A wilting plant has not suddenly grown weak stems; it has lost pressure. Water leaves the vacuole, the cells go slack, and the cellulose wall is still perfectly intact. As water runs short the turgor pressure falls and the blade droops; further still and the cell reaches plasmolysis, a far more serious state in which the plasma membrane peels away from the wall. Strong light drives the chloroplasts and speeds up cytoplasmic streaming. The three features that separate this cell from an animal one are all here: the cellulose wall, the chloroplasts and a central vacuole that fills most of the volume.
A wilting plant has not suddenly grown weak stems; it has lost pressure. Water leaves the vacuole, the cells go slack, and the cellulose wall is still perfectly intact. As water runs short the turgor pressure falls and the blade droops; further still and the cell reaches plasmolysis, a far more serious state in which the plasma membrane peels away from the wall. Strong light drives the chloroplasts and speeds up cytoplasmic streaming. The three features that separate this cell from an animal one are all here: the cellulose wall, the chloroplasts and a central vacuole that fills most of the volume.
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