Water Transport through a plant. By: Aisha Al Misnad & Luma Mansi. How the Water Transports.
By: Aisha Al Misnad & Luma Mansi
There is a water concentration gradient across the root which means that water which has entered the root hair cell continues to move across the cortex to the endodermis by osmosis. The route taken by much of the water is through the cellulose cell walls, the rest of the water either passes through the cytoplasm of the cells or through the cell vacuoles.
Once it reaches the endoderm cells, the water is forced to move through the cytoplasm. This is because the radial and transverse cell walls of the young endodermis are impregnated with an impervious material. The gradient of water concentration that exists across the cortex creates a pushing force called "root pressure” that pushes the water across. Root pressure can happen by cutting a stem at soil level, after a time, droplets of water can be seen exuding from the cut surface.
In some plants the process occurs naturally when droplets of water are forced through special pores on the leaf edges.