الفهرس 
ContentsOnly 14 pages are availabe for public view
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Abstract
The problem of heavy metal pollution in agricultural environments water bodies and air is metat present with greatest world concern threatening an ever increasing portion of human plant and animal life The adaptation of plants to toxic concentrations of metals depends upon various mechanisms among which are restricted uptake or translocation and formation of metal chelates with organic acids or proteins In this investigation sunflower H. annuus was used as the plant material to study the effect of some heavy metals on its growth and major metabolic processes. The changes in the activities of some enzymes NR and lipase were also investigated under the various heavy metal concentrations, as well as the change in organic acid contents in the plant tissue and nutrient medium The heavy metals chosen were Al³+, Cd³+ and Zn³+ because of their common occurrence in industrial effluents, biological wastes and municipal and agricultural drainage The seeds were germinated in purified sand for 7 days then transferred to Hoagland solution ( 1/4 strength ) supplemented with 0-20 ppm of the heavy metals chosen ( supplied as chlorides).