关键词: 沙生植物, 抗脱水性, 膜脂过氧化, 高温和干旱胁迫

Abstract: Changes in water content, cell membrane's relative permeability, malondialdehyde (MDA) content of several desert plants: Agriophyllum squarrosum and Convolvulus chinensis grown in shifting sand dune, Artemisia halodendron grown in semi fixed dune, Pennisetum centrasiaticum and Setaria viridis grown in fixed sand dune were determined under atmosphere dehydration stress, high temperature stress. For A. squarrosum and C. chinensis grown in shifting dune two stresses led to an accumulation of MDA, a decrease rapidly in water content and an increase in cell membrane's relative permeability, and MDA still increased after rehydration and resume at home temperature, then plants went dead. However, MDA and permeability declined, RWC increased after rehydration and house temperature in A. halodendron, P. centrasiaticum and S. viridis grown in fixed sand dune, the plants survived the two stresses. These results have revealed that there was a positive correlation between membrane permeability in the cell and lipid peroxidation. The injury level in cell membrane was not related to the absoluted amount of MDA accumulation under the stresses, while related to ability of cell membrane resistance to lipid peroxidation.

Key words: Desert plant, Resistance to dehydration, Lipid peroxidation, Atmosphere-dehydration and high temperature stresses