Involved in metal ions homeostasis, including iron ions (Fe) acquisition, via the regulation of NAS4 and NAS2 genes expression. Necessary for plant survival in alkaline soil where iron availability is greatly restricted (PubMed:18088336, PubMed:24278034). Involved in the up-regulation of several biosynthesis genes of secondary metabolites involved in iron uptake under conditions of iron deficiency (PubMed:25138267). Triggers tolerance to nickel (Ni) and zinc (Zn) ions (PubMed:24278034). Required in the roots during early signaling steps of rhizobacteria-mediated (e.g. P.fluorescens WCS417r) and beneficial fungi-mediated (e.g. T.asperellum T34) broad-spectrum induced systemic resistance (ISR) against several pathogens (e.g. P.syringae pv tomato, H.parasitica, P.cucumerina, A.brassicicola and B.cinerea) and implying enhanced callose deposition (PubMed:18218967, PubMed:19121118). Required for the induction of some genes (e.g. BGLU42) upon rhizobacteria-mediated ISR (PubMed:25138267). Interacts with EIL3. Accumulates strongly in the root stele when exposed to iron (Fe)-deficient conditions (PubMed:24278034). Accumulates upon potassium ion (K) depletion (PubMed:15489280). Induced in roots by zinc (Zn) and cadmium (Cd) ions (PubMed:18088336). Specifically activated in the roots upon colonization by nonpathogenic P.fluorescens WCS417r (PubMed:18218967). Shorter roots due to increased sensitivity to excess zinc ions (Zn) and iron ions (Fe) deficiency, respectively (PubMed:18088336). Reduced production of root-derived phenolics upon iron ions (Fe) depletion (PubMed:25138267). Plants lacking myb10 and myb72 fail to induce transcript accumulation of the nicotianamine synthase genes NAS4 and NAS2 in iron ions (Fe) deficiency, and exhibits nickel (Ni) and zinc (Zn) sensitivity (PubMed:24278034). Impaired P.fluorescens WCS417r- and T.asperellum T34- mediated broad-spectrum induced systemic resistance (ISR) against the pathogens P.syringae pv tomato, H.parasitica, A.brassicicola, P.cucumerina and B.cinerea and characterized by blocked priming of enhanced callose deposition (PubMed:18218967, PubMed:19121118). Misregulation of several genes (e.g. BGLU42) triggered by P.fluorescens WCS417r upon ISR (PubMed:25138267).