Abstract Nitrogen metabolism of aluminum tolerant peanut cell suspension cultures under aluminum stress

M. A. Syed*, M. Marziah and A.M. Puad

Department of Biochemistry and Microbiology, Universiti Putra Malaysia, 43400 Serdang, Selangor D.E

(Received 24 September 1998 / Accepted 2 November 1998)

Abstract.
Plant cell suspension culture was used to select and isolate for A1 tolerance cell lines in peanut. Selected Altolerant cells were then studied for cell growth and nitrogen metabolising enzyme activities in the presence and absence of A1. Under A1 stress, nitrate reductase (NR) activity of Al tolerant cells was higher compared to normal cells. Glutamine synthase (GS) activities also increased probably due to the increase in NH⁴⁺ uptake. However, glutamate dehydrogenase (NADH-GDH) activity in A1 tolerant cells grown in the presence of Al was lower compared to Al tolerant cells grown in the absence of A1. Glutamate synthase (NADH-GOGAT) activities on the other hand show little changes when Al tolerant cells were grown in the presence and absence of Al indicating that Al does not affect the enzyme activity in the Al tolerant cells. This condition was different in Al sensitive cells (normal cells) in which the presence of A1 resulted in the reduction of enzyme activity.

Keywords: aluminum, cell suspension cultures, tolerant, nitrogen metabolism