Protein and lipid characterization of wheat roots plasma membrane damaged by Fe and H 2 O 2 using ATR-FTIR method

In plant cells the plasma membrane is a highly elaborated structure that functions as the point of exchange with adjoining cells, cell walls and the external environment. In this study, we investigated the structure and function characteristic of wheat root plasma membrane (PM) as affected by H2O2 and Fe by using fluorescence spectroscopic and attenuated total reflectance infrared (ATR-IR) techniques. The results showed that these oxidant damaged induced an obviously reduced membrane fluidity were observed in the roots PM treated with the 200 μM H2O2, FeSO4, and FeCl3. Computer-aided software analyses of the FTIR spectrum indicated that the content of the α-helices decreased and β-sheet increased in the secondary structures of proteins after exposure to the oxidants of 200 μM H2O2, FeSO4, and FeCl3. The number of P=O and C=C bonds area declined rapidly in the lipids of the membrane under the oxidants stress. These structural alterations might explain the reason of the roots PM instability under most of the abiotic stress.