Figure 5.

Concentration of endogenous IAA determined by ELISA (A; Peres et al., 1997) and by GC-SIM-MS (B; Chen et al., 1988). In A, the IAA was measured in the attached cotyledons from intact seedlings of H. courbaril growing in light, darkness, or with shoot excised above the cotyledons insertions (shoot excised) at 34 d. The only isolated cotyledons used as a reference in this case were the ones detached at 34 d and subsequently kept in the darkness. The plant materials used for auxin analyses were selected according to availability of tissue and to maximize the differences observed during the period of analysis. In B, the IAA was also measured in attached cotyledons of intact seedlings of H. courbaril grown in the light and in intact seedlings treated with NPA at 200 μm (NPA 200 μm). In the last technique, the IAA was also evaluated in shoot excised seedlings at 34 d (shoot excised), in shoot excised seedlings with light-protected cotyledons (shoot excised LPC), and in seedlings with the shoot apex excised (top shoot excised). Bars represent sd of the mean of three composed replicates.