Fig. 3.

Model of processes controlling the metabolic and Fe-mediated regulation of AR formation in petunia cuttings. Crucial metabolic pathways, enzymes and metabolites are assigned to the involved compartments at the source and sink sites. Arrows indicate directions of transport or conversion of iron in blue colour. Red and blue discs indicate metabolite and iron transporters, respectively. apoinv, apoplastic invertase; cytinv, cytosolic invertase; hxk, hexokinase; IRT1, iron-regulated transporter 1; STP, monosaccharide transporter; vacinv, vacuolar invertase. Further explanations are provided in the text.