Isolation and analysis of a gene bbe1 encoding the berberine bridge enzyme from the California poppy Eschscholzia californica

A genomic clone, bbe1 was isolated that encodes the methyl jasmonate-inducible berberine bridge enzyme of antimicrobial benzophenanthridine alkaloid biosynthesis in the California poppy Eschscholzia californica. Genomic DNA gel blot analysis indicates that two genes are present in the E. californica genome that code for the berberine bridge enzyme reading frame. Each coding region is apparently preceeded by a unique promoter sequence. The bbe1 gene contains no introns and one transcriptional start site. A 41 nucleotide region between -496 and -455 of the 5'-flanking region appears to be essential for promoter activity in E. californica. The promoter displayed an unexpectedly high species specificity, being active in only E. californica and Thalictrum bulgaricum, out of 28 cell suspension cultures tested.