Osmotic adjustment in plants is a mechanism by which plants regulate their internal water balance in response to environmental stresses such as drought, salinity, or temperature fluctuations. This process involves adjusting the concentration of solutes (such as sugars, amino acids, and ions) in plant cells to help maintain a balance between water uptake and loss.
In drought conditions, plants accumulate osmolytes, such as sugars and proline, which lower the water potential inside the plant cells. This allows the plant to retain water even when external conditions are dry. In saline environments, plants may accumulate salt in vacuoles or use ions like potassium and chloride to balance the osmotic pressure inside their cells, preventing water loss and maintaining cell turgidity. Osmotic adjustment ensures that plants can continue to function under water-limiting conditions by preventing excessive water loss from cells.