Background: Sinosenecio B. Nordenstam (Asteraceae) currently comprises 44 species. To investigate the interspecific relationship, several chloroplast markers, including ndhC-trnV, rpl32-trnL, matK, and rbcL, are used to analyze the phylogeny of Sinosenecio. However, the chloroplast genomes of this genus have not been thoroughly investigated. We sequenced and assembled the Sinosenecio albonervius chloroplast genome for the first time. A detailed comparative analysis was performed in this study using the previously reported chloroplast genomes of three Sinosenecio species. Results: The results showed that the chloroplast genomes of four Sinosenecio species exhibit a typical quadripartite structure. There are equal numbers of total genes, protein-coding genes and RNA genes among the annotated genomes. Per genome, 49–56 simple sequence repeats and 99 repeat sequences were identified. Thirty codons were identified as RSCU values greater than 1 in the chloroplast genome of S. albonervius based on 54 protein-coding genes, indicating that they showed biased usage. Among 18 protein-coding genes, 46 potential RNA editing sites were discovered. By comparing these chloroplast genomes' structures, inverted repeat regions and coding regions were more conserved than single-copy and non-coding regions. The junctions among inverted repeat and single-copy regions showed slight difference. Several hot spots of genomic divergence were detected, which can be used as new DNA barcodes for species identification. Phylogenetic analysis of the whole chloroplast genome showed that the four Sinosenecio species have close interspecific relationships. Conclusions: The complete chloroplast genome of Sinosenecio albonervius was revealed in this study, which included a comparison of Sinosenecio chloroplast genome structure, variation, and phylogenetic analysis for related species. These will help future research on Sinosenecio taxonomy, identification, origin, and evolution to some extent.

A new species Sinosenecio yangii D.G. Zhang & Q. Zhou (Asteraceae, Senecioneae) from Guizhou Province, China, is described and illustrated based on its morphological characteristics and molecular evidence. It closely resembles S. confervifer and S. guangxiensis, the former in the scapigerous habit and smooth and glabrous achene surface, the latter in the calyculate involucre and purple abaxial leaf surface, and both in the shape and indumentum of leaf lamina, but differs markedly from the latter two in having fewer capitula and epappose achenes. Phylogenetic analysis based on nrITS and ndhC-trnV sequences shows that this new species belongs to the S. latouchei clade and is sister to S. guangxiensis with moderate support.

Background: Eucommia ulmoides Oliver is a unique high-quality natural rubber tree species and rare medicinal tree species in China. The rapid characterization of E. ulmoides gene function has been severely hampered by the limitations of genetic transformation methods and breeding cycles. The polyethylene glycol (PEG)-mediated protoplast transformation system is a multifunctional and rapid tool for the analysis of functional genes in vivo, but it has not been established in E. ulmoides. Methods: In this study, a large number of highly active protoplasts were isolated from the stems of E. ulmoides seedlings by enzymatic digestion, and green fluorescent protein expression was facilitated using a PEG-mediated method. Results: Optimal enzymatic digestion occurred when the enzyme was digested for 10 h in an enzymatic solution containing 2.5% Cellulase R-10 (w/v), 0.6% Macerozyme R-10 (w/v), 2.5% pectinase (w/v), 0.5% hemicellulase (w/v), and 0.6 mol/L mannitol. The active protoplast yield under this condition was 1.13 × 106 protoplasts/g fresh weight, and the protoplast activity was as high as 94.84%. Conclusions: This study established the first protoplasm isolation and transient transformation system in hard rubber wood, which lays the foundation for subsequent functional studies of E. ulmoides genes to achieve high-throughput analysis, and provides a reference for future gene function studies of medicinal and woody plants.

A new species Sinosenecio yangii D.G. Zhang & Q. Zhou (Asteraceae, Senecioneae) from Guizhou Province, China, is described and illustrated based on its morphological characteristics and molecular evidence. It closely resembles S. confervifer and S. guangxiensis, the former in the scapigerous habit and smooth and glabrous achene surface, the latter in the calyculate involucre and purple abaxial leaf surface, and both in the shape and indumentum of leaf lamina, but differs markedly from the latter two in having fewer capitula and epappose achenes. Phylogenetic analysis based on nrITS and ndhC-trnV sequences shows that this new species belongs to the S. latouchei clade and is sister to S. guangxiensis with moderate support.

The formation of pantropical intercontinental disjunction (PID) in plants has generally been attributed to vicariance, boreotropical migration, and long-distance dispersal. However, this pattern has primarily been examined in herbs, shrubs, and trees, and less commonly studied in interlayer plant taxa. Here we examined evolutionary processes that resulted in the PID of a pantropical woody liana, Uncaria (Rubiaceae). We first constructed a comprehensive phylogeny by employing 73 plastid protein-coding sequences from 29 accessions of Uncaria (including 16 newly sequenced) from different continents. We then inferred divergence time, history and ecological niche evolution of this genus. Our results showed that Uncaria consisted of four well-supported clades that belonged to two geographically distinct lineages: the Asia-Oceania lineage and the Afro-Neotropical lineage. Biogeographic reconstruction showed this genus likely originated in Asia during the early Miocene (ca. 19.03 Ma) and the Middle Miocene Climatic Optimum may have triggered the early diversification of Uncaria. Due to its recent origin and small seeds with long wings, wind or water-mediated long-distance dispersal may have contributed to the distribution of Uncaria in tropical Oceania (via stepping-stone dispersal) and tropical Africa and America (by transoceanic dispersal). Our findings also indicate that diversification of Uncaria was primarily driven by ecological niche divergence, particularly climatic factors. Our study emphasizes the dual role of climatic niche divergence and long-distance dispersal in shaping the PID of Uncaria, providing references for many other extant lineages with similar distributions.

Background: Shancigu is a traditional Chinese medicine which is effective at clearing heat, detoxifying, dissipating masses, and resolving nodules. It consists of the dried pseudobulbs of orchids such as Cremastra appendiculata, or Pleione yunnanensis. To deeply understand the differences in the compositional and pharmacological active compounds in Shancigu, this study employed widely targeted metabolomics to analyze differential metabolites between two Shancigu species, C. appendiculata and P. yunnanensis. Methods: In this study, ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) was used to qualitatively, quantitatively, and differentially analyze the metabolites of C. appendiculata and P. yunnanensis. Results: Metabolite profiling identified 2890 compounds across 13 classes. Within these, 687 metabolites showed significant differential abundance (23.76% total), including 331 upregulated and 356 downregulated compounds. Pathway enrichment analysis revealed these differential metabolites primarily concentrated in stilbenoid biosynthesis (types I and II) and flavonoid aglycone biosynthesis. The most highly expressed metabolites in the Cremastra group were L-tyrosine, dopamine and 3,4-dihydroxybenzaldehyde-xylose-glucoside, while in the Pleione group, the most abundant metabolites were 3,5-dihydroxy-2’-methoxy-4-methylbibenzyl, Shancigusin F and aloifol I. C. appendiculata preferentially accumulates flavonoids and phenolic acids whereas P. yunnanensis favors terpenoid and nucleotide derivative production. Conclusions: This study identifies key differential metabolites in C. appendiculata and P. yunnanensis, providing basic data for the overall evaluation and breeding of Shancigu, laying a foundation for further quality control and precise medication of Shancigu.