Chilling requirement activates strigolactones signaling to balance bud germination and the cold stress response in apple

Chilling requirement (CR) is critical for breaking the natural dormancy of deciduous fruit trees, as an insufficient CR will affect bud germination, branching, and fruit yield. However, the mechanisms by which meeting CR regulates bud germination in apple (Malus domestica) have remained unclear. Here we found that strigolactones (SLs) play a crucial role in receiving the CR signal and function in bud germination and the coldstress response in apple. Sufficient CR activates the interaction of MdCBF4 with MdTCP14 to induce MdDWARF53 expression, promoting bud germination and branching, while insufficient CR does not.