Abstract
Dehydrodiconiferyl glucoside (DCG) is a neolignan isolated from Vinca rosea tumor cells that induces cell division. We isolated cDNA of a peroxidase, AoPOX1, secreted to cell walls during asparagus somatic embryogenesis. AoPOX1 exhibited the activity to convert coniferyl alcohol (CA) to dehydrodiconiferyl alcohol (DDCA). DDCA is aglycone of DCG. We hypothesized the autocrine mechanism in somatic embryogenesis via neolignan molecule (Takeda et al. 2003). There are two possible pathways for DCG biosynthesis; 1) CA is converted to DDCA then glucosylated in apoplast; 2) Coniferyl alcohol glucoside (CAG) is synthesized in symplast and CA and CAG are coupled by apoplastic peroxidase. The glucosyltransferase activity was not detected in the cell-wall protein fraction. The glucosyltransfelase activity in the symplast and concentration of DCG or CAG in the medium are under investigation.
