Mildew locus o (MLO) is a plant-specific gene family. Specific members of the Mildew Locus O gene family act as powdery mildew susceptibility factors. Their inactivation, as the result of a loss-of-function mutation, gene knock-out, or knock-down, is associated with a peculiar form of resistance, referred to as mlo resistance.[1][2] The mlo gene family is widely conserved across the plant kingdom with some members evolving as early as the first land plants.[3] Mlo proteins contain seven highly conserved transmembrane domains, as well as a calmodulin-binding domain.[1]TaMLO genes are the MLOs in bread wheat, Triticum aestivum.[4]
