Osmosis and water potential
Osmosis is the net movement of water across a selectively permeable membrane. With equal pressure and a membrane impermeable to the relevant solute, water tends to move toward the higher solute concentration. Tonicity predicts sustained effects on cell volume using effectively nonpenetrating solutes. Animal cells may swell or lyse in hypotonic surroundings and shrink in hypertonic surroundings. Plant walls resist expansion; increasing pressure potential can counter a negative solute potential and produce turgor. Solute potential is Ψs = −iCRT, with temperature in Kelvin and units matched to R. Water-potential equilibrium can occur even when solute concentrations differ if pressure compensates.
A plant cell has Ψs = −0.8 MPa and Ψp = +0.3 MPa, so Ψ = −0.5 MPa. In a bath at −0.2 MPa, water initially enters because −0.2 is higher than −0.5. As pressure rises, net entry can slow or stop.
More negative is lower, not higher. Do not decide water direction from solute concentration alone when pressure differences are supplied.