Overview of Plant Genetic Engineering Glossary

agrobacterium

A soil bacteria that can be a plant pathogen. It works as a natural genetic engineer by invading a plant through wounds and inserting a piece of DNA into the plant's chromosomes. The plant will then begin producing the protein encoded by the inserted gene. Bacillus thuringiensis is a strain of agrobacteria.

backcross

A breeding method used to move one or a only a few desirable genes from an agronomically poor crop line to an elite line. This is done by crossing a donor parent to an elite line, and crossing offspring with the 'desired gene(s)' back to the elite parent.

backcross breeding

After a plant has been transformed, the event must be moved into an elite genetic background. This is done by mating the transformed plant back to elite plants over several generations.

Bt corn

Corn that has been transformed with the Bt gene and is resistant to European corn borer.

Bt gene

A gene originating from the Bacillus thuringiensis soil bacteria that encodes a protein toxic to the European corn borer.

Bt genes

Genes originating from the Bacillus thuringiensis soil bacteria that encode a protein toxic to the European corn borer.

Bt protein

Another name for the CryIA proteins. These proteins occur naturally in Bacillus thuringiensis bacteria and are toxic to European Corn Borer.

callus

A mass of undifferentiated cells used in tissue culture.

chromosome

A genetic structure in a cell composed of condensed DNA, which contains the genetic code for an organism.

crossing

The deliberate mating of two parental types of organisms in genetic analysis.

DNA

(deoxyribonucleic acid) The molecule that encodes genetic information. DNA is a double-stranded molecule held together by weak bonds between base pairs of nucleotides. It is the fundamental substance of which genes are composed.

DNA extraction

The process of isolating the DNA from cells of an organism to allow scientists to work with and study it further.

electroporation

A method of cell transformation using a pulse of electricity to open small temporary holes in the plant or bacteria cells. The foreign DNA mixed with these cells is able to pass into the cell through these holes.

elite

A crop line that has many genes for good agronomic traits that result in high yields in a particular environment.

enzyme

A protein that catalyzes, or speeds up, a specific biochemical reaction without changing the nature of the reaction.

European corn borer

Ostrinia nubilalis (Hübner) is a major insect pest in corn that costs farmers millions of dollars annually in control expenditures and yield loss. The European corn borer (ECB) larva feed on the leaves and bore holes into the stalks where they tunnel.

gene

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

gene cloning

Finding and making copies of a specific gene. This is the first part of the genetic engineering process.

gene gun

Also known as microprojectile bombardment and particle acceleration. The method used to transform cells using small gold or tungsten particles which are coated with DNA and literally shot into the cell.

genetic engineering

The process of adding foreign DNA to the genome of an organism.

genome

All the genetic material in the haploid set of chromosomes for a particular organism.

genotype

The allelic composition of a cell or organism.

hybrids

Individuals produced by crossing two parents of different genotypes.

line

Plants within a species that have the same genetic composition and are genetically pure, (i.e., inbred line). Lines are typically not agronomically competitive and are used only in plant breeding.

microfibers

A method used to transform tissue culture cells using tiny fibers coated with DNA. These fibers are combined in solution with the cells and shaken vigorously causing the fibers to stab the plant cells delivering the DNA to them.

nucleus

The part of the plant or animal cell that contains the chromosomes.

promoter

A specific DNA sequence to which RNA polymerase binds and initiates transcription. This region contains information which regulates when and how often the gene is transcribed and ultimately the amount of protein it produces.

protein

A large molecule composed of one or more chains of amino acids in a specific order. Proteins are necessary for the structure, function, and regulation of an organism's cells, tissues, and organs. Each protein has a unique function determined by its shape.

tissue culture

Plant cells are grown in culture which allows them to be manipulated and then induced to develop into whole plants.

totipotent

The ability of a single plant cell to grow, divide, and differentiate into an entire plant. Mammalian cells do not have this ability.

trait

The characteristic that results from an expressing gene(s). Ex. Upright leaves, drought tolerance, Bt resistance. A trait can be influenced by the environment.

transformation

A process by which extra genetic material is inserted into the cells of an individual.

transgene

A gene that has been genetically altered. They are usually used to transform organisms.

transgenic

An organism that has a new genetically engineered DNA sequence found in every one of its cells. Genetically engineered organisms are transgenic. These two terms are used interchangeably.

undifferentiated

Cells that have not developed into specialized tissues. Undifferentiated cells, called callus, are used in tissue culture during the transformation process.

yield potential

The highest yield a plant (hybrid, variety, etc.) is capable of producing when grown in ideal conditions.