Involved in strigolactone signaling pathway (PubMed:22357928). Does not move long distances acropetally in the plant to regulate shoot branching and is rapidly degraded in the presence of strigolactones (PubMed:24610723). Functions downstream of strigolactone synthesis, as a component of hormone signaling and as an enzyme that participates in the conversion of strigolactones to the bioactive form (PubMed:22357928). Acts probably as a strigolactone receptor (PubMed:24610723). Strigolactones are hormones that inhibit tillering and shoot branching through the MAX-dependent pathway, contribute to the regulation of shoot architectural response to phosphate-limiting conditions and function as rhizosphere signal that stimulates hyphal branching of arbuscular mycorrhizal fungi and trigger seed germination of root parasitic weeds (PubMed:22357928). Hydrolyzes methyl carlactonoate (MeCLA), but not carlactone (CL) or carlactonoic acid (CLA) (PubMed:25425668). Hydrolyzes the butenolide ring of strigolactones (PubMed:23381136). The initial nucleophilic attack causes an electron shift, followed by the addition of a water molecule, to lead to the release of the ABC ring product and the formation of a 'Ser-97'-stabilized open lactone intermediate (PubMed:23381136). Has no esterase activity for 4-nitrophenyl butyrate (PubMed:23381136). Binds and hydrolyzes the synthetic strigolactone analog GR24 in vitro. Forms a stable covalent complex with the D-ring of strigolactone, which is essential for hormone bioactivity. The D-ring is attached to His-247 of the catalytic triad. The hydrolysis of strigolactone into a covalently linked intermediate molecule initiates a conformational change of D14 to facilitate interaction with MAX2 and formation of the D14-MAX2-SKP1/ASK1 complex to trigger strigolactone signaling. This mechanism defines D14 as a non-canonical hormone receptor with dual functions to generate and sense the active form of strigolactone (PubMed:27479325). Interacts with SMXL6, SMXL7 and SMXL8 (PubMed:26546446, PubMed:25713176). The interaction with SMXLs occurs in the presence of (2'R) stereoisomers of strigolactones, but not (2'S) stereoisomers (PubMed:25713176). Interacts with MAX2. Forms a complex with MAX2 and SKP1A/ASK1 in presence of strigolactone (PubMed:27479325). Expressed at high levels in rosette and cauline leaves and at lower levels in axillary buds, inflorescences, stems, roots and developing vascular tissue of cotyledons. Not regulated by strigolactone, auxin signaling or bud growth status. Increased shoot branching. The initial nucleophilic attack of strigolactones by D14 causes an electron shift, followed by the addition of a water molecule, to lead to the release of the ABC ring product and the formation of a S97-stabilized open lactone intermediate. Belongs to the AB hydrolase superfamily.