ATM Kinase in Plants: Integrating DNA Damage Response, Development, and Stress Adaptation

• ATM links genome surveillance with plant development and stress signaling • Plant-specific modules: SOG1 axis and ATM–MKP2–MPK6 in senescence • Controls cell-cycle arrest, HR repair, senescence, and immune defense • Species divergence guides breeding/editing for stress-resilient, high-yield crops Ataxia Telangiectasia Mutated (ATM) kinase is a central regulator of genome integrity in plants, integrating DNA damage responses with developmental and environmental signaling. While several mechanistic aspects of ATM activation derive from mammalian systems, plant studies reveal both conserved architecture and lineage-specific diversification. This review provides recent advances in plant ATM biology, emphasizing the ATM-SOG1 signaling axis, and multi-site phosphorylation models that coordinate checkpoint enforcement, homologous recombination, and programmed cell death. Species-dependent functional divergence emerges as a defining feature of plant ATM signaling: Arabidopsis atm mutants exhibit partial sterility, rice mutants are infertile, whereas maize atm mutants maintain normal fertility despite elevated DNA damage markers, suggesting altered ATM-ATR balance in large and complex genomes. Beyond canonical DNA damage responses, we discuss ATM function in oxidative stress signaling via the ATM-MKP2-MPK6 module, distinguishing DDR-dependent activation from redox-associated signaling. Finally, we evaluate crop-relevant implications, separating experimentally supported findings from theoretical applications in seed vigor, stress resilience, and genome editing. Together, these insights position ATM as a critical integrator of genome surveillance and stress adaptation in plants.