developmental cues, programmed cell death, and stress responses; and as a valuable genetic resource for breeding stress-resilient woody plants.

Populus tomentosa↗
PubMed1992

Maternal transmission of mitochondrial DNA in interspecific hybrids of Populus.

Restriction fragment analysis was conducted to investigate the mode of inheritance of mitochondrial (mt) DNA in F1 progeny of two P. deltoides x P. deltoides, three P. deltoides x P. nigra, and two P. deltoides x P. maximowiczii controlled crosses, and in Populus x canadensis by using 16 restriction endonucleases and two heterologous probes of cloned mtDNA fragments of maize. Five restriction fragment length polymorphisms (RFLPs) of mtDNA differentiated P. deltoides from P. nigra, whereas three RFLPs of mtDNA separated P. deltoides from P. maximowiczii. In all cases, F1 progeny of P. deltoides x P. nigra, and P. deltoides x P. maximowiczii, crosses had mtDNA restriction fragments of only their maternal P. deltoides parents. P. x canadensis had mtDNA restriction fragments of only P. deltoides. F1 progeny of intraspecific P. deltoides crosses also had the same mtDNA fragments as their maternal parent. The results clearly demonstrate uniparental-maternal inheritance of the mitochondrial genome in F1 interspecific hybrids of P. deltoides with P. nigra and P. maximowiczii.

Crosses, Genetic↗
PubMed1976

Trinucleate pollen in the genus Populus.

It is shown by light microscopy and microspectrophotometry that several Populus species produce trinucleate pollen. Such pollen seems more widespread than previously acknowledged.

Cell Nucleus↗
PubMed1992

Platelet aggregation inhibitors from Populus sieboldii Miquel.

The water extract of Populus sieboldii Miquel (Salicaceae) inhibited arachidonic acid-induced platelet aggregation. Pyrocatechol and salicyl alcohol were isolated as active constituents. Pyrocatechol showed an inhibitory effect on platelet aggregation induced by arachidonic acid with IC100 value of 4 microM, which was 25 times more potent than aspirin.

Drugs, Chinese Herbal↗
PubMed1992

Study of the anti-inflammatory activity of Populus tremula, Solidago virgaurea and Fraxinus excelsior.

Aqueous/alcoholic extracts of Populus tremula, Solidago virgaurea and Fraxinus excelsior (components of Phytodolor N) were tested individually and in 3 different combinations for anti-inflammatory activity using carrageenan induced edema and/or adjuvant induced arthritis of the rat paw. The tested combinations as well as the individual extracts significantly reduced the paw edema to varying degrees and also dose dependently inhibited the arthritic paw volume. The anti-inflammatory activity of the combinations was respectively comparable to the tested doses of diclofenac.

Animals↗
PubMed2026

Functional study of the AfRAP2 gene in Amorpha fruticosa L. tolerance to saline-alkali and drought stress.

BACKGROUND: Amorpha fruticosa L. is a leguminous shrub with high tolerance to drought, poor soil, and saline-alkali stress conditions. As a member of the family of transcription factors in higher plants, the ethylene response factor AP2/ERF plays a crucial role in both plant adaptation to abiotic stress and in growth and development. In this study, based on genes identified from the transcriptomic sequencing of Amorpha fruticosa L. under drought stress, the upregulated gene AfRAP2 was isolated from its seedlings, with the aim of elucidating its stress-response function using molecular biological techniques. RESULTS: In this study, the AfRAP2 gene was cloned from the leaves of Amorpha fruticosa L. using RT-PCR. Bioinformatics analysis revealed that AfRAP2 contains an AP2 domain and belongs to the DREB subfamily of the AP2/ERF transcription factor family, showing close phylogenetic relationships with LaEREBP from Lathyrus albus. Real-time quantitative PCR (RT-qPCR) results indicate that AfRAP2 is expressed in various tissues of Amorpha fruticosa L., with the highest expression in leaves and the lowest in stems, furthermore, its expression is significantly upregulated in roots and leaves upon induction by NaHCO3 and PEG6000. Subcellular localization experiments confirmed that the AfRAP2 protein is localized to the nucleus, and GUS histochemical staining assay revealed that its promoter drives GUS expression in anthers. Resistance analysis of overexpressing yeast strains showed that yeast transformed with the AfRAP2 gene exhibited significantly better growth under sorbitol, mannitol, and NaHCO3 stress conditions compared to the control, indicating that this gene enhances yeast tolerance to drought and saline-alkali stress. We screened transgenic tobacco and Populus davidiana &#xd7; P. alba var. Pyramidalis. The results showed that under natural drought and saline-alkali stress treatments, the transgenic lines exhibited significantly improved growth and higher activities of the physiological indicators of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) compared with wild-type plants, indicating that the overexpression of the AfRAP2 gene plays a key role in the response to saline-alkali stress and drought stress. CONCLUSION: In summary, AfRAP2 contains an AP2 domain and belongs to the DREB subfamily of transcription factors, under abiotic stress induced by NaHCO&#x2083; and mannitol, it can induce the expression of the AfRAP2 gene in tobacco and Populus davidiana&#xd7;P. alba var. pyramidalis. AfRAP2 plays a vital role in the plant response to saline-alkali stress and drought stress and is a promising candidate gene for stress-tolerant breeding.

Plant Proteins↗
PubMed2025

Factors underlying a latitudinal gradient in the S/G lignin monomer ratio in natural poplar variants.

The chemical composition of wood plays a pivotal role in the adaptability and structural integrity of trees. However, few studies have investigated the environmental factors that determine lignin composition and its biological significance in plants. Here, we examined the lignin syringyl-to-guaiacyl (S/G) ratio in members of a Populus trichocarpa population sourced from their native habitat and conducted a genome wide association study to identify genes linked to lignin formation. Our results revealed many significant associations, suggesting that lignin biosynthesis is a complex polygenic trait. Additionally, we found an increase in the S/G ratio from northern to southern geographic origin of the trees sampled, along with a corresponding metabolic and transcriptional reprogramming of xylem cell wall biosynthesis. Further molecular analysis identified a mutation in a cell wall laccase genetically associated with higher S/G ratios that predominate in trees from warmer lower latitudes. Collectively, our findings suggest that lignin heterogeneity arises from an evolutionary process enabling poplar adaptation to different climatic challenges.

Populus↗
PubMed2025

Evolutionary Genomics Unravels the Responses and Adaptation to Climate Change in a Key Alpine Forest Tree Species.

Despite widespread biodiversity loss, our understanding of how species and populations will respond to accelerated climate change remains limited. In this study, we integrate population genomics, experimental evolution, and environmental modeling to elucidate the evolutionary responses to climate change in Populus lasiocarpa, a key alpine forest tree species primarily distributed in the mountainous regions of a global biodiversity hotspot. Over historical timescales, our findings demonstrate that demographic dynamics, divergent selection, and long-term balancing selection have shaped and maintained genetic variation within and between populations. In examining genomic signatures of contemporary climate adaptation, we found that haplotype blocks, potentially caused by inversion polymorphisms that suppress recombination, are linked to enriched combinations of locally adaptive environmental variations. We further assessed the relative contributions of environmentally induced plastic responses, constitutive expression divergence between genetic clusters, and their interactions in driving gene expression variation and divergence. Notably, we observed a strong correlation between sequence divergence and constitutive differential expression among genetic clusters. Finally, by incorporating genetic adaptation, migration, and genetic load into our predictions of population-level climate change risks, we identified western populations-primarily distributed in the Hengduan Mountains, a region known for its environmental heterogeneity and significant biodiversity-as the most vulnerable to climate change. These populations should be prioritized for conservation and management. Overall, our study advances the understanding of the relative roles of long-term natural selection, local environmental adaptation, and immediate plastic expression changes in shaping the responses of natural populations of keystone species to climate change.

Climate Change↗