Biomedical subjects

Mingchun Liu

Publications and source records attributed to Mingchun Liu.

3 recordsLinked to original sources

PubMed2026

Methylation histology reveals the molecular mechanism by which red light-mediated DNA methylation delays leaf senescence in pak choi (Brassica rapa subsp. chinensis).

Leaf senescence is a key factor affecting the postharvest quality and shelf life of vegetables. The specific mechanisms by which light environment and DNA methylation mediate leaf senescence remain unclear. This study explored the molecular mechanism by which red light (RL) LED delays leaf senescence through DNA methylation in pak choi (Brassica rapa subsp. chinensis). In this study, RL treatment significantly suppressed leaf senescence in pak choi during postharvest storage and downregulated the expression of senescence-associated genes (SAGs). Experiments with methylation inhibitors confirmed its association with DNA methylation. Furthermore, whole-genome bisulfite sequencing revealed that during storage-induced senescence, pak choi exhibited significantly reduced methylation levels across its genome, particularly in promoter regions, and RL treatment reversed this effect. Furthermore, virus-induced gene silencing and overexpression experiments confirmed the central role of the demethylase BrDML3 (BraA01g004250.3.5C) in this process. Subsequently, a transcription factor under its regulation, BrNAC55 (BraA05g032630.3.5C), was identified and shown to promote leaf senescence by activating downstream SAGs (BrSGR1, BrPPH, BrSAUR36) to promote leaf senescence. In addition, this study found that BrNAC55 can also form a feedback loop with BrDML3, continuously amplifying leaf senescence. This study elucidates the mechanism by which RL-mediated DNA methylation delays leaf senescence, providing a foundation for postharvest preservation technologies.

DNA Methylation↗

PubMed2026

Arginine-substituted Mastoparan-C derivatives combat dual bacterial pathogens: in vitro mechanistic insights and in vivo efficacy in polymicrobial wounds.

UNLABELLED: The synergistic interactions in multi-pathogen infections compromise wound healing and limit therapeutic efficacy. In this study, we designed and synthesized arginine-substituted derivatives of the antimicrobial peptide Mastoparan-C (MP-C). Among them, Arg²MP-C and Arg4.11.12MP-C exhibited potent, broad-spectrum activity against both Escherichia coli and Staphylococcus aureus. Their enhanced antibacterial activity is associated with increased positive charge and optimized hydrophobicity. Mechanistically, both peptides employ a dual-target strategy, disrupting bacterial membranes and binding genomic DNA; Arg²MP-C acted most rapidly against the E. coli envelope, while Arg4.11.12MP-C caused the strongest membrane damage to S. aureus. In a murine polymicrobial wound model, Arg²MP-C treatment nearly achieved complete wound closure by day 10, significantly reduced bacterial loads, and promoted tissue regeneration. This study demonstrates that arginine engineering can yield peptides with potent, multi-mechanistic action, identifying Arg²MP-C as a promising candidate for combating polymicrobial wound infections. IMPORTANCE: Wounds infected with multiple bacterial species are notoriously difficult to treat, often leading to poor healing and limited effectiveness of existing therapies. In this study, we developed new antimicrobial peptides by introducing arginine substitutions into a natural peptide called Mastoparan-C. Two of our engineered peptides, Arg²MP-C and Arg4.11.12MP-C, showed potent activity against two common wound pathogens, Escherichia coli and Staphylococcus aureus. These peptides work through a dual mechanism: disrupting bacterial membranes and binding to bacterial DNA. In a mouse model of mixed-infection wounds, treatment with Arg²MP-C led to nearly complete wound closure by day 10, drastically reduced bacterial counts, and promoted tissue repair. Our findings highlight arginine engineering as a promising strategy to create next‑generation antimicrobial agents that can effectively combat complex polymicrobial wound infections, addressing a critical unmet need in clinical wound care.

Animals↗

PubMed2024

Haplotype-resolved genome assembly and implementation of VitExpress, an open interactive transcriptomic platform for grapevine.

Haplotype-resolved genome assemblies were produced for Chasselas and Ugni Blanc, two heterozygous Vitis vinifera cultivars by combining high-fidelity long-read sequencing and high-throughput chromosome conformation capture (Hi-C). The telomere-to-telomere full coverage of the chromosomes allowed us to assemble separately the two haplo-genomes of both cultivars and revealed structural variations between the two haplotypes of a given cultivar. The deletions/insertions, inversions, translocations, and duplications provide insight into the evolutionary history and parental relationship among grape varieties. Integration of de novo single long-read sequencing of full-length transcript isoforms (Iso-Seq) yielded a highly improved genome annotation. Given its higher contiguity, and the robustness of the IsoSeq-based annotation, the Chasselas assembly meets the standard to become the annotated reference genome for V. vinifera. Building on these resources, we developed VitExpress, an open interactive transcriptomic platform, that provides a genome browser and integrated web tools for expression profiling, and a set of statistical tools (StatTools) for the identification of highly correlated genes. Implementation of the correlation finder tool for MybA1, a major regulator of the anthocyanin pathway, identified candidate genes associated with anthocyanin metabolism, whose expression patterns were experimentally validated as discriminating between black and white grapes. These resources and innovative tools for mining genome-related data are anticipated to foster advances in several areas of grapevine research.

Vitis↗