Expression and Location of Lipoxygenases in Soybean Seeds and Seedlings

Expression of LOX is differentially regulated during soybean development and germination. It was suggested that the plant hormones may affect the expression of LOXs in soybean (Liu et al. 1991). The fact that pre-existing LOX-1, -2 and -3 disappear and new LOXs (LOX-4, -5 and -6) appear in germinating soybean cotyledons suggests that these newly synthesized LOX may play an important role in some aspect of seedling growth. Mobilization of lipid body triglyceride starts after 3 days of germination, and at this stage LOX-4, -5 and -6 reach high levels in cotyledons. These observations raise the obvious question of whether LOX (seedling or embryo LOX) were associated with lipid body and also where LOX was localized in germinating soybean seedlings. In this report, the effects of plant growth regulators on LOX expression and localization of LOX were thoroughly investigated in soybean.