Effect of aluminum on 32P uptake and translocation by red spruce seedlings

Abstract

32P uptake and translocation was simultaneously studied in 11-week-old red spruce (Picearubens Sarg.) seedlings that had been pretreated for 24 h in hydroponic culture with or without 10 mg Al L−1. Aluminum in solution enhanced the accumulation of 32P in roots by more than two orders of magnitude over uptake in control seedlings, while the translocation of 32P to apical buds and mature primary needles was reduced to 20.0 and 9.1% of control levels, respectively. Kinetic analysis of 32P uptake indicated that P absorption is mediated by an uptake system exhibiting Michaelis–Menten behavior from solutions ranging from 0.01 to 5.00 mM KH2PO4; uptake at 10.0 mM KH2PO4 was inconsistent with this model. Changes in the patterns of 32P uptake and translocation in seedlings treated with Al suggest that Al in solution altered accumulation processes.