Comparative Transcriptomics for Genes Related to Berberine and Berbamine Biosynthesis in Berberidaceae

Abstract

Berberine and berbamine are bioactive compounds of benzylisoquinoline alkaloids (BIAs) present in Berberis species. The contents of berbamine are 20 times higher than berberine in leaf tissues in three closely related species: Berberis koreana, B. thunbergii and B. amurensis. This is the first report on the quantification of berberine compared to the berbamine in the Berberis species. Comparative transcriptome analyses were carried out with mRNAs from the leaf tissues of the three-species. The comparison of the transcriptomes of B. thunbergii and B. amurensis to those of B. koreana, B. thunbergii showed a consistently higher number of differentially expressed genes than B. amurensis in KEGG and DEG analyses. All genes encoding enzymes involved in berberine synthesis were identified and their expressions were variable among the three species. There was a single copy of CYP80A/berbamunine synthase in B. koreana. Methyltransferases and cytochrome P450 mono-oxidases (CYPs) are key enzymes for BIA biosynthesis. The current report contains the copy numbers and other genomic characteristics of the methyltransferases and CYPs in Berberis species. Thus, the contents of the current research are valuable for molecular characterization for the medicinal utilization of the Berberis species.

Isolation and Characterization of the Genes Involved in the Berberine Synthesis Pathway in Asian Blue Cohosh, Caulophyllum robustum

“…BIA biosynthesis starts with the condensation of dopamine and 4-hydroxyphenylacetaldehyde, both derived from L -tyrosine, to become ( S )-norcoclaurine, which then undergoes enzyme-mediated stepwise reactions including oxidation, reduction, methylation, acetylation, and decarboxylation, resulting in structural changes in the molecules [ 35 ]. The biosynthetic steps and enzymes have been well elucidated in the Coptis species [ 26 ], Berberis species [ 21 , 36 ], and other plants [ 34 ]. We identified all biosynthetic enzymes for berberine synthesis in the transcriptomes of C. robustum .…”

“…We also isolated berberine synthesis genes from the transcriptomes in the NCBI database in other berberine-producing plants, which revealed that the copy numbers of each enzyme-encoding gene were highly variable in each species. The copy numbers of the berberine synthesis genes were also variable among the three closely related species in the genus Berberis [ 36 ]. In contrast to our results, half of the genes identified in the BIA synthesis were identical copies between Coptis teeta and C. chinensis [ 26 ].…”

“…NCS is a key enzyme for the biosynthesis of all BIA alkaloids as it catalyzes the condensation of dopamine and 4-hydroxyphenylacetaldehyde (4-HPAA) to form ( S )-norcoclaurine, which is the entry molecule for BIA synthesis [ 34 , 36 , 37 ]. C. robustum has ten copies of NCS, which is the highest number among the BIA synthesis enzymes in C. robustum .…”

“…The number of CYP copies in C. robustum was lower than that in the Berberis species, which belongs to Berberidaceae as Caulophyllum. The CYP copy numbers were 257 in Berberis koreana , 255 in B. thunbergii , and 253 in B. amurensis [ 36 ]. Nelson [ 47 ] grouped 16,000 plant CYPs into 277 families on the basis of 40% or higher sequence sharing so that we also adopted his suggestion on the identification of CYP families.…”

“…Nelson [ 47 ] grouped 16,000 plant CYPs into 277 families on the basis of 40% or higher sequence sharing so that we also adopted his suggestion on the identification of CYP families. In C. robustum , we identified 56 CYP families and the Berberis species had 31 families [ 36 ], in which 18 families shared between the Caulophyllum and Berberis species. The 31 CYP families in the C. robustum were further classified into 56 subfamilies, in which, only 16 subfamilies were shared with the Berberis species, implying that CYP differentiation was evident in subfamilies, and occurred even within Berberidaceae.…”