Impact of nano calcium hydroxide and calcium oxide on some metabolic activities and phenolic compounds of Lupinus termis seedlings

Abstract

The effect of 0.5, 1.0 and 2.0 mM nano calcium hydroxide Ca(OH)2 andcalcium oxide CaO or bulk calcium carbonate CaCO3 on growth and metabolicchanges of Lupines termis seedlings was assessed. Root fresh and dry weights wereincreased by nano CaO at 0.5 and 1.0 mM compared with the control, while they weredecreased by increasing nano Ca(OH)2. Shoot fresh and dry weights were increasedby increasing the concentration of nano Ca(OH)2 and CaO reaching their maximumat 0.5 and 2.0 mM, respectively. Bulk CaCO3 concentrations increased root and shootfresh and dry weights at the highest concentration (2mM). The photosyntheticpigments (chl.a, chl.b and carotenoids) were markedly increased with increasing theconcentration of nano Ca (OH)2, nano CaO and bulk CaCO3 with the highestmagnitude recorded for nano Ca(OH)2, while the lowest was for CaCO3. The totalsoluble carbohydrate biosynthesis of both shoot and root was reduced by nanocalcium particles, whereas it was enhanced by bulk calcium compared with control.The root soluble protein was decreased by different concentrations of either nano orbulk calcium, while shoot soluble protein was increased by all calcium treatmentscompared with the control. The nano calcium especially Ca(OH)2 activated theprotein metabolism compared with the bulk. The root and shoot phenolic compoundswere decreased by different concentrations of either nano or bulk calcium, except ofthe shoot phenolic compounds at CaCO3. Nano CaO at 0.5 mM increased shootphenolic compounds by 10% compared with control.