Involved in a signaling pathway that modulates root auxin transport and auxin gradients. Acts partially by positively regulating the auxin carrier PIN2 and AUX1 (PubMed:19948787). Acts, together with GB1 as positive regulator of meristem initiation and branching. GB1 and NDL2 positively regulate basipetal inflorescence auxin transport and modulate MAX2 expression in shoots, which regulates organ and lateral meristem formation by the establishment and maintenance of auxin gradients (PubMed:24223735). Interacts with the heterodimers formed by GB1 and GG1, or GB1 and GG2. Interacts with RGS1. Belongs to the NDRG family.