Aging is a time-dependent biological phenomenon governed by complex networks of regulatory components and their transitions over lifetime. Yet, there have been limited efforts to pin down age-associated networks and map their dynamic characteristics onto aging phenotypes. Here, we built time-course genetic regulatory networks of NAM/ATAF/CUC (NAC) transcription factors during the course of leaf aging in Arabidopsis, using causal regulatory relationships among NACs identified from mutants of 49 aging-associated NACs. These temporal networks revealed a regulatory inversion from activating to repressive regulatory modes at a pre-senescent stage. The inversion was governed by three hub NACs, and their mutants conferred earlier aging with altered expression of reactive oxygen species and salicylic acid response genes. Overexpression of the hub NACs delayed the regulatory inversion, rendering delayed age-dependent cell death. We conclude that the regulatory inversion in NAC networks at a pre-senescent stage directs when age-dependent cell death should proceed in plants. Overall design: We measured mRNA expression of 49 NACs in wild type (col-0) and 49 knockout mutant lines of NACs (duplicate for each mutant) at 4 stages (14, 18, 22, and 26 days of leaf age) 434 samples consist of: 34 wild type samples (=10, 8, 8 and 8 replicates for the four time points, respectively) 16 samples of anac092 mutant, one of the ANAC gene (=4 replicates for each of four time points) 384 samples of 48 anac mutants including at3g12910 and ntl9 (=2 replicates for each of four time points).