The wheat powdery mildew resistance genePm4also confers resistance to wheat blast

AbstractWheat blast, caused by the fungusMagnaporthe oryzae, threatens global cereal production since its emergence in Brazil in 1985 and recently spread to Bangladesh and Zambia. Here we demonstrate that theAVR-Rmg8effector, common in wheat-infecting isolates, is recognised by the genePm4, previously shown to confer resistance to specific races ofBlumeria graminisf.sp.tritici, the cause of powdery mildew of wheat. We show thatPm4alleles differ in their recognition of differentAVR-Rmg8alleles, and some confer resistance only in seedling leaves but not spikes making it important to select for those alleles that function in both tissues. This study has identified a gene recognising an important virulence factor present in wheat blast isolates in Bangladesh and Zambia and represents an important first step towards developing durably resistant wheat cultivars for these regions.