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Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Biotechnology

1983

Articles 1 - 2 of 2

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Reversible Dark-Induced Senescence Of Soybean Root Nodules, N. E. Pfeiffer, Nasir S.A. Malik, Fred W. Wagner Jan 1983

Reversible Dark-Induced Senescence Of Soybean Root Nodules, N. E. Pfeiffer, Nasir S.A. Malik, Fred W. Wagner

Biochemistry -- Faculty Publications

Nodule senescence was induced in intact soybean Glycine max. (L.) Merr., cv Woodworth plants by an 8-day dark treatment. Dark-induced senescence resulted in the complete loss of acetylene reduction activity, a 67% loss of total soluble protein, and an almost complete loss in total leghemoglobin of nodule extracts. Isoelectric focusing gels demonstrated a preferential loss of certain proteins, which was correlated with an increase in endoprotease specific activity toward azocasein. Nodules were completely green after the 8-day dark treatment. If plants were returned to a normal photoperiod after 8 days in the dark, nodules recovered from the dark treatment in ...


Proteolytic Activity In Soybean Root Nodules: Activity In Host Cell Cytosol And Bacteroids Throughout Physiological Development And Senescence, Nancy E. Pfeiffer, Cecilia M. Torres, Fred W. Wagner Jan 1983

Proteolytic Activity In Soybean Root Nodules: Activity In Host Cell Cytosol And Bacteroids Throughout Physiological Development And Senescence, Nancy E. Pfeiffer, Cecilia M. Torres, Fred W. Wagner

Biochemistry -- Faculty Publications

Root nodules were harvested from chamber-grown soybean (Glycine max L. Merril cv Woodworth) plants throughout development. Apparent nitrogenase activity (acetylene reduction) peaked before seeds began to develop, but a significant amount of activity remained as the seeds matured. Nodule senescence was defined as the period in which residual nitrogenase activity was lost. During this time, soluble protein and leghemoglobin levels in the host cell cytosol decreased, and proteolytic activity against azocasein increased. Degradative changes were not detected in bacteroids during nodule senescence. Total soluble bacteroid protein per gram of nodule remained constant, and an increase in proteolytic activity in bacteroid ...