The ultrastructural changes in leaf cells of submerged maize (Zea mays L.) were observed. After 2 h under submergence, an inward collapse of tonoplast was immediately observed while other cell components remained unaltered. After 6 h under submergence, the chloroplast envelope started to degrade and the inward collapse of tonoplast became more prominent. Until 12 h under submergence, localized splitting of the tonoplast appeared; the stromatic thylakoid membrane of the chloroplast started to be vacuolated when its envelope underwent further degradation. With prolongation of submergence to 18 h, the injury of chloroplast was enhanced. As the envelope was completely destroyed and disappeared and degraded the stromatic thylakoid membrane degraded. Meantime, the mitochondrial and nuclear membrane also started to be destroyed. During 24-48 h under submergence, the chloroplast, mitochondria and nucleus of the anoxic leaf cells became gradually disintegrated. Finally, under 72 h of submergence, the leaf cells became completely degraded with little condensed contents. The results indicated that the injury in membrane structure of various organelles, especially vacuole and chloroplast, was closely associated with the eventual demise of leaf cells of the submerged maize.
淹水对玉米叶片细胞超微结构的影响
魏和平 利容千* 王建波
（武汉大学生命科学学院，武汉430072）
摘要：对淹水过程中玉米 (ZeamaysL .)叶片细胞超微结构的变化进行连续观察。淹水 2h后 ,液泡膜发生明显内陷。淹水 6h后 ,液泡膜内陷加剧 ,呈极度松弛状态 ;叶绿体被膜局部向外突出一个由单层膜包裹的泡状结构。淹水 1 2h后 ,液泡膜局部破裂 ;叶绿体被膜破坏加剧 ,成为一松弛的单膜结构 ,同时 ,基质类囊体出现空泡化。淹水 1 8h后 ,叶绿体的破坏进一步加剧 :被膜完全消失 ,基质类囊体开始消化 ;同时 ,线粒体膜和核膜也开始出现明显的破坏。在淹水 2 4～ 48h时 ,叶绿体、线粒体和细胞核逐渐解体。最终 ,在淹水 72h后 ,整个叶片细胞死亡、解体。结果表明 :细胞器特别是液泡和叶绿体膜结构的破坏与受淹玉米叶片细胞最终死亡密切相关。
关键词： 淹水；玉米；叶片细胞；超微结构
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