Biological complexity: how plants construct cells (Introduction)

by David Turell , Wednesday, February 20, 2019, 22:51 (1883 days ago) @ David Turell

A molecular control of cell construction after cell division:

https://www.sciencedaily.com/releases/2019/02/190220103444.htm

"For their study, the plant researchers examined the roots of the thale cress plant, Arabidopsis thaliana. They cultivated normal plants and plants in which they artificially switched off certain enzymes that affect the composition of the membranes.

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"For plants to develop, their cells have to divide. First, the genetic material located in the cell nucleus divides. Two whole new cell nuclei are formed from the duplicated genetic material. The other components of the cell, for example the chloroplasts and mitochondria, are distributed between the two future daughter cells. All this takes place in the parent cell.

"Only then the daughter cells will be separated by a new cell wall. The whole process can be compared to a construction site. First, a temporary scaffold made of protein fibres, the so-called phragmoplast, forms in the middle of the cell. Like railway tracks, these fibres guide the building materials needed for the cell wall. Small bubbles gradually transport new cell wall material along the rails. This is assembled together by a complex fusion machinery to form a larger structure: the cell plate. The cell plate continues to grow at its edges from the centre of the cell outwards until a cell wall disc completely separates the daughter cells from one another. "The fusion machinery has to correctly coordinate the protein fibres for everything to function properly, otherwise the freight cars will transport the cell wall material to the wrong spot or at the wrong time and cell plate formation will cease," explains Heilmann.

"For plants to develop, their cells have to divide. First, the genetic material located in the cell nucleus divides. Two whole new cell nuclei are formed from the duplicated genetic material. The other components of the cell, for example the chloroplasts and mitochondria, are distributed between the two future daughter cells. All this takes place in the parent cell.

"Only then the daughter cells will be separated by a new cell wall. The whole process can be compared to a construction site. First, a temporary scaffold made of protein fibres, the so-called phragmoplast, forms in the middle of the cell. Like railway tracks, these fibres guide the building materials needed for the cell wall. Small bubbles gradually transport new cell wall material along the rails. This is assembled together by a complex fusion machinery to form a larger structure: the cell plate. The cell plate continues to grow at its edges from the centre of the cell outwards until a cell wall disc completely separates the daughter cells from one another. "The fusion machinery has to correctly coordinate the protein fibres for everything to function properly, otherwise the freight cars will transport the cell wall material to the wrong spot or at the wrong time and cell plate formation will cease," explains Heilmann.

"The results of the research group from Halle help to better understand the dynamics of the plant's cytoskeleton of microtubules. The cytoskeleton not only determines the direction of cellular transport processes during cell division, but also directs general plant growth. "

Comment: Again a very complex system which requires very specific molecules to direct the work. Not by chance. This process is inherited from the very first bacteria of life.