Nickel induces changes in expression of genes encoding 1-aminocyclopropane-1-carboxylic acid deaminase and glutathione reductase in Picea glauca

Nickel (Ni) in trace amounts is important in plant nutrition; it can also be toxic in excess. The objective of this study was to determine if nickel affects gene expression in white spruce (Picea glauca). Nickel toxicity was assessed by treating seedlings with an aqueous solution of nickel nitrate salt [Ni(NO3)(2)] at different doses (150, 800 mg/kg, and 1600 mg/kg) using a completely randomised design. Expression of the genes encoding 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD) and glutathione reductase (GR) in roots and needles were investigated using RT qPCR analysis. No damage was observed on P. glauca seedlings. This study revealed that Ni induces an upregulation of ACCD at low and high doses tested in roots. Nickel treatments resulted in a downregulation of GR at low dose (150 mg/kg) in needles and an upregulation at low and high doses in roots. This suggests that the low level of bioavailable nickel in mining sites in Ontario and other regions can trigger changes in gene expression. The results also show that potassium nitrate induces a significant effect on gene expression in P. glauca mostly at high concentrations.