Copper Nutrition of Sugarbeet

Sugarbeet (Beta vulgaris L.) plants were grown in refined sand at graded levels of copper ranging from acute deficiency (0.000325 μg Cu cm−3) to excess (65 μg Cu cm−3). Visible effects of copper deficiency appeared up to 0-00065 μg Cu cm−3and depression in growth up to 00065μCu cm−3. Copper deficiency decreased the concentrations of DNA and RNA and the activities of polyphenol oxidase, cytochrome-c oxidase, catalase and aldolase; and it increased the activities of peroxidase, ribonuclease and acid phosphatase in leaves. The maximum sucrose concentration in roots was obtained at 0-65μCucm−3 Twenty four h after infiltration of a solution of 65μCu cm−3into copper deficient leaves, the activities of cytochrome-c oxidase and peroxidase had increased even in the presence of cycloheximide but that of polyphenol oxidase increased only in the absence of this inhibitor.