Abstract:

For study the cell structure changes of flue-cured tobacco leaves during the drought stress, and analysis of alterations in the structure of each organelle, when the leaf cells responded to the stress, based on the observation of ultra structure of tobacco leaves using transmission electron microscope. The results indicated that: the organelles of tobacco leaves were morphologically integrated before stress. Under stress, the thylakoids of chloroplast became more round and even disintegrated. The plates inside arranged disorderly first, as the stress last, the lamellae began deformed, fractured and completely disorganized. Comparing to senescence, the starch became larger in shape, but not burst the membrane of chloroplast into the cytoplasm. Mitochondrial inner membrane showed to be invaginated and fractured in the end, but most of the outer membrane was intact. The phenomenon of hetero chromatinization and plasmolysis appeared in the nucleus and cells, the proportion of vacuole to cell became smaller.