ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
The effect of aluminium on plasma membrane-bound enzymes and ion uptake was studied with spruce cuttings (Piccu abies Karst.) grown in nutrient solution, pH 4.2, for 5 weeks. The H+– ATPase and glucan synthase II activities of isolated root plasma membranes were inhibited by the presence of aluminium during growth (0.1–3 mM), with glucan synthase II being more sensitive than the ATPase. The active K+-uptake obtained with intact roots was also inhibited by aluminium, whereas the passive uptake was stimulated ca 4-fold by moderate amounts of aluminium (0.1 mM). The uptake of Ca2+ (passive) was severely inhibited at all external aluminium concentrations tested. Experiments were also performed with aluminium added during the assay, or in preincubations of isolated plasma membranes. Again, the glucan synthuse II activity was severely inhibited bv aluminium. There were no signs of adaptation, i.e., the activities with plasma membranes from cuttings given aluminium during growth, were equally sensitive as the control. The aluminium additions in vitro were at pH 6.5 (ATPase) or 7.2? (glucan synthase II) indicating that lor the enzymes studied, aluminium can be toxic although the pH is neutral.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1994.tb08836.x
