(botany) Symplastic pathway; i.e. the pathway formed by a system of interconnected protoplasts and made continuous by the presence of plasmodesmata
There are three fundamental lateral routes in which water and minerals move within tissues and organs of the plant. The first route involves the transit of water and minerals through crossing the plasma membranes and cell walls. The second route is via the apoplast. The apoplast is a continuum of intercellular space formed by the cell walls of adjacent cells. The pathway formed by the apoplast is called apoplastic pathway or apoplasty. Through apoplasty, water and minerals diffuse freely through the spaces. In the root, a hydrophobic band of cell wall material (chiefly, suberin), called Casparian strip, that forms on the radial and transverse walls of the endodermis. The presence of Casparian strip interrupts the flow of water and minerals or solutes via the apoplastic pathway. As a result, they flow via the symplastic pathway or symplasty in order to pass through the endodermal layer of the root. Symplasty is a route formed by a system of interconnected protoplasts. The protoplasts are made continuous via the plasmodesmata. The selective flow of materials is important to prevent the passage of solutes that may harm the plant.
The symplastic route is relatively slower than the apoplastic route. And since the protoplast is involved the metabolic state of the cell may affect the transit of materials.
- symplast (noun)