环境胁迫对库拉索芦荟叶片超微结构影响研究

Effects of Environmental Stress on Ultra-structure of Aloe

对1年生库拉索芦荟分别用盐(1.8%的NaCl)、低温(10℃)、干旱[25%(w/v)的聚乙二醇-6000]3种胁迫条件处理7d后,对其叶肉细胞超微结构进行观察.结果发现:3种胁迫处理均可使库拉索芦荟细胞膜系统、叶绿体、线粒体、细胞核等结构受到不同程度的破坏,叶绿体周围出现许多小泡,导致细胞内膜系统紊乱,细胞器结构稳定性降低;盐胁迫下高尔基体在细胞质中解体;盐和低温胁迫下均可见线粒体膜与叶绿体膜发生融合、线粒体嵌在叶绿体当中的现象.另外,本研究发现,盐胁迫、低温胁迫比干旱胁迫对库拉索芦荟细胞膜的损伤更严重,而水分胁迫对其的伤害程度较小,表明库拉索芦荟的抗旱性较其抗盐性更强.

One year old aloe seedlings were placed under three kinds of environmental stress, which were created with salt （NaCl at 1.8%）, low temperature （10 C） and drought[simulated with PEG 6000 at 25% （w/v）],for seven days,and then the ultra structures of their mesophyll cells were observed. It was found that all the three kinds of environmental stress could damage membrane system,organelle structure stabilities,mitoehondria structure and nucleus structure of aloe in various degrees and many vesicles appeared around the chloroplasts, which resulted in the cellular endomembrane system falling into disorder and the organelles becoming destabilized; under salt stress, the Golgi bodies disintegrated in the cytoplasm; under both salt stress and low temperature stress,there appeared a phenomenon that the mitochondria and chloroplast membranes fused and as a result the mitochondria embedded in the chloroplasts. In addition, the study found that salt stress and low temperature stress damaged cellular membrane of aloe more severely than drought stress,i, e. water stress showed less severe damage to the cellular membrane of aloe,and this indicated aloe performed better in drought resistance than in salt resistance.