Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Phoebe bournei”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

4 recordsLinked to original sources

Genome-Wide Identification and Colchicine-Responsive Expression Profiling of the Tubulins (TUA and TUB) Gene Family in Phoebe bournei.

Phoebe bournei is an economically and ecologically important woody species native to China. As a core component of colchicine-triggered polyploid breeding, the tubulin genes (TUA and TUB) have been identified and functionally analyzed in many plants, but not yet in P. bournei. Here, tubulin family members in P. bournei were identified through sequence alignment and subsequently characterized using comprehensive bioinformatic analyses. In particular, a total of six PbTUA and ten PbTUB members were identified and grouped into two and five subfamilies, respectively, according to phylogenetic relationships. Most tubulin proteins were small (414-522 aa) with predicted stability. Furthermore, 36 collinear gene pairs were identified, suggesting a possible contribution to the evolutionary expansion of this family. For different tissues, the expression levels of most tubulin genes were generally lower in leaves but higher in roots. Besides, treatment with 1.0% colchicine inhibited the expression of all 15 tubulin genes except PbTUB6. These results provide preliminary insights into tubulin genes associated with polyploid induction and supply candidate genes for future functional studies toward polyploid germplasm creation of P. bournei.

Phoebe bournei↗

Integrated phenotype, endogenous hormones and transcriptome analysis revealed the mechanism of response of Phoebe bournei seedlings to shade signals.

Understory tree seedlings are subjected to prolonged shading stress imposed by the canopy foliage, which significantly impedes their growth. A hallmark of shaded environments is a reduced red to far-red light ratio (R: FR). This study elucidates the physiological and molecular responses of the endangered tree species Phoebe bournei to shading signals. Seedlings were exposed to white light (control) and simulated shading environments with R: FR ratios of 1.5, 0.8, and 0.2. The findings reveal that an increase in the proportion of far-red light significantly enhances seedling height, root-collar diameter, internode length, petiole length, leaf surface area, and leaf biomass. Differentially expressed genes (DEGs) in each treatment group predominantly enrich pathways associated with hormone signaling, stress responses, and photosynthesis. Validation experiments demonstrate that shading promotes the activity of Rubisco and RCA enzymes, total chlorophyll (Chl) accumulation, and elevated levels of hormones including indole-3-acetic acid (IAA), gibberellic acid (GA3), salicylic acid (SA)/methyl salicylate (MeSA), cytokinins (CK), abscisic acid (ABA), and jasmonic acid (JA). Weighted Gene Co-expression Network Analysis (WGCNA) identifies seven hub genes linked to photosynthesis and plant hormone regulation: MYB, KSC, SUAR, CESA POD, CESA, and SAUR. Collectively, shading signals induce P. bournei seedlings to elongate their stems and petioles, enhance photosynthetic enzyme activity, and accumulate specific hormones, with pertinent genes actively participating in light signal transduction. This research sheds light on the shading response mechanism of P. bournei, providing a robust theoretical framework for the breeding of shade-tolerant trees and the conservation of endangered species.

Transcriptome↗

Population and landscape genomics provide insights into the adaptive genetic variation and future climate-induced vulnerability of the endangered tree species Phoebe bournei.

Elucidating the genomic underpinnings of adaptive variation is highly important for the conservation, landscape application, and management of ornamental trees against the backdrop of global climate change. However, research on the genetic mechanisms underlying climate adaptation in Phoebe bournei-a near-threatened subtropical tree species endemic to China, which is endowed with exceptionally high ornamental and ecological value-remains scarce. Whole-genome resequencing was conducted on 362 individuals from 27 natural populations across the geographical range of the species. Genome-environment association analyses were employed to identify 1556 climate-associated variants and 167 candidate genes associated with temperature and precipitation variables. Through functional annotation and expression profiling, pivotal genes, including TRX-M4 and FBD1, were identified as integral to drought and heat stress responses, with adaptive alleles displaying distinct geographic frequency distributions and significant phenotypic differentiation. Divergent evolutionary trajectories were deduced among populations, with southeastern populations distinguished by elevated genetic diversity and strong signatures of local adaptation. Nevertheless, projections derived from the Risk of Non-Adaptedness and gradient forest models suggest that these southeastern populations will face substantial genomic offset under future climate scenarios, signaling heightened vulnerability and the need for prioritized conservation and management. This study provides the first genome-wide perspective into the adaptive evolution of P. bournei and offers a robust foundation for its conservation and climate-resilient management.

Journal Article↗

Exploring the Mitochondrial Genomes of Phoebe Species (Lauraceae): Structural Dynamics and Functional Conservation.

Plant mitochondrial genomes (mitogenomes) vary markedly in size and architecture despite generally slow rates of sequence evolution. Phoebe is an ecologically and economically valuable genus of Lauraceae, yet its mitogenome diversity remains poorly characterized. In this study, we newly sequenced, assembled, and annotated the mitogenomes of three nationally protected Class II wild plants (P. bournei, P. chekiangensis, P. zhennan) from China and compared their mitogenomic characteristics. The three assemblies were resolved into representative circular configurations ranging from 808 to 864 kb, with similar GC contents and conserved protein-coding capacity. Each mitogenome contained distinct 41 protein-coding genes, 27-28 transfer RNAs, and three ribosomal RNAs. Synteny analysis revealed extensive changes in homologous-block order and orientation despite substantial sequence homology among the three species. Abundant repeats occurred predominantly in noncoding regions, while plastid-derived fragments documented historical intracellular DNA transfer. The three species exhibited similar codon usage and predicted RNA-editing patterns, whereas low synonymous divergence limited inference from pairwise ratios. Phylogenetic analysis based on mitochondrial protein-coding genes recovered Phoebe as a well-supported monophyletic lineage. These results reveal substantial structural divergence accompanied by conserved nucleotide composition and coding capacity, providing valuable data for further understanding the evolutionary variation of plant mitogenomes of Phoebe and the Lauraceae.

Phoebe↗