Plants live in fixed location and survive adversity by integrating growth responses to multiple environmental signals. For example, plants are highly responsive to subtle changes in ambient temperature and have evolved efficient mechanism to coordinate their growth accordingly. Like all multicellular organisms, this coordination requires communication mediated by signal molecules including phytohormones that move between distant organs of the plant. Gibberellins (GAs) are a large family of tetracyclic diterpenoid compounds controlling major aspects of plant growth and development. Although previous studies suggested the existence of a transport of GAs in plants, the nature and properties associated with this transport were unknown. By mixing grafting with molecular genetics in Arabidopsis, we showed that the GA12 precursor, although biologically inactive, is the chemical form of GA undergoing long-distance transport across plant organs. Furthermore, our recent work shows that long-distance transport of GA12 enables plants to adjust their growth in response to change in ambient temperature.