Bioagent seed coating effect on polyamine oxidase activity in maize under cadmium stress

The pollution of agricultural land with heavy metals such as cadmium provide challenges for the quality of environment and food supply. According to recent researches, cadmium stress leads to structural, physiological and biochemical changes in plants. One of the biochemical changes in plant cells under cadmium stress is the changes of catabolism polyamines via the alteration of polyamine oxidase activity. Using seed coating technique with biological compounds (salep) can decrease the negative effects of heavy metals in plants. Considering the economic and agricultural importance of maize, the effects of maize seed coating (salep) and cadmium contamination (cocopeat containing 100 mg/l cadmium chloride) on polyamine oxidase enzymes activity at buffer pH 6.5 and 8 was analyzed. The measurements of enzyme activity performed at 3, 6 and 12 days after cultivation. The results showed that the enzyme activity of polyamine oxidase varied in different pH. At buffer pH 6.5, a lower enzyme activity was shown compared to buffer pH 8. The activity of polyamine oxidase in root was higher than stem, which indicated more cadmium effects on the root than the stem. Under cadmium contamination, seedlings grown from coated seeds showed high activity of polyamine oxidase and its activity decreased in without Cd contamination. This result was more obvious at pH 8, that seems as a result of its peroxisomal isozyme activity. Further research on analysis of the other enzymes such as diamine oxidase that are involved in polyamine catabolism provide a better understanding of polyamine catabolism in maize under cadmium stress

کلیدواژه ها:

Cadmium ، Polyamine oxidase ، Salep ، Zea mays