Water Potential in Plants

Study Notes

Solute Potential (ψs): the energy associated with the concentration of solutes in a solution
- Negative value, as solutes decrease water potential
Pressure Potential (ψp): the energy associated with the pressure exerted on water in a plant cell
- Positive value, as pressure increases water potential
Matric Potential (ψm): the energy associated with the attraction between water and the cell wall
- Negative value, as the cell wall attracts water

ψ = ψs + ψp + ψm
Typically, ψs and ψm are negative, while ψp is positive
The total water potential is usually negative, indicating that water tends to move into the plant cell

Water moves from an area of higher water potential to an area of lower water potential
Plants with a lower water potential tend to absorb water, while those with a higher water potential tend to lose water
Water potential affects plant growth, stomatal opening, and cell turgor pressure

Solute Potential (ψs): reduces water potential due to the concentration of solutes in a solution, with a negative value.
Pressure Potential (ψp): increases water potential due to the pressure exerted on water in a plant cell, with a positive value.
Matric Potential (ψm): reduces water potential due to the attraction between water and the cell wall, with a negative value.

The total water potential is the sum of solute potential, pressure potential, and matric potential: ψ = ψs + ψp + ψm.
Typically, the total water potential is negative, indicating that water tends to move into the plant cell.

Water flows from an area of higher water potential to an area of lower water potential.
Plants with a lower water potential tend to absorb water, while those with a higher water potential tend to lose water.
Water potential affects plant growth, stomatal opening, and cell turgor pressure.