Figure 6.

Nitrilase activity converting IAN to IAA with maize protein extracts from embryo (A), endosperm (B), and aleurone/pericarp (C). For each test, 40 μg of total protein was included in 250 μL of reaction buffer (pH 8.0) containing 1 mm IAN as substrate. Values show the produced IAA after 3 h determined by fluorescence emission at 360 nm with excitation at 285 nm in HPLC analysis. Nonspecific conversion was corrected, and data are presented as means ± se, n = 4. As proven by t test, the endogenous activity is significantly higher in embryo than in endosperm and significantly increases between weeks 3 and 4.