act as growth repressors. Auxin promotes GA-induced DELLA destabilization, whereas ethylene and abscisic acid stabilize DELLA proteins, illustrating a multi-directional regulatory interface among these pathways.

Brassinosteroids influence both meristematic cell division and elongation. Optimal brassinosteroid levels are required for proper auxin responsiveness, and brassinosteroid-deficient mutants show reduced meristem size and impaired auxin-induced transcriptional responses. Brassinosteroids also stimulate ethylene biosynthesis, adding