How do organisms, organs, tissues, and cells alter their fate as they age toward aging and death? Plant leaves provide a unique window to explore this question. Throughout their lifespan, leaves undergo a series of developmental changes from leaf primordium initiation through growth and maturation to senescence, which requires intricately coordinated temporal and spatial regulations. All living organisms are unavoidably exposed to a variety of endogenous and environmental stresses during their lifetimes that can trigger potentially fatal DNA damage. While a growing body of evidence suggests that DNA damage is a primary driver of the aging process in animals, our understanding of the significance of DNA damage and repair in controlling lifespan in plants remains limited. In this talk, I will discuss the importance of DNA double-strand breaks (DSBs) and DNA-protein crosslinks (DPCs) as conserved aging mechanisms in both plants and animals through the control of genomic instability. Additionally, I will present recent advancements in understanding the molecular mechanisms underlying DNA damage-mediated leaf senescence in Arabidopsis, particularly the regulatory roles of ATM, the primary transducer of DSB signals, and WSS1A, an essential component of DPC repair.