“…For this reason, fraction D is one of the most important fractions for metals metabolism. Phytochelatins, metallothioneins, non-heme proteins, enzymes, phytoferritin and various chelating agentsmugineic acid (Takemoto et al 1978), deoxymugineic acid, avenic acid (Fushiya et al 1981), amino acid nicotianamine (Buděšínský et al 1980, Rudolph et al 1985 can be present in fraction D. Nicotianamine has an optimal molecular structure for chelating iron ions and is considered to be a phytosiderophore with an essential function in cellular iron transport and/or metabolism. Walker and Welch (1987) reported these compounds to form stable anionic complexes with several trace elements.…”