Linked Life Data

11525519

Source:http://linkedlifedata.com/resource/pubmed/id/11525519

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-8-29
pubmed:abstractText
The cytochrome P450 CYP79A1 catalyzes the conversion of L-tyrosine to p-hydroxyphenylacetaldoxime, the first step in the biosynthetic pathway of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench. We have demonstrated that introduction of CYP79A1 into Arabidopsis thaliana (L.) Heynh. results in the production of the tyrosine-derived glucosinolate p-hydroxybenzylglucosinolate (p-OHBG), not found in wild-type A. thaliana (Bak et al., 1999, Plant J. 20: 663 671). In the present study, glucosinolate profiles and contents in various tissues (roots, leaves, stems, closed flower buds and green siliques) of A. thaliana plants expressing CYP79A1 were analyzed by high-performance liquid chromatography. The total glucosinolate content in these tissues was increased 3.5- to 4.5-fold in comparison with the level of the control plants. The increase was due solely to the production of p-OHBG, as the composition of the major endogenous aliphatic and indole glucosinolates was not affected. Conversely, in mature seeds the total glucosinolate content of CYP79A1 and control plants was similar, with p-OHBG accounting for ca. 30%. The transcript level of the postoxime enzyme UDP-glucose:thiohydroximate glucosyltransferase in leaves of CYP79A1 plants was increased ca. 50% compared with control plants, indicating that the post-oxime enzymes in the biosynthetic pathway are up-regulated. Western blot analysis and activity measurements showed similar amounts and activities of myrosinase in CYP79A1 and control plants. Thus, the increase in glucosinolate content in CYP79A1 plants was not accompanied by an increase in content or activity of degradation enzyme. The present data demonstrate that the high biosynthetic capacity of the postoxime enzymes combined with a low substrate-specificity of the post-oxime enzymes in A. thaliana provide a highly flexible system for metabolic engineering of glucosinolate profiles, including new (non-endogenous) glucosinolates derived from oximes introduced into the plant, e.g. by transformation with CYP79 homologues.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
212
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
612-8
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Characterization of transgenic Arabidopsis thaliana with metabolically engineered high levels of p-hydroxybenzylglucosinolate.
pubmed:affiliation
Department of Plant Biology, Center of Molecular Plant Physiology (PlaCe), Royal Veterinary and Agricultural University, Copenhagen, Denmark.
pubmed:publicationType
Journal Article