Crown gall is caused by which type of organism?

Crown gall is caused by a specific type of bacterium known as Agrobacterium tumefaciens. This bacterium infects various plants, leading to the formation of tumor-like growths, or galls, primarily at the crown of the plant where the stem meets the roots. The organism is particularly adept at transferring a segment of its DNA into the host plant's genome, leading to uncontrolled growth that manifests as these galls.

In contrast, fungi, viruses, and nematodes are responsible for other plant diseases but do not produce crown gall. Fungi can cause issues like root rot or blights, viruses might induce stunting or mottling on leaves, and nematodes are typically associated with root damage or gall formation that differs from the one caused by the bacteria. Understanding the specific pathogens responsible for various plant diseases is crucial for effective management and treatment strategies in agricultural practices.