在干旱、高温胁迫中沙生植物抗脱水性与膜脂过氧化关系的研究

在高温、自然脱水和干旱处理中不同类型沙生植物叶形态、相对含水量(RWC)、质膜相对透性、丙二醛(MDA)含量变化不同,其中流动沙地的沙米、欧亚旋覆花在胁迫中MDA积累,RWC下降快,膜透性增大,复水后MDA增多而植株死亡;半固定沙地的差不嘎蒿和固定沙地的狗尾草、白草,胁迫下MDA积累,RWC下降,但复水后RWC上升、膜透性下降,MDA下降,植株存活。自然脱水处理中植物细胞膜相对透性与膜脂过氧化成正相关,但细胞膜受损程度与MDA积累的绝对量无密切关系,而与膜忍受膜脂过氧化能力相关。

Correlation between Resistance to Dehydration and Lipid Peroxidation of Desert Plants under Atmosphere Dehydration and High Temperature Stresses

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.