Brassinosteroid Signaling Pathways Interplaying with Diverse Signaling Cues for Crop Enhancement

The signaling pathways of brassinosteroids (BRs), a unique plant steroid hormone, are critically involved in a diverse range of plant growth and developmental processes as well as many important agronomic traits. Recent advances in the understanding of BR biosynthetic and signaling pathways in model organisms and crops have increased the feasibility of modulating BR responses in crop plants to enhance adaptation to various vulnerable environmental changes. In particular, the identification and functional analysis of BR signaling components in rice (Oryza sativa) present the possibility of their utilization to improve many agricultural traits involved in crop yields. In this review, we summarize recent advances and progress in the understanding of the BR signaling pathway and its interactions with diverse internal and external signaling cues. We also discuss how these physiological modulations of BR and the abundant signaling crosstalk can be applied to enhance rice productivity through the manipulation of plant architecture and fine-tuning of stress responses. Finally, we discuss how the complex regulation of BR signaling pathways could favor application in the molecular design of plant growth and development, precise breeding strategies, and cultivation methods for rice crop improvement.