Novel phytohormones involved in long-range signaling

Communication between distant organs is an essential feature of multicellular organisms. Plants are no exception to this rule and long-range signals are involved in the regulation of many aspects of organ growth and development. In this review, we use two specific examples to illustrate this point. The first is a novel upwardly mobile hormone involved in the regulation of shoot branching. The second is a root-derived hormonal signal that regulates leaf development.