Peanut, Arachis hypogaea L., is well known as having aerial flowers and subterranean fruit.Due to the subterranean fructification after flowering, the gravitropic gynophore elongation and penetration into the soil are essential for the fruiting in peanut.During the event, gravity is related to the orientation of gynophore growth.Recently, however, we found the gynophore grows upward in mycoplasma-like organisms (MLO) infected peanut plants.