Functional divergence of CYP76AKs shapes the chemodiversity of abietane-type diterpenoids in genus Salvia

Genome-Wide Identification and Characterization of Diterpenoid Pathway CYPs in Andrographis paniculata and Analysis of Their Expression Patterns under Low Temperature Stress

Andrographis paniculata is known for its diterpenoid medicinal compounds with antibacterial and anti-inflammatory properties. However, it faces production and cultivation challenges due to low temperatures (LTs). Cytochrome P450 monooxygenases (CYPs) are key enzymes in diterpenoid accumulation. Nevertheless, the functions and LT-related expression patterns of diterpenoid pathway CYPs in Andrographis paniculata remain poorly understood. In this study, 346 CYPs were discovered in Andrographis paniculata. Among them, 328 CYPs belonged to 42 known subfamilies. The remaining 17 CYPs might have represented novel subfamilies unique to this species. A total of 65 candidate CYPs associated with diterpenoid modification were identified. Of these, 50 were transmembrane proteins, and 57 were localized to chloroplasts. The CYP71 subfamily was the most abundant and had the highest motif diversity. Promoters of all candidate CYPs commonly contained elements responsive to gibberellins (GAs), methyl jasmonate (MeJA), and abiotic stresses. Notably, the XP_051152769 protein, corresponding to a CYP gene over 40,000 bp in length, featured an extraordinarily long intron (40,751 nts). Functional elements within this intron were related to LT, GAs, and dehydration pathways. Based on the promoter element arrangement and subfamily classification, 10 representative candidate CYPs were selected. Under LT stress, significant expression changes were observed in three representative CYPs: CYP71D, ent-kaurenoic acid oxidase (KAO), and ent-kaurene oxidase (KO). KAO and KO were significantly upregulated during early LT stress. KAO and KO interacted with each other and jointly interacted with GA20OX2-like. CYP71D acted as a negative response factor to LT stress. Among the 37 proteins interacting with CYP71D, 95% were CYPs. This study provides a critical preliminary foundation for investigating the functions of diterpenoid pathway CYPs in Andrographis paniculata, thereby facilitating the development of LT-tolerant cultivars.

Regulatory network of flavonoids, phenolic acids and terpenoids biosynthesis in Zizyphus jujuba Mill. cv. Goutou jujube fruits

Flavonoids, phenolic acids and terpenoids are important active ingredients that are biomarkers for evaluating the quality of Zizyphus jujuba Mill. Cv. Goutou jujube fruit. Nevertheless, regulatory network of these active ingredients biosynthesis in jujube fruit is still unclear. Here, integrated metabolomics and transcriptomics analyses were conducted at four different stages during the ripening of jujube fruits. Cytochrome P450 enzymes (CYP450s) and uridine 5'-diphospho-glucuronosyltransferases (UGTs) are pivotal enzymes for flavonoids, phenolic acids and terpenoids biosynthesis in plants. Benzoylmalic acid, a phenolic acid, 4', 5, 7-trihydroxyflavanon and quercetin-3-O-(6″-p-coumaroyl), two flavonoid metabolites, and jujuboside B1, a triterpenoid metabolite were targeted as they were correlated with both CYP450s and UGTs. Furthermore, networks of TFs, CYP450s and UGTs involved in the target metabolites biosynthesis were elucidated. NAC_1 and bZIP2 up-regulated CYP71A7 expression, while G2-like2 and bHLH_1 positively regulated the CSE expression contributing to promoted benzoylmalic acid biosynthesis. G2-like2, bHLH_1 and bHLH_2 indicated a positive relationship with CYP93D1, CYP86C2/3 or UGT71A16 which were positively correlated with 4', 5, 7-trihydroxyflavanon biosynthesis. MYB1/2/3, C2H2_2 and WRKY positively regulated expression of CYP82A4 or UGT_1 resulted in increased quercetin-3-O-(6″-p-coumaroyl) galactoside biosynthesis. G2-like2 and bHLH_1 up-regulated 4 C L, CYP93D1 or UGT71A16 was the reason for an increase of jujuboside B1 biosynthesis. The findings provide new insight into molecular breeding of high-quality jujube fruits.

Versatile CYP98A enzymes catalyse meta-hydroxylation reveals diversity of salvianolic acids biosynthesis

Salvianolic acids (SA), such as rosmarinic acid (RA), danshensu (DSS), and their derivative salvianolic acid B (SAB), etc. widely existed in Lamiaceae and Boraginaceae families, are of interest due to medicinal properties in the pharmaceutical industries. Hundreds of studies in past decades described that 4-coumaroyl-CoA and 4-hydroxyphenyllactic acid (4-HPL) are common substrates to biosynthesize SA with participation of rosmarinic acid synthase (RAS) and cytochrome P450 98A (CYP98A) subfamily enzymes in different plants. However, in our recent study, several acyl donors and acceptors included DSS as well as their ester-forming products all were determined in SA-rich plants, which indicated that previous recognition to SA biosynthesis is insufficient. Here, we used Salvia miltiorrhiza, a representative important medicinal plant rich in SA, to elucidate the diversity of SA biosynthesis. Various acyl donors as well as acceptors are catalysed by SmRAS to form precursors of RA and two SmCYP98A family members, SmCYP98A14 and SmCYP98A75, are responsible for different positions' meta-hydroxylation of these precursors. SmCYP98A75 preferentially catalyses C-3' hydroxylation, and SmCYP98A14 preferentially catalyses C-3 hydroxylation in RA generation. In addition, relative to C-3' hydroxylation of the acyl acceptor moiety in RA biosynthesis, SmCYP98A75 has been verified as the first enzyme that participates in DSS formation. Furthermore, SmCYP98A enzymes knockout resulted in the decrease and overexpression leaded to dramatic increase of SA accumlation. Our study provides new insights into SA biosynthesis diversity in SA-abundant species and versatility of CYP98A enzymes catalytic preference in meta-hydroxylation reactions. Moreover, CYP98A enzymes are ideal metabolic engineering targets to elevate SA content.

Haplotype-phased genome unveils the butylphthalide biosynthesis and homoploid hybrid origin of Ligusticum chuanxiong

Butylphthalide is one of the first-line drugs for ischemic stroke therapy, while no biosynthetic enzyme for butylphthalide has been reported. Here, we present a haplotype-resolved genome of Ligusticum chuanxiong, a long-cultivated and phthalide-rich medicinal plant in Apiaceae. On the basis of comprehensive screening, four Fe(II)- and 2-oxoglutarate-dependent dioxygenases and two CYPs were mined and further biochemically verified as phthalide C-4/C-5 desaturases (P4,5Ds) that effectively promoted the forming of (S)-3-n-butylphthalide and butylidenephthalide. The substrate promiscuity and functional redundancy featured for P4,5Ds may contribute to the high phthalide diversity in L. chuanxiong. Notably, comparative genomic evidence supported L. chuanxiong as a homoploid hybrid with Ligusticum sinense as a potential parent. The two haplotypes demonstrated exceptional structure variance and diverged around 3.42 million years ago. Our study is an icebreaker for the dissection of phthalide biosynthetic pathway and reveals the hybrid origin of L. chuanxiong, which will facilitate the metabolic engineering for (S)-3-n-butylphthalide production and breeding for L. chuanxiong.