Ethylene-Triggered Rice Root System Architecture Adaptation Response to Soil Compaction

Soil compaction is a major constraint on global agriculture productivity. It disrupts soil structure, reduces soil porosity and fertility, and increases mechanical impedance, thereby restricting root growth and crop yield. Recent studies on rice (Oryza sativa) reveal that the phytohormone ethylene serves as a primary signal and functions as a hub in orchestrating root response to soil compaction. Mechanical impedance promotes ethylene biosynthesis and compacted soil impedes ethylene diffusion, resulting in ethylene accumulation in root tissues and triggering a complex hormonal crosstalk network to orchestrate root system architectural modification to facilitate plant adaptation to compacted soil. This review summarizes the recent advances on rice root adaptation response to compacted soil and emphasizes the regulatory network triggered by ethylene, which will improve our understanding of the role of ethylene in root growth and development and provide a pathway for breeders to optimize crop performance under specific agronomic conditions.