Which disease is caused by bacteria?

Which disease is caused by bacteria?

• A. Crown gall
• B. Verticillium wilt
• C. Dutch elm disease
• D. Pine wilt

Answer: (A)

Crown gall is caused by bacteria. Bacteria are single-celled organisms that can enter plants through wounds and cause disease by inserting genetic material into plant cells. In crown gall, the bacterium Agrobacterium tumefaciens transfers DNA into the plant, triggering excessive cell division and forming tumor-like galls at the crown or roots. These galls disrupt normal nutrient and water movement, weakening the plant. The other diseases listed come from fungi or nematodes: verticillium wilt is a fungal disease that clamps down on the plant’s vascular system, Dutch elm disease is caused by a fungal pathogen, and pine wilt is caused by a nematode that blocks water-conducting tissues. So crown gall is the bacterial disease.

Crown gall is caused by bacteria. Bacteria are single-celled organisms that can enter plants through wounds and cause disease by inserting genetic material into plant cells. In crown gall, the bacterium Agrobacterium tumefaciens transfers DNA into the plant, triggering excessive cell division and forming tumor-like galls at the crown or roots. These galls disrupt normal nutrient and water movement, weakening the plant. The other diseases listed come from fungi or nematodes: verticillium wilt is a fungal disease that clamps down on the plant’s vascular system, Dutch elm disease is caused by a fungal pathogen, and pine wilt is caused by a nematode that blocks water-conducting tissues. So crown gall is the bacterial disease.