Abstract
After prolonged (3-9 weeks) hydroponic treatment of Scots pine seedlings with different concentrations (0.5-4.0 mM) of Al (AI(N03)3), the levels of pyridine nucleotides were determined in root homogenates. After 3 weeks of Al stress, a significant decrease of the anabolic reduction charge (ARC: NADPH/(NADP+ + NADPH)) and an increase of the redox status (NAD(P)H/NAD(P)+), catabolic reduction charge (CRC: NADH/(NAD+ + NADH)) and phosphorylation capacity expressed as NADP+/NAD+ ratio was found in the 4.0 mM Al treatment. After 6 weeks, Al at concentrations of 0.5 and 1.0 mM induced an enhancement of the NADH level and a reduction of NADPH level, but the redox ratios were not changed significantly. After 9 weeks treatment with Al concentrations ranging from 0.5 to 4.0 mM, decreases of the relative level of NADP+, NADPH and NADH and increases of NAD+ were found. Consequently, the CRC, NAD(P)H/NAD(P)+ and NADP+/NAD+ ratios reached a minimum and ARC a maximum as compared to previous measurements.
Keywords
Al; Pinus sylvestris; pyridine nucleotides; redox ratios; roots