PHRAGMOPLAST Meaning and
Definition
-
Phragmoplast is a specialized structure found in plant cells that plays a crucial role in cell division during cytokinesis. It is a temporary scaffold-like arrangement of microtubules and associated proteins that help guide the formation of cell walls between daughter cells.
During cytokinesis, the phragmoplast forms between the two sets of chromosomes at the equator of the dividing cell. Microtubules radiate outwards from each set of chromosomes and interdigitate in the middle to create the phragmoplast. These microtubules act as tracks for vesicles containing cell wall materials, such as cellulose, hemicellulose, and pectin, to be transported to the division plane.
As the vesicles move towards the equator, they fuse with the existing plasma membrane and release their contents, forming a new cell plate. This cell plate expands outwards, guided by the microtubules of the phragmoplast, until it reaches the existing cell walls on either side of the dividing cell. These fusion events and cell plate expansion ultimately lead to the formation of two daughter cells.
The phragmoplast is a dynamic structure that is extensively reorganized during cell division, and its proper formation and function are essential for successful cytokinesis. This process helps ensure accurate separation of genetic material while maintaining the integrity of the individual cells. Understanding the mechanisms and regulation of phragmoplast formation provides insights into fundamental aspects of plant growth and development.
Etymology of PHRAGMOPLAST
The word "phragmoplast" derives from the Greek words "phragmḗ" (φραγμή) meaning "a fence" or "a barrier", and "plastos" (πλαστός) meaning "molded" or "shaped". When combined, the term "phragmoplast" can be interpreted as "a shaped barrier". The term was initially coined in botany to describe the structure formed during plant cell division, which acts as a barrier or partition between the two newly forming daughter cells.
