Zhonghui Ma

Accurate species delimitation serves as a cornerstone for effective biodiversity conservation strategies, particularly for rare taxa where misclassification of taxa may lead to misallocation of limited resources. Callicarpa oligantha , one of only two plant species declared extinct in Guangdong Province, South China, was historically documented solely from its type specimen--a single individual collected in 1917 at Luofushan (Loh Fau Mountain). However, the morphological similarities with C. brevipes have long challenged the taxonomic status of C. oligantha . Following the rediscovery of the species at its type locality in 2024, we conducted an integrative taxonomic reassessment of C. oligantha and C. brevipes based on the newly collected materials using combined analyses of molecular phylogenetics and morphological comparisons. Both molecular and morphological evidence congruently support the conspecificity of C. oligantha and C. brevipes . We therefore propose synonymizing C. oligantha under C. brevipes and recommend its exclusion from extinction lists. This study underscores the importance of robust taxonomic frameworks in preventing conservation misprioritization, and highlights the value of integrative, multidisciplinary approaches for establishing accurate biodiversity baselines prior to biological conservation action.

Stellaria (Caryophyllaceae) comprises approximately 112 species globally, with China serving as a significant center of diversity hosting about 64 species. Despite its taxonomic importance, the genus remains insufficiently studied in China. Previous phylogenetic studies relying on limited DNA barcodes produced weakly supported inferences, while those based on chloroplast genomes are currently lacking. Here, we characterize the chloroplast genome structure and reconstruct its highly resolved infrageneric phylogeny using 60 newly sequenced plastomes. All plastomes displayed a conserved quadripartite structure, with lengths varying from 147,205 bp to 149,409 bp, GC contents ranging from 36.6% to 36.7%, and gene counts spanning 128 to 129 genes. Codon usage patterns were highly conserved with leucine encoded by UUA exhibiting the highest relative synonymous codon usage. A total of 55–74 simple sequence repeats and 42–64 long repeats were detected. Three hypervariable regions— petN-psbM , trnP-rpl33 , and ycf1 were identified as promising candidate DNA barcodes. Phylogenomic analysis resolved Stellaria into three strongly supported major clades and 15 well-defined subclades. The results are largely consistent with the established phylogeny of Stellaria . However, we observed certain discrepancies within specific clades. We propose some suggestions for these clades and species based on morphological and molecular evidence. This study provides the first comprehensive phylogenetic framework for Stellaria based on the chloroplast genome, establishing a robust foundation for future taxonomic revisions and evolutionary studies.

The thiazole compounds cystothiazole A (7) and melithiazol F (9) potently inhibited Fusarium sacchari by suppressing its growth and spore germination and disrupting cell membrane integrity.

Conventional chromosome preparation methods were used to observe and analyze the karyotypes of six Callicarpa species. We also analyzed the evolutionary trends and performed parametric clustering based on karyotypic features for 22 Callicarpa species. This research aimed to complement the chromosomal information for Callicarpa, and provide a cytological basis for further exploration of phylogenetic relationships in this genus. The results showed that (1) six Callicarpa species were diploid with chromosome number 2n=2x=34, 36, and 38. The karyotypes consisted of median centromeric chromosomes (m) and submedian centromeric chromosomes (sm), and the karyotypes were 1B, 2A, and 2B, which suggested relatively primitive types. (2) C. integerrima, C. rubella, and C. macrophylla were inferred to be the more advanced species, with C. integerrima having the most advanced karyotype according to Stebbins’ theory of karyotype evolutionary trends in plants. (3) Clustering of karyotypic parameters classified 22 species of Callicarpa into four major groups. In addition, we discussed the clustering results in comparison with the traditional classification system of Callicarpa, which showed partial agreement between the karyotypic clustering and the traditional classification.

Callicarpa nudiflora is one of high medicinal and economic value plants in China, which was recorded in Chinese pharmacopoeia (2020 edition) and widely used to treat tropical bacterial infections, acute infectious hepatitis, and internal and external bleeding. In this study, we assembled the C. nudiflora genome with a size of approximately 597.82 Mb and a contig N50 length of 34.14 Mb. A total of 98.61% of the assembled sequences were anchored to 17 pseudo-chromosomes by using PacBio long reads and Hi-C sequencing data. We totally predicted 31,266 protein-coding genes, of which 92.45% could be annotated in databases such as NR, GO, KOG, and KEGG. In addition, we identified 2,303 rRNAs, 884 MicroRNAs and 531 tRNAs from the genome. The chromosome-scale genome represents a crucial resource for investigating the molecular mechanisms underlying the biosynthesis of medicinal components and facilitates the exploration and conservation of C. nudiflora.

The increasing challenge of marine biofouling, mainly due to barnacle settlement, necessitates the development of effective antifoulants with minimal environmental toxicity. In this study, fifteen derivatives of brusatol were synthesized and characterized using ¹³C-NMR, ¹H-NMR, and mass spectrometry. All the semi-synthesized compounds obtained using the Multi-Target-Directed Ligand (MTDL) strategy, when evaluated as anti-settlement agents against barnacles, showed promising activity. Compound 3 exhibited the highest anti-settlement capacity, with an EC₅₀ value of 0.1475 μg/mL, an LC₅₀/EC₅₀ ratio of 42.2922 (>15 indicating low toxicity), and a resuscitation rate of 71.11%, while it showed no significant phenotypic differences in the zebrafish embryos after treatment for 48 h. The toxicity screening of zebrafish also demonstrated the low ecotoxicity of the selected compounds. Furthermore, homology modeling of the HSP90 structure was performed based on related protein sequences in barnacles. Subsequently, molecular docking studies were conducted on HSP90 using these newly synthesized derivatives. Molecular docking analyses showed that most activated derivatives displayed low binding energies with HSP90, aligning well with the biological results. They were found to interact with key residues in the binding site, specifically ARG243, TYR101, and LEU73. These computational findings are anticipated to aid in predicting the enzyme targets of the tested inhibitors and their potential interactions, thus facilitating the design of novel antifoulants in future research endeavors.

The phylogenetic studies of the tribe Alsineae (Caryophyllaceae) have revealed a clearer boundary between the genus Stellaria and related genera, primarily relying on the morphological characteristics of style 3, stamens 10 and petals deeply bifid. However, the newly-published species in China, which have 5 styles or ten or more lobes per petal, challenge this boundary and necessitate further studies. In this paper, we reviewed six newly-published Chinese species of Stellaria, utilising both molecular phylogenetic evidence from nuclear ribosomal internal transcribed spacer (ITS) and four plastid regions (trnL-F, matK, rbcL, rps16) and morphological evidence. Our results demonstrated that the five new species (Stellaria abaensis, S. multipartita, S. pentastyla, S. procumbens and S. zhuxiensis) were nested within the genus Stellaria, but Stellaria motuoensis was sister to the genus Schizotechium. Herein, we accepted four new Stellaria species and proposed a new combination in Schizotechium and a new synonym in Stellaria. Additionally, we described a new species Stellaria longipedicellata from Sichuan Province, China, which was distinguished from the closely-related species Stellaria decumbens by its glabrous body, linear-lanceolate leaves, long pedicellate flowers, prostrate growth habit and flowers nearly equal to or slightly shorter than sepals. Both molecular and morphological evidence support the treatment of S. longipedicellata as a new species of the genus Stellaria.