Understanding brassinosteroid-centric phytohormone interactions for crop improvement

Brassinosteroids (BRs) play a crucial role in regulating multiple biological processes in plants, particularly those related to crop productivity and stress tolerance. During their functioning, BRs engage in extensive and intricate interactions with other phytohormones, including auxin, cytokinins, gibberellins, abscisic acid, ethylene, jasmonates, salicylic acid, and strigolactones. These interactions facilitate the integration of internal and external signals, ultimately shaping the physiological status of the plant. In this review, we introduce BR metabolism and signaling and discuss their role in modulating agronomic traits that directly contribute to grain yield in rice (Oryza sativa), the model plant for crops. We also summarize recent advances in the crosstalk between BRs and other phytohormones in regulating agronomic traits in crops. Furthermore, we highlight significant research that provides insights into developing high-yielding and stress-resistant crop varieties from the perspective of hormone crosstalk. Understanding the genetic and molecular mechanisms through which BRs and other phytohormones collaboratively control agronomic traits offers new approaches for crop improvement.