Transcriptome Analysis of CYP450 Family Members in Fritillaria cirrhosa D. Don and Profiling of Key CYP450s Related to Isosteroidal Alkaloid Biosynthesis

Integrative analysis of the metabolome and transcriptome provides insights into the mechanisms of lignan biosynthesis in Herpetospermum pedunculosum (Cucurbitaceae)

BACKGROUND

Herpetospermum pedunculosum (Ser.) C. B. Clarke is a traditional Chinese herbal medicine that heavily relies on the lignans found in its dried ripe seeds (Herpetospermum caudigerum), which have antioxidant and hepatoprotective functions. However, little is known regarding the lignan biosynthesis in H. pedunculosum. In this study, we used metabolomic (non-targeted UHPLC-MS/MS) and transcriptome (RNA-Seq) analyses to identify key metabolites and genes (both structural and regulatory) associated with lignan production during the green mature (GM) and yellow mature (YM) stages of H. pedunculosum.

RESULTS

The contents of 26 lignan-related metabolites and the expression of 30 genes involved in the lignan pathway differed considerably between the GM and YM stages; most of them were more highly expressed in YM than in GM. UPLC-Q-TOF/MS confirmed that three Herpetospermum-specific lignans (including herpetrione, herpetotriol, and herpetin) were found in YM, but were not detected in GM. In addition, we proposed a lignan biosynthesis pathway for H. pedunculosum based on the fundamental principles of chemistry and biosynthesis. An integrated study of the transcriptome and metabolome identified several transcription factors, including HpGAF1, HpHSFB3, and HpWOX1, that were highly correlated with the metabolism of lignan compounds during seed ripening. Furthermore, functional validation assays revealed that the enzyme 4-Coumarate: CoA ligase (4CL) catalyzes the synthesis of hydroxycinnamate CoA esters.

CONCLUSION

These results will deepen our understanding of seed lignan biosynthesis and establish a theoretical basis for molecular breeding of H. pedunculosum.

Applications of some advanced sequencing, analytical, and computational approaches in medicinal plant research: a review

The potential active chemicals found in medicinal plants, which have long been employed as natural medicines, are abundant. Exploring the genes responsible for producing these compounds has given new insights into medicinal plant research. Previously, the authentication of medicinal plants was done via DNA marker sequencing. With the advancement of sequencing technology, several new techniques like next-generation sequencing, single molecule sequencing, and fourth-generation sequencing have emerged. These techniques enshrined the role of molecular approaches for medicinal plants because all the genes involved in the biosynthesis of medicinal compound(s) could be identified through RNA-seq analysis. In several research insights, transcriptome data have also been used for the identification of biosynthesis pathways. miRNAs in several medicinal plants and their role in the biosynthesis pathway as well as regulation of the disease-causing genes were also identified. In several research articles, an in silico study was also found to be effective in identifying the inhibitory effect of medicinal plant-based compounds against virus' gene(s). The use of advanced analytical methods like spectroscopy and chromatography in metabolite proofing of secondary metabolites has also been reported in several recent research findings. Furthermore, advancement in molecular and analytic methods will give new insight into studying the traditionally important medicinal plants that are still unexplored.