Intercellular water transport, bulk movement of water, Soil Plant Atmosphere Continuum (SPAC)
Intercellular water transport:- Path of Water:- There are two routes of water absorption - i. Apoplast:- When absorbed water moves through the cell wall and inter-cellular spaces. In this route, water does not enter the cytoplasm inside the cell. ii. Symplast:- When absorbed water moves through plasma membrane and plasmodesmata. In this route, water enters the cytoplasm inside the cell. Bulk movement of water ( Ascent of Sap):- The upward movement of water from roots to the aerial parts of a plant is known as an ascent of sap. Theories of Ascent of Sap:- 1. Vital Force Theory 2. Root-pressure Theory 3. Physical Force Theory 1. Vital Force Theory:- Ascent of sap was brought about by the living cells of the stem. a. Relay-Pump Hypothesis:- - It was proposed by Godlewski (1884). - According to this theory, the upward movement of water is due to the pumping activity of the living cells of the xylem parenchyma and medullary rays. b. Pulsatory Movement Theo...