A plant-microbe codriven perspective on the nitrogen cycle

The nitrogen (N) cycle is traditionally framed as a microbe-dominated process, with plants treated largely as passive sinks. We challenge this dichotomy by proposing a codriven framework where N cycling emerges from tight plant-microbe coregulation. While microorganisms execute biochemical machinery for transformations, plants actively steer the rate, location, and pathways of these processes through strategic carbon allocation, chemical signaling, and root trait deployment. We argue that plants dynamically balance 'Outsourcing' strategies that stimulate microbial N mobilization with 'Do-It-Yourself' foraging to synchronize N supply with plant demand. Reframing the N cycle as a coregulated system shifts theory from reaction-based to control-based, providing a mechanistic foundation to integrate plant traits into next-generation biogeochemical models, improving N use efficiency and reducing environmental risks.