| Noun | 1. | Plasmodiophora brassicae - a fungus resembling slime mold that causes swellings or distortions of the roots of cabbages and related plants genus Plasmodiophora, Plasmodiophora - type genus of Plasmodiophoraceae comprising minute plant parasitic fungi similar to and sometimes included among the slime molds fungus - an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia |