Hairy vetch

Hairy Root

Hairy root is a plant disease syndrome that is caused by the soil-borne bacterium Agrobacterium rhizogenes. This bacterium has the ability to infect a wide range of dicotyledonous (dicot) plants and induce the formation of proliferating, genetically transformed root tissues. The disease is named for the characteristic 'hairy' appearance of the infected roots.

History

The phenomenon of hairy root was first observed in the early 20th century, but it was not until the 1980s that the causative agent, Agrobacterium rhizogenes, was identified. Since then, hairy root has been extensively studied for its potential applications in plant biotechnology.

Causes

Hairy root disease is caused by the bacterium Agrobacterium rhizogenes. This bacterium is able to transfer a portion of its own DNA, known as the T-DNA, into the plant's genome. This results in the transformation of the plant's cells and the formation of hairy roots.

Symptoms

The most obvious symptom of hairy root disease is the formation of numerous, thin, hair-like roots at the site of infection. These roots are typically white or light brown in color and have a rough, 'hairy' appearance. Other symptoms may include stunted growth, wilting, and leaf yellowing.

Treatment and Control

There is currently no effective treatment for hairy root disease. Control measures typically involve the removal and destruction of infected plants to prevent the spread of the bacterium. In some cases, resistant varieties of plants may be used to reduce the incidence of disease.

Applications in Biotechnology

Despite its status as a plant disease, hairy root has found a number of applications in the field of plant biotechnology. The ability of Agrobacterium rhizogenes to genetically transform plant cells has been exploited for the production of transgenic plants. In addition, hairy root cultures have been used for the production of secondary metabolites, including pharmaceuticals and other valuable compounds.