ISSN:
1573-5028
Keywords:
genetic engineering
;
4-hydroxybenzoic acid glucoside
;
Lithospermum erythrorhizon
;
menisdaurin
;
shikonin
;
ubiC
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The biosynthetic pathway to 4-hydroxybenzoate (4HB), a precursor of the naphthoquinone pigment shikonin, was modified in Lithospermum erythrorhizon hairy root cultures by introduction of the bacterial gene ubiC. This gene of Escherichia coli encodes chorismate pyruvate-lyase (CPL), an enzyme that converts chorismate into 4HB and is not normally present in plants. The ubiC gene was fused to the sequence for a chloroplast transit peptide and placed under control of a constitutive plant promoter. This construct was introduced into L. erythrorhizon by Agrobacterium rhizogenes-mediated transformation. The resulting hairy root cultures showed high CPL activity. 4HB produced by the CPL reaction was utilized for shikonin biosynthesis, as shown by in vivo inhibition of the native pathway to 4HB with 2-aminoindan-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia-lyase. A feeding experiment with [1,7-13C2]shikimate showed that in the absence of AIP the artificially introduced CPL reaction contributed ca. 20% of the overall 4HB biosynthesis in the transgenic cultures. ubiC transformation did not lead to a statistically significant increase of shikonin formation, but to a 5-fold increase of the accumulation of menisdaurin, a nitrile glucoside which is presumably related to aromatic amino acid metabolism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006185806390
