Root hair reinfection in Chinese cabbage seedlings by the secondary zoospores of Plasmodiophora brassicae Woronin

The root hair reinfection by Plasmodiophora brassicae occurred in healthy Chinese cabbage seedlings grown around the infected plant in which the fungus was present only in the zoosporangial stage. When reinfected seedling were transplanted again as an inoculum into the non-inoculated soil, root hairs in healthy seedlings became infected and the zoosporangial stage was developed. Our study revealed that the secondary zoospores released from zoosporangia in infected root hairs are able to reinfect healthy root hairs and repeat the zoosporangial stage in root hairs and epidermal cells.