S. Bak et al., Metabolic engineering of p-hydroxybenzylglucosinolate in Arabidopsis by expression of the cyanogenic CYP79A1 from Sorghum bicolor, PLANT J, 20(6), 1999, pp. 663-671
Glucosinolates are natural products in cruciferous plants, including Arabid
opsis thaliana. CYP79A1 is the cytochrome P450 catalysing the conversion of
tyrosine to p-hydroxyphenylacetaldoxime in the biosynthesis of the cyanoge
nic glucoside dhurrin in sorghum. Both glucosinolates and cyanogenic glucos
ides have oximes as intermediates. Expression of CYP79A1 in A. thaliana res
ults in the production of high levels of the tyrosine-derived glucosinolate
p-hydroxybenzylglucosinolate, which is not a natural constituent of A. tha
liana. This provides further evidence that the enzymes have low substrate s
pecificity with respect to the side chain. The ability of the cyanogenic CY
P79A1 to integrate itself into the glucosinolate pathway has important impl
ications for an evolutionary relationship between cyanogenic glucosides and
glucosinolates, and for the possibility of genetic engineering of novel gl
ucosinolates.