Litchi (Litchi chinensis Sonn.) fruit is known for its rich source of phenolics. Litchi pericarp contains high levels of epicatechin that may form oligomers of various lengths. Except for several A or B type epicatechin dimers, other soluble oligomers have rarely been identified in the pericarp. Here, bioassay-guided column fractionation was applied to isolate bioactive phenolics from aqueous pericarp extract. A fraction (S3) was obtained by two rounds of Sephadex LH-20 column chromatography, and showed higher antioxidant activity and inhibition on the proliferation of human lung cancer cells (A549) than Litchi anthocyanins. S3 was further separated to isolate fractions P1–P4, which all showed higher antioxidant activity than vitamin C. P3 showed 32.9% inhibition on A549 cells at 30 μg/mL, higher than other fractions and cis-Dichlorodiamineplatinum (DDP, 0.5 μg/mL), but not as high as the combination of the four fractions. Using HPLC-Q-TOF-MS/MS, one B-type and complex A/B type epicatechin trimers were identified in P3; another B-type and two A/B-type trimers were identified in P4. P1 and P2, containing epicatechin and proanthocyanidin B2, respectively, showed no cell inhibition at 30 μg/mL. It is the first time that the two B type trimers of epicatechins (Litchitannin B1 and B2), have been found in Litchi species. The identified proanthocyanidins were detected in the pericarp of the young fruit, and the levels of the compounds decreased as the fruit developed, correlating to the decreasing patterns of the expression of LcLAR and LcANR, two key genes in the catechin biosynthesis pathway.

Mitochondria play an important role in the energy production of plant cells through independent genetic systems. This study has aimed to assemble and annotate the functions of the mitochondrial (mt) genome of Luffa cylindrica. The mt genome of L. cylindrica contained two chromosomes with lengths of 380,879 bp and 67,982 bp, respectively. Seventy-seven genes including 39 protein-coding genes, 34 tRNA genes, 3 rRNA genes, and 1 pseudogene, were identified. About 90.63% of the codons ended with A or U bases, and 98.63% of monomers contained A/T, which contributed to the high A/T content (55.91%) of the complete mt genome. Six genes (ATP8, CCMFC, NAD4, RPL10, RPL5 and RPS4) showed positive selection. Phylogenetic analysis indicates that L. cylindrica is closely related to L. acutangula. The present results provide the mt genome of L. cylindrica, which may facilitate possible genetic variation, evolutionary, and molecular breeding studies of L. cylindrica.

The effects of nanoparticles (NPs) on microbiota homeostasis and their physiological relevance are still unclear. Herein, we compared the modulation and consequent pharmacological effects of oral administration of (−)-epigallocatechin-3-gallate (EGCG)-loaded β-cyclodextrin (β-CD) NPs (EGCG@β-CD NPs) and EGCG on gut microbiota. EGCG@β-CD NPs were prepared using self-assembly and their influence on the intestinal microbiome structure was analyzed using a metagenomics approach. The “Encapsulation efficiency (EE), particle size, polydispersity index (PDI), zeta potential” of EGCG@β-CD NPs were recorded as 98.27 ± 0.36%, 124.6 nm, 0.313 and –24.3 mV, respectively. Surface morphology of EGCG@β-CD NPs was observed as spherical. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and molecular docking studies confirmed that EGCG could be well encapsulated in β-CD and formed as EGCG@β-CD NPs. After being continuously administered EGCG@β-CD NPs for 8 weeks, the serum cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and liver malondialdehyde (MDA) levels in the rats were significantly decreased, while the levels of catalase (CAT) and apolipoprotein-A1 (apo-A1) in the liver increased significantly in the hyperlipidemia model of rats, when compared to the high-fat-diet group. Furthermore, metagenomic analysis revealed that the ratio of Verrucomicrobia/Bacteroidetes was altered and Bacteroidetes decreased in the high-fat diet +200 mg/kg·bw EGCG@β-CD NPs group, while the abundance of Verrucomicrobia was significantly increased, especially Akkermansia muciniphila in rat feces. EGCG@β-CD NPs could be a promising EGCG delivery strategy to modulate the gut microbiota, enhancing its employment in the prevention of hyperlipidemia.

Background: Purple flowering stalk (Brassica rapa var. purpuraria) is a widely cultivated plant with high nutritional and medicinal value and exhibiting strong adaptability during growing. Mitochondrial (mt) play important role in plant cells for energy production, developing with an independent genetic system. Therefore, it is meaningful to assemble and annotate the functions for the mt genome of plants independently. Though there have been several reports referring the mt genome of in Brassica species, the genome of mt in B. rapa var. purpuraria and its functional gene variations when compared to its closely related species has not yet been addressed. Results: The mt genome of B. rapa var. purpuraria was assembled through the Illumina and Nanopore sequencing platforms, which revealed a length of 219,775 bp with a typical circular structure. The base composition of the whole B. rapa var. purpuraria mt genome revealed A (27.45%), T (27.31%), C (22.91%), and G (22.32%). 59 functional genes, composing of 33 protein-coding genes (PCGs), 23 tRNA genes, and 3 rRNA genes, were annotated. The sequence repeats, codon usage, RNA editing, nucleotide diversity and gene transfer between the cp genome and mt genome were examined in the B. rapa var. purpuraria mt genome. Phylogenetic analysis show that B. rapa var. Purpuraria was closely related to B. rapa subsp. Oleifera and B. juncea. Ka/Ks analysis reflected that most of the PCGs in the B. rapa var. Purpuraria were negatively selected, illustrating that those mt genes were conserved during evolution. Conclusions: The results of our findings provide valuable information on the B.rapa var. Purpuraria genome, which might facilitate molecular breeding, genetic variation and evolutionary researches for Brassica species in the future.

Introduction: This study reports for the first time the complete sequence characteristics of the mitochondrial genome of the tea plant cultivar Camellia sinensis cv. ‘Baihaozao’. It systematically unveils its multi-chromosomal structure, RNA editing patterns, and adaptive evolutionary mechanisms, providing critical theoretical insights into the structural complexity and evolutionary mechanisms of the tea plant mitochondrial genome.Methods: The mitochondrial genome was fully analyzed using genome sequencing and annotation techniques. RNA editing sites were predicted to evaluate editing patterns. Codon usage bias analysis was conducted to identify high-frequency codons. Repeat sequence analysis was used to characterize dispersed and tandem repeats. Adaptive evolutionary analysis, based on Ka/Ks ratios, was performed to investigate gene selection pressures.Results: The mitochondrial genome consists of 11 linear chromosomes, with a total length of 909,843 bp and a GC content of 45.62%. A total of 73 functional genes were annotated, among which 14 variable genes (e.g., ribosomal protein coding genes) retain intact functions without pseudogenization, which is rare among Theaceae plants. RNA editing site prediction revealed significant spatial heterogeneity, with the cox1 gene being a hotspot containing 19 editing sites. Approximately 58.49% of editing events were concentrated on the second base of codons, and 48.61% of the sites resulted in amino acid changes from hydrophilic to hydrophobic. Codon usage bias analysis showed significant enrichment of high-frequency codons, including UUU (phenylalanine), AUU (isoleucine), and UUC (phenylalanine). The genome’s repeat sequences were predominantly dispersed repeats (70.6%), with forward and palindromic repeats of 30–40 bp being dominant. Tandem repeats exhibited significant distribution heterogeneity among chromosomes. Adaptive evolution analysis showed that most PCGs (protein-coding genes) had Ka/Ks ratios below 1 (ranging from 0.07 to 0.78), with the atp9 gene showing the lowest ratio (0.07), while the mttB gene exhibited a significantly higher Ka/Ks ratio of 3.48. Additionally, 1.62% of the mitochondrial genome sequence was homologous to the chloroplast genome, carrying 26 complete functional genes, including 15 tRNA and 2 rRNA genes.Discussion: Codon usage bias may be related to mutation pressure due to the high AT content of the genome or reflect adaptive selection pressures for translational efficiency. The Ka/Ks results align with the widespread purifying selection observed in mitochondrial genomes, while the high Ka/Ks ratio of the mttB gene suggests it might be under positive selection to adapt to environmental pressures. The evolutionary evidence of inter-organelle gene transfer highlights the homologous sequences between mitochondria and chloroplasts. Overall, these findings systematically elucidate the adaptive evolutionary mechanisms and functional regulation of the tea plant mitochondrial genome.

Introduction: Tea (Camellia sinensis) is a significant economic crop, and investigations into the structure and function of its mitochondrial genome are crucial for understanding the evolutionary history and genetic characteristics of this species. This study presents the first comprehensive analysis of the mitochondrial genome of the tea cultivar ’Zhuyeqi‘ (Camellia sinensis cv. ‘Zhuyeqi’), aiming to elucidate its genomic structural features, gene composition, and evolutionary patterns. The findings provide a theoretical foundation for genetic breeding and molecular biology research in tea plants.Methods: High-throughput sequencing was employed to sequence the mitochondrial genome of ’Zhuyeqi‘. Bioinformatics approaches were utilized for genome assembly and annotation. Various analytical strategies, including identification of RNA editing sites, codon usage bias analysis, repeat sequence recognition, calculation of non-synonymous substitution rates (Ka) and synonymous substitution rates (Ks), comparative genomics, and collinearity analysis, were applied to comprehensively analyze the structural features and evolutionary dynamics of the mitochondrial genome.Results and discussion: The mitochondrial genome of ‘Zhuyeqi’ consists of one circular chromosome and six linear chromosomes, with a total length of 911,255 bp and a GC content of 46%. Genome annotation identified 77 functional genes, including 38 protein-coding genes (PCGs). The study revealed heterogeneously distributed introns within genes such as trnM-CAT (5 copies) and nad1/2/5/7. RNA editing analysis identified 556 C-to-U editing sites, notably enriched in ccmFn (38 sites) and ccmB (34 sites). Codon usage bias analysis indicated that leucine (Leu, 10%) and arginine (Arg, 7%) were the most frequently used amino acids. Repeat sequence analysis showed that dispersed repeats (780, 72%) dominated, with satellite DNA exhibiting significant distribution biases on chr1 (11) and chr3 (5). Ka/Ks analysis revealed that 37 PCGs were under varying selective pressures (0.09–2.70), with rps4 (Pi=0.09) and atp8 (Pi=0.09) showing exceptionally high variability, while rps19 (Pi=0) was completely conserved. Comparative genomics uncovered 66 homologous segments (25,656 bp) between the mitochondrial and chloroplast genomes, containing 27 intact genes such as trnA-UGC, confirming horizontal gene transfer events. Collinearity analysis demonstrated a high degree of conservation in genomic structures between ‘Zhuyeqi’ and closely related Camellia species. This study lays an important theoretical foundation for further elucidating the structural characteristics and evolutionary mechanisms of the tea plant mitochondrial genome.