Physiological responses of Miscanthus sinensis seedlings to PEG water stress

The effects of different concentrations of polyethylene glycol (PEG) solution intimidated water stress on physiological property of Miscanthus sinensis were studied. The results showed that the content of malondialdohyde(MDA) and relative conductivity increased, superoxide dismutase(SOD), peroxidase(POD), catalase (CAT), ascorbate dependent peroxidase (APX), glutathione reductase(GR), ascorbate(ASA) and glutathione(GSH) increased firstly and then decreased with PEG stress extension. However, the variation of each index was different under different PEG stress conditions. Each of indices could maintain similar levels with control (CK) in low PEG concentration (10% or less). These indices were significantly different with CK in high PEG concentration (20% or higher). These results showed that M.sinensis seedlings can stand less than 20% PEG stress and had a certain degree of drought tolerance. More than 20% PEG could bring M.sinensis seedlings severe drought stress and even death.