Harnessing brassinosteroid signaling in rice: from molecular pathways to environmentally adaptive breeding

Brassinosteroids (BRs), a class of steroidal phytohormones, play crucial roles in regulating plant growth, development, and environmental adaptation in rice. With the elucidation of BR signaling pathways in Arabidopsis, the rice BR regulatory network has been progressively uncovered, revealing both conserved and unique features. In this review, we first summarize recent advances in understanding BR signaling mechanisms in rice. We then focus on how BR signaling integrates environmental cues, including nutrient availability, high-temperature stress, drought stress, and pathogen responses, to fine-tune growth and yield. Moreover, we highlight the complex cross-talk between BR signaling and other phytohormones that enables dynamic responses to environmental fluctuations. Finally, we discuss the potential applications of BR-related genes in rice production, together with the challenges of their translation into practical agricultural systems, providing perspectives and opportunities for environmentally adaptive breeding. Taken together, recent discoveries deepen our understanding of BR signaling in rice and provide a conceptual framework for exploring its roles in environmentally adaptive growth regulation and crop improvement.