Distinct lipoxygenase species appear in the hypocotyl/radicle of germinating soybean

• Published in: Plant physiology (Bethesda) Vol. 90; no. 1; pp. 285 - 290
• Main Authors: Park, T.K. (University of Missouri, Columbia, MO), Polacco, J.C
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01-05-1989
• Subjects: Biological and medical sciences; Cotyledons; Electrophoresis; FENOTIPOS; Fundamental and applied biological sciences. Psychology; Gels; Genotypes; GERMINACION; GERMINATION; Germination and dormancy; GLYCINE MAX; HIPOCOTILOS; HYPOCOTYLE; INHIBIDORES DE ENZIMAS; INHIBITEUR D'ENZYME; ISOTOPE RADIOACTIF; OXIDORREDUCTASAS; OXYDOREDUCTASE; PHENOTYPE; Plant physiology and development; Plants; PROTEINAS; PROTEINE; RADICULA; RADICULE; RADIOISOTOPOS; Seedlings; Seeds; Soybeans; Radiolabelling; Isozyme; Germination; Genotype; Glycine max; Immunological method; Hypocotyl; Leguminosae; Enzymatic activity; Isoelectric point; Dicotyledones; Angiospermae; Spermatophyta; Intraspecific comparison; Lipoxygenase; Radicle
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.90.1.285

Three lipoxygenase isozymes are synthesized in developing soybean (Glycine max [L.] Merr. cv Williams) embryos and are found in high levels in cotyledons of mature seeds (B Axelrod, TM Cheesbrough, S Zimmer [1981] Methods Enzymol 71: 441-451). Upon germination at least two new protein species appear which are localized mainly (on a protein basis) in the hypocotyl/radicle section. These lipoxygenase species appear also in seedlings of each of three lipoxygenase nulls (1X1, 1X2, and 1X3) deficient in one of the dormant seed lipoxygenases. The germination-associated species are distinguishable from dry seed lipoxygenase by their more acidic isoelectric points as revealed in isoelectric focusing gels. They are active from as early as 2 to at least 5 days after the start of imbibition. These germination-stimulated species qualify as lipoxygenase by their inhibition by the lipoxygenase inhibitors n-propyl gallate and salicyl hydroxamic acid and their lack of inhibition by KCN. Further, they are not active on the peroxidase substrate pair H2O2/3-amino-9-ethyl carbazole. They are recognized on Western blots by polyclonal antibodies to the seed lipoxygenase-1 isozyme and the major induced species has a molecular weight of approximately 100,000, similar to that of the cotyledon lipoxygenases. These lipoxygenases appear to be synthesized de novo upon germination since they comigrate with radioactive protein species from seeds germinated in [35S]methionine