ABSTRACT
Soilborne plant pathogens are a diverse group of bacteria, fungi, nematodes, parasitic higher plants, and viruses that survive in soil between infection cycles of their hosts. Many soilborne fungal pathogens are either hemibiotrophs that invade host cells but keep the cells alive for a period prior to killing the cell or necrotrophs that kill the host cells prior to invading the cells. A few soilborne fungal pathogens, such as the club root pathogen, Plasmodiophora brassicae, are obligate biotrophs that infect only living host cells.
