Which organism is used for biological control of Crown Gall?

The organism used for biological control of Crown Gall is Agrobacterium tumefaciens. This soil bacterium is known for its role in causing Crown Gall disease, which leads to the formation of tumor-like galls on the roots and stems of many plants. However, specific strains of Agrobacterium tumefaciens can be utilized for biological control purposes.

These beneficial strains can outcompete or inhibit the pathogenic strains responsible for Crown Gall, thereby reducing the prevalence of the disease. The mechanism of action typically involves the competition for resources and space, as well as the production of antibacterial compounds that suppress the growth of the pathogenic bacteria. Utilizing a form of the same organism in a beneficial context demonstrates a unique aspect of biological control, leveraging natural interactions to manage plant diseases effectively.

Other organisms listed do not target Crown Gall specifically through biological control. For instance, Escherichia coli is a common bacterium found in the intestines of humans and animals and is not involved in this type of plant disease control. Bacillus thuringiensis is an insect pathogen used for controlling caterpillars and other insect pests, while Pseudomonas fluorescens is utilized for its antifungal properties but does not have a direct role in