Molecular and physiological mechanisms of strigolactones-mediated drought stress in crab apple (Malus hupehensis Rehd.) seedlings

•GR24 effectively mitigates the drought damage suffered by apples.•GR24 suppresses drought-induced decrease in photosynthesis by regulating photosynthetic pigments and stomatal opening.•GR24 reduces oxidative damage by enhancing antioxidant capacity.•GR24 enhances drought tolerance in apple by triggering the expression of Ca2+ signaling-related genes.