Cardamine hupingshanensis (K. M. Liu, L. B. Chen, H. F. Bai and L. H. Liu) is a perennial herbal species endemic to China with narrow distribution. It is known as an important plant for investigating the metabolism of selenium in plants because of its ability to accumulate selenium. However, the phylogenetic position of this particular species in Cardamine remains unclear. In this study, we reported the chloroplast genome (cp genome) for the species C. hupingshanensis and analyzed its position within Cardamine. The cp genome of C. hupingshanensis is 155,226 bp in length and exhibits a typical quadripartite structure: one large single copy region (LSC, 84,287 bp), one small single copy region (17,943 bp) and a pair of inverted repeat regions (IRs, 26,498 bp). Guanine-Cytosine (GC) content makes up 36.3% of the total content. The cp genome contains 111 unique genes, including 78 protein-coding genes, 29 tRNA genes and 4 rRNA genes. A total of 115 simple sequences repeats (SSRs) and 49 long repeats were identified in the genome. Comparative analyses among 17 Cardamine species identified the five most variable regions (trnH-GUG-psbA, ndhK-ndhC, trnW-CCA-trnP-UGG, rps11-rpl36 and rpl32-trnL-UAG), which could be used as molecular markers for the classification and phylogenetic analyses of various Cardamine species. Phylogenetic analyses based on 79 protein coding genes revealed that the species C. hupingshanensis is more closely related to the species C. circaeoides. This relationship is supported by their shared morphological characteristics.

Rungia pectinata is an important traditional Chinese herbal medicine from the family Acanthaceae. The complete chloroplast genome (cp genome) of the genus Rungia was sequenced for the first time. The cp genome of R. pectinata was 149,627 bp in length. It was consisted of a large single copy (LSC) region (81,976 bp) and a small single copy (SSC) region (16,626 bp), which were separated by two inverted repeats (IRs, 25,511 bp). This plastome contained 114 unique genes, including 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. The overall GC content was 38.0%. Phylogenetic analysis of nine species in Acanthaceae was also conducted. This newly sequenced cp genome will be useful to further evolutionary studies, phylogenetic studies, and pharmacognostic identification in the genus Rungia.

This study systematically investigated the application effects of exogenous enzymes (tannase/papain) during black tea fermentation, aiming to optimize flavor. Tannase treatment significantly reduced astringent substances like tea polyphenols and enhanced 11 metabolites, including Myricetin-3-O-arabinoside, thereby effectively enhancing fruity and sweet aromas. Papain treatment increased free amino acids and accumulated Myricetin-3-O-arabinoside and Vitexin-7-O-glucoside, significantly enhancing umami and floral flavors. Both enzyme treatments increased the odor activity value (OAV) of key aroma compounds such as (Z)-3-Hexen-1-ol and 1-Hexanol. Molecular docking revealed that hydrophobic interactions and hydrogen bonding are the key driving forces for aroma compound binding, OR5M3 and OR1A1 are key olfactory receptors for black tea aroma perception, and Benzene, n-butyl- was identified as a key aroma compound for the studied receptors. Overall, exogenous enzyme technology significantly changed the flavor of traditional black tea by reducing bitterness and astringency, as well as enhancing sweetness and floral aroma.