Transcript pattern of cytochrome P450, antioxidant and ginsenoside biosynthetic pathway genes under heavy metal...

The differential transcript patterns of five antioxidant genes, four genes related to the ginsenoside pathway and five P450 genes related to defense mechanism were investigated in in vitro adventitious roots of Panax ginseng after exposure to two different concentrations of heavy metals for 7 days. PgSOD-1 and PgCAT transcription increased in a dose-dependent manner during the exposure to CuCl(2), NiCl(2), and CdCl(2), while all other tested scavenging enzymes didn't show significant increase during heavy metal exposure. Conversely, the mRNA transcripts of PgSQE, PgDDS were highly responsive to CuCl(2) compared to NiCl(2) exposure. However, the transcript profile of Pgβ-AS was highly induced upon NiCl(2) treatment compared to CuCl(2) and CdCl(2) exposure. The expressions of PgCYP716A42, PgCYP71A50U, and PgCYP82C22 were regulated in similar manners, and all showed the highest transcript profile at 100 μM of CuCl(2), CdCl(2), and NiCl(2) except PgCYP71D184, which showed the highest transcript level when subjected to 10 μM CuCl(2) and NiCl(2). Thus it may suggest that in P. ginseng heavy metal interaction on cell membrane induced expression of various defense related genes via jasmonic acid pathway and also possesses cross talk networks with other defense related pathways.