Tissue Specific Heterogeneity of Lipoxygenase in Cucumber Seedlings

Abstract

Most of the lipoxygenase (LOX) activity in cucumber seedlings was detected in the cotyledons. Other tissues, such as the hypocotyls and roots, showed low but appreciatable activities. During seed germination, LOX activity increased once, then declined in both the cotyledons and roots. The activity was predominantly recovered in the cytosol fractions after differential centrifugation of both tissues. The soluble enzymes were partially purified from both the roots and cotyledons. Root LOX was most active at pH 8.0, but the cotyledon enzyme was at pH 6.0. We propse that LOX in the cotyledons may differ from the enzyme in the roots.