Growth versus decline: root aging and plant performance

Roots play a central role in plant growth, survival, and fitness and are increasingly recognized as key determinants of crop yield and sustainability traits, including soil carbon sequestration. While extensive research has focused on the regulatory mechanisms of root growth and development, the process of root aging and its impact on root growth has received considerably less attention. This is in part due to the technical challenges of sampling and analyzing older roots. However, growing evidence indicates that root growth often declines with age. In this review, we synthesize current knowledge on the molecular and physiological mechanisms regulating root growth and the mechanisms and effects of root aging, providing a conceptual bridge between 2 processes. Moreover, we discuss potential genetic and synthetic biology approaches and strategies to delay root aging or reactivate growth in old roots and how such interventions could ultimately enhance crop productivity and support plant-based strategies for climate change mitigation.