Myrosinase in Brassicaceae (Cruciferae)

Abstract

The effect of L-ascorbic acid (AA) on myrosinase activity was studied in white mustard, Sinapis alba L. Enzyme extracts were prepared from different organs of dark- and light-grown seedlings. The highest activation caused by AA was found for myrosinase from light-grown primary roots. The activation level was more than 12 times higher than that of the control. The maximum activation generally occurred at 1–10 mM AA, and in the case of myrosinase from light-grown hypocotyls even at 50 mM AA. The myrosinases from cotyledons were least affected by addition of AA. To study the effect of AA on different isoenzymes of myrosinases, the isoenzymes were separated on polyacrylamide gels. When the gels were incubated in an AA solution, after electrophoresis differences were found in the activation of isoenzymes of different myrosinases.