AUTHOR=Wu Hao , Shen Yu , Zou Fen , Yao Shiqing , Chen Yaling , Yang Huilin , Luo Xiangdong 

TITLE=Combined transcriptome and widely targeted metabolome analysis reveals the potential mechanism of HupA biosynthesis and antioxidant activity in Huperzia serrata

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1411471

DOI=10.3389/fpls.2024.1411471

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p><italic>Huperzia serrata</italic> is a traditional Chinese herb that has gained much attention for its production of Huperzine A (HupA). HupA has shown promise on treating Alzheimer's disease (AD). However, the biosynthetic pathway and molecular mechanism of HupA in <italic>H. serrata</italic> are still not well understood.</p></sec><sec><title>Methods</title><p>Integrated transcriptome and metabolome analysis was performed to reveal the molecular mechanisms related to HupA biosynthesis and antioxidant activity in <italic>Huperzia serrata</italic>.</p></sec><sec><title>Results</title><p>HT (<italic>in vitro H. serrata</italic> thallus) exhibits higher antioxidant activity and lower cytotoxicity than WH (wild <italic>H. serrata</italic>). Through hierarchical clustering analysis and qRT-PCR verification, 7 important enzyme genes and 13 transcription factors (TFs) related to HupA biosynthesis were detected. Among them, the average |log<sub>2</sub>FC| value of <italic>CYP</italic> (Cytochrome P450) and <italic>CAO</italic> (Copper amine oxidase) was the largest. Metabolomic analysis identified 12 metabolites involved in the HupA biosynthesis and 29 metabolites related to antioxidant activity. KEGG co-enrichment analysis revealed that tropane, piperidine and pyridine alkaloid biosynthesis were involved in the HupA biosynthesis pathway. Furthermore, the phenylpropanoid, phenylalanine, and flavonoid biosynthesis pathway were found to regulate the antioxidant activity of <italic>H. serrata</italic>. The study also identified seven important genes related to the regulation of antioxidant activity, including <italic>PrAO</italic> (primary-amine oxidase). Based on the above joint analysis, the biosynthetic pathway of HupA and potential mechanisms of antioxidant in <italic>H. serrata</italic> was constructed.</p></sec><sec><title>Discussion</title><p>Through differential transcriptome and metabolome analysis, DEGs and DAMs involved in HupA biosynthesis and antioxidant-related were identified, and the potential metabolic pathway related to HupA biosynthesis and antioxidant in <italic>Huperzia serrata</italic> were constructed. This study would provide valuable insights into the HupA biosynthesis mechanism and the <italic>H. serrata</italic> thallus medicinal value.</p></sec>