Do Plants Suffer from Diseases the Same Way Humans Do?

When cancer develops in the human body, abnormal cells begin to grow uncontrollably, often forming solid tumors. These cancerous tumors can spread, invading nearby tissues and sometimes spreading throughout the body via the bloodstream or the lymphatic system. Plants can also develop tumors, mostly brought on by infection, but because plant cells have rigid cell walls, the cancerous cells can’t metastasize to other parts of the plant. So when plant cells begin proliferating rapidly, the growth is contained -- often seen, for example, in tree growths known as galls or burls.

Trees with the Big C?

• Fungi, bacteria, viruses, and insect infestations are connected to cancerous growth in plants. Oak trees, for example, can develop tumors that become homes for insect larvae.
• In plants, a bacterial infection can alter the hormone balance, triggering abnormal cell growth. In humans, the phenomenon is typically genetic.
• Some common plant tumors can result from fungal infections like black knot, caused by Dibotryon morbosum, and azalea leaf gall, which is caused by the Exobasidium vaccinii fungus.