Involved in cytokinin-mediated development (PubMed:16709198, PubMed:29467189). Promotes the expression of cytokinin synthases (e.g. IPT3 and IPT7), thus triggering the accumulation of trans-zeatin riboside, trans-zeatin riboside monophosphate and isopentenyladenine 9-glucoside (PubMed:16709198). Expressed in vegetative tissues (hydathodes and trichomes of leaves, shoot meristems and roots) as well as in floral tissues (pistil tips, developing anthers and sepal vasculature) with higher levels in young and developing tissues than in mature ones (PubMed:16709198). Expressed in seedlings, leaves, flowers and siliques, but not in roots (PubMed:29467189). Domains SOFL-A and SOFL-B are required for function in cytokinin-mediated development. No obvious phenotypes. Belongs to the SOFL plant protein family.