Cloning and functional identification of a strigolactone receptor gene MdD14 in apple

Strigolactones (SLs) are phytohomones that regulate shoot branching and hypocotyl elongation. Here, the strigolactone receptor gene MdD14 in apple was cloned. MdD14 was localized to the nucleus and cytoplasm. GUS staining showed that MdD14 was expressed in various tissues. A promoter analysis revealed that MdD14 contained multiple response elements and its expression levels were induced by various abiotic stress treatment. The post-translational of MdD14 was regulated by the SL analog GR24. Ectopic expression of MdD14 in Arabidopsis is resulted in a phenotype that inhibited shoot branching and hypocotyl elongation, as well as increased tolerance to salt, drought and low temperature stresses. These findings reveal the functions of MdD14 and lay a foundation for studying SLs in apple.