Inhibition by lipoxygenase-3 of n-hexanal generation in soybeans.

Soybean seeds contain three lipoxygenase isozymes. The functions of these lipoxygenase isozymes in n-hexanal generation were investigated by using mutant lines which lack two or three isozymes. In the presence of linoleic acid, the level of n-hexanal produced was highest in the lipoxygenase-1, -3 double deficient line, followed by the lipoxygenase-2, -3 double deficient, wild type, and lipoxygenase-1, -2, -3 triple deficient lines in that order, and lowest in the lipoxygenase-1, -2 double deficient line. This suggests that lipoxygenase-3 itself cannot produce the n-hexanal precursor and inhibits the n-hexanal generation through other pathways.