Angraecum, commonly known as Darwin’s orchid, is the largest genus of Angraecinae (Orchidaceae). This genus exhibits a high morphological diversity, making it as a good candidate for macroevolutionary studies. In this study, four complete plastomes of Angraecum were firstly reported and the potential variability hotspots were explored. The plastomes possessed the typical quadripartite structure and ranged from 150,743 to 151,818 base pair (bp), with a guanine–cytosine (GC) content of 36.6–36.9%. The plastomes all contained 120 genes, consisting of 74 protein-coding genes (CDS), 38 transfer RNA (tRNA) genes and 8 ribosomal RNA (rRNA) genes; all ndh genes were pseudogenized or lost. A total of 30 to 46 long repeats and 55 to 63 SSRs were identified. Relative synonymous codon usage (RSCU) analysis indicated a high degree of conservation in codon usage bias. The Ka/Ks ratios of most genes were lower than 1, indicating that they have undergone purifying selection. Based on the ranking of Pi (nucleotide diversity) values, five regions (trnS^GCU-trnG^GCC, ycf1-trnN^GGU, trnN^GUU-rpl32, psaC-ndhE and trnS^GCU-trnG^GCC) and five protein-coding genes (rpl32, rps16, psbK, rps8, and ycf1) were identified. The consistent and robust phylogenetic relationships of Angraecum were established based on a total of 40 plastomes from the Epidendroideae subfamily. The genus Angraecum was strongly supported as a monophyletic group and sister to Aeridinae. Our study provides an ideal system for investigating molecular identification, plastome evolution and DNA barcoding for Angraecum.

Camellia oleifera Abel. is a critical oil tree species. Camellia oil, which is extracted from the seeds, is widely regarded as a premium cooking oil, with the content of oleic acid being over 80%. Light is thought to be one of the largest essential natural components in the regulation of plant developmental processes, and different light qualities can considerably influence plant physiological and phenotypic traits. In this research, we examined the growth and physiological responses of C. oleifera “MIN 43” cultivar plantlets to three different wavelengths of light, containing white, red, and blue light, and we utilized the combination of the PacBio single-molecule real-time (SMRT) and Illumina HiSeq RNA sequencing to obtain the mRNA expression profiles. The results showed that plantlets growing under blue light conditions displayed superior growth performance, including stimulated enhancement of the leaf area, increased leaf number, increased chlorophyll synthesis, and improved photosynthesis. Furthermore, SMAT sequencing created 429,955 reads of inserts, where 406,722 of them were full-length non-chimeric reads, and 131,357 non-redundant isoforms were produced. Abundant differentially expressed genes were found in leaves under different light qualities by RNA-sequencing. Gene expression profiles of actin, dynein, tubulin, defectively organized tributaries 3 (DOT3), and ADP ribosylation factor 5 (ARF5) were associated with the greatest leaf performance occurring under blue light conditions. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis identified hundreds of pathways involved in different light conditions. The pathways of the plant circadian rhythm and hormone signal transduction were associated with different light quality responses in C. oleifera. Phytochrome B (PHYB), constitutively photomorphogenic 1 (COP1), long hypocotyl 5 (HY5), auxin/indole-3-acetic acid (AUX/IAA), Gretchen Hagen 3 (GH3), and small auxin-up RNA (SAUR), which were differentially expressed genes involved in these two pathways, play a vital role in responses to different wavelengths of light in C. oleifera. In addition, blue light significantly promotes flavonoid biosynthesis via changing expression of related genes.

Endophytic fungi enhance plant growth and stress resilience, yet their molecular roles in the roots of the endangered tree Phoebe bournei remain unclear. A comparative RNA-seq analysis was performed on root transcriptomes from wild, endophyte-colonized adult trees (OT) and axenically grown seedlings (ST). Unmapped reads were analyzed against the NCBI nucleotide (NT) database using BLASTN (v2.17.0), revealing Rhizophagus irregularis as the predominant endophytic fungus. Differential expression analysis identified 5891 DEGs, which were significantly enriched in pathways related to plant–pathogen interactions, phenylpropanoid biosynthesis, plant hormone signal transduction, and MAPK signaling. Key upregulated genes included PbMPK3, PbCML42, PbCML41.2, and PbGSTU28, suggesting enhanced ROS scavenging, calcium signaling, and defense activation. RT-qPCR validation confirmed the transcriptomic trends for selected genes. Our findings reveal that root endophytic fungi modulate a coordinated network involving immune priming, phytohormone regulation, and redox homeostasis, thereby supporting root development and enhancing resistance to biotic and abiotic stresses in P. bournei. This study provides foundational molecular insights into beneficial plant–endophyte interactions and identifies candidate genes that are valuable for the conservation and breeding of this threatened species.

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.