Transformation Glossary

• Agrobacteria– a soil bacteria that is a plant pathogen in the wild. It works as a natural genetic engineer by invading a plant through wounds and inserting a piece of DNA into the plant’s DNA. The plant will then begin producing the protein encoded by the inserted gene.
• Cotyledons– the first leaf or leaves produced by a plant when it sprouts.
• Gene– a sequence of DNA that provides the instructions for making a protein.
• Growth medium (media)– gel that contains all the nutrients that both plant cells and Agrobacterium need to survive.
• Hood– the workspace of a plant transformation specialist.  This space is sterile and continually blows sterilized air to keep fungus and bacteria from the air from contaminating the Agrobacterium and plant cultures.
• Plasmid– a small circular piece of DNA from bacteria that often contains antibiotic resistance genes. The plasmid in Agrobacterium can be replicated in the bacteria and can ‘send’ a sequence of DNA into a plant cell to be incorporated into the plant’s genome.  Therefore, the plasmid is essential for plant transformation using Agrobacterium.
• Shoots– portion of the developing seedling above the root system.
• Sticky ends– When double stranded DNA is cut unevenly, it leaves an overhang of nucleotides one of the strands.  This single stranded area is attracted to a complementary strand of single-stranded DNA and is known as a ‘sticky end.’  These sticky ends are used to incorporate a piece of DNA into a plasmid so it can be transferred by the bacteria.
• Transformation– A process by which extra genetic material is inserted into a cell.  The two most common methods currently are Agrobacterium or gene gun transformation.