Identification of regulatory protein genes involved in alkaloid biosynthesis using a transient RNAi system.

RNAi (RNA interference, RNA silencing) is a powerful tool in functional genomics. We report here the use of transient RNAi to isolate regulatory factor genes involved in isoquinoline alkaloid biosynthesis in Coptis japonica protoplasts. Double-stranded (ds) RNAs prepared against candidate regulatory factors, which were predicted from an EST library, were introduced into C.

Identification of a WRKY protein as a transcriptional regulator of benzylisoquinoline alkaloid biosynthesis in Coptis japonica.

Selected cultured Coptis japonica cells produce a large amount of the benzylisoquinoline alkaloid berberine. Previous studies have suggested that berberine productivity is controlled at the transcript level of biosynthetic genes. We have identified a regulator of transcription in berberine biosynthesis using functional genomics with a transient RNA interference (RNAi) and overexpression of the candidate gene.

Transient RNA silencing of scoulerine 9-O-methyltransferase expression by double stranded RNA in Coptis japonica protoplasts.

RNAi (RNA interference, RNA silencing) is a powerful tool for functional genomics, but the construction of an RNAi vector(s) and the establishment of stable transformants are time-consuming and laborious. Here we report the transient RNAi of endogenous biosynthetic genes involved in isoquinoline alkaloid biosynthesis in Coptis japonica protoplasts. Double stranded (ds) RNA fragments of various lengths prepared from several different positions of the coding sequence of scoulerine 9-O-methyltransferase (SMT) were introduced into C.