Water potential is denoted by the greek symbol Psi`(Psi)` and is expressed in pressure units such as pascals (Pa).

Answer

### Step-by-Step Solution:

1. **Understanding Water Potential**: Water potential (Ψ) is a measure of the potential energy in water and is an important concept in plant biology. It determines the direction of water movement in plants.

2. **Denotation of Water Potential**: Water potential is denoted by the Greek letter Psi (Ψ). This is a standard notation used in biological sciences to represent water potential.

3. **Units of Measurement**: Water potential is expressed in pressure units, specifically in Pascals (Pa). This is because water potential is related to the pressure exerted by water in a system.

4. **Characteristics of Pure Water**: Pure water has the highest water potential, which is defined as zero (0) at standard temperature and pressure. This is because it has the highest concentration of water molecules and thus the greatest kinetic energy.

5. **Effect of Solutes on Water Potential**: When solutes are added to water, the concentration of water decreases, leading to a decrease in water potential (Ψ). The more solute that is added, the more negative the water potential becomes.

6. **Pressure Potential**: In addition to solute potential, pressure potential also affects water potential. The relationship can be described by the equation:
\[ Ψ = Ψ_s + Ψ_p \]
where Ψ_s is the solute potential and Ψ_p is the pressure potential.

7. **Conclusion**: Since the statement provided in the question accurately describes the denotation and units of water potential, we conclude that the statement is true.

### Final Answer:
The statement is **True**: Water potential is denoted by the Greek symbol Psi (Ψ) and is expressed in pressure units such as Pascals (Pa).

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