Plant-herbivore interactions : The indigestibility of C bundle sheath cells by grasshoppers.

Plants with the C dicarboxylic acid pathway of photosynthetic CO fixation are generally nutritionally inferior to C (Calvin cycle) plants as foodstuff for herbivores. A possible contributing factor to this nutritional inferiority is the concentration, in C plants, of large quantities of nutritional material in very tough, thick-walled vascular bundle sheath cells which herbivores may not be able to break down. Experiments with 10 species of grass-hoppers from different areas in the United States revealed large numbers of unbroken bundle sheath cells, contents intact, in fecal pellets produced when the grasshoppers were fed C vegetation. We conclude that the material stored in C bundle sheath cells is at least partially unavailable to herbivores, and that this may contribute to the observed nutritional inferiority of C vegetation.