Localization of Lipoxygenases 1 and 2 in Germinating Soybean Seeds by an Indirect Immunofluorescence Technique

Lipoxygenases 1 and 2 were localized in etiolated germinating soybean seeds (Glycine max [L.]. Merr. var. Williams) by an indirect immunofluorescence staining technique. Sections of paraffin-embedded seedlings were stained with affinity-purified antibodies directed against lipoxygenase 1 or 2. The specificity of the immunofluorescence technique was examined by use of nonimmune serum or immunoglobulin G preparations after total adsorption with the appropriate lipoxygenase coupled to Sepharose 4B.After immunofluorescence staining with antilipoxygenase 1 or 2 IgG storage tissues of cotyledons fluoresce strongly the first days of germination. After 3 days, the abaxial hypodermis, the epidermis, and the vascular bundle sheaths show fluorescence, especially after incubation with antilipoxygenase 2 IgG. Fluorescence in cortex and pith of the hypocotyl migrates to the vascular cylinder during germination. In primary leaves, all tissues show fluorescence after 1 day of germination. In storage tissues of cotyledons, cytoplasm around the protein bodies fluoresces, whereas in other tissues protein bodies or other large cell organelles fluoresce.It is reasonable to suggest that lipoxygenase exerts its function in cells at the time that rigorous changes in metabolism take place, namely at the start of mobilization of reserves in storage tissues and start of biosynthesis of chloroplastids in several tissues.