Tag: biotechnology in agriculture

• Biolistics (gene gun), Microinjection and Electroporation are direct methods of gene transfer.
  
• Agrobacterium tumefaciens is a gram-negative soil bacterium, which can cause crown gall tumors at wound sites of infected dicotyledonous plants.
• Agrobacterium tumefaciens acts as a vector for the transfer of genetic material hence it cannot be used for direct gene transfer.
• Hence Agrobacterium tumefaciens cannot be used for direct gene transfer.
• So, the correct answer is 'Agrobacterium tumefaciens'.

In gene therapy trials, the retrovirus is used as a vector to treat X-linked severe combined immunodeficiency (X-SCID) represent the most successful application of gene therapy. The retrovirus genetic material is in the form of RNA molecules, and their hosts genetic material is in the form of DNA. When a retrovirus infects a host cell, it will introduce its RNA together with some enzymes, namely reverse transcriptase and integrase, into the cell. This RNA molecule from the retrovirus must produce a DNA copy from its RNA molecule before it can be integrated into the genetic material of the host cell. The process of producing a DNA copy from an RNA molecule is termed reverse transcription.

In the gene gun method, microscopic pellets of gold or tungsten are coated with the transgene fragments and shot into the plant cells or tissues at high velocity.