Fritillaria ussuriensis is an endangered medicinal plant known for its notable therapeutic properties. Unfortunately, its population has drastically declined due to the destruction of forest habitats. Thus, effectively protecting F. ussuriensis from extinction poses a significant challenge. A profound understanding of its genetic foundation is crucial. To date, research on the complete mitochondrial genome of F. ussuriensis has not yet been reported. The complete mitochondrial genome of F. ussuriensis was sequenced and assembled by integrating PacBio and Illumina sequencing technologies, revealing 13 circular chromosomes totaling 737,569 bp with an average GC content of 45.41%. A total of 55 genes were annotated in this mitogenome, including 2 rRNA genes, 12 tRNA genes, and 41 PCGs. The mitochondrial genome of F. ussuriensis contained 192 SSRs and 4,027 dispersed repeats. In the PCGs of F. ussuriensis mitogenome, 90.00% of the RSCU values exceeding 1 exhibited a preference for A-ended or U-ended codons. In addition, 505 RNA editing sites were predicted across these PCGs. Selective pressure analysis suggested negative selection on most PCGs to preserve mitochondrial functionality, as the notable exception of the gene nad3 showed positive selection. Comparison between the mitochondrial and chloroplast genomes of F. ussuriensis revealed 20 homologous fragments totaling 8,954 bp. Nucleotide diversity analysis revealed the variation among genes, and gene atp9 was the most notable. Despite the conservation of GC content, mitogenome sizes varied significantly among six closely related species, and colinear analysis confirmed the lack of conservation in their genomic structures. Phylogenetic analysis indicated a close relationship between F. ussuriensis and Lilium tsingtauense. In this study, we sequenced and annotated the mitogenome of F. ussuriensis and compared it with the mitogenomes of other closely related species. In addition to genomic features and evolutionary position, this study also provides valuable genomic resources to further understand and utilize this medicinal plant.

Melatonin treatment has been reported to effectively preserve and improve the postharvest quality of fruits and vegetables during storage. This research focused on examining the significance of melatonin on maintaining the quality of fresh Gastrodia elata tubers throughout the storage period. The findings demonstrated that melatonin application effectively reduced the deterioration rate and inhibited the rise in respiratory rate, malondialdehyde content, and weight loss, while slowing down the decline in soluble solid content. Melatonin treatment led to a decrease in hydrogen peroxide production and a rise in non-enzymatic antioxidant concentrations, including ascorbic acid. Furthermore, it boosted both the activity and expression of indispensable antioxidant enzymes, like superoxide dismutase, catalase, and ascorbate peroxidase. Additionally, melatonin treatment promoted the accumulation of total phenols, flavonoids, and lignin in fresh G. elata, while enhancing both the activity and expression of critical enzymes in the phenylpropanoid pathway, including phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, and 4-coumarate-CoA ligase. Moreover, melatonin treatment boosted the activity and expression of energy-associated enzymes including H⁺-ATPase, succinate dehydrogenase, Ca²⁺-ATPase, and cytochrome C oxidase, contributing to the improvement of energy levels in fresh G. elata. In summary, melatonin enhances the antioxidant potential and reduces oxidative damage in fresh G. elata by activating reactive oxygen species, phenylpropanoid metabolism, and energy metabolism, thereby maintaining its postharvest quality.

In this study, lactic acid bacteria were isolated from traditional fermented foods in Guizhou. The fermentation supernatant and cell disruption extract were used to screen lactic acid bacteria with α-glucosidase inhibitory activity, and the active lactic acid bacteria strains with potential hypoglycemic effect were screened. The results showed that 10 strains were screened from 27 strains of lactic acid bacteria with α-glucosidase inhibitory activity, of which 5 strains had good acid and bile salt tolerance. The best acid resistance was XG01, and the survival rate was as high as 98.5%. ST01 had the strongest tolerance to bile salt, up to 77.3%. The lactic acid bacteria cell extracts of HLG01, YR01, ST01 and XG01 could better inhibit the activity of α-glucosidase, and the inhibition rates were 39.27, 38.6, 38.53, and 34.4%, respectively. The fermentation supernatant of JR01 could better inhibit the activity of α-glucosidase, and the inhibition rate reached 33.8%. Through molecular biological identification, HLG01, YR01, and ST01 were were Lactiplantibacillus plantarum, XG01 was Pediococcus pentosaceus, and JR01 was Weissella cibaria. Weissella cibaria JR01 is the first reported lactic acid bacterium with α-glucosidase inhibitory activity. Five strains of lactic acid bacteria with good tolerance were screened out, which provided a strain basis for the subsequent study of the hypoglycemic effect of lactic acid bacteria and the development of various functional foods.

Fresh Gastrodia elata tubers are highly perishable after harvest because pathogen infection accelerates quality deterioration and limits their storage and commercial utilisation. This study examined lesion development in wounded, pathogen-inoculated tubers held at 24 ± 1 °C and, in a separate experiment, quality and physiological changes in non-inoculated tubers stored at 4 ± 1 °C. In the inoculation assay, 1 mM salicylic acid (SA) reduced lesion development following inoculation with Fusarium sp. (isolate 1022-1-1) and Aspergillus sp. (isolate 1022-11). During cold storage, SA-treated tubers maintained higher soluble solid content and showed less weight loss, membrane permeability, and malondialdehyde accumulation than controls. SA application promoted the enzymatic activities and transcriptional expression of superoxide dismutase, catalase, and peroxidase. It also activated the ascorbate–glutathione cycle by promoting ascorbic acid and glutathione accumulation, along with increasing the enzymatic activities and transcript abundance of several cycle-related enzymes, including ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase. These responses limited superoxide anion production and excessive hydrogen peroxide accumulation, thereby alleviating oxidative damage. SA enhanced phenylpropanoid metabolism through the upregulation of phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, and 4-coumaroyl-CoA ligase at both enzymatic and transcriptional levels, contributing to increased levels of total phenolics, flavonoids, and lignin. Furthermore, SA contributed to ATP maintenance by upregulating hexokinase, succinate dehydrogenase, cytochrome c oxidase, H⁺-ATPase, and Ca²⁺-ATPase at both enzymatic and transcriptional levels. Overall, SA treatment reduced lesion development in inoculated G. elata tubers and helped maintain the quality of non-inoculated tubers during cold storage.

To isolate lactic acid bacteria with significant triglyceride‐degrading ability from traditional fermented foods in Guizhou and develop probiotic tablets, providing a basis for the development of functional probiotics. Strains with triglyceride‐degrading ability were screened from 26 isolated strains. Morphological analysis, 16S rRNA gene sequencing, and stress resistance tests were conducted. The lyoprotectant composition for tablet preparation was optimized, and the stability and survival rate of the probiotic tablets were evaluated. Six LAB strains were selected, all exhibiting a triglyceride degradation rate exceeding 60%. Among them, PYC02 ( Limosilactobacillus fermentum ), SZ02 ( Weissella cibaria ), and PLHB02 ( Weissella cibaria ) showed degradation rates greater than 80%. PYC02 and PLHB02 maintained survival rates above 80% under conditions of pH 3 and 0.3% bile salts. The optimal lyoprotectant composition for maximum probiotic survival was 8% defatted milk powder, 5% sodium alginate, 2% maltodextrin, and 8% trehalose. After 30 days of storage at 4°C and 25°C, the survival rates of the probiotic tablets exceeded 80% and 60%, respectively, with triglyceride degradation rates greater than 60%. The triglyceride‐degrading effects of PYC02 and PLHB02 were significant. These strains exhibited strong stress resistance and high safety, showing potential for the development of functional probiotics, offering new approaches for the prevention and treatment of hypertriglyceridemia.

Hyperuricemia (HUA) is a metabolic disorder characterized by elevated serum uric acid (UA) levels resulting from the dysregulation of purine metabolism. The use of lactic acid bacteria (LAB) to alleviate HUA has attracted considerable attention. This study aimed to isolate LAB capable of degrading UA and purine precursors from traditionally fermented salt-free pickled vegetables in Guizhou Province, China, to evaluate their degradation characteristics, and to explore the underlying metabolic mechanism. A strain designated DF2 was isolated and identified as Limosilactobacillus fermentum (L. fermentum). In vitro experiments at 37 °C for 1 h showed that the DF2 strain could completely degrade guanosine, inosine, and adenosine, whereas its degradation rates for UA, xanthine, hypoxanthine, adenine, and guanine were 1.99%, 3.03%, 2.17%, 3.79%, and 12.12%, respectively. Notably, the strain converted the nucleosides to their purine bases and fully degraded guanosine-derived guanine within 7 h. Genomic analysis identified genes responsible for purine metabolism in the DF2 genome (accession number: SAMN62640203), and a metabolic pathway of UA and its precursors in the DF2 strain was proposed. These findings not only expand microbial resources for degrading UA and its precursors but also provide a basis for developing microbial agents to control UA levels in HUA.