Aristolochia contorta Bunge has been widely used as traditional Chinese medicine materials. However, its utility faces a great challenge due to the presence of aristolochic acids (AAs), a class of benzylisoquinoline alkaloid (BIA) derivatives. The first step in BIA skeleton formation is catalysis by norcoclaurine synthase (NCS). To gain knowledge of BIA and AA biosynthesis in A. contorta, genome-wide characterizations of NCS genes were carried out. This resulted in the identification of 15 A. contorta NCSs, namely, AcNCS1–AcNCS15. The AcNCS1–AcNCS8 proteins contained one catalytic domain, whereas the AcNCS9–AcNCS15 proteins had two. Phylogenetic analysis shows that AcNCS proteins can be classified into two clades. Gene expression analysis shows that five AcNCSs, including AcNCS2, AcNCS4, AcNCS5, AcNCS14, and AcNCS15, exhibited relatively high expression in roots and flowers, where norcoclaurine accumulated. An enzyme catalytic activity assay shows that all five of the AcNCSs can catalyze norcoclaurine formation with AcNCS14 and AcNCS15, exhibiting higher catalytic efficiency. Precolumn derivatization analysis shows that the formed norcoclaurine included (S)- and (R)-norcoclaurine, with more (S)-configuration. The results provide useful information for further understanding BIA and AA biosynthesis in A. contorta and for AA elimination and bioactive compound improvement in AA-containing medicinal materials.

YTH domain-containing proteins act as the primary readers of N⁶-methyladenosine (m⁶A), playing an important role in plant development and stress responses. However, little is known about the YTH proteins in medicinal plants. Genome-wide identification of the YTH gene family in the medicinal model plant, Salvia miltiorrhiza Bunge, identified a total of nineteen SmYTH genes from five chromosomes, with SmYTH8–SmYTH19 clustered on chromosome 8. Phylogenetic analysis showed that SmYTH proteins belong to the YTHDF category. No YTHDC members were identified. Conserved domain identification, amino acid sequence alignment, and phase separation prediction revealed that SmYTH1–SmYTH4 exhibited the characteristic m⁶A reader protein feature, containing conserved aromatic cages (WWW) capable of binding m⁶A residues. SmYTH5–SmYTH19 proteins contain a unique conserved F-box protein interaction domain that has not been reported previously. qRT-PCR analysis revealed tissue-specific patterns, with SmYTH1–SmYTH4 genes highly expressed in roots and leaves, whereas SmYTH8–SmYTH19 were mainly expressed in leaves. The results were consistent with RNA-seq data. The expression of various SmYTHs and the content of phenolic acid active ingredients were significantly altered under MeJA and SA treatments. The results provide useful information for further studies on the biological functions of m⁶A and YTH proteins in S. miltiorrhiza.