Expression of Genes Associated with Nickel Resistance in White Spruce (<i>Picea glauca</i>) under Nickel Stress: Analysis of AT2G16800 and <i>NRAMP</i> Genes

Abstract

Heavy metals such nickel (Ni) can cause toxicity by 1) displacing essential components in the biomolecules, 2) blocking the functional group of molecules, or 3) modifying enzymes, proteins, the plasma membrane, and membrane transporters. The main objective of the present study was to investigate the effect of nickel (Ni) on gene expression of nitrate on gene expression with a focus on the genes coding for the high affinity Ni transporter family protein AT 2 G 16800, and natural resistance-associated macrophage protein ( NRAMP ). Ni toxicity was assessed by treating seedlings with an aqueous solution of nickel nitrate salt [Ni(NO 3 ) 2 ] at the concentrations of 150 mg, 800 mg, and 1600 mg of nickel per 1 kg of dry soil. RT-qPCR was used to measure the expression of AT 2 G 16800, and NRAMP genes in samples treated with nickel nitrates and controls. The results revealed that P. glauca is resistant to Ni based on lack of plant damage at all nickel concentrations. Ni has no effect on the expression of the AT 2 G 16800 gene in needles or roots. However, it induced an upregulation of the NRAMP genes in roots at all the doses tested (150 mg/kg, 800 mg/kg, and 1600 mg/kg). On the other hand, Ni has no effect on the expression of the NRAMP gene in needle but the lowest dose of potassium (150 mg/kg) upregulated this gene in needle tissues.