LIFE SCIENCE

Detailed explanation-1: -The Gram-negative soil bacterium Agrobacterium tumefaciens has the capacity to genetically engineer plants in nature. As a consequence of the expression of the transferred agrobacterial genes in plant cells, tumors called crown galls develop at the infection sites.

Detailed explanation-2: -This whole process of transferring DNA and mobilizing in the host chromosome is performed & monitored by the bacteria itself. That is why Agrobacterium tumefaciens are called the natural genetic engineers of plants. They are utilised as vectors for plant genetic engineering.

Detailed explanation-3: -tumefaciens (a pathogen of several dicot plants) has natural ability to transfer T-DNA of their Ti (tumour inducing) plasmids into plant genome upon infecting them. This causes an unorganised growth of a cell mass or tumor known as crown gall. A. tumefaciens, thus functions as a natural genetic engineer of plants.