Under salty conditions, rice plants experience a decrease in the activity of an enzyme called glutamine synthetase (GS) in their roots and leaves. The GS activity in leaves is more affected by salt stress than in roots. This decrease in GS activity correlates with a reduction in biomass and soluble proteins in both roots and leaves. The study used techniques like Native PAGE, activity staining, and immunoblotting to show that the decline in GS activity is mainly due to lower levels of specific GS proteins in roots and leaves.