FIGURE 7.

Cysteine protease activity is decreased in roots of sag12 under LN conditions. Soluble proteins were extracted from roots harvested at the reproductive stage (85 DAS) from Col and sag12 plants cultivated under high (HN) or low (LN) nitrogen conditions. The cysteine and total protease activities were determined by monitoring the degradation of four endogenous proteins (95, 76, 50, 37 kDa) in the presence or the absence of the cysteine protease inhibitor E64. The protease activities are expressed as a percentage relative to the activity in the Col roots under HN conditions (100%; dot line). Values are means ± SE, n = 3. For a given protease activity (total or cysteine), significant differences (p ≤ 0.05, n = 3) are indicated by different lower case letters.