Differences between Mesophyll and Bundle Sheath Cells and Chloroplasts in C4 Plants
(Mesophyll vs Bundle Sheath Chloroplasts: A Comparison Table)
The C4 cycle or Hatch and Slack pathway of dark reaction of photosynthesis are characterized by two structurally and functionally different chloroplasts in their leaves. The leaves of C4 plants such as maize possess the classical Kranz anatomy. In Kranz anatomy, each vascular bundle is surrounded by a ring of bundle sheath cells, followed by one or more concentric layers of mesophyll cells. Bundle sheath cells have thick cell walls and contain centrifugally arranged chloroplasts with large starch granules and unstacked thylakoid membranes, whereas the mesophyll cells contain randomly arranged chloroplasts with stacked thylakoids and little or no starch grains.