Embryogenesis Glossary

callus

A mass of undifferentiated cells used in tissue culture.

cotyledon

The first leaf or leaves produced by the embryo of a flowering plant.

cytoplasmic cell

The smaller, cytoplasm-rich cell from the cell division of a progenitor cell. Also called embryogenic cell. It will develop into either proembryonal complex or a somatic embryo.

differentiation

The developmental process that specializing cells' function and shape.

embryo proper

A cell mass that will develop into an embryo.

epiphyseal cells

The meristem cells in epiphysis.

epiphysis

The shoot apical meristem tissue.

globular stage

The developmental stage of embryogenesis that the embryonic tissues organized as a ball.

ground miristem

The primary embryonic tissues that surround the plant stem and branches.

heart stage

A developmental stage in embryogenesis that the young embryo looks like a heart.  At this stage, most all organs in a young plant have been formed.

hypophyseal region

The tissue of a developing embryo that is derived from the topmost cell of the suspensor and is later incorporated into the root apex of the embryo, giving rise to part of the root cap, its initial cells and the ground meristem initial cells.

inducing medium

The tissue culture media for helping the start of organ or embryonic cell development.

metabolism

A general term referring to the change of a herbicide from an active to an inactive state.

mRNA

(messenger ribonucleic acid) The message made during transcription by reading the DNA sequence to build a particular protein. A single-stranded nucleic acid similar to DNA but having a ribose sugar rather than deoxyribose sugar and a uracil rather than thymine as one of the bases.

O line

A structure in young embryo which is the lower boundary of shoot apical tissues.

procambium

The tissue in the central portion of an embryo.

proembryonal complex

A mass of embryogenic cells.

progenitor cell

A cell that is able to produce embryogenic cells by cell division.

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.

protoderm

A primary embryonic tissue that is located on the surface of young embryos.

secondary embryogenesis

The development of embryos from young embryos.

suspensor

The organ anchoring and supporting a developing embryo. Suspensor connects embryo with its mother body.

vacuolate cell

A cell derived from a progenitor cell during embryogenesis and having a large vacuole. Vacuolate cells usually are larger than cytoplasmic cells which result from the same cell division.

zygote

The cell formed when the egg and sperm fuse. The cell has two copies of each chromosome (2n) and will continually divide to develop into an entire organism.