Figure 1.

Effect of Si on root elongation (A) and on Al-induced callose formation (B) of maize cv Lixis supplied without or with 25 μm Al in a solution containing 500 μm CaCl₂ and 8 μm H₃BO₃, pH 4.3. Plants were precultured for 36 h without or with 1.4 mm Si and then treated without or with 25 μm Al for 12 h in the presence or absence of 1.4 mm Si. Si, Without Si during preculture and Al treatment; +Si, with Si during preculture, without Si during Al treatment; ++Si, with Si during preculture and Al treatment. Bars show sd. Significant differences between mean values are indicated by different letters at the P < 0.05 level (Tukey test). n = 3 for root elongation, n = 5 for callose formation.