Diversity of defence mechanisms in plant–oomycete interactions: a case study of Lactuca spp. and Bremia lactucae

摘要: Plant pathogenic oomycetes, including biotrophic downy mildews and hemibiotrophs/necrotrophs such as Phytophthora Pythium, cause enormous economic losses on cultivated crops. Lettuce breeders growers face the threat of Bremia lactucae, causal agent lettuce mildew. This pathogen damages leaf tissues heads is also frequent wild Asteraceae plants. The interactions Lactuca spp. with B. lactucae (abbr. lettuce–Bremia) display extreme variability, due to a long co-evolutionary history. For this reason, during last 30 years, lettuce–Bremia pathosystem has been used model for many studies at population, individual, organ, tissue, cellular, physiological molecular levels, well genetic variability genetics host–parasite interactions. first part review summarizes recent data specificity, host resistance mechanisms second focuses development infection structures. Phenotypic expression infection, behaviour surfaces, process penetration, primary structures, hyphae haustoria are discussed in relation different mechanisms. In third part, components defence responses analysed. role reactive oxygen species (ROS), antioxidant enzymes, nitric oxide (NO), phenolic compounds, reorganization cytoskeleton, electrolyte leakage, membrane damage, cell wall disruption, hypersensitive reaction plant energetics responses. general, between Bremia, their phenotypic expression, results from diversity background. Different conditioned by an orchestra cell, levels. various events responsible involve complex interaction processes reactions mentioned above. provides overview timing development, pathological anatomy, cytology physiology associations. significance these factors (non-host resistance, race-specific race non-specific field resistance) discussed.