**4.2. Polyethylene glycol application**

Polyethylene glycol (PEG) is a polymer used to modify the osmotic potential of nutrient solutions cultures to induce plant water deficit in experimental protocols. PEG 8000 (18%) is used as an osmoticum to induce drought in wheat genotypes after 1 week of plantation. Water stress greatly suppresses cell expansion and cell growth due to low turgor pressure. Osmotic regulation can enable the maintenance of cellular turgor for plant survival. The reduction in plant height was associated with a decline in the cell enlargement and more leaf senescence. The plants grown in nutrient culture containing PEG suffered from hypoxia, and such system should be oxygenated for running drought-stress experiments [16].
