Figure 5.

Subapical root hairs in the tomato fer mutant. The tomato fer mutant (left) does not develop either subapical root hairs (right, top; Romera and Alcántara, 2004) or root transfer cells (Schmidt et al., 2000a) when grown under Fe deficiency. However, it develops both root hairs (right, bottom; Romera and Alcántara, 2004; see Supplementary Material) and transfer cells (Schmidt et al., 2000a) upon ACC treatment. This suggests that FER could influence these morphological responses through its possible indirect effect on ethylene synthesis (see Figure 1).