ABSTRACT
Biotic stresses including fungal, bacterial, and viral pathogens are a major constraint to wheat production world-wide. Significant changes in the pathotype situation within rusts along with emergence of new diseases such as wheat blast have occurred in recent years. Such example highlights the urgent need to better understand host–pathogen interactions and how this knowledge can be applied in better disease management strategies. The ability of the host plant to recognize the pathogen and activate these responses is regulated in gene-for-gene-specific manner. This chapter discusses scientific advances which took place in the past for the understanding of the host–pathogen interactions in wheat diseases. Cellular modifications in the plant cell wall serve as an important defense mechanism operating in the defense response of plants against parasites. Reinforcement of the cell wall involves callose deposition at attempted penetration sites, making the cell wall less vulnerable to degradation by cellwall degrading enzymes (CWDEs).
