Comparative transcriptome analysis of different tissues of Mahonia bealei provided new insights into the biosynthetic pathway of Benzylisoquinoline alkaloids

Mahonia bealei is a traditional Chinese medicinal plant. M. bealei is rich in Benzylisoquinoline alkaloids (BIAs), which have shown significant therapeutic effects in treating conditions like acute pharyngitis and endometritis, and possess various pharmacological activities such as anti-inflammatory and antibacterial properties. By conducting network pharmacology analysis on the molecular mechanisms of BIAs in antimicrobial and anti-inflammatory actions, potential therapeutic targets were identified. Due to the lack of whole genomic information, transcriptome of M. bealei was firstly generated by RNA sequencing analysis (RNA-seq) in this study. A total of 183,900 unigenes were obtained. Additionally, functional annotation of these genes revealed that 111,875 (60.803%) of the unigenes were annotated by seven major databases, among which 75 unigenes related to the BIA biosynthetic pathway were identified. Correlation analys is revealed that the expression levels of O-Methyltransferases family genes are significantly and positively correlated with BIAs content. By conducting structural and sequence analysis of the unigenes encoding (RS)-norcoclaurine6-O-methyltransferase (DN15317) and 3'-hydroxy-N-methyl-(S)-coclaurine4'-O-methyltransferase (DN556-12), and studying their binding with substrates, their potential biological functions can be assessed. This study, for the first time, provides a transcriptome profile of M. bealei, offering information for further understanding the BIAs biosynthetic pathway in M. bealei and laying the foundation for elucidating the molecular mechanisms of BIAs biosynthesis.

阔叶十大功劳（Mahonia bealei）是一种传统药用植物。该植物富含苄基异喹啉类生物碱（Benzylisoquinoline alkaloids, BIAs），这类生物碱在治疗急性咽炎、子宫内膜炎等病症中表现出显著疗效，同时具备抗炎、抗菌等多种药理活性。本研究通过网络药理学分析BIAs抗菌与抗炎作用的分子机制，筛选得到潜在治疗靶点。鉴于该物种全基因组信息的缺失，本研究首次利用RNA测序（RNA-seq）技术构建了阔叶十大功劳的转录组，共获得183900个单基因簇（unigenes）。随后对这些基因进行功能注释，其中111875个单基因簇（占比60.803%）可通过7个主流数据库完成注释，并鉴定出75个与BIAs生物合成途径相关的单基因簇。相关性分析结果显示，O-甲基转移酶家族基因的表达水平与BIAs含量呈显著正相关。通过对编码(RS)-去甲乌药碱6-O-甲基转移酶（DN15317）和3'-羟基-N-甲基-(S)-乌药碱4'-O-甲基转移酶（DN556-12）的单基因簇进行结构与序列分析，并研究其与底物的结合特性，可评估其潜在生物学功能。本研究首次公开了阔叶十大功劳的转录组图谱，为深入解析该物种中BIAs的生物合成途径提供了数据支持，同时为阐明BIAs生物合成的分子机制奠定了基础。