Influence of Osmotic Stress on Nitrate Reductase Activity in Wheat (Triticum aestivum L.) and the Role of Abscisic Acid

摘要: Wheat seedlings (Triticum aestivum L. cv. Timmo) were treated with up to 20% (w/v) polyethylene glycol (PEG, mol. wt. 3350) in the nutrient medium for 6 d. Shoot growth and nitrate transport metabolism substantially affected by PEG treatment. At (corresponding a water potential of approximately — 1-6 MPa), which caused plants wilt within 1-2 h, activity reductase (NR.) declined half-life 5 h both roots shoots. The decline was considerably slower at lower concentrations. Significant increases levels abscisic acid (ABA) only occurred Application ABA intact or excised shoots did not induce accelerate shoot NR activity. rapid during wilting appears unrelated flux ABA. concentrations long-term, however, corroborates rates growth-related utilization nitrate. role this context be indirect through its action on stomatal function reduces gas exchange.