Fig. 6

Levels of Ethylene Production and Free ACC in Soybean Under Drought Stress Conditions. Values were determined for ethylene production and free ACC (1-aminocyclopropane-1-carboxylic acid) in roots and leaves of soybean cultivars BR16 and EMBRAPA48 after the application of different durations of drought stress. The codes a1 and a2 represent levels of free ACC; b1 and b2 represent levels of ethylene production. The statistical analysis was performed by comparing similar tissues in both cultivars under the same conditions of drought stress (same durations). The asterisks represent the level of statistical significance: (*) p ≤ 0.05; (**) 0.05 < p ≤ 0.01; (***) 0.01 < p ≤ 0.001. Each dot represents the average amount (± standard error) of three replicates in different plants. The standard error is not presented with some dots because their absolute values are lower than the scale