Brassinosteroids in Cucurbits: Modulators of Plant Growth Architecture and Stress Response.

Brassinosteroids (BRs) are steroid hormones that are essential for plant growth, development, and environmental adaptation. They control the division, elongation, and differentiation of various cell types throughout the entire plant life cycle, affecting growth and the stress response. Therefore, fine-tuning of BR biosynthesis and modulation of signaling pathways offer possibilities for developing cultivars characterized by adjusted plant architecture or improved stress tolerance to benefit crop production. Additionally, precise BR treatments can be employed to increase the productivity of crop plants. This review aims to provide a comprehensive summary of the genetic basis of traits related to BR metabolism and signaling in cucurbits, the second largest vegetable family, which contributes significantly to global vegetable production and nutritional security. We summarize the current knowledge concerning BR biosynthesis mutants, the role of BRs in stress mitigation, and the potential of the exogenous application of BRs to alleviate stress during cucurbit production. We also discuss how genes related to BR metabolism can be used to develop gene editing strategies to advance precision breeding in cucurbits.