We also noticed that Fig. 5A exhibited different shapes and sizes of lateral roots after various treatments. As we can see from the pictures, the shape and size of root system with the presence of NAA were the most different from others, since the primary root was severely inhibited. A similar result was reported previously (Correa-Aragunde et al., 2004), suggesting that higher branching and elongation of lateral roots in NAA-treated seedlings might compensate for a shorter primary roots. The role of stress-elicited changes in auxin metabolism in stress-induced morphogenic responses (SIMR) has been suggested previously (Potters et al., 2007).