BIOSYNTHESIS OF CHLOROPHYLL-LIKE Cu(Ⅱ)-PHEOPHYTIN

摘要

Electron paramagnetic resonance is a very useful tool in the analysis of the reactivity and structural characteristics of the Cu(Ⅱ) adsorbed in plants, although the exact details of the process are not yet clear. The investigated plants were grown in dietary media containing Cu(Ⅱ) ions in concentrations ranging from 0.0125 to 0.5%. The Cu(Ⅱ) in excess affects the leaf integrity, resulting in the blue-green coloured domains which are gradually extended (3-5 days) on the full outline of the leaves. The EPR investigations offers the possibility to understand certain steps in the mechanism of Cu(Ⅱ) toxicity, because the adsorption of Cu(Ⅱ) ions in plants results in their accumulation in the leaves as soluble complexes and/or immobile species.