Abstract
Germin, a molecular marker of wheat embryo germination, has been shown to have an activity of oxalate oxidase which utilizes oxalate to generate hydrogen peroxide, and to localize in cell walls. We examined the role of this enzyme in the modification of phenolic constituents in cell walls of wheat seedlings. The histochemical staining showed that the activity was mainly present in cell walls, and that shoots as well as roots had a strong activity. Enzymically active cell wall materials prepared from shoots were incubated with oxalate or hydrogen peroxide, and then the amounts of ester-linked phenolic constituents, such as ferulic and diferulic acids, in cell walls were determined. By both treatments, the level of diferulic acid was significantly increased. These results suggest that oxalate oxidase stimulates the coupling reaction by peroxidase of ferulic acid in cell wall architecture via generating hydrogen peroxide.
