Abstract
Late blight, caused by one of the most infamous plant pathogen Phytophthora infestans, is highly devastating disease of potato. None of the potato cultivars have adequate tolerance to the late blight pathogen, because resistance due to the disease resistance genes (R-genes) that confer immunity only to some strains of the pathogen harboring corresponding avirulent gene is soon broke down in the field. A mitogen-activated protein kinase (MAPK) cascade has been shown to play a pivotal role in the plant innate immunity. Here we show that the transgenic potato plants, which were introduced by a constitutive active form of MAPK kinase driven by a pathogen-inducible promoter of potato, showed highly resistance to early blight pathogen Alternaria solani as well as a compatible race of P. infestans. In the compatible race and transgenic plant interaction, elevation of MAPK activity, H2O2 accumulation and up-regulation of various defense-related genes were observed.
