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Abstract:
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Tobacco plants are able to grow, although slowly, in saline culture solutions of at least 200 mol m-3 NaC1; that is, an osmotic pressure of 0.9 MPa (Flowers et al. 1986). Since tobacco roots contain large cortex cells with an average volume of 2.5 x 10-13 m3, and are therefore suited to pressure probe measurements, tobacco plants were chosen to study effects of exposure of the roots to NaC1 on some important water relations parameters. Using roots in a quasi-steady-state or after sudden decreases in exterl NaC1 concentration, studies were made of: 1. turgor regulation; 2. water permeability; and 3. cell wall elasticity. Turgor pressures determined using the pressure probe were compared with those determined after expressing sap from tissue and calculati
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