Glucosinolates pathway

Figure 13.2 Biosynthetic pathways of (A) cyanogenic glucosides and (B) glucosinolates. The CYP79s are assumed to catalyze the same reaction in both pathways. It is not known whether the oxime is oxidized to an aci-nitro compound or a nitrile oxide in the glucosinolate pathway.

THE OXIME-METABOLIZING ENZYME AS BRANCH POINT BETWEEN THE CYANOGENIC GLUCOSIDE AND THE GLUCOSINOLATE PATHWAY... 

K. B. Axelsen, A.X Hick et al. (2001). CYP83BI is the oxime metabolizing enzyme in the glucosinolate pathway in Arabidopsis. J. Biol. Chem. 276, 24790-24796. 

An S-GT from Brassica napus was the first thiohydroximate S-glycosyltransferase of the glucosinolate pathway to be partially characterized in vitro [104]. T-DNA insertions in the corresponding gene in Arabidopsis (UGT74B1) cause low levels of glucosinolates, leaf vein chlorosis, and impaired auxin metabolism [105]. 

Line lx also had a normal phenotype and typical phenylpropanoid profile but accumulated additional glucosinolates derived from tyrosine, evidently through transformation of intermediate SI by endogenous A. thaliana enzymes of the glucosinolate pathway (aided by possible co-localisation of El and E5). In contrast the 2x line exhibited a stunted phenotype and unusual metabolic profile with reduced... 

These reactions to 4-methylthiobutyl glucosinolate, the precursor for sulforaphane formation, have been extensively studied in Eruca sativa (arugula, rocket).64 A gene controlling variation in the glucosinolates of Arabidopsis is part of the methionine elongation pathway just described.65... 

Figure 8.4 Glucosinolate and IAA pathways. IAA indole-3-acetic acid IAN indole-3-acetonitrile IAOx indole-3-acetaldoxime. A loss of function of CYP83B drives the IAOx to IAA and an auxin-overproducing phenotype is the result.

S. alba has been used as a model plant for biochemical studies of the oxime-metabolizing enzyme in the biosynthetic pathway of glucosinolates.33 The major... 

A glucosinolate metabolism pathway in living plant cells mediates broad-spectrum antifungal... 

Mahadevan reviewed research up to 1973, with respect to the pathways of oxime metabolism in plants, and evaluated a series of aliphatic and aromatic oximes that are precursors for the biosynthesis of plant secondary metabolites (as opposed to basic metabolism products that are essential for cell survival), such as cyanogenic glycosides, glucosinolates and certain phytohormones . Some of these oximes are shown below. 

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