The mineral nutrient concentrations in soil are affected by factors such as pH, organic matter, clay and redox potentials. The solubility of such micronutrients as Zn, Cu and Mn is increased by lower pH, or vice versa. The alterations in concentration of these nutrients may affect the growth and development of plants, but also lead to their senescence and programmed cell death related to age and mineral nutrient concentrations. This study aimed to explore the senescence rate due to lack of some essential micronutrients, such as Zn, Cu and Mn, associated with indole acetic acid (IAA). In addition to peroxidase and protease activity, total chlorophyll, nitrogen and protein values were determined. Decreased catabolic reactions and delayed senescence were indicated in excised cotyledons from lack of Zn.