Investigating the interaction of zinc and copper on the accumulation of elements, antioxidant enzymes, photosynthetic pigments and malondialdehyde in basil (Ocimum basilicum)

Zinc and copper are essential elements for plant growth and development. Basil (Ocimum basilicum) is an important herb of medicine and nutrition. The aim of this study was to investigate the effect of these elements on Basil. In this study, seeds were planted in pots containing cocopeat and perlite and the four-leaf seedlings were treated with zinc sulfate at of 0, 350 and 550 micro-molar concentrations and 0, 20 and 40 micro-molar copper sulfate in three replications. After a month, accumulation of these elements, proline, soluble sugars, total proteins, photosynthetic pigment and malon dialdehyde contents, leaf area, number of leaves were investigated. The results showed that different concentrations of copper and zinc effects were not significant on germination percentage, number of leaves and stem length. However increased zinc and copper were significantly increased fresh and dry weight of root and shoot. Copper and zinc treatment had no significant effects on peroxidase and catalase enzyme activities while malondialdehyde, proline, soluble sugars, total proteins contents increased. In this study, with increased concentrations of copper and zinc in the medium, copper and zinc accumulation increased in the root. The root accumulates more ions than the shoot. The accumulation of copper (shoot and roots) and zinc (shoot) decrease with increasing concentrations of copper and zinc in the medium which shows the interaction between the two elements. No significant decrease in chlorophyll content indicates that basil is resistant to copper and zinc metals in these concentrations. Antioxidant enzymes do not activate in these concentrations