Pathogenesis by fungi and by parasitic plants: Similarities and differences

The processes by which fungi and parasitic plants infect their plant host are compared. The steps considered are: location of the host by the pathogen, the concept of the haustorium, attachment of the pathogen to the host, mechanism of penetration into the host, responses of the host to infection by fungi and by parasitic plants, and the suppression of the host response by the pathogen. Although superficially similarities between fungal infection and infection by parasitic plants exist, the underlying mechanisms appear to be different and only in the penetration step are similar strategies used, including the use of lytic enzymes. These differences are important when seeking ways of combating the parasitic plants. The strategies used against the parasitic plants must be different from those used to combat fungal infections and should not be based only on analogies with host resistance to fungal pathogens.