Probable transcription factor that functions as a negative regulator of lateral branching, presumably through its expression in axillary buds (PubMed:12581309, PubMed:20547591). Involved in the fine tuning of shoot branching. May function as an integrator of multiple signaling pathways to regulate the development of axillary buds. Works partially downstream of strigolactones to inhibit bud outgrowth (PubMed:20547591). Binds to MADS57 to suppress the negative regulation of D14 by MADS57 and balance the expression of D14 for tillering (PubMed:23463009). Interacts with MADS57. Expressed in the axillary bud of the first formed leaf node (PubMed:17655651). Expressed in axillary buds, shoot apical meristem, young leaves, vascular tissues and the tips of crown roots (PubMed:20547591). Increased lateral branching. Plants over-expressing TB1 exhibit markedly reduced lateral branching, but normal propagation of axillary buds.