Traditional paradigms of root architectural plasticity emphasize physical spatial distribution. However, facing physical and energetic constraints in soil exploration, plants leverage root architecture as a strategic platform for biological extension. This presentation redefines root plasticity as a "functional composite," integrating physical roots with symbiotic mycorrhizal networks for spatial reach and dynamic rhizosphere microbiomes for chemical bioavailability.

We explore this composite plasticity across varying disturbance regimes: post-fire pine forests, perennial pomelo orchards, and annual maize fields. In acute natural disturbances like post-fire forests, root plasticity drives the transition from combustion-oriented to decomposition-oriented nutrient recycling, relying on resilient mycorrhizal networks to recapture nutrient pulses and stabilize plant-soil feedbacks (PSFs). Conversely, under chronic anthropogenic disturbances in agriculture (pomelo and maize), plasticity shifts away from symbiotic reliance toward localized, physical foraging, often driving rapid nutrient depletion and negative PSFs.

Finally, we highlight the critical role of metagenomics in decoding these interactions. By shifting focus from morphological traits to the microbiome's functional genomic potential, we mechanistically link composite root plasticity to nutrient cycling. This perspective reveals how preserving or losing evolutionary symbiosis dictates PSF trajectories, informing both ecological restoration and sustainable soil management.

東京大学大学院理学系研究科・生物科学専攻・植物生理学研究室