Water potential consists of matric potential, osmotic or solute potential, hydrostatic pressure, and gravitational pressure. Which of the following statement is true?

Correct option is B

1. Matric Potential:
· Refers to the potential energy of water due to its interaction with solid surfaces, such as cell walls, colloids, or soil particles.
· It is always negative because water is tightly bound to the solid surfaces, reducing its free energy.
· The statement in Option 2 is correct, as matric potential determines this interaction.
2. Osmotic Potential:
· Also called solute potential, it represents the effect of solutes in reducing the water potential.
· Osmotic potential is always negative because the presence of solutes reduces the free energy of water.
· Option 1 is incorrect because matric potential is not always positive.
3. Incorrect Concepts:
· Option 3: Incorrect because osmotic potential is never positive.
· Option 4: Incorrect because osmotic or solute potential does not measure ionic potential; they are entirely different concepts.
Information Booster: 1. Components of Water Potential:
· ΨΨΨ (Water Potential): Represents the total energy of water in a system.
· Components:
· Matric Potential (Ψm​): Interaction with solid surfaces; always negative.
· Osmotic Potential (Ψs​): Solute concentration; always negative.
· Pressure Potential (Ψp): Hydrostatic pressure; positive in turgid cells, negative in xylem tension.
· Gravitational Potential (Ψg​): Influenced by height; usually negligible in small systems.
2. Role in Plants:
· Matric Potential: Important in soil for water absorption by roots.
· Osmotic Potential: Governs osmosis, influencing water uptake and maintaining turgor pressure.
3. Applications:
· Used to assess soil moisture availability.
· Essential for understanding water movement in plants and ecosystems.
Additional Knowledge: · Water Movement in Plants:
· Water moves from regions of higher water potential (less negative) to lower water potential (more negative).
· Significance of Matric Potential:
· Determines soil water retention.
· Influences plant-water relationships in arid and semi-arid conditions.
· Pressure Potential:
· Positive in plant cells due to turgor pressure.
· Negative in xylem vessels due to transpiration pull.