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Zemei Zhu

Publications and source records attributed to Zemei Zhu.

3 recordsLinked to original sources

Assembly and comparative analysis of the mitochondrial genome of Pleione yunnanensis: genome structure and evolutionary insights.

BACKGROUND: Pleione yunnanensis a terrestrial or semi-epiphytic herbaceous plant belonging to the Orchidaceae family, is valued for both its medicinal uses and ornamental appeal. Although its chloroplast genomes have been sequenced, its complete mt genome had not previously been resolved, limiting genetic and evolutionary studies of the species. RESULTS: In this work, we assembled and characterized the first complete mt genome of P. yunnanensis, revealing a structurally complex, multibranched system composed of 14 circular-mapping molecules totaling 468,176 bp with a GC content of 44.32%. The genome encodes 44 annotated genes, including 28 protein-coding genes (PCGs), 15 tRNAs, and one rRNA. The multibranched architecture provides new evidence supporting the dynamic and recombinational nature of plant mt genomes. Repeat analysis uncovered 29 simple sequence repeats (SSRs), 19 tandem repeats, and 118 dispersed repeats, indicating a comparatively lower repeat abundance than that found in closely related orchids with similar mt genome sizes. Codon-usage profiling of PCGs showed a marked bias toward A/T-ending codons. Prediction of RNA editing sites identified 4,708 putative edits across mitochondrial PCGs. Most mitochondrial genes displayed Ka/Ks ratios close to 1.0, suggesting relaxed selective constraints or lineage-specific evolutionary patterns rather than strong positive selection. Moreover, we detected 69 chloroplast-derived homologous fragments, including 15 intact genes, suggesting ongoing plastid-mitochondrial DNA transfer. Phylogenetic reconstruction and collinearity comparisons demonstrated that P. yunnanensis clustered closely with Dendrobium species, including D. amplum and D. hancockii, within the Orchidaceae clade. CONCLUSIONS: This study provides the first complete mt genome of P. yunnanensis, providing a foundational genomic resource for the genus Pleione. The results not only improve our understanding of mt genome structure and evolution in Orchidaceae, but also offer valuable molecular evidence for phylogenetic inference, germplasm identification, and conservation of this endangered medicinal species.

Orchidaceae

Characterization and comparative analysis of the complete mitochondrial genome sequence of Aucklandia lappa Decne.

BACKGROUND: Aucklandia lappa Decne, a precious medicinal herb in China, utilises the dried rhizome as its medicinal part, which riches in volatile oils, sesquiterpene compounds and other active constituents. Although the mitogenome of A. lappa has been assembled, related research remains in its preliminary stages, far from achieving comprehensive and in-depth understanding. RESULTS: In this paper, the complete mitogenome of A. lappa was assembled by employing a hybrid strategy that combined Illumina short-read and Nanopore long-read sequencing. The assembled mitogenome is 436,648 bp in size with a GC content of 45.06%. The mitogenome has only one chromosomal structure, It contains 54 genes, including 31 protein-coding genes(PCG), 19 tRNA genes, and 4 rRNA genes. A total of 32 high-frequency codons exhibiting significant AT-bias, 431 RNA editing sites, and 26 homologous fragments were transferred from the chloroplast to mitochondria genes (7,337 bp, 1.68%). Furthermore, we conducted a phylogenetic analysis involving in A. lappa and 27 other taxa to clarify its evolutionary and taxonomic status. These findings provide a foundation for further understanding the evolutionary relationships within Asteraceae plant. CONCLUSION: Through the assembly and comprehensive analysis of A. lappa mitogenome, This study has for the first time fully elucidated its mitogenomic structural characteristics.These results not only provide high-quality genetic resources for research on the Asteraceae mitogenome but also lay a solid foundation for in-depth exploration of the evolution and functional genomics of medicinal plants in the Asteraceae family.

Genome, Mitochondrial