What substance is crucial for maintaining turgor pressure in plants?

Water is crucial for maintaining turgor pressure in plants, which is the pressure of the fluid (typically water) inside the plant cells against the cell wall. This pressure is essential for a plant’s structural integrity and rigidity. When plant cells take up water through osmosis, they swell and exert pressure on the surrounding cell wall. This turgor pressure helps support the plant's structure, allowing it to stand upright and effectively maintain its shape.

If a plant loses water, turgor pressure decreases, resulting in wilting. Thus, the relationship between water and turgor pressure is vital for many physiological functions in plants, including nutrient transport and growth. Other substances like oxygen and carbon dioxide play important roles in respiration and photosynthesis, respectively, but they do not have a direct role in maintaining turgor pressure. Nutrients are essential for overall plant health and growth but do not specifically impact the turgor pressure like water does.