Evaluation of catalase and peroxidase activity as indicators of Fe and Mn nutrition for soybean

Abstract

The influence of Fe and Mn supply on plant growth, Fe and Mn uptake and catalase and peroxidase activities of soybean (Glycine max L. Merr.) cv. Williams was studied. Plants were grown in nutrient solutions until the second trifoliate stage under growth chamber conditions. Growth was depressed by the lowest Mn (0.0 ppm) and Fe (0.25 ppm) levels, and also by Mn in excess (5.0 ppm). The levels of Fe and Mn, and the interaction FexMn affected Mn and Fe uptake. Peroxidase activity was greatest at the highest Mn concentration at each Fe treatment level. On the other hand, catalase activity increased with Fe supply but no relation was observed with leaf Fe concentration. The interferences observed on both indicators make the use of these metalloenzymes difficult to appraise Fe nutritional status.

Key words:

• Glycine max
• Catalase
• Iron
• Manganese
• Peroxidase