Plasmodiophora brassicae is a soil-borne protist that causes the disease known as clubroot in plants, particularly affecting members of the Brassicaceae family, such as cabbage and broccoli. This pathogen infects the roots of these plants, leading to the formation of galls or swellings, which can hinder nutrient and water uptake. The life cycle of Plasmodiophora brassicae involves both a resting spore stage and an active phase where it multiplies within the plant roots. Control measures include crop rotation, soil pH management, and the use of resistant plant varieties to minimize the impact of this disease on agricultural production.