Abstract: Jasmonates (jasmonic acid and its derivatives) seem to be involved in the morphogenesis of underground storage organs in plants, such as tuberization (potato, yam, and Jerusalem artichoke), tuberous root formation (sweet potato), and bulb formation (onion and garlic). JA and MeJA can induce tuber formation in vitroand cells expansion of medullary tissue. JA_induced expansion of cells is attributable to both the increase of osmotic pressure due to the accumulation of sucr ose and the changes in cell wall architecture that appears to affect extensibility of the wall. Moreover, the synthesis of cellulose and the involvement of microtubles (MTs) might be indispensable for JA_induced expansion. But so far we do not know what is the real trigger of potato tuberization. The exact nature of JAs-mediated morphogenesis of underground storage organs in plants remains to be e lucidated.