Effect of cadmium stress on antioxidative enzymes during the germination of Serbian spruce [Picea omorika (Pan..) Purkynĕ]

Abstract

When considering the effect of heavy metals on trees generally and on forest ecosystems especially,  importance is given to their influence on seed germination in metal polluted soil. There is insufficient data on  this subject, especially when conifers are concerned. In this work, the influence of high cadmium  concentrations on percentage germination, specific activities and isoenzyme patterns of catalase (CAT),  superoxide dismutase (SOD), and peroxidase (POD) during the germination of Serbian spruce [Picea omorika (Pan..) Purkynĕ] was studied. Cadmium chloride concentrations of up to 0.1 mM did not cause an inhibition of germination, while 1 mM concentration inhibited germination and the activities of catalase, superoxide  dismutase and peroxidase. The isoenzyme profile of catalase and superoxide dismutase did not change at high cadmium concentrations, while peroxidase expression of basic peroxidase (B5) with pI value of 9.1 increased. This isoform of POD can play an important role in the early development of Serbian spruce and its defense mechanism against heavy metals.

Key words: Seed germination, catalase, peroxidase, superoxide dismutase, heavy metals.