水分胁迫下玉米叶片光合作用、脂质过氧化及超微结构变化的关系

Correlation among photosynthesis,Lipid Peroxidation and Ultrastructural Changes of Mesophyll Cells in Corn Leaves under Water Stress

研究了不同耐旱性品种在不同生育时期水分胁迫下叶片光合作用和呼吸作用、脂质过氧化作用、膜系统伤害、叶肉细胞超微结构变化之间的关系。在各生育时期水分胁迫下，光合作用和呼吸作用强度下降，ＳＯＤ活性降低，脂质过氧化作用增强，膜透性增加，叶肉细胞的细胞器和质膜遭到严重破坏。结果表明，水分胁迫下脂质过氧化作用增强是造成细胞内膜系统紊乱和伤害的原因，而超微结构的破坏造成光合作用和呼吸作用的降低是导致作物减产的生理因素。

The correlation among photosynthesis and respiration, lipid peroxidation,destructure of membrane systems and ultrastructure changes of mesophyll cells at different growth stages under water stress was studied between two corn hybrids,drought tolerant cv.Yuyu No.3 and more drought sensitive cv.Xinhuangdan 85-1.The plants were exposed to water deficit for 7 days at the differnt growth stages,photosynthesis and respiration in leaves decreased,SOD activity lowered,MDA content increased obviously,permeability of plasma membrane increasesd,and the cellular organs and membrane of mesophyll cell were ruined severely.The results indicated that the increase of lipid peroxidation might cause disorder and damage of membrane systems,and decrease of photosynthesis and respiration resulting from damaged ultrastructure was the physiological factor resulting in decreased grain yield.