Am. Shalaby et Sam. Alwakeel, CHANGES IN NITROGEN-METABOLISM ENZYME-ACTIVITIES OF VICIA-FABA IN RESPONSE TO ALUMINUM AND CADMIUM, Biologia plantarum, 37(1), 1995, pp. 101-106
Nodules of faba bean (Vicia faba L. cv. Giza 3) plants grown in pots c
ontaining clay-loam soil for 90 d have an active nitrate reductase (NR
), while the leaves did not show detectable activity. Spraying the pla
nt with increasing concentrations of Al3+ or Cd2+ (0 - 1000muM) signif
icantly inhibited the nodules NR activity, the decline being more pron
ounced in Cd2+ treatment. The specific activity of glutamate-oxaloacet
ate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) were
more prominent in the 60- than in 90-d-old plants; GOT was always high
er than GPT. Furthermore, GOT was more sensitive to Al3+ and Cd2+ trea
tments and its activity was significantly decreased when the metal con
centration increased. Also, Cd2+ proved to be more effective than Al3 in suppressing the GOT activity in the nodules, with less significant
effect observed in the leaves. In contrast, GPT was hardly affected b
y the various metal treatments, particularly in the leaves.