Primordium
Encyclopedia
A primordium in embryology
, is defined as an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells
A primordium can be considered the simplest set of initial conditions capable of triggering growth. Within any meristem are minute primordia that resemble knobby outgrowths or ribbed inverted cones.
and flower
primordia arise from the shoot lateral meristem
. The process is intricately regulated by a set of genes
that affect the positioning, growth and differentiation of the primordium.
The plant hormone auxin
has also been implicated in this process, with the new primordia being initiated at the placenta where the auxin concentration is the highest. Genes like STM (shoot meristem less) and CUC (cup-shaped cotyledon) are involved in defining the borders of the newly formed primordium.
Embryology
Embryology is a science which is about the development of an embryo from the fertilization of the ovum to the fetus stage...
, is defined as an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells
A primordium can be considered the simplest set of initial conditions capable of triggering growth. Within any meristem are minute primordia that resemble knobby outgrowths or ribbed inverted cones.
Primordium development in plants
Primordial development in plants is critical to the proper positioning and development of plant organs. Different primordial types like the leafLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
and flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
primordia arise from the shoot lateral meristem
Meristem
A meristem is the tissue in most plants consisting of undifferentiated cells , found in zones of the plant where growth can take place....
. The process is intricately regulated by a set of genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
that affect the positioning, growth and differentiation of the primordium.
The plant hormone auxin
Auxin
Auxins are a class of plant hormones with some morphogen-like characteristics. Auxins have a cardinal role in coordination of many growth and behavioral processes in the plant's life cycle and are essential for plant body development. Auxins and their role in plant growth were first described by...
has also been implicated in this process, with the new primordia being initiated at the placenta where the auxin concentration is the highest. Genes like STM (shoot meristem less) and CUC (cup-shaped cotyledon) are involved in defining the borders of the newly formed primordium.