Xanthomonas campestris pv. campestris is a gram-negative bacterium that belongs to the family Xanthomonadaceae. It is a plant pathogen that causes black rot disease in a wide range of cruciferous plants, including cabbage, broccoli, cauliflower, and radishes.
The bacterium is rod-shaped and motile, and it is characterized by its ability to produce colonies that appear yellow and mucoid on nutrient agar plates. It is a facultative anaerobe, meaning it can grow both in the presence and absence of oxygen.
Xanthomonas campestris pv. campestris is primarily transmitted through contaminated seeds, soil, or plant debris. Once it enters the host plant, it colonizes the intercellular spaces and multiplies rapidly. The infection causes characteristic symptoms such as yellow V-shaped lesions on the leaves, wilting, and eventually leads to the development of blackened rot in the vascular tissues.
The bacterium possesses various virulence factors that aid in its pathogenicity, including the production of extracellular enzymes and toxins that degrade plant cell walls and suppress the host's defense mechanisms. It also utilizes a type III secretion system to deliver effector proteins into host cells, which manipulate the plant's immune response.
Management of Xanthomonas campestris pv. campestris involves employing various strategies such as crop rotation, sanitation practices, and the use of disease-resistant cultivars. Chemical control measures may be employed, although their effectiveness can be limited due to the emergence of resistant strains.
Overall, Xanthomonas campestris pv. campestris is an economically significant pathogen that poses a threat to cruciferous crops worldwide and requires integrated management approaches to mitigate its impact. Less...