Zn-acquisition and its role in growth, photosynthesis, photosynthetic pigments, and biochemical changes in essential monoterpene oil(s) of Pelargonium graveolens

Culturing geranium at different doses of Zn from 0-1.0 g m(-3) (Zn-0 to Zn-1.000) revealed that Zn is an antioxidant promoter, apart from its micronutrient essentiality. Zn-0.250 was the critical concentration for maximum content (0.21 %) of total essential monoterpene oil(s). At Zn-0.005-Zn-0.250, net photosynthetic rate, and contents of chlorophyll and essential monoterpene oil(s) were affected. The maximum peroxidase activity was obtained at Zn-0.250, with the production of biomolecule geraniol. We found an oxido-reducible reaction of Zn in the formation of monoterpene essential oil(s) and possibly major constituents of geraniol.