Characterization of ent -kaurene synthase and kaurene oxidase involved in gibberellin biosynthesis from Scoparia dulcis

AbstractGibberellins (GAs) are ubiquitous diterpenoids in higher plants, whereas some higher plants produce unique species-specific diterpenoids. In GA biosynthesis,ent-kaurene synthase (KS) andent-kaurene oxidase (KO) are key players which catalyze early step(s) of the cyclization and oxidation reactions. We have studied the functional characterization of gene products of a KS (SdKS) and two KOs (SdKO1 andSdKO2) involved in GA biosynthesis inScoparia dulcis. Using an in vivo heterologous expression system ofEscherichia coli, we found that SdKS catalyzed a cyclization reaction froment-CPP toent-kaurene and that the SdKOs oxidizedent-kaurene toent-kaurenoic acid after modification of the N-terminal region for adaptation to theE. coli expression system. The real-time PCR results showed that theSdKS,SdKO1 andSdKO2 genes were mainly expressed in the root and lateral root systems, which are elongating tissues. Based on these results, we suggest that these three genes may be responsible for the metabolism of GAs inS. dulcis.
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research