Which of the following bacterium causes crown gall disease in plants? A)Bacillus thurigiensis B)Agrobacterium tumefaciens C)Pseudomonas fluorescens D)None of these
Option B) Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die.
