Abstract

Abstract: The effect of phosphorus (P) supply on P uptake, plant growth, and phenols production with either antioxidant or structural function was investigated in wheat. Ten wheat cultivars were grown hydroponically at 0, 0.01, 0.1, 0.4 mM P. After harvest, P concentration, plant growth, lipid peroxidation and total phenols concentration were determined. Chloroplasts hydrogen peroxide (H2O2) production and lignin distribution were also analyzed. According to the nutritional requirements of wheat, the application of both 0.1 mM P and 0.4 mM P provided sufficient P levels. However, P concentration in wheat cultivars treated with either 0 or 0.01 mM P reached a P deficient state. Almost all cultivars reduced shoot biomass under P shortage, which in turn led to increase root growth and root/shoot ratio. Consequently, genotypes with contrasting P efficiency were defined. The oxidative damage, chloroplast H2O2 production, total phenols and lignin accumulation augmented in wheat cultivars as P supply decreased. Moreover, P-inefficient genotypes accumulated more total phenols in their tissues than P-efficient genotypes under P-deficient conditions. In fact, a clear relationship between P efficiency and phenol metabolism was found. Additionally, based on our results, we ranked wheat cultivars according to their susceptibly to P deficiency.