Selection of Catechin Biosynthesis-Related Genes and Functional Analysis from Chromosome-Level Genome Assembly in C. sinensis L. Variety 'Sangmok'.

Camellia is an important plant genus that includes well-known species such as C. sinensis, C. oleifera, and C. japonica. The C. sinensis cultivar 'Sangmok', one of Korea's standard types of tea landraces, is a small evergreen tree or shrub. Genome annotation has shown that Korean tea plants have special and unique benefits and superior components, such as catechin. The genome of Camellia sinensis cultivar 'Sangmok' was assembled on the chromosome level, with a length of 2678.62 Mbp and GC content of 38.16%. Further, 15 chromosome-scale scaffolds comprising 82.43% of the assembly (BUSCO completeness, 94.3%) were identified. Analysis of 68,151 protein-coding genes showed an average of 5.003 exons per gene. Among 82,481 coding sequences, the majority (99.06%) were annotated by Uniprot/Swiss-Prot. Further analysis revealed that 'Sangmok' is closely related to C. sinensis, with a divergence time of 60 million years ago. A total of 3336 exclusive gene families in 'Sangmok' were revealed by gene ontology analysis to play roles in auxin transport and cellular response mechanisms. By comparing these exclusive genes with 551 similar catechin genes, 17 'Sangmok'-specific catechin genes were identified by qRT-PCR, including those involved in phytoalexin biosynthesis and related to cytochrome P450. The 'Sangmok' genome exhibited distinctive genes compared to those of related species. This comprehensive genomic investigation enhances our understanding of the genetic architecture of 'Sangmok' and its specialized functions. The findings contribute valuable insights into the evolutionary and functional aspects of this plant species.

Changes in the Ginsenoside Content During Fermentation Using an Appliance for the Preparation of Red Ginseng.

The total amount of ginsenoside in fermented red ginseng (FRG) is increased by microbial fermentation. The aim of this study was to evaluate whether fermentation time and temperature affect the ginsenoside content during fermentation using an appliance for the preparation of red ginseng. The FRG and fermented red ginseng extracts (FRG-e) were prepared using an appliance for the preparation of red ginseng. The temperature was recorded and time points for sampling were scheduled at pre-fermentation (0[Formula: see text]h) and 18, 36, 48, 60 and 72[Formula: see text]h after the addition of the microbial strains. Samples of FRG and FRG-e were collected to identify changes in the ginsenoside contents at each time point during the fermentation process. The ginsenoside content was analyzed using high performance liquid chromatography (HPLC). The levels of ginsenoside Rh1, Rg3, and compound Y, which are known to have effective pharmacological properties, increased more than three-fold in the final products of FRG relative to samples prior to fermentation. Although the ginsenoside constituents of FRG-e decreased or increased and then decreased during fermentation, the total amount of ginsenoside in FRG-e was even higher than those in FRG; the total amounts of ginsenoside in FRG-e and FRG were 8282.8 and 738.0[Formula: see text]mg, respectively. This study examined the changes in composition of ginsenosides and suggests a method to manufacture high-content total ginsenosides according to the fermentation temperature and process time. Reducing the extraction time is expected to improve the decrease of ginsenosides in FRG-e as a function of the fermentation time.