Manipulating brassinosteroid signaling pathway to genetically improve horticultural plants

Brassinosteroids (BRs), a class of plant-specific steroidal hormones, play crucial roles in regulating various plant physiological functions, such as growth, development, and adaptability to the environment. Despite this broader role of BRs, previously published reviews mainly focused on the molecular mechanisms of BR-mediated regulation of vegetative and reproductive growth of model plants like Arabidopsis and some food crops, such as rice, maize, and wheat. While horticultural plants hold significant economic importance in modern agriculture, less attention has been paid to understanding the role of BRs in regulating the physiological functions of these plants. Given the lack of relevant reviews, this article aims to discuss the major roles of BRs in horticultural plants, particularly fruit and leaf development, whole plant architecture, and adaptive stress response. We also highlight key challenges and provide some future research directions for genetically improving horticultural plants by altering the BR signaling pathway.