Contributed by: vaaran
Submitted: April 7th, 2005 What is
endocytosis and its role in nutrient uptake?
Endocytosis is an active transport mechanism of
larger molecules, particles or bacteria (that are too
large to pass through the cell membrane the ion ways)
into the cell cytoplasm.
Molecules pass the cell
wall to reach the cell membrane and settle at the
surface. The plasma membrane vaginates the molecules and
forms a coated vessel. This vessel moves into the cell
cytoplasm and embarks at predetermine locations where it
releases its content of molecules. The vessel now loads
new matter for building cell walls, membranes or to be
circulated to other cells.
Until recently, it was thought that only
human or animal cells are capable of endocytosis,
leading to the belief that nothing larger than ions can
cross the cell membrane and therefore the only way of
nutrient uptake would be that of mineral ions.
With this premise the concept of "cation
exchange" became the accepted theory with the "CEC" as
the basis of soil analysis. Newer studies strongly
suggest that endocytosis is an inherent feature of
higher plants cells including root cells.
Indirect influence of endo/exocytosis in
-Root symbiosis with fungus
enhancing nutrient uptake and efficiency
symbiosis with nitrogen fixing bacteria by building root
endocytic steps necessary for nutrient uptake
Direct influence of endocytosis in nutrient
-Direct absorption of larger
molecules like amino acids by plant roots thus bypassing
mineralization References: Actin-dependent fluid-phase endocytosis in
inner cortex cells of maize root apices Exocytosis and Endocytosis Actinorhizal, mycorhizal and rhizobial
symbioses: How much do we know? (.pdf) Plant nitrogen uptake Probiotic fertilizer
special thanks to medical grade
Disclaimer: Information in this
text may not be completely correct. This text is meant
as a starting point for further study.