To dissect the mechanisms that control and mediate cellular iron homeostasis, we conducted quantitative high-resolution iTRAQ proteomics and microarray-based transcriptomic profiling of iron-deficient Arabidopsis thaliana plants. Proteomic and transcriptomic profiling of Arabidopsis Col and RING DOMAIN LIGASE1 (RGLG1) and RING DOMAIN LIGASE2 (RGLG2) double mutation in response to iron deficiency were conducted. This integrative analysis provides a detailed catalog of post-transcriptionally regulated proteins and allows the concept of a chiefly transcriptionally regulated iron deficiency response to be revisited.