Transformation 1 - Plant Tissue Culture Glossary

BAR gene

Also called the PAT gene; it is the bacterial gene that encodes the protein phosphinothricin (PAT) which detoxifies the Liberty herbicide molecule resulting in Liberty resistance.

Bt corn

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

callus

A mass of undifferentiated cells used in tissue culture.

chimeric plants

Transformed plants that have the new gene in only some of their cells.

chromosome

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

co-transforming

Transforming a cell with two different genes at the same time.

cross

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.

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 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.

genes

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.

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.

germline cells

Cells that give rise to gametes, the reproductive cells of an organism, (such as an egg or sperm), that have only one set of chromosomes. When the two unite, they form a living embryo.

hybrid

An individual produced by crossing two parents of different genotypes.

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.

lines

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.

marker

An easy to detect trait controlled by a known gene. Markers, such as antibiotic or herbicide resistance, are often used to determine if an organism is transgenic.

marker gene

A gene controlling an easily detectable trait used to select transgenic cells or plants from non-transgenic ones, (i.e., herbicide and antibiotic resistance).

mutation

Any change in a DNA sequence.

nucleus

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

PAT

The enzyme that controls resistance of Liberty herbicide by detoxifying the herbicide molecule.

progeny

The offspring of an organism.

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.

resistance

The ability of an organism to survive and thrive in the presence of something that would normally cause damage or death, i.e., herbicide-resistant corn, Roundup-ready corn.

selectable marker gene

A gene encoding an easily detectable trait transferred into a cell with another gene encoding a less detectable trait. The selectable marker gene allows genetic engineers to select transgenic cells and plants from those that are non-transgenic.

selection media

Agarose media containing the substance for which the selectable marker gene encodes resistance. When tissue culture cells are place on this media, cells that have not been transformed and do not contain the gene conferring resistance to the substance will die leaving only those cells that are transgenic.

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.

transforming

The process of introducing foreign DNA into an organism which is then passed on to the organism’s progeny.

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.

transgenic plant

A plant that has a new genetically engineered DNA sequence present in every one of its cells. Genetically engineered plants are transgenic plants. 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.

variety

Crop plants within a species that have the same genetic composition. Because plants in a variety are usually heterozygous, their offspring will not remain genetically pure (i.e., corn hybrid varieties).