Root pressure

As a root pressure is defined as the pressure that builds up by osmosis in the root tissue of plants. Together with the transpiration that occurs due to the evaporation of the leaves, characterized the water transport in the plant is made.

Cause

The transfer of cells Xylemparenchyms, which are cells in the wood give part, by a secondary active transport of osmotically active substances ( in particular inorganic ions) in the conductive elements of the piece of wood ( xylem ). Thus there lowers the osmotic potential ( osmotic pressure increases ), resulting in an influx of water result. The water from the root surface follows the osmotic potential gradient in the plant tissue to the inner endodermis, where the Casparian strips prevent direct advancement. At least here and at the earliest, the water must flow into the symplast to the cells of the Wurzeloberfäche. After passing through the Endodermisgewebes the water in the symplast continues to flow to the conductive Xylemgefäßen. In this builds up due to the incoming water, a hydrostatic pressure, that is the root of pressure to.