Subcellular iron transport genes in Arabidopsis thaliana: insights into iron homeostasis

Abstract

Subcellular iron homeostasis genes (SIHGs) take part in sequestration, translocation and remobilization of iron between compartmentalized organs and cytoplasm. Therefore, to shed light on these genes’ functions in different biological processes, in silico analyses of these proteins were conducted. The evolutionary tree of SIHGs revealed that VIT1, NRAMP3, and NRAMP4 may be derived from a common ancestral protein. In Protein-Protein Interaction (PPI) network analysis, VIT1 gene was identified as an essential gene in subcellular iron homeostasis in Arabidopsis. Expression and co-expression analyses showed that these proteins may be components of various metabolic pathways, in a way explained as follows: NRAMP3 may be involved in starch metabolism, pathogen defense mechanism, and nutrient mobilization in senescence, and interact with aldehyde dehydrogenases (ADH), a protein superfamily regulating plant growth stages and regulated by abiotic stress mechanism. NRAMP4 is involved in iron uptake mechanism, acclimation, and stratification processes in dormant seeds with the stimulation of ethylene and CBFs. The VIT1 expression may be regulated by nicotianamine (NA). Salicylic acid (SA), as a plant hormone, may be the key activator of PIC1 expression. PIC1 appears to have taken part in DNA repair, pathogen response mechanisms, and sugar metabolism. Additionally, PIC1 may have vital roles in cellular redox environment, in particular, chloroplast development. FRO8 may take part in SA-mediated systemic acquired resistance (SAR) network and DNA double-strand break repair mechanism. Lastly, similar to PIC1, FRO7 may be a component in DNA repair, SA, and pathogen defense mechanisms as well.